Faculty of Applied Sciences

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Analysis of the nutritional status and dietary intake data of a group of elderly at a day and frail care centre in Verulam
(2011) Govender, Theloshni; Oldewage-Theron, Wilna; Napier, Carin E.
Background: South Africa, a richly diverse developing country has been faced by the consequences of transition attributed to urbanisation and acculturation. A Westernised lifestyle has, therefore, resulted in increasing disease patterns that are characterized by a combination of poverty-related diseases together with the emerging chronic diseases. The shift to a Westernised lifestyle has resulted to a shift in the composition of dietary staples leading to dietary factors related to an increase in lifestyle diseases. These include a high fat, low fibre diet, as well as an inadequate intake of fruits and vegetables. However, this in turn has led to higher energy intakes with insufficient and imbalanced micronutrient intake. Research conducted amongst the elderly in South Africa has clearly indicated that the elderly live within a limited financial budget leading to extreme levels of food insecurity and the social burden of being the head of the household, in addition to being the caregiver to grandchildren and sick children. Due to the current living status the elderly encounter reduced food intake in addition to a reduced variety in their diet, therefore, micronutrient deficiencies are common amongst this age group. Therefore, a consumption of energy-dense foods, particularly staple foods, to stretch the food budget which are more affordable and thus allow for an increased consumption is evident. Aim: To determine the socio-demographic profile, health and nutritional status in relation to the dietary intake patterns to reflect malnutrition among free living elderly (60yrs+) in Verulam. Methodology: Fifty nine randomly selected men and 191 women aged 60+ participated on a voluntary basis in this study. A descriptive survey method was used for this cross sectional study. Trained fieldworkers assisted with the administration of all questionnaires and a registered nurse measured blood pressure. Socio-demographic questionnaires were administered to determine the socio-economic characteristics of the elderly within this community. Anthropometric measurements determined the Body Mass Index according to the World Health Organisation and Asian cut-off points to indentify the risk factors. The Health questionnaire identified the health status correlated to the respondent’s profundity of disease and deficiencies associated to dietary patterns. Blood pressure measurements were taken to determine the hypertension prevalence related to the dietary intake. Two 24-Hour Recall questionnaires were completed by the 250 respondents to identify actual vii food intake and measured against the Dietary Recommended Intake (DRIs). A food frequency questionnaire (FFQ) determined the respondent’s food variety score over a period of one week. The socio-demographic questionnaire, health questionnaire, food frequency questionnaire and anthropometric measurements were captured on an Excel® spread sheet by the researcher and analyzed for descriptive statistics using the Statistical Package for the Social Sciences (SPSS) version 17.0 with the assistance of a statistician. The 24-Hour Recall data were captured and analyzed by a nutrition professional using the MRC Food Finder® version 3.0 software, based on the South African Food Composition tables. Results: The majority of the respondent’s role in the family was mothers (70.8%) and lived in an urban area (68.8%). In addition, 73.2 percent (n=183) of the respondents shared the house with one to five people, and lived in a brick house (74.4%, n=186) with more than 3 rooms (74.0%, n=185). The elderly in this sample were pensioners and, therefore, 76.0 percent (n=190) received state grants of which the total household income ranged between R1001-R1500 (35.2%, n=88). Food insecurity is prevalent as reported by 28.4 percent. Primary school was the highest level of education completed by 52.4 percent (n=131) and English is the most spoken language amongst this group (74.0%, n=185). Women had higher BMI values particularly in the overweight (18.32%, n=35) and obese I and II (58.6%, n=112) categories when compared with men. Blood pressure measurements indicated that 60.0 percent (n=150) of the respondents suffered from hypertension. The use of chronic medication was reported by 84.4 percent (n=212). The total range of individual food items consumed by an individual during the seven-day data collection period measured by the (FFQ) was between 4-66 foods. However, the highest consumption was four food items by 23.2 percent (n=58) of the respondents. The summary of the food variety within food groups indicated a high dietary diversity, of which the other vegetable group reported the highest individual mean FVS (±SD) of 10.86 (±5.82), followed by other fruit, cereal, flesh and Vitamin A rich groups with 5.73 (±4.41), 5.03 (±1.85), 4.08 (±2.23) and 2.43 (±1.09) respectively. The nutrient analysis indicated a deficient intake by both men and women of all the nutrients, except for the mean (±SD) total protein in the women 45.10 (±12.55) and carbohydrate 212.83 (±36.97) in the men. The energy contribution indicated 98.3 percent (n=58) men and 85.72 percent (n=158) women consumed <100 percent of the EER for viii energy. However, the findings from the Top 20 food items measured by the 24-Hour Recall indicated that this community’s diet is largely carbohydrate-based, containing primarily starchy staple foods, sufficient intake of animal products, and insufficient intakes of dairy foods, fruit and vegetables, possibly resulting in the micronutrient deficiencies. The energy distribution of the macronutrients from the average of both 24-Hour Recalls indicates that both men and women are in range of 15-30 percent total fat intake, 10-15 percent protein and 55-75 percent carbohydrate. Conclusion: The results of the study reflect that the elderly in this community are faced with poverty, food insecurity as well as social factors thus contributing to a compromised nutritional status. The progression of malnutrition in particular overnutrition is experienced by the majority of the respondents in this study, however, an increased BMI and the prevalence of hypertension is a risk marker for noncommunicable diseases. However, the high prevalence of inadequate food and nutrient intake amongst elderly discloses the need for nutrition interventions and should be aimed at modifying the elderly food choices when purchasing food, healthier food preparation methods, increasing fruit and vegetable portions and improving daily physical activity to attain a better quality of life.
Anthropometric profile and food consumption patterns of an emerging middle income community in Umlazi
(2017) Memela, Sinenhlanhla Ntokozo; Napier, Carin E.
Introduction: The nutrition transition is a global phenomenon affected by developing economic prosperity. ‘Nutrition transition’ may be defined as changes in dietary patterns and nutrient intakes occurring in individuals, families, groups of people or whole populations when the food environment and other circumstances change. Post-1994 democratic elections in South Africa, economic laws called for the de-racialization of the economy. As a result of the annulment of the apartheid laws in the 1990s entrepreneurial opportunities became available for black people. Based on the 2011 Census, the middle class constituted 8.3 million (17%) out of the 51 million population in South Africa. Blacks made up 51%, whites 34%, coloureds 9% and Indians 6%. This is a vast difference from two decades prior to this when blacks made up only 3.3% of the population, with coloureds making up 9.1% and Indians 18.5%. In a number of Sub-Saharan African studies obesity has been shown to have a significant link to socio-economic status determined by access to water and electricity, smaller numbers of members residing in one household and increased amounts of money spent on food among other factors, which all promote a tendency to leading a more Westernised lifestyle. The main objective of the study was to determine the anthropometric status and analyse the food consumption of a community of emerging middle income status in Umlazi Township (Ward 84) outside Durban in the province of KwaZulu-Natal. Methods: This study had a sample size of n=250 adult men (n=56) and women (n=194) who were heads of households or primary caregivers above the age of 19 years old with households receiving a total household income of more than R100 000.00 per annum/ more than R8000.00 per month. The study was quantitative and descriptive in nature with different tools used to measure the sample population. These included waist circumference and height and weight measurement to determine BMI and WHtR. A socio-demographic questionnaire was completed where the multi-dimensional poverty index (MPI) was established; a food frequency questionnaire (FFQ) and three 24-hour food recall were also administered to all participants; one weekend day recall and two weekday recalls. Data were analysed on SPSS and nutrient analysis done through Food Finder Version 3 Software and compared to the World Health Organisation standards recommendations for optimal health. Results: The mean age of the group was 52 years old. Slightly more than half (51.6%; n=129) of the population was unemployed. Retired participants made up 27.2% (n=68) of the population. The majority (80%) of the households indicated that between one to three members contributed to the total household income. The MPI of the Ward 84 community amounted to 9.09. The prevalence of obesity was 37.59% (n=21) among men and 76.80% (n=149) for women. Women had a higher prevalence of risk factors linked to non-communicable diseases than men. Mineral and fat soluble vitamin intake was deficient; however protein and carbohydrates were consumed in excess with means of 187.70% and 111.43% respectively. Top 20 foods consumed lists indicated that little fruit or vegetables were consumed. The average food variety score was medium indicating the consumption of between >30 but <60 different foods across the total population. A positive relationship of statistical significance was found between food variety score and income (p=0.007). Conclusion: The Ward 84 community consisted of an ageing population with households mostly supported by another member’s income from within or outside the household. The adults had sufficient education to have secured promotions in the employment arena and could afford a lifestyle similar to that of those who had always been more privileged. Although the Umlazi residents benefited from good housing and infrastructure and appeared to have averted poverty, the prevalence of overnutrition malnutrition was high and linked with an excessive intake of macronutrients. Majority (70%) of the community of Ward 84 is ‘food secure’ as indicated by the number of participants’ households indicating never having a shortage of money to buy food. This correlates negatively with the high prevalence of overweight and obesity (BMI) (p=-0.029). According to literature a persistent issue in black communities is the acceptance of an overweight body image being perceived as ‘healthy’ and an indicator of affluence. This community appears to be in the 4th stage/ pattern of the nutrition transition. It appears that a ‘westernised diet’ and lifestyle is more accessible and is embraced by this urban community as described in various literature and seen in the top 20 foods lists compiled from the 24 hour recalls. There is some oversight regarding the nutrient quality of a varied diet and achieving energy balance with macronutrient intake linked to informed nutritional choices. Suggested interventions could include the dissemination of information regarding nutrition and practical suggestions to achieve energy balance. In addition, future research could investigate the prospects of introducing participation in urban agriculture, investigate the issue of physical activity, and foster an environment for more physical activity and increase availability and access to micronutrient dense foods and investigate the development of a body mass index specifically for the black African population.
Anticancer activity of silver nanoparticles embedded in porous starch as a potential delivery system
(2024-05) Mohan, Naaznee; Mellem, John Jason
Silver nanoparticles have been proven to have anticancer abilities but they have been known to agglomerate and become toxic. Therefore, various studies have been conducted to explore ways of preventing aggregation using biopolymers such as starch. This study makes use of Lablab purpureus (hyacinth bean) porous starch to biosynthesize and encapsulate silver nanoparticles and then test its anticancer potential. Porous starches were produced from hyacinth bean using three different techniques. These were compared against the native starch with silver nanoparticles, then synthesized and encapsulated using the porous starch. In comparison to the native starch, the porous starches made through solvent exchange and enzyme hydrolysis had similar outcomes with granules exhibiting pores, as shown by the structural and chemical characteristics. The lack of pasting properties and extremely distinct chemical and structural graphs of the porous starch, produced by freeze-thaw procedures, may be related to the presence of mercaptosuccinic acid. It was decided to employ porous starch made by solvent-exchange (SE) for the manufacture of silver nanoparticles as it contained resistant starch. Nanoparticles were produced using the porous starch from solvent-exchange, characterised and tested for their anticancer potential. Silver nanoparticles were indicative of a colour change from clear to brown, as well as, the characteristic peak at 425 nm for silver nanoparticle formation. Silver nanoparticles were implanted into porous starch at a size of around 50 nm, as further evidenced by the particle size distribution and TEM images of spherical granules with dark spots within. The zeta potential for the silver nanoparticles was -34 mV, thereby indicating that aggregation was minimized and particles were stable. The nanoparticles demonstrated less cytotoxicity in the human colon (CACO) and cervical (HELA) cancer cell lines, but more inhibition in the human breast (MCF-7) cancer cell line than the positive control camptothecin. The human muscle (C2C12), normal cell line's capacity to sustain cell viability for silver nanoparticles demonstrated that AgNP were not toxic. However, to maximize the potential of the silver nanoparticles implanted in porous starch, more research is necessary.
Artificial intelligence for the evaluation of operational parameters influencing Nitrification and Nitrifiers in an activated sludge process
(Springer Science+Business Media, 2016) Awolusi, Oluyemi Olatunji; Nasr, Mahmoud; Kumari, Sheena K.; Bux, Faizal
Abstract Nitrification at a full-scale activated sludge plant treating municipal wastewater was monitored over a period of 237 days. A combination of fluorescent in situ hybridiza-tion (FISH) and quantitative real-time polymerase chain reac-tion (qPCR) were used for identifying and quantifying the dominant nitrifiers in the plant. Adaptive neuro-fuzzy infer-ence system (ANFIS), Pearson’s correlation coefficient, and quadratic models were employed in evaluating the plant oper-ational conditions that influence the nitrification performance. The ammonia-oxidizing bacteria (AOB) abundance was with-in the range of 1.55 × 108–1.65 × 1010 copies L−1, while Nitrobacter spp. and Nitrospira spp. were 9.32 × 109–1.40 × 1011 copies L− 1 and 2.39 × 109 –3.76 × 1010 copies L−1, respectively. Specific nitrification rate (qN)was significantly affected by temperature (r 0.726, p 0.002), hy-draulic retention time (HRT) (r −0.651, p 0.009), and ammo-nia loading rate (ALR) (r 0.571, p 0.026). Additionally, AOB was considerably influenced by HRT (r −0.741, p 0.002) and temperature (r 0.517, p 0.048), while HRT negatively impact-ed Nitrospira spp. (r −0.627, p 0.012). A quadratic combina-tion of HRT and food-to-microorganism (F/M) ratio also im-pacted qN (r2 0.50), AOB (r2 0.61), and Nitrospira spp. (r2 0.72), while Nitrobacter spp. was considerably influenced by a polynomial function of F/M ratio and temperature (r2 0.49). The study demonstrated that ANFIS could be used as a tool to describe the factors influencing nitrification process at full-scale wastewater treatment plants.
Assessment of a biological nutrient removal process for the remediation of edible oil effluent
(2002-05-10) Mkhize, Sandile Psychology; Bux, Faizal
Eutrophication is a natural process that is greatly aggravated by the action of man in the natural environment. Deterioration of South Africa's natural water resources results directly or indirectly from the discharge of industrial effluent rich in nutrient nitrogen and phosphorus. The South African edible oil refmeries generally discharge poor quality effluent which impacts negatively on the water resources and wastewater treatment installations. The main aim of this study was to assess the capacity of a laboratory scale effluent treatment process that will produce final effluent of acceptable quality with regards to organic load and phosphate concentration prior to its discharge into the municipal sewerage system. The study was conducted in three stages: wastewater characterization, treatability studies, and laboratory scale treatment investigations. After analysing various effluent parameters, treatability studies were conducted using an aerobic-anaerobic sequencing batch reactor with a total hydraulic retention time of 24 hours. The results showed an average of 75 % reduction of COD and more than 90 % removal of fats, oils and grease (FOG). Based on the results of effluent characterisation and treatability studies, a laboratory scale activated sludge effluent treatment process was designed and operated with two bioreactors (aerobic and anaerobic) in series. The system was operated for a period of one-month resulting in 70 % removal of COD and 4% reduction in phosphate (P04-P). After some structural and operational changes from the original design configuration, the system was the operated continuously for the duration of the study period. An optimum COD removal of 75 % and 107 mgll P04-P reduction was achieved during the last operational phase of the system. More than 95 % reduction in fats, oils and grease (FOG) had been achieved in both semi-continuously and continuously operated systems.b.7
Assessment of heavy metals and pathogens removal from municipal wastewater using a constructed rhizofiltration system
(2018) Odinga, Christine Akinyi; Swalaha, Feroz Mahomed; Bux, Faizal; Otieno, Fredrick Alfred O.
Wastewater discharged from municipal treatment plants contain a mixture of organic contaminants, trace metals, enteric pathogens, viruses, and inorganic materials. The presence of such pollutants in wastewater poses a huge challenge to the choice and applications of the preferred treatment method. Conventional treatment methods are inefficient in the removal of some environmentally toxic pollutants and pathogens. This study evaluated the effectiveness of a constructed rhizofiltration system in the removal of heavy metals and enteric pathogens from municipal wastewater. The study was conducted at an eThekwini municipal wastewater treatment plant in Kingsburgh - Durban in the province of KwaZulu-Natal. The pilot-scale rhizofiltration unit included three different layers of substrates consisting of medium stones, coarse gravel and fine sand. The system had one section planted with Phragmites australis and Kyllinga nemoralis while the other section was unplanted and acted as the reference section. Influent and effluent, plant tissue and sediment from the rhizofilter were sampled bi-monthly for a period of two years and assessed for the presence and removal of selected enteric pathogens, trace heavy metals and changes in physicochemical and biological parameters using standard methods. Antibacterial potential of the two experimental plants was determined by the agar-well diffusion method using plant root exudates exposed to selected pathogenic bacteria. Observation of details of plant morphology, distribution and assessment of the metals attachment onto the various plant tissues was determined using images from scanning electron microscopy (SEM). The Langmuir model was used to assess the heavy metal adsorption of the plants. There was an increase in pH from 6.95 pH units to 7.55 pH units in the planted and 6.72 to 7.23 pH units in the reference sections. There was an average reduction in biochemical oxygen demand (BOD) by 79% and chemical oxygen demand (COD) by 75%. Suspended solids were reduced by 86% in the planted section and 59.8% in the reference section, Electrical conductivity was reduced by 7.7% in the planted section and 0.83% in the reference section, Total Dissolved Solids was reduced by 11.5% in the planted section and 3.5% in the reference section, temperature was reduced by 11.9% in the planted section and 1.2% in the reference section, while dissolved oxygen was raised by 10% in the planted section and 5% in the reference section. Turbidity was reduced by 9.7 NTU in the planted section and 9.1 NTU in the reference section, while alkalinity was reduced by 46.3% in planted and 45.5% on reference sections of the rhizofilter. There was a significant reduction in organic loading in the system which was statistically significant (phosphorous, p = 0.029; ammonia, p = 0.03).These average reductions and increases were observed after the system was fully established. The results indicate a comparatively better removal efficiency in the planted than the reference sections of the system. Considering the entire rhizofilter, heavy metals were accumulated at varying percentages of 96.69% on planted and 48.98% in reference sections for cadmium. Chromium was 81% and 24%, Copper was 23.4% and 1.1%, Nickel was 72% and 46.5, Lead was 63% and 31%, while Zinc was 76% and 84% in the planted and reference section of the rhizofilter respectively. The planted section had a much higher removal efficiency as compared to the reference section of the rhizofilter. The macrophytes were found to display some metals binding potential according to observations from SEM and EDX analysis. Significant amounts of Cu deposits were recorded on the roots of K. nemoralis at 0.31wt% with a peak at 0.6cps/eV than on P. australis which was at 0.31wt% with a peak at 0.6cps/eV. Further, higher deposits of Ni at 0.01 wt% with peak at 0.5 cps/eV and 0.0 wt% with peak at 0.2 cps/eV, Pb at 0.22 wt% with peak at 0.2 cps/eV and 0.21wt% with peak at 0.2 cps/eV were recorded on the roots of K. nemoralis and P. australis respectively. Kyllinga nemoralis was found to have greater metals adsorptive capabilities than P. australis. The planted and reference sections had varied removal capacities of between 45% and 98% for the various pathogens detected in the influent wastewater. For example, the concentration of coliphage was reduced by 94.6% in the planted section and 93.6% in the reference section, Candida spp. removal was 64.7% in the planted section and 62.5% in the reference section. Escherichia coli was reduced by 65%- 85% while Salmonella spp. was removed by 94% in the planted section compared to 78% in the reference section. Ascaris lumbricoides was reduced by 77% in the planted section and 53% in the reference section. Accordingly, higher pathogens reduction was achieved in the planted section as compared to the reference section of the rhizofilter. Root exudates from Kyllinga nemoralis were found to display a wider zone of growth inhibition at 9.97±0.19 mm compared to P. australis which had a zone of 8.63 ± 0.22 mm when exposed to cultured colonies of Escherichia coli.
Assessment of the anaerobic baffled reactor for treatment of vegetable oil effluent
(2001) Frost, Lee-Anne; Tivchev, G. N.
The vegetable oil industry produces effluent containing quantities of fat, oil, sodium, phosphates as well as other pollutants. Oils and greases tend to clog sewers and pumps, thus creating difficulties within the municipal wastewater treatment works. Physico-chemical treatment methods, such as (Dissolved Air Flotation) OAF, gravity separation and the use of coagulants have been attempted providing a considerable reduction in organic loading; however, discharge standards are still not met. Thus, biological treatment methods are being sought after. Aerobic treatment has been attempted however, shock loads cause problems while running such a process. The objective of this study was to assess the efficiency of anaerobic digestion to degrade Vegetable Oil Effluent (VOE) as well as the efficiency of the Anaerobic Baffled Reactor (ABR). Anaerobic digestion involves the breakdown of organic matter by the action of microorganisms in the absence of oxygen, producing methane-rich biogas. The VOE was characterized, providing significant information on its chemical composition. It was found that the effluent had high sulphate content as well as a high COD content. High sulpahte content of wastewaters have known to promote growth of Sulphate Reducing Bacteria (SRB), which utilize the same energy source as Methane Producing Bacteria (MPB) and therefore compete for the same energy source. Sulphate and lipid reduction pretreatment experiments were carried out, using barium chloride and gravitational separation respectively. The results obtained, showed that the use of barium chloride to reduce sulphate content in VOE was successful, with significant sulphate reduction. The lipid reduction experiments however, did not show any significant lipid reduction. Batch tests were conducted in serum bottles to assess the extent of biodegradation of the VOE in its raw state as well as with reduced sulpahte content. Methanogenic toxicity tests on the raw and pretreated VOE provided a range of toxicity results. These assays are relatively simple and inexpensive. Gas production was monitored to determine the rate and extent of biodegradation. The efficiency of digestion was assessed by COD reduction. Results indicated potential inhibition of the methanogenic bacteria responsible for methane production by the
Bioaugmentation with Bacillus spp. for bioremediation of synthetic wastewater using a fluidized-bed reactor
(2020-03-25) Roets, Yrielle; Bux, Faizal; Lalloo, Rajesh; Kumar, Sheena
South Africa’s freshwater resources, including rivers, man-made lakes and groundwater are under severe threat due to an ever-expanding population and economy, which is depleting these resources. The increase in population has a direct correlation with the increase in wastewater generated. The remaining fresh water resources need to be preserved therefore recycling of wastewater, to replenish our water supplies and preserve the environment, is a solution to the problem. For a developing country, it is important to use treatment methods that are cost effective and do not exert a negative impact on the environment, such as biological wastewater treatment options. One of the systems commonly used in biological wastewater treatment is the fluidized-bed bioreactor (FBBR) due to its advantages such as higher biomass concentration and a higher mass transfer thus resulting in a higher rate of biodegradation. This study focused on evaluating the efficacy of augmenting with Bacillus spp. to enhance the bioremediation of wastewater using a FBBR. Bacillus spp. used in this study were isolated from a municipal wastewater treatment plant (10 isolates) and the remaining three isolates were selected from the CSIR Bacillus database. The isolates (13 in total) were screened for 1) their ability grow in wastewater, 2) ability to reduce high concentrations of COD, ammonium, nitrates and phosphates in flask studies containing synthetic wastewater (SWW) and 3) ability to produce common enzymes such as amylase, cellulase, lipase and protease. Isolates showed varying bioremediation potential for different compounds analysed. Isolate B006 showed the highest phosphate removal rate (3.290 mg.L-1.h-1) where as D005 showed the highest growth rate (0.955 h-1), COD reduction rate (55 mg.L-1.h-1) and cellulase activity (5.485 mm) among all the isolates. Isolate D014 presented the highest ammonium removal rate (12.43 mg.L-1.h-1), amylase (5.00 mm) and protease (10.00 mm) activity whilst B001 displayed the highest nitrate removal rate (9.4 mg.L-1.h-1). The results for the individual assays were assessed and weighted in a matrix and the isolates that scored above 50% were selected for consortium studies. Four Bacillus spp. that scored above 50% in the scoring matrix were then evaluated for their ability to co-exist as a consortium. The consortium studies were then compared with results obtained for individual isolates. The selected Bacillus isolates were identified and assessed for their safety to the environment and to the end user. Identification was conducted using 16s rDNA sequencing and results showed that B006 identified as B. cereus, D005 as B. cereus and D014 as B. subtilis. Isolates, B006 and D005 were further assessed for enterotoxin production and the presence of anthrax virulent plasmids pX01 and pX02. After conducting the biosafety assays, the isolates were rendered safe for use. The isolates were then cryopreserved as spores in 25% glycerol and stored at -80 °C. The impact of the cryopreservation method and the storage conditions on the viability of the isolates was assessed after six months of storage and it was established that the isolates were still viable and that the method was adequate. The bioremediation potential of the consortium was further evaluated using a 17 L Pilot scale fluidised-bed bioreactor. The reactors were fed at three different flow rates of 1.5 L.h-1, 2 L.h-1 and 3 L.h-1 over steady state conditions (~3months). The results showed that the FBBR augmented with the selected Bacillus isolates, resulted in improved nutrient (COD, ammonium and phosphates) removal efficiencies compared to the non-bioaugmented control. The highest ammonium removal (62.8%) was observed at a flow rate of 1.5 L.h-1 (11.30 h retention time), whereby there was an overall 29.8% improvement in ammonia removal in comparison to the non-augmented control. Similarly, an overall improvement in phosphate (14.73%) was observed at a flow rate of 2 L.h-1 (8.48 h retention time) with 50% removal efficiency. The highest COD removal was observed at a flow rate of 1.5 L.h-1 (11.30 h retention time) whereby 74.5% COD was reduced with a 32.6% improvement when compared to the non-bioaugmented control. Our work has demonstrated the potential application of Bacillus as bioaugmentation agents to enhance wastewater treatment efficiency as a potential solution to water challenges in developing countries. This technology could also be utilized for addressing the challenges of a wider range of different effluents.
Carbapenem resistance profiling of selected bacterial species belonging to the Enterobacteriaceae family in various water matrices
(2021) Dludla, Winile Nokwazi; Stenström, T. A.; Pillai, S. K. K.; Adegoke, Anthony Ayodeji
Carbapenems are broad-spectrum β-Lactams exhibiting bactericidal activity by binding to penicillin-binding proteins (PBPs). These antibiotics are the last resort drugs prescribed for severe infections when other administered ones have failed to produce enough responses in patients. Bacteria belonging to the Enterobacteriaceae family, including Escherichia coli and Klebsiella pneumoniae were identified as “priority pathogens” by the World Health Organization (WHO) in 2017 due to their resistance against carbapenems and have been ranked as “Priority 1: Critical” for research. Among the various types of carbapenem-resistant Enterobacteriaceae (CRE), carbapenemase-producing CRE (CP-CRE) have drawn the most attention since they can contribute to the overall challenge of antimicrobial resistance. Wastewater treatment plants (WWTPs) have been considered a potential hub for antibiotic resistance gene exchange and further release into the environment. Therefore, antimicrobial resistance surveillance using sewage isolates has been presented as a way to study the occurrence and spread of specific clonal groups or sequence types within a community or population. Thus, this study aimed to investigate the occurrence of carbapenem-resistant K. pneumoniae and E. coli and their virulence genes in selected WWTPs treating municipal wastewater in Durban, South Africa, and to assess the efficiency of these WWTPs in removing these microorganisms. The samples were taken from two WWTPS (WWTP I and WWTP II) monthly from six sampling points (influent, aeration/biofilter, pre-chlorination, post-chlorination, upstream and downstream from the WWTP’s discharge points) from January to September 2018. Primary isolation and enumeration were carried out on CHROMagarTM ECC and Klebsiella ChromoSelect Selective Agar Base, for E. coli and K. pneumoniae, respectively. A total of 120 carbapenem-resistant E. coli (CR E. coli) and 100 carbapenem-resistant K. pneumoniae (CR K. pneumoniae) were randomly selected, further identified using biochemical tests and confirmed using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF), polymerase chain reaction (PCR) and 16S rRNA sequencing. The confirmed isolates were then subjected to antimicrobial susceptibility testing (AST) using eight antibiotics (third-generation cephalosporins and carbapenems) to determine their resistance profile. Extended-spectrum beta-lactamases (SHV, CTX-M, TEM, and OXA-1) and carbapenemase genes (NDM-1, OXA-48, IMP and VIM) and virulence genes such as stx 1 and 2, rfbE, hly, eae, and fliC were targeted using PCR. While carbapenem-resistant E. coli was detected in both WWTPs, the carbapenem-resistant K. pneumoniae was only detected in WWTP II. The total E. coli count in the influent ranged from 6.8 to 7.1±0.06 log10 CFU/100 mL (WWTP I) and 6.9 to 7.2±0.08 log10 CFU/100 mL (WWTP II) with a carbapenem resistance percentage of 0.01% and 0.07%, respectively. A complete reduction of CR E. coli was observed in both WWTPs surveyed and was not detected from the receiving water bodies. The total K. pneumoniae in the influent of WWTP II ranged between 7.1 to 7.3±0.1 log10 CFU/100 mL. For carbapenem-resistant K. pneumoniae, the highest percentage was detected in the aeration tank (3.03%), followed by the pre-chlorinated effluent (1.33%), with the influent having the least (0.34%). However, carbapenem-resistant K. pneumoniae was not detected from the post-chlorinated effluent and the receiving water bodies, indicating a complete removal. The third-generation cephalosporin resistance profile showed high resistance against cefixime in both E. coli and K. pneumoniae isolates. Among these, the influent of WWPT II showed the highest percentage of resistant E. coli against cefixime (92%) compared to WWTP I E. coli (62%) and WWTP II K. pneumoniae (81%). In addition, the resistance profile of carbapenems showed that most of the isolates were resistant to ertapenem in both WWTPs. Of the 120 E. coli isolates, 60 in WWTP I and II showed 100% and 95% resistance against ertapenem, respectively. Additionally, K. pneumoniae showed 100% resistance against ertapenem. The predominant ESBL genes detected in the E. coli isolates were TEM and SHV, showing a 100% carriage in both WWTPs. The least detected ESBL gene was OXA-1, at 98% and 52% carriage in WWTP I and II, respectively. The occurrence of the ESBL genes in K. pneumoniae isolates was slightly different between the sampling points. In the influent, the dominant genes were TEM and CTX-M at 75% and 62%, respectively. In the aeration and pre-chlorinated effluent, the dominant genes were TEM and SHV with 100% carriage. The least detected gene was the CTX-M at 13% in the influent, with no detection at the other sampling points. Both E. coli and K. pneumoniae isolates showed NDM-1 and OXA-48 to be the predominant genes identified of the carbapenemase-producing genes investigated. In the influent of WWTP I and II, the E. coli isolates that harboured NDM-1 were 100% and 82%, respectively. However, the modified Hodge test did not correlate with the detection of CRE since the test was positive for only 34 isolates (15%), while 168 isolates carried the carbapenemase genes based on PCR test. Out of the six virulence genes tested in CR E. coli, three (hly, rfbE, and eae) were detected. The predominant gene in both WWTPs was hly, with the highest percentage in WWTP II (88%) compared to WWTP I (33%). The least detected gene was eae, only detected in WWTP II at 8%. For K. pneumoniae, out of the three virulence genes (wabG, urea, and rmpA) tested, wabG was the only gene detected. This gene was detected at all the sampling points, with the highest percentage being in the pre-chlorinated effluent (50%), followed by the influent (11%) and the least in the aeration (10%). The investigated WWTPs showed carbapenem-resistant E. coli and K. pneumoniae isolates in their influent samples and the various stages of the treatment except in the post chlorinated effluent indicating their efficient removal during the disinfection process. Future research to determine the presence of viable but not culturable (VBNC) carbapenem-resistant Enterobacteriaceae in these treated effluent and recipient water bodies, and the use of advanced molecular methods capable of identifying these bacteria at lower concentrations is hereby recommended as these water bodies are routinely used for agricultural, industrial, and household purposes by the local communities.
Characterisation of the microbial communities present in an anaerobic baffled reactor utilising molecular techniques
(2005) Lalbahadur, Tharnija; Bux, Faizal
The provision of safe and sanitary water is a constitutional right and above all, a necessity of life. As a result of the rapid urbanisation and the past policies of apartheid, a large population of South Africa dwell in informal settlements, where there is very little hope of development, as the government does not possess the resources that are necessary for a full-scale sanitation programme. Therefore, on-site treatments have been considered to provide sanitation in these dense peri-urban areas. The anaerobic baffled reactor (ABR) is one such sanitation system. This reactor utilises the phenomenon of anaerobic digestion to degrade substrates. One of the major disadvantages of any anaerobic treatment processes is the extreme sensitivity of the bacterial communities, thus inducing slow recovery rates following toxic shocks. Therefore, an understanding of these microbial consortia is essential to effectively control, operate and optimise the anaerobic reactor. Fluorescence in situ hybridization, 4’,6-diamidino-2-phenylindole (DAPI) staining and DNA sequencing techniques were applied to determine the microbial consortium, as well as their reactions to daily operating conditions. With an understanding of these populations and their responses to perturbations within the system, it is possible to construct an anaerobic system that is successful in its treatment of domestic wastewater. In situ hybridizations were conducted for three operating periods, each characterised by specific flow rates. Results showed Eubacterial population dominance over the Archaeal population throughout both of the operating periods investigated. However, these cells cumulatively consisted of 50% of the total biomass fraction, as determined by DAPI staining. Group-probes utilised revealed a high concentration of fermentative acidogenic bacteria, which lead to a decrease in the pH values. It was noted that the ABR did not separate the acidogenic and methanogenic phases, as expected. Therefore, the decrease in pH further inhibited the proliferation of Archaeal acetoclastic methanogens, which were not present in the second operating period. DNA sequencing results revealed the occurrence of the hydrogenotrophic Methanobacterium and Methanococcus genera and confirmed the presence of Methanosarcina. Sequencing of the bacterial DNA confirmed the presence of the low G+ C Gram Positives (Streptococcus), the high G+C Gram Positives (Propionibacterium) and the sulfate reducing bacteria (Desulfovibrio vulgaris). However, justifications were highly subjective due to a lack of supportive analytical data, such as acetate, volatile fatty acids and methane concentrations. Despite this, findings served to add valuable information, providing details on the specific microbial groups associated with ABR treatment processes.
A comparative microbiological assessment of river basin sites to elucidate fecal impact and the corresponding risks
(2017) Sithebe, Ayanda; Stenström, Thor-Axel; Singh, Gulshan; Bux, Faizal
The study aims to assess and compare the concentration of microbial contaminants, their sources and distribution in surface water and sediment, and to determine the impact of seasonal variations and corresponding risks of faecal contamination using conventional and molecular methods. Historical data analysis was conducted using E. coli values from the eThekwini Water and Sanitation (EWS) department for 66 months (2009-2014). E. coli and Enterococci were analysed in surface water and sediment samples using the mFC/ spread plate and Colilert-18 (IDEXX) methods. The impact of seasonal variations was assessed using E. coli and Enterococci data collected during rainfall and no rainfall events, using an auto-sampler and sediment trap in parallel. Conventional standard membrane filtration methods using mFC agar, Slanetz & Bartley/ Bile Esculin and Brilliance E. coli selective agar were compared to the enzymatic Colilert-18 and Enterolert (IDEXX) test methods along the Isipingo and Palmiet Rivers. In addition, comparison of the analytical performance of droplet digital PCR (ddPCR) and qPCR for the detection of Salmonella targeting ttr gene in river sediment samples collected from the four sites of the Palmiet River in Durban, South Africa was done. In order to assess the public health risk associated with exposure of men, women and children to microbial pathogens in polluted surface water during recreational activities, the QMRA tool was employed in relation to the risk exposure to pathogenic E. coli, Campylobacter, Salmonella and Shigella. Also, the risk associated with crop irrigation (on farmers) as well as the consumption of crops irrigated with surface water from the Isipingo river was determined. Analysis of the historical data gave a baseline of the two rivers of interest, thus helps understand the current situation of the rivers enabling researchers to pick up potential gaps. In this study after the analysis of the historical data it was evident that at the Palmiet river, microbial analysis must be conducted around the QRI settlements which is a major pollution source. Also, from this study it was found that sampling points situated close to wastewater treatment plants, pump stations or informal settlements were of major concern, thus were considered for the study. It was found that sediment exhibited higher microbial concentrations than surface water, which was observed in both rivers. Also, rainfall had a significant impact on microbial variability. Higher microbial concentrations (indicator organisms) were observed in surface water after a heavy rainfall as appose to when there was no rainfall. This was due to contamination that is washed off into the river and sediment resuspension. Methodology comparison revealed that Colilert-18 and Brilliance E. coli were more selective compared to mFC agar. Brilliance E. coli /Coliform agar was comparable with Colilert-18 IDEXX, which was also observed with Slanetz & Bartley and Enterolert IDEXX. However, when mFC agar was compared with Colilert-18 IDEXX, significant difference was observed. In comparison of two Molecular methods, ddPCR were found to be fully amenable for the quantification of Salmonella and offer robust, accurate, high-throughput, affordable and more sensitive quantitation than qPCR in complex environmental samples like sediments. Quantitative Microbial Risk Assessment (QMRA) relating to recreational and occupational exposure showed that children were at the highest risk of getting infected. Also, it was observed that the probability of infection upon exposure to surface water from the Isipingo and Palmiet rivers was significantly high, hence exceeded the WHO guidelines values. Risk assessment on crops revealed that pathogenic bacteria may pose a risk to the consumer, however, a 9-log reduction may be achieved according to the WHO multi-barrier approach which involves proper washing and proper cooking of the crop before ingestion. Overall the sampling points that had the highest pollution level and constantly exceeded the WHO and DWAF guidelines at the Isipingo river were the points situated and named “Next to the WWTP”, and “Downstream of QRI” at the Palmiet River.
Development and microbial community analysis of a biological treatment process for edible oil effluent
(2003) Bux, Faizal; Tivchev, G. N.
Globally, wastewaters emanating from edible oil manufacturers contain high organic (BOD & COD) and phosphate loads and known for creating shock-loading problems for the receiving wastewater treatment installations. Discharge of poor quality final effluents also negatively impact on and cause eutrophication of natural water sources such as rivers and dams. In South Africa, a large concentration ofthe edible industries are localized in the Pietermaritzburg region of Kwa-Zulu Natal and have been regularly associated with discharge of poor quality final effluent that did not subscribe to municipal regulation standards. Current treatment of choice for wastewater's in the edible oil industry have been limited primarily to dissolved air flotation combined with the use of chemical coagulants or physical separation of oil and grease via a gravity fat trap and subsequent pH correction. These physico-chemical methods have achieved limited success and the emulsified grease tends to clog sewer pipes and pumps producing poor quality effluents. Therefore, the aim of the current research was to develop suitable treatment technology focussing on adapting activated sludge process to remediate edible oil effluents and determine the microbial community of the process using novel molecular techniques.
Development of CIELAB colour system for colorimetric detection of heavy metals in wastewater using metal nanoparticles
(2021) Shange, Sindisiwe Fortunate; Mdluli, Phumlane Selby; Mbambo, Mbuso
This study presents a simple colorimetric assay that was used to develop gold nanoparticles (AuNPs) enabled optical sensor. The sensor was fabricated using 3-(p-tolyl)-2,3- dihydropyrazolo[3,4-b] indole-1(4H)-carbothioamide (TRPIDA_CH3) complex synthesized through one pot reaction of toluidine, thio-semi-carbazide and indole in the presence of indium chloride as a catalyst under reflux. The attained product was then characterized fully by Fourier Transform Infrared (FT-IR), 1H and 13C Nuclear Magnetic Resonance (NMR), Time of flight (Mass Spectroscopy (TOF-MS) and elemental analysis for selective detection of hexavalent chromium (Cr(VI)). Two well-separated Surface Plasmon Resonance (SPR) peaks were observed in the spectra at 520 nm and 645 nm, respectively. The introduction of Cr(VI) into TRPIDA_CH3-AuNPs solution resulted in a decrease of SPR intensity at 520 nm with an increase of the peak at 645 nm. ImageJ software version 1.8.0_172 was used to measure the colour dynamics between the reaction of TRPIDA_CH3-AuNPs and Cr(VI) for image processing. The CIE L*a*b* colour system was utilized to analyse the digital images obtained which were converted to CIE Yxy chromaticity diagram. The chromaticity diagram of gold nanoparticle TRPIDA_CH3 complex was in agreement with colour change as observed from RGB values after addition of different concentration of the chromium standards. The obtained recoveries for both tap and river water which was spiked with chromium ranged from 72 to 101 % with a limit of detection (LOD) and limit of quantification (LOQ) of 0.14 and 0.47 µM, respectively. Nine possible interfering ions (Cr, Cu, Fe, Ni, Zn, Pb and Mn) were investigated and showed low detection, thus, indicating low interference with the analyte of choice. Additionally, a significant feature of this method is that it involves a simple technique exhibiting high selectivity to Cr(VI) over other heavy metal ions that were tested. The application of CIE L*a*b*/Yxy colour space based on the TRPIDA_CH3-AuNPs aggregation to quantify Cr(VI) in wastewater effluent was studied. The colorimetric sensor showed an excellent linear range of 0.01-100.0 µM (R2=0.9856). Additionally, the residual plot showed that residual errors were randomly distributed, meaning we should accept the results of a linear regression. The wastewater effluent samples were collected over a period of 10 days and each sample was analysed in triplicate for statistical purposes. The concentration in the collected wastewater effluent samples were in the range of 0.5-25.0 µM. Furthermore, the measured concentrations of Cr(VI) in wastewater effluent samples using the proposed colorimetric method agreed with those obtained when using the traditional 1,5-diphenyl carbazide (DPC) method. The DPC method also showed an excellent linear range of 10.0-100.0 µg/L (R2=0.9955) with a residual plot showing random distribution of residual errors. The RGB colour coordinates of the TRPIDA_CH3-AuNPs with wastewater effluent were compared with one without TRPIDA_CH3-AuNPs to determine the effect of the TRPIDA_CH3-AuNPs on the water samples. Development of a Smartphone and spectrophotometric based systems for colorimetric detection of Cr(VI) using functionalized AuNPs supported by CIEL*a*b*/Yxy colour space and molecular dynamics was also conducted in this study. This demonstrated the comparative study of the application of smartphone as well as spectrophotometer as tools to detect colour variation of functionalized DPC-AuNPs. These tools were demonstrated for their potential use as a colorimetric device for detecting Cr(VI) in wastewater. Color Grab 3.6.1 app was used to capture and recognize colours from samples containing gold nanoparticles with different concentrations of chromium standards. The RGB values obtained were compared with those obtained from spectrophotometer. It was observed that DPC-AuNPs aggregated in the presence of Cr(VI), with clear colour change from pink to blue due SPR of AuNPs. This resulted in a decrease in the intensity of the SPR band at 520 nm and the formation of a new red-shifted band at 670 nm and a colour change from red to blue from UV-Visible spectra. The R colour coordinates decreased as Cr(VI) concentration was increased to 16 µM then a rapid decreased was noted between 18–25 µM and G and B colour coordinates followed the same trend. Colour difference (∆E) increased significantly as the Cr(VI) concentration was increased. A rapid decrease was noticed in hue angle between 16-25 µM while chroma decreased significantly as the Cr(VI) concentration increased. Molecular dynamics using gold cluster was used to simulate the aggregation process. The radial distribution [g(r)] was calculated from cluster models. The radial distribution of Cr-DPC complex was more than twofold than for Cr-AuNPs. This was associated with the aggregation of AuNPs leading to the appearance of blue colour of AuNPs solution which was also supported by the intensity obtained from Color Grab. The other case study presented herein is on the development of a simple and facile colorimetric method for the detection of lead (Pb(II)) ions using silver nanoparticles (AgNPs) functionalized with 1-methyl-6-phenyl-6, 7-dihydro-5H-indolo [3, 2-c] [1, 8] naphthyridine (TRPIDB_H) ligand. The synthesized AgNPs were characterized by UV-Vis, TEM and Dynamic Light Scattering (DLS). The UV–Vis spectrum displayed a local surface Plasmon resonance (LSPR) absorption with a peak maximum at 410 nm and TEM results image showed that the synthesised AgNPs were well dispersed in aqueous solution. The TRPIDB_H complex was synthesized through Povarov reaction [4+2] cycloaddition and yielded 80% of the product which was characterized by FT-IR, 1H and 13C NMR, TOF-MS. The Pb(II) ions induced aggregation of the TRPIDB_H-AgNPs in solution from 60-100 mg/L. This resulted in a colour change from yellow to reddish brown which was accompanied by the appearance of the second surface plasmon absorption peak at 505 nm. Moreover, further study reported herein focus on the development of a rapid and efficient colorimetric method for the detection of Mn(II) with high selectivity and sensitivity using 3- (4-hydroxy-3-methoxyphenyl)-2, 3-dihydropyrazolo [3, 4-b] indole-1(4H)-carbothioamide (TRPIDA_V) modified gold nanoparticles (TRPIDA_V-AuNPs). The TRPIDA_V-AuNPs aggregated upon the introduction of 2 mg/L, this led to a change in colour of the dispersed TRPIDA_V-AuNPs from red to blue and a decrease of the surface plasmon absorption intensity at 520 nm. The TRPIDA_V-AuNPs aggregated between 2-10 mg/L resulting in the formation of a second peak at 655 nm. The colorimetric detection showed high selectivity to Mn(II) ions and was not selective to other investigated metal ions as there was no aggregation induced upon addition of 2 mg/L of other metal ions. Furthermore, only Mn(II) ion resulted in colour change from wine red to blue and forming a second absorption peak at 655 nm. Additionally, the colorimetric detection system yielded a detection limit of 0.00691 mg/L showing excellent sensitivity towards Mn(II). The results obtained on the spiked river and tap water samples further confirmed that the TRPIDA_V-AuNPs colorimetric detection system is applicable for Mn(II).
Development of paper-based microfluidic strips for quantification of ammonia
(2019) Nxumalo, Nonhlazeko Loveday; Mdluli, Phumlane S.; Madikizela, Lawrence Mzukisi
Water is one of the most valuable and crucial of life and therefore accurate monitoring and assessment of water resources for sustainability is imperative. Conventional water investigation includes manual gathering of tests, their transportation and resulting examination in the research center. This is time and labour-intensive, costly and requires exceptionally qualified personnel. Sovereign of this procedure empowers more continuous examination, sparing time and cash for analysts, ventures and administering bodies. Consequently, there is requirement for advancement of minimal effort ecological microfluidic paper-based expository gadget that is fundamental for compelling administration of our profitable water assets. This will address the huge and growing demand for low-cost ammonia sensors as legislation becomes more stringent and as more frequent monitoring becomes essential for legislative compliance. Subsequently, this thesis reports on the development of a low-cost, colorimetric, wax- printed microfluidic paper-based analytical device (µPAD) to detect ammonia in industrial wastewaters. Microfluidic innovation was utilized to facilitate the examination of analytes on the colorimetric explanatory techniques onto a convenient detecting gadget. This therefore empowers the blending of little volumes of analytes with synthetic reagents to form a coloured/hued product in the sight of the analyte of interest. The µPAD fabricated was an oval shaped pattern which was designed on Corel draw software. The hydrophilic segments were made by printing a chromatographic paper with hydrophobic paper sizing agents utilizing a standard Xerox wax printer (Xerox colorqube 8570). The quantification of ammonia in wastewater was performed on the µPADs using two typical colorimetric methods namely, Nessler reagent and Salicylate. The reaction of ammonia with the Nessler reagent resulted in a brown or intense yellow colour whereas with the salicylate method, the final colour was green. For both methods, the colour intensity increased proportionally with the analyte concentration, and all images of the μPADs were captured and colorimetrically analyzed with ImageJ software for quantification. The analytical performances of the µPAD were linear from 0 to 5 mg L-1 with a limit of detection of 3.37 mg L-1 and 3.20 mg L-1 for the Nessler vii reagent and salicylate methods respectively. The validity and accuracy of aforementioned methods was supported by the standard UV Visible spectrophotometric method and applied to the measurement of wastewater effluent samples. Wastewater samples were analyzed and the results obtained were similar to those obtained with a spectrophotometric method, demonstrating that the µPAD is suitable to determine ammonia in wastewater.
Efficacy and mechanisms of antiretroviral drugs removal by algaefrom wastewater treatment plants
(2024-05) Reddy, Karen; Bux, Faizal; Kuttan Pillai, Sheena Kumari; Renuka, Nirmal; Moodley, Brenda
The presence, risks, and fate of pharmaceutical pollutants in the environment have raised concerns worldwide. South Africa, with the largest population consuming antiretroviral (ARV) drugs in Africa, faces challenges in efficiently removing these compounds from water bodies. This study's primary focus was to investigate the efficiency and mechanisms of nevirapine (NVP) removal by algae isolated from wastewater treatment processes. It included the isolation and screening of algal strains from wastewater treatment plants for their potential to remove ARV drugs, optimizing culture conditions to enhance removal efficiency, determining the potential mechanisms employed by selected algal strains for NVP remediation, and assessing the associated metabolic responses of algal cells to NVP using gene expression and metabolomics analyses. Eleven green indigenous fresh water microalgal isolates were screened from wastewater treatment plants (WWTPs) in KwaZulu-Natal, resulting in the selection of two strains, Coelastrella tenuitheca and Tetradesmus obliquus, based on their growth rates, biomass productivity and toxicity tolerance. In the ecotoxicity study, the calculated IC50 values of NVP (0–100 mg L−1) on selected algal strains after 96 h of exposure were 23.45 mg L−1 (C. tenuitheca) and 18.20 mg L−1 (T. obliquus), which far exceeds the concentration of NVP found in wastewater. Hence, T. obliquus and C. tenuitheca was selected for further NVP remediation studies using different cultivation conditions. A concentration range of 0-4000 ng L-1 of NVP was tested to assess the potential for NVP removal by both microalgae (autotrophic cultivation). Lower concentrations of NVP (up to 200 ng L−1) have shown to have a positive impact on microalgae growth. Specifically, in T. obliquus, the highest dry cell weight of 941.27 mg L−1 was obtained when exposed to a NVP concentration of 50 ng L−1. Both microalgae showed varying removal efficiencies (19.53–74.56%) when exposed to different NVP concentrations. During the late log phase on day 8, T. obliquus achieved the highest NVP removal efficiency, removing 74.56% of the NVP, while C. tenuitheca achieved a removal rate of 48% at an NVP concentration of 50 ng L−1. The photosynthetic efficiency (Fv/Fm and rETR) of both microalgal species was found to be unaffected by environmental concentrations of NVP (up to 4000 ng L−1) during the mid-log phase of growth. Furthermore, the scanning electron microscopy (SEM) analysis demonstrated that both algal species produced distinct ridges on their cell surfaces after NVP uptake. Additional evaluations were conducted on the microalga, T. obliquus, for the removal of NVP at 4000 ng L-1, as well as their cellular response (expression of antioxidant enzymes and metabolomics) and biomass production under different cultivation modes (autotrophic, heterotrophic, and mixotrophic). The highest NVP removal efficiency was observed under mixotrophic (80.13%) growth on day 8, whilst heterotrophic and autotrophic cultivation modes removed 70.30% and 64.40%, respectively. Mass balance calculations showed that the primary removal mechanism was identified as biodegradation, with a relatively low contribution from bioadsorption (2.39-3.36%) and bioaccumulation (0.55- 0.87%). Fourier-transform infrared (FTIR) spectroscopy results of harvested microalgal cells displayed bands in the region of 950-1000 cm-1, indicating the presence of aromatic C-H rings found in NVP. Additionally, 6 possible biotransformation products of NVP were identified by untargeted liquid chromatography-time of flight mass spectrometry. Additionally, under autotrophic conditions, the gene expression analysis revealed heightened activities of superoxide dismutase (sod1), glutathione peroxidase (gpx1) and catalase (cat2) in T. obliquus. The upregulation of antioxidant genes enhances the organism's ability to defend against oxidative stress induced by NVP. The expression levels of antioxidant genes were significantly reduced during heterotrophic and mixotrophic growth, suggesting microalgae can overcome oxidative stress with glucose supplementation. To further investigate the cellular level response of microalgal cells to NVP, metabolomic analysis was carried to out to identify and quantify key algal metabolites during mixotrophic cultivation. The increase in activity of the fatty acid biosynthesis pathway and carbohydrate synthesis was observed by T. obliquus in the presence of NVP under mixotrophic growth conditions. The findings from this study emphasize the significant potential of microalgae in the field of ARV drug remediation.
Food security and coping strategies of an urban community in Durban
(2016) Mtolo, Andile; Napier, Carin E.
Introduction: Food and Agriculture Organisation (FAO 2015a) estimated that 220 million people (23.2%) in Sub-Saharan Africa were undernourished. Parallel to hunger, obesity rates have more than doubled globally since 1980; in 2014, 1.9 billion adults in the world were overweight and 600 million were obese (FAO 2015a). Obesity is a serious concern facing the world today and a major contributor to chronic disease such as diabetes and cardiovascular disease, which are often fatal (Bray, Frühbeck, Ryan and Wilding 2016: 1947). In South Africa, overweight and obesity have reached unacceptable numbers as over 60% of South Africans are overweight or obese. Furthermore, in 2015 South Africa was declared the fattest nation in Sub-Saharan Africa, adding another burden to the HIV epidemic (Ng, Fleming, Robinson, Thomson, Graetz, Margono, Mullany, Biryukov, Abbafati and Abera 2014: 777). Unemployment is one of the major factors that drive household food insecurity due to the fact that most people access food commercially. Therefore, income is a significant factor in ensuring that a healthy and nutritious diet is consumed regularly. The study community was at Umbilo, Durban, KwaZulu-Natal in a government owned estate called Kenneth Gardens. The estate has 286 units and accommodates approximately 1500–1800 residents. It formed part of an extensive network of cluster housing schemes developed by the apartheid government as a protectionist strategy to provide safe and affordable housing for poor and working class whites. Kenneth Gardens is currently managed by KwaZulu-Natal (KZN) Province and offers subsidized housing to residents from diverse background. Residents are low income bracket earners and many rely on state disability and pension grants for survival. Kenneth Gardens faces a wide range of social problems such as alcohol, drug abuse, domestic violence, unemployment and limited access to education (Marks 2013:26). Aim: The aim of the study was to determine the food security status, coping strategies, food intake and the nutritional status of the Kenneth Gardens community, which is situated in an urban area in KwaZulu-Natal. Methodology: One hundred and fifty (n=150) randomly selected caregivers participated in the study. The sample size was calculated using a power calculation indicating that 150 participants represent a reliable sample. The sampling procedure was simply random sampling. This study was quantitative and partly qualitative and descriptive in nature therefore, different measuring instruments were used to collect relevant data. The research tools for various variables measurements included; food security questionnaire, anthropometric measurements, a socio-demographic questionnaire, a food frequency questionnaire, and 24-hour recall questionnaires conducted in triplicate. Food security coping strategies were documented through a focus group interview with the Kenneth Gardens community members to determine strategies used to address food scarcity. All participants were weighed and measured to determine body mass index (BMI), classified according to the World Health Organisation (WHO) cut-off points. Data for socio demographic, FFQ, anthropometric measurements, and coping strategies was captured by the researcher on Excel® Spread sheets and analysed by a statistician for descriptive statistics using the Statistical Package for the Social Science (SPSS) version 17.0. Data for the 24-hour recall was captured and analysed by a nutrition professional using the MRC Food Finder® version 3.0 software, based on the South African composition tables. Results: The study population consisted of 150 households, including women (n=122) and men (n=28). The results revealed that the majority of households (52.7%, n=79) were headed by a mother, and only 40% (n=60) of households were headed by a father. Majority (47.3%, n=71) of the participants had completed matric and 7.3% (n=11) had tertiary education. English, (52%, n=78), was the most spoken home language, followed closely by Zulu, (43.3%, n=65). Thirty six percent (n=54) of the participants were unemployed and 26.7% (n=40) were employed; however over, 50% (n=40) of the employed participants were temporary. Twenty eight percent (n=42) of the participants earned less than R3000.00 per month and 31.3% (n=47) earned between R3000.00 and R6000.00 per month. Pensioners were 17.3% (n=26), who therefore received a government grant that ranges between R1500 and R1520 per month depending on the claimant’s age. The average household income was reported as R4429.20. The average number of people in the household was five, which equates to R6.00 per person per day. The results also revealed that 38% (n=57) of the household had a sole contributor to the household income; other households had two contributors (42.7, n=64) and 11.3% (n=17) had three contributors. Urban South Africans tend to purchase food as opposed to growing their own food. A lack of purchasing power results in food insecurity that eventually leads to malnutrition. The majority (56.6%, n=85) of the participants indicated a shortage of money to buy food and this inevitably leads and drive utilisation of coping strategies with high severity rate during periods of food scarcity. Bulk food was purchased once a month by the majority (68%, n=102) of the participants. The most commonly used coping strategy during periods of food scarcity was “Rely on less expensive and preferred food” with the mean score of 4.56 (±SD 2.772). The second used coping strategy was “Reduce the number of meals eaten in a day” with a mean score of 3.85 (±8.163), followed by “Contribute to a food stokvel in order to ensure food over a scarce period” (3.31, ±7.505) and “Restrict consumption by adults in order for small children to eat” (2.24, ±5.333). Utilisation of these food coping indicate a degree of food insecurity. The Body Mass Index (BMI) classification indicated that women had a higher (31.46 ±8.474) BMI than men (26.00±5.445). A total of 26.2% (n =32) women were overweight and 51.7% were obese category I, II and III. The mean BMI for the whole group was (30.44±8.261) which clearly demonstrated obesity. Nonetheless, men were not overweight; however 25% (n=7) were obese category I. Collectively, underweight was prevalent in women (3.3%, n=4) and men (3.6%, n= 1). The Food Variety Score was medium (31.91, ±10.573), which indicated a consumption of 30- 60 individual foods from four to five food groups during the seven day period; however the top 20 foods consumed from the 24-hour recall revealed that the diet was energy dense and the most consumed foods were primarily from the carbohydrate and fat group and a low consumption of fruits and vegetables was reported; hence the nutrient analysis showed a deficient intake of several nutrients, such as: calcium, vitamin A, zinc, vitamin D, vitamin E, vitamin K, zinc, magnesium, phosphorus, selenium and thiamine by both men and women. According to the WHO dietary factor goals, the acceptable macronutrient distribution ranges (AMDRs) and fruit and vegetable intake based on the 24-hour recalls, fat and protein intake exceeded the recommended 15-30 percent goal. Fruit and vegetable intake was very low in comparison to the minimum recommended intake of >400g. Carbohydrates intake for women were within the recommended 55-75 percent; however, men aged 19-50 years (50.70%) and >50 years (53.74%) did not meet the recommended intake. Conclusion: The results of this study reveal that the nutrition status of this community was compromised. The top 20 food intake indicated inadequate eating patterns and that diets comprised of energy dense foods, such as carbohydrates and fats, which could directly be responsible for the high obesity levels of >50% in women and >25% in men. Furthermore, there was low income and a high unemployment rate that proliferates the prevalence of food insecurity, hence the coping strategies reported. Malnutrition exists in communities as a result of food and nutrition insecurity which is affected by a significant number of factors that need to be considered and addressed. Nutrition interventions and nutrition education on a balanced diet, healthier methods of preparing food, and physical activity are required to ensure and improve health status, quality of life and better and sustainable coping strategies for our communities.
Hollow fibre liquid phase microextraction of pharmaceuticals in water and Eichhornia crassipes
(2019) Mlunguza, Nomchenge Yamkelani; Madikizela, Lawrence Mzukisi; Chimuka, Luke; Mahlambi, Precious N.
This work describes a simple and rapid method for the simultaneous isolation, enrichment, and quantitation of selected pharmaceuticals in aqueous environmental samples and Eichhornia crassipes. This was achieved by developing a hollow fiber liquid phase microextraction (HF-LPME) technique coupled with ultra-high-pressure liquid chromatography-high resolution mass spectrometry for the simultaneous extraction, pre- concentration and quantitation of four non-steroidal anti-inflammatory drugs (NSAIDs) and three antiretroviral drugs (ARVDs) from aqueous matrices and different segments of water hyacinth plant species. The target compounds for NSAIDs were naproxen (NAP), fenoprofen (FENO), diclofenac (DICLO) and ibuprofen (IBU) whereas the selected ARVDs included emtricitabine (FTC), tenofovir disoproxil (TD) and efavirenz (EFV). A multivariate approach by means of a half-fractional factorial design was used to optimize the HF-LPME technique focusing on six factors; donor phase (DP) pH, acceptor phase (AP) pH, extraction time, stirring rate, supported liquid membrane carrier composition (SLM carrier comp.) and salt content. Four of these factors (DP pH, AP pH, stirring rate and extraction time) were identified as vital for an enhanced enrichment of each of the selected NSAIDs and four of the previously mentioned vital factors including the SLM carrier composition were classified as significant for the selected ARVDs from aqueous samples into the hollow fiber. These essential factors were further paired according to their level of significance. The paired significant factors were then optimized using central composite designs (CCD) where empirical quadratic response models were used to visualize the response surface through contour plots, surface plots and optimization plots of the response outputs. The optimized factors for individual analytes belonging to each class were then altered to universal conditions for their simultaneous extraction from same sample solution. The acceptability of the universal conditions was defined using desirability studies. A composite desirability value of 0.7144 was obtained when the optimum factors of the three ARVDs were applied for their simultaneous extraction while a simultaneous extraction of NSAIDs had a desirability value of 0.7735. This implied that the set conditions were ideal for a combined extraction of the target compounds from the donor phase into the acceptor phase across a supported liquid membrane impregnated with a carrier molecule. For the simultaneous extraction of ARVDs, the universal optimum HF- LPME conditions were found to be DP pH of 4, AP HCl conc. of 200 mM (pH = 0.4) with SLM carrier comp. set at 4.5 (%w/w) and stirring at 1000 rpm. Under optimum conditions, the enrichment factors (EF) for ARVDs from aqueous phase were 78 (FTC), 111 (TD) and 24 (EFV). These conditions yielded recoveries in the range of 96 to 111%. The sensitivity of the analytical method through limits of quantification (LOQ) for the selected ARVDs in wastewater samples were 0.033 μg L-1 (FTC), 0.10 μg L-1 (TD) and 0.53 μg L-1 (EFV). The LOQ values were computed for surface water samples using the same target ARVDs were 0.169 μg L-1 (FTC), 0.018 μg L-1 (TD) and 0.113 μg L-1 (EFV). For NSAIDs, the overall conditions were DP pH of 10, AP pH of 3 at an extraction time of 60 min with stirring rate at 1000 rpm. The recoveries yielded under these optimum conditions for the target compounds ranged from 86 to 116%. The EF for the target NSAIDs from aqueous media were 49 (NAP), 126 (FENO), 93 (DICLO) and 156 (IBU). The LOQ values for each target NSAID in wastewater samples were 0.47 μg L-1 (NAP), 0.09 μg L-1 (FENO), 0.59 μg L-1 (DICLO) and 0.49 μg L-1 (IBU). The specific universal conditions were then used in the analysis of ARVDs in wastewater and surface water whereas for NSAIDs analysis, only wastewater samples were analysed. The surface water samples were obtained from North of Johannesburg in Hartbeespoort dam and the wastewater samples were collected from various wastewater treatment plants located in Durban, KwaZulu-Natal. The technique was also applied in the analysis of the target compounds in plant samples obtained from Hartbeespoort dam in North of Johannesburg, Umgeni river located in Springfield (Durban in KwaZulu-Natal) and Mbokodweni river located in south of Durban city, KwaZulu-Natal. The plant samples were first cut and separated into different segments (roots, stems and leaves) and the target analytes then extracted into 20 mL water using an optimized microwave assisted extraction technique (MAE). The HF-LPME technique initially optimized for water samples was then applied for pre-concentration of the target pharmaceuticals from the MAE water extract. Factors that were optimized for MAE technique were irradiation time and temperature for ARVDs whereas irradiation time and solvent volume were optimized for the extraction of NSAIDs. For extraction of both ARVDs and NSAIDs, the optimum irradiation time was 20 min while the irradiation temperature was set at 90 ̊C during the extraction of ARVDs and 100 ̊C for NSAIDs. Generally, the studied ARVDs were all detected in most samples with concentrations for FTC (0.11 – 3.10), TD (0.10 – 0.25) and EFV (1.09 up to 37.3) μg L-1 recorded in wastewater samples. EFV had the highest concentration of 37.3 μg L-1 in the wastewater effluent. The concentration of ARVDs in the roots of the water hyacinth ranged from 7.4 to 29.6 μg kg-1, 0.97 to 11.42 μg kg-1 in the stem and 0.98 to 9.98 μg kg-1 in the leaves of the aquatic plant. Roots of the water hyacinth plant had higher concentrations of the investigated ARVDs. Lastly, the NSAIDs were also detected in various wastewater samples with concentration for NAP (1.15 to 3.30) μg L-1, FENO (
The impact of an orange-fleshed sweet potato yoghurt on the nutritional status of pre-school children in Durban, South Africa
(2022-03-16) Makanjana, Onwaba Z.; Napier, Carin E.; Naicker, Ashika
Background: Malnutrition exists globally due to various factors including basic, underlying and immediate factors. Goal two of the global targets in the 2030 Agenda for Sustainable Development is to end hunger and ensure that even the poorest people have access to sufficient, nutritious and safe food all year round. The Department of Social Development (DSD) in South Africa identified Early Child Development (ECD) centres as an ideal platform for implementing strategies aimed at improving the wellbeing of children below five years of age. ECD centres are facilities designed to provide early childhood development services and programmes that include good health, proper nutrition and early learning, through a holistic approach in promoting a healthy environment that is conducive for learning and development. Rationale and objectives: The health and nutritional status of young children is a global priority, as indicated in the 2030 Agenda for Sustainable Development. The arguments in favour of promoting the development of children at a very young age are clear and compelling. Effective interventions aimed at the vulnerable groups can make a positive contribution towards the achievement of Sustainable Development Goal (SDG) 2 which aims to end hunger, achieve food security and improved nutrition and promote sustainable agriculture. Inadequate nutrition in young children not only affects physical growth and development, but mental functioning as well. The pre-school years are associated with a phase of rapid growth. Adequate nutrition during the pre-school years is critical as proper nutrition plays an essential role in preventing malnutrition and other childhood-related diseases. Dietary diversification is one of the most effective strategies in preventing malnutrition and it is recommended that it is implemented during the stage of complementary feeding. Diets lacking dietary diversity lead to inadequate intake of vital nutrients such as vitamin A and iron, which may result in micronutrient deficiencies. Vitamin A and iron deficiencies are common among pre-school children in South Africa (SA) and the orange-fleshed sweet potato (OFSP) was identified as a potentially effective strategies to address vitamin A deficiency (VAD). The purpose of the study was to determine the nutrient intake, to develop and test the impact of an OFSP yoghurt on nutritional status of pre-school children in Durban, KwaZulu-Natal, SA, by determining the vitamin A and iron status of preschool children. The objectives of the study were to establish the socio-demographic profile of the children, to take anthropometric measurements (weight and height) to establish their nutritional status, to assess the dietary intake using a 24-hour recall questionnaire, (which was repeated three times) and a Food Frequency Questionnaire (FFQ). Furthermore, the study also aimed to determine the levels of vitamin A and iron in the blood at the time of the study using the finger-prick dried blood spot method, develop a yoghurt using an OFSP, administer the yoghurt as an intervention for three consecutive months and thereafter test the impact of the yoghurt on the nutritional status of the participants. Methodology: In this intervention trial, two ECD centres, an experimental group (EG) and control group (CG) comprising of 116 children aged 24–60 months were randomly selected. In each group, the participants were stratified according to age: 24–47 months and 48–60 months. At baseline, through the caregiver of the child participant, socio-demographic data was captured, and dietary intake was measured through three 24-hour dietary recall questionnaires, which were then analysed using Food Finder® software version 3.0 developed by the South African Medical Research Council (SAMRC). The food frequency questionnaire was used to calculate the food variety and food group diversity scores. Anthropometric measurements (weight and height) were taken and the World Health Organization (WHO) Anthro software® version 3.1 was used to convert these into nutritional data indices. Blood samples were collected through dried blood spot cards in order to determine serum retinol and haemoglobin (Hb) levels, which were assessed using the WHO indicators. A yoghurt with OFSP was developed following the steps of product development. The participants in the EG were given 100g of the developed OFSP yoghurt daily for three months, while the participants in the CG were given 100g of a peach flavoured yoghurt bought from the supermarket daily for three months, excluding weekends. The peach flavour was chosen for the CG as the colour was closest to the developed OFSP yoghurt. After the intervention period, anthropometric measurements were taken, dietary intake was assessed and blood samples were taken to assess impact on serum retinol and Hb levels. Results: Regarding the socio-demographic profile, unemployment was high, as 45.6% (n=36) and 54.1% (n=20) of the participants in the EG and CG respectively, were unemployed. In terms of household characteristics, 45.6% (n=36) of the participants in the EG and 32.4% (n= 12) in the CG had a tap inside the house. Access to a flush/sewage toilet was very limited in both groups, as less than half of participants had a flush toilet (39.2%; n=31) and 40.5% (n=15) in EG and CG, respectively) and more than half of the participants had a pit latrine (60.8%; n=48) in the EG and 59.5% (n= 22) in the CG. At baseline, anthropometric results in the current study showed that 16.6% (n=2) of CG girls 48-60 months of age were stunted. Among boys, 10.5% (n=12) and 36.4% (n=4) of EG and CG boys 48-60 months of age respectively, were stunted. No change was noted among EG boys 24-47 months of age of age, as 4.8% (n=1) were severely stunted at baseline and at endline. At baseline, 8.7% (n=2) of EG girls 24-47 months of age were overweight. In the CG group, 28.6% (n=2) and 16.7% (n=2) of girls 24-47 months of age and 48-60 months of age, respectively, were overweight. Furthermore, 9.5% (n=2) of EG boys and 42.8% (n=3) of CG boys 24-47 months of age were overweight. The prevalence of overweight among boys 48-80 months of age was 10.5% (n=2) and 27.3% (n=3) in the EG and CG, respectively. The prevalence of the risk of overweight increased from 21.7% (n=5) among EG girls 24-47 months of age at baseline to 45.0% (n=9) at endline and from 14.3% (n=1) to 28.6% (n=2) in the CG group. In the CG, an increase in the prevalence of the risk of overweight was noted among boys 48-60 months of age from 36.3% (n=4) at baseline to 54.5% (n=6) at endline. At baseline, the energy intake of girls and boys 24-47 months of age was more than the estimated energy requirement (EER) for both groups, whereas for the 48-60 month age group, it was less than the EER. The mean intake of fibre and calcium was lower than the recommended dietary allowance (RDA) for all groups and most participants consumed less than the RDA for fibre and calcium. The mean fruit and vegetable intake was less than the WHO recommendation of 320g to 480g per day for 24-47 month old children, and 400g to 480g for 48-60 month old children for all participants in the current study, and there was low variety in both groups. When comparing baseline with endline results between age groups within a group, there was a decrease in energy intake in all groups. Significant differences were found among EG girls 24-47 months of age (p=0.008) and CG girls (p=0.003 for 24-47 months and p˂0.001 for 48-60 months) for energy intake. Furthermore, baseline results showed that 2.7% (n=2) and 14.3% (n=3) of participants had low serum retinol levels in the EG and CG, respectively. At endline, serum retinol increased in 5.5% (n=3) of participants in the EG and 4.5% (n=1) in the CG. Low Hb levels were found in 19.2% (n=14) of participants in the EG and 32.1% (n=9) in the CG. At endline, Hb levels increased in 3.7% (n=2) and 9.0% (n=2) of participants in the EG and CG, respectively. Conclusion: Despite the numerous efforts to improve the nutritional status of children, a high prevalence of malnutrition still exists in South Africa. Consumption of the OFSP yoghurt made a small contribution to dietary vitamin A intake for some participants and iron intake levels did not increase from baseline to endline. The intervention period was too short to show an impact on anthropometric measurements such as stunting. The socio-demographic profile indicated that participants were predominantly from low-income households, and deprived of some essential sanitation services. Other issues in the current study population included overcrowding and high unemployment, with some households running out of money to buy food. The diet of the participants, was sub-optimal for optimum growth. Malnutrition, presented through micronutrient deficiencies, stunting, overweight and obesity, co-exist in this vulnerable population.
An integrated approach for biofuel and fertilizer production using microalgae grown in wastewater
(2022-09) Musetsho, Pfano; Bux, Faizal; Renuka, Nirmala; Guldhe, Abhishek
Microalgae are recognized as potential candidates for resource recovery from wastewater and are projected for biorefinery models. Therefore, this study was undertaken to evaluate the potential of poultry litter and municipal wastewater as nutrient and water sources, for the cultivation of Acutodesmus obliquus for lipids production for biodiesel application. The efficacy of lipid extracted biomass (LEA) as fertilizer for mung bean crops was also assessed in microcosm. A. obliquus cultivation in acid pre-treated poultry litter extract (PPLE) showed maximum biomass production of 1.90 g L-1 , which was 74.67% and 12.61% higher than the raw poultry litter extract (RPPE) and BG11 respectively. Higher NO3-N, NH3-N, and PO4-P removal of 79.51%, 81.82%, and 80.52% respectively were observed in PPLE as compared to RPLE treatment. The highest biomass (140.36 mg L-1 d -1 ), lipids (38.49 mg L-1 d -1 ), and carbohydrates (49.55 mg L-1 d -1 ) productivities were observed in the PPLE medium. The application of LEA as a fertilizer for mung bean crops showed improvement in plant growth and soil microbial activity. A maximum increase in organic carbon (59.5%) and dehydrogenase activity (130.8%) was observed in LEA amended soil which was significantly higher than chemical fertilizer (CF) control in 30 days. Whilst plant fresh weight and leaf chlorophyll in the LEA amended soil was comparable to whole algal biomass (WA) and CF control. The findings of the present study could be a basis for sustainable biorefinery for the valorization of wastewater for the production of microalgae-derived biofuel and byproducts for agricultural applications.
Ion doped metal oxide and its power conversion efficiency influence on Perovskite solar cells
(2024-09) Reddy, Dwayne Jensen; Lazarus, Ian Joseph
ABSTRACT Ion Doped Metal Oxide and its Influence on the Power Conversion Efficiency of Perovskite Solar Cells Dwayne Jensen Reddy Doctor of Applied Sciences This study focuses on the fabrication and characterization of Zinc-doped Titanium dioxide (ZnTiO2) as an Electron Transport Layer (ETL) in CH3NH3PbI3-based perovskite solar cells (PSCs). A one-step spin coating technique under controlled ambient conditions (relative humidity < 65%, room temperature ∼ 20oC ) for the development of PSC was applied to investigate the effects of Zn-ion doping on the structural, morphological, optical, and photovoltaic properties. Numerical simulations using SCAPS 1D were additionally performed to further investigate the influence of ion doping on the power conversion efficiency (PCE) of PSCs. Zn-doped TiO2 was successfully incorporated into the TiO2 crystal structure using the solgel technique. Characterization through X-ray diffraction (XRD) and Energy Dispersive X-ray Spectroscopy (EDX) confirmed the incorporation of Zn ions. The crystallite size ranged from 19.99 to 7.1 nm, depending on the Zn ion doping concentration. XRD results also indicate the formation of a highly crystalline tetragonal perovskite (CH3NH3PbI3) phase. Fourier Transform Infrared (FTIR) spectroscopy verified the presence of the anatase phase of Zn-doped TiO2, while the formation of the adduct of Pb2 with dimethyl sulfoxide (DMSO) and methylammonium iodide (MAI) was confirmed at 1015 cm-1. Scanning Electron Microscope (SEM) images exhibited fairly smooth and uniform surface coverage for the Zn-doped TiO2 layers. The Root Mean Square (Rq) values for surface roughness showed a decrease from 26.85 nm for undoped TiO2 to 23.4 nm for the 5 mol% Zn-doped TiO2 layer. UV-Vis spectroscopy demonstrated low light transmission loss characteristics from 300 to 790 nm, with the 2 mol% Zn-doped TiO2 showing slightly improved light transmission between 550 and 800 nm. The bandgap energy of undoped and Zn-doped TiO2 ranged from 3.53 to 3.38 eV, while the perovskite layer exhibited a bandgap energy of 2.06 eV. Experimentally, an optimum PCE of 5.67% was achieved with a 2 mol% dopant concentration. However, increasing the Zn dopant to 5 mol% led to a slight deterioration in the PCE. Numerical simulations revealed that increasing the donor doping concentration in the ETL improved the conduction band alignment at the ETL and perovskite interface, resulting in a PCE of 6.17%. Optimizing the absorber acceptor doping concentration and band gap improved the PCE to 10.79%, however, created a pronounced conduction band offset at the ETL/perovskite interface. This was mitigated by introducing an interfacial layer of Cubic Silicon Carbide (3C-SiC) between the absorber and ETL to minimize the conduction band offset, ultimately achieving a PCE of 12.09%.