Faculty of Engineering and Built Environment

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39th Johannesburg International Conference on “Chemical, Biological and Environmental Engineering” (JCBEE-23) Nov. 16-17, 2023 Johannesburg (South Africa)
(International Institute of Chemical, Biological & Environmental Engineering (IICBEE), 2023-11-16) Chetty, Manimagalay; Rathilal, Sudesh; Tetteh, Emmanuel; Singh, Nikita
Abstract—Recent energy demand and environmental concerns associated with fossil fuels makes algae biomass a desirable energy source. Algal biomass has a high organic content and a variety of metabolic properties that make it a promising resource for managing wastewater and sequestering CO₂, in addition to producing profitable biobased products. However, the operation and valorization of algae biomass on a large scale are accompanied by significant costs and setbacks. Therefore, the transition towards a biobased economy requires this study to examine emerging technologies that could utilize algae biomass as an industrialized feedstock from the wastewater settings. A comprehensive analysis of various green technologies of producing high-value products (lipids and hydrocarbons) from algae biomass was reviewed. The fundamental principles that limit the cultivation , extraction, and conversion of different types of algae biomasses for commercialization are discussed. Furthermore, the challenges, future research directions and potential opportunities of valorizing algae biomass was highlighted. It was noted that, exploring algae biomass towards sustainable waste management with resources recovery is viable for industrialization.
The academic benefit of experiential learning for Civil Engineering students on the Pietermaritzburg campus of the Durban University of Technology
(SASEE, 2013-06) McKune, Tom
Academic training evaluation of building technology programme
(Department of Construction Economics and Management, University of Cape Town, 2022-08-01) Obaju, Biodun; Fagbenle, Olaposibo; Amusan, Lekan; Olaniran, Temitope
Training evaluation is one method through which tertiary institutions examine the effectiveness of the training they deliver in order to establish their students' readiness for the workplace. However, several higher institutions' evaluation methods have been confined to assessment in tests and exams without considering the knowledge and competencies acquired by students via training in fulfilling workplace expectations. Hence, the study assessed the training received by Building technology graduates in construction management and construction technology courses. The study adopted the Kirkpatrick model's first two stages of training evaluation (Reaction and Learning levels) with a questionnaire distributed to purposively selected Building technology graduates from two polytechnics in Southwestern Nigeria using a snowball sampling technique. Data obtained were analysed using descriptive statistical tools. The study's findings show that respondents were satisfied with the training acquired and possess the basic competency from the training. However, the graduates lack sufficient knowledge of laws and regulations governing construction work, the use of computer programme for planning and scheduling projects and the ability to use tools and equipment for construction work. The study findings imply that building graduates would be unable to work adequately in the construction industry without additional training, putting enormous strain on construction firms to re-training them to meet their expectations. Tertiary institutions need to revamp their training strategies and methods for students to improve their competency to strive in the construction industry.
Acetic acid adsorption onto activated carbon derived from pods of Acacia nilotica var astringens (Sunt tree) by chemical activation with ZnCl2
(IISTE, 2015) Elhussien, Mutasim H.; Isa, Yusuf Makarﬁ
The purpose of this study is to prepare and investigate the adsorption behavior of acetic acid onto two samples of activated carbon prepared from Acacia nilotica var astringens, Sunt tree,( SUNT-C1 and SUNT-C2). Applicability Langmuir, Freundlich, Temkin and Dubinin-Radushkevitch models of adsorptions isotherm have been tested, while acetic acid initial concentration varied between (0.010 – 0.300) mol/dm3. A comparative study of adsorption capacities of these samples was performed. The obtained data were compared and fitted well with the four models; there exist a correlation between physico- chemical properties of the activated carbons and the sorption processes. The maximum monolayer coverage (Qo) from Langmuir isotherm model was determined to be 1.016mg/g. Also from Freundlich Isotherm model, the sorption intensity (n) which indicates favourable sorption and the correlation value are 1.11 and 1.09 respectively.
Acousto-ultrasonics for defect assessment of composite materials
(2002) Dugmore, Kevin M.; Jonson, Jon David; Walker, Mark
The experiments and their results contained herein will form the basis for the development of a portable non-destructive testing device for composite structures. This device is to be capable of detecting any of a variety of defects and assessing their severity within a short time
Adapt or Die! Building Information Modelling (BIM)
(Association of Schools of Construction of Southern Africa, 2016) Haupt, Theo C.; Hefer, Elke
Purpose: The emergence of Building Information Modelling (BIM) demands that quantity surveyors review their roles in the construction sector. This study examines the responsiveness of the quantity surveying discipline to BIM. Design/methodology/approach: A sample of quantity surveyors in Durban will be surveyed using an instrument developed from published literature on responses of quantity surveying to BIM. Research limitations: The sample of quantity surveyors was drawn from the Durban area using the Association of South African Quantity Surveyors (ASAQS) and South African Council for the Quantity Surveying Professions (SACQSP) database. Findings: Preliminary findings suggest that quantity surveyors’ knowledge about BIM, software and innovation was at best rather average. They recognized the most obvious benefits of embracing BIM such as the time taken to produce Bills of Quantities and accurate cost estimation. Largely because of their lack of knowledge of available technologies they could not comment assertively on many of the issues surrounding the relationship between BIM and quantity surveying. This further resonates with the uncertainty that exists surrounding BIM and its business value and return on investment. They disagreed that technological advancements presented threats to their existence or the services that they traditionally offered. In the main the findings of the study resonated with those of other studies done particular in developing countries. Response to conference theme: This study identifies the reasons why BIM is not being readily embraced by quantity surveyors more pervasively. Practical implications: The findings provide the opportunity to improve the services currently offered by quantity surveyors but also new and innovative services driven by BIM
An adaptive neuro-fuzzy inference scheme for defect detection and classification of solar Pv cells
(Academy Publishing Center, 2024-09-12) Moyo, Ranganai Tawanda; Dewa, Mendon; Romero, Héctor Felipe Mateo; Gómez, Victor Alonso; Aragonés, Jose Ignacio Morales; Hernández-Callejo, Luis
This research paper presents an innovative approach for defect detection and classification of solar photovoltaic (PV) cells using the adaptive neuro-fuzzy inference system (ANFIS) technique. As solar energy continues to be a vital component of the global renewable energy mix, ensuring the reliability and efficiency of PV systems is paramount. Detecting and classifying defects in PV cells are crucial steps toward ensuring optimal performance and longevity of solar panels. Traditional defect detection and classification methods often face challenges in providing precise and adaptable solutions to this complex problem. In this study the researchers pose an ANFIS-based scheme that combines the strengths of neural networks and fuzzy logic to accurately identify and classify various types of defects in solar PV cells. The adaptive learning mechanism of ANFIS enables the model to continuously adapt to changes in operating conditions ensuring robust and reliable defect detection capabilities. The ANFIS model was developed and implemented using MATLAB and a high predicting accuracy was achieved.
An adaptive quotation system for web-based manufacturing
(2005) Li, Qingxue; Walker, Mark
Increased global competition is challenging manufacturing industries to bring competitively priced, well-designed and well-manufactured products into the marketplace as quickly as possible. Manufacturing companies are responding to these challenges in their industry by extending current internet trends to create virtual marketplaces where factories, suppliers, and customers are part of the solution. Pressing demands to reduce lead-time by providing a suitable manufacturing price for a product has become an important step in the current competition age. This thesis presents an approach for providing a quotation for a product via the web, automatically and autonomously.
Adoption of intelligent transport systems for sustainable transportation in secondary cities of South Africa : a case of Port Shepstone
(2019-08) Madihlaba, Goodness Lerato; Musvoto, Godfrey Gombana
Transportation is one of the major phenomenon which often directs population increase, investments and land use patterns in cities. Most cities, particularly secondary cities often do not entirely plan for future transportation when planning for massive investment developments thus leaving such cities with transportation challenges which include aging transport infrastructure, increased traffic patterns, insufficient parking spaces, high-accidents rates, to name a few. The most ignored transportation solution in secondary cities is the use of technology to manage transportation challenges in which such solutions may include the establishment of Intelligent Transport Systems (ITS). This research study seeks to examine what are the possibilities of using ITS to address the transportation challenges of the secondary city of Port Shepstone, what are the recommendations that can be put forward for establishment of ITS in Port Shepstone. In an attempt to discover these questions, the study conducts a literature review analysis which outlines what others have done in this research area and progressively attempts to provide recommendations on the possible establishment of ITS solutions in Port Shepstone. The literature review focuses on five (5) functional areas (i.e. Advanced Traveller Information Systems (ATIS); Advanced Transportation Management Systems (ATMS); Advanced Public Transport Systems (APTS); Enabled Transportation Pricing System (ETPS) and Data Acquisition Management Systems (DAMS)) which their possibility of being established in the secondary city of Port Shepstone is investigated The literature review analysis is supplemented by semi-structured interviews with various stakeholders within the transportation sector; and their views are constructively analysed to draw converging findings. The empirical findings from both literature review analysis and conducted interviews provide meaningful answers to the research questions and enabled the researcher to draw fundamental recommendations and possible ITS solutions to address the transportation challenges of Port Shepstone.
Advanced distributed cooperative secondary control of Islanded DC Microgrids
(MDPI AG, 2022-05-28) Aluko, Anuoluwapo; Buraimoh, Elutunji; Oni, Oluwafemi Emmanuel; Davidson, Innocent Ewean
In an islanded DC microgrid with multiple distributed generators (DGs), the droop control is employed to realize proportional current sharing among the DGs in the microgrid. The action of the droop control causes a deviation in the DC bus voltage which is exacerbated by the line impedance between the DG and the DC bus. In this paper, an advanced distributed secondary control scheme is proposed to simultaneously achieve accurate voltage regulation and cooperative current sharing in the islanded DC microgrid system. The proposed distributed secondary controller is introduced in the cyber layer of the system, and each controller shares information with neighbouring controllers via a communication network. The distributed technique maintains the reliability of the overall system if some part of the communication link fails. The proposed controller uses the type-II fuzzy logic scheme to adaptively select the secondary control parameters for an improved response of the controller. The sufficient conditions to guarantee the stability of the proposed controller are derived using the Lyapunov method. Comprehensive tests under different operating scenarios are conducted to demonstrate the robustness of the proposed control scheme.
Advanced reliability analysis of road-slope stability in soft rock geological terrain
(2023-05) Sengani, Fhatuwani
Most of the national, regional, and local roads in Limpopo Province have been developed through a rugged topography and artificial slopes have been created with loose rocks scattered across the slopes as a results road slope instability is the common challenge. The objective of this research study is to conduct an advanced reliability analysis of road-slope stability in soft rock geological terrain using the national road (N1) and its tributary (R71) as case studies. Limit analysis, limit equilibrium, finite element methods, finite difference methods, machine learning and GIS-based tools have been used for this purpose. Meanwhile, the accuracy classification chart of limit equilibrium methods in homogenous slope and a new method for predicting the stability of slope in multiple faulted slopes were developed. The reproduction of failure evolution of slope instability was also performed, followed by reliability analysis of the slope based on probabilistic analysis. Lastly, an integrated approach to slope stability assessment based on machine learning, geographic information systembased tools and geotechnical methods was presented. To achieve the above, field observations and measurements, structural mapping, limit equilibrium, limit analysis, Monte Carlo simulation, fuzzy inference analysis, and GIS digitization and analysis were performed. Software packages such as SLIDE, FLACslope, Optimum 2G, DIPS, RocLab, and ArcGIS, were used. The accuracy classification chart for Limit Equilibrium Methods LEM), a new method for performing stability analysis in multiple faulted slopes, reproduction of failure evolution of slope was developed. Monte Carlo simulation was established as the most reliable and effective technique to analyze slope stability. The steepness of the slope, rock and soil properties, extreme rainfall and geological features were demonstrated to influence slope instability based on an integrated approach as stated above. From the above-mentioned major findings, it was concluded that the developed accuracy error classification chart of LEMs and the new method of slope stability in multi-faulted slopes are useful. Though the reproduction of failure evolution of slope was successfully achieved, for material to flow for a longer distance, high kinetic energy and more shearing of material are expected to take place during this process. It is recommended that other sophisticated methods be utilized to expand the results.
Advances in sintering of titanium aluminide : a review
(Springer Science and Business Media LLC, 2022) Mphahlele, Mahlatse R.; Olubambi, Peter Apata; Olevsky, Eugene A.
Aerobic sequencing batch reactor for the treatment of industrial wastewater from the brewery
(2017) Shabangu, Khaya Pearlman; Chetty, Maggie; Bakare, Babatunde F.
One of the major effects of socio-economic change due to industrialisation is the generation of industrial wastewater, which requires treatment before being released into the environment. Laboratory-scale aerobic sequencing batch reactors under suspended-growth heterotrophic activated sludge were operated in different aeration configurations to study their effect on the treatment of wastewater generated by a local brewery. The main purpose of this study was to evaluate the performance of the two laboratory-scale aerobic sequencing batch reactors treating brewery wastewater under continuous low-oxygen dosing concentration and cyclic aeration schemes on SBR operation. The characterisation of brewery wastewater was undertaken to assess the physicochemical composition of the wastewater produced from one of the breweries in South Africa (SAB). The data showed distinctive characteristics of brewery wastewater, which coincided with studies previously carried out on characterisation of brewery wastewater. The COD average concentration of the brewery influent was 7100 mg/L, with average pH values of 7. The BOD and the total solids content of the brewery wastewater influent from the facility were both high, implying that the influent was very rich in organic content and its discharge into water-receiving bodies or the municipal treatment plant could have adverse effects. From these results, a need for a competitive treatment technology was clearly highlighted so as to carry out a feasible treatment of the influent for the brewery industry. The aerobic sequencing batch reactors were designed, fabricated and set up for laboratory-scale treatment of wastewater from the brewery for 15 weeks. The performance of the two SBR configurations was determined with reference to COD, BOD, TS, VS and TSS. The experimental results demonstrated that wastewater generated from the breweries can be treated successfully using both aeration configurations. The results obtained indicated that treatment efficiencies in terms of COD and BOD were 94 % and 85 % respectively, for the reactor operated under continuous aeration configuration, while 81 % and 65 % was achieved for the reactor operated in the cyclic aeration scheme. The findings from this study demonstrate that the performance of the reactor operated under the continuous aeration scheme was successful, and showed statistically significant differences from the performance of the reactor operated under cyclic aeration schemes. These findings imply that there is a potential for the equipment, including financial benefit as a result of operating aerobic sequencing batch reactors for treating brewery wastewater under continuous low-oxygen concentration dosing schemes. In this study, it was also established that the maximum COD removal could be reached at an optimum hydraulic retention times of 5 days for both reactors. This was based upon viewing the experimental data; it appeared that the most significant difference in percentage COD removal was for HRTs 3 days and 4 days. Although, due to less percentage COD removal observed from HRTs 5 days till 7 days, it was hence established that the optimum removal of high strength organics in the brewery wastewater could be achieved within 5 days of treatment time. The pH adapted at an average of 7 for all batch experimentations of the study. The temperature maintained an average of 23 oC ambient, throughout the experimental period. These physical parameters ensured that the microbial population was kept healthy, without inhibiting its biological degradation activity. Although, sludge build up was observed in both aerobic SBRs on completion of each batch operation due to solids retention and organic pollutants biodegradation from the brewery wastewater. It was perceived that frequently reseeding both aerobic SBRs, as an alternative to 28 days sludge retention time would enhance the recovery of biomass, thus improving the overall removal of TSS consequently minimising sludge bulking in both reactors.
Airborne antenna systems for DVB-RCS solutions
(IEEE, 2016) Ilcev, Stojce Dimov
This paper introduces development and implementation of new Airborne Satellite Antenna (ASA) used for Very Small Aperture Terminal (VSAT) of Aeronautical Satellite Broadband System (ASBS) known as a Digital Video Broadcasting-Return Channel via Satellite (DVB-RCS). Directional High Gain Antenna (HGA) of ASA system usually needs to be protected by special radome and always positioned in the focus of satellite by a special antenna mechanical and electrical antenna tracking mechanism situated on the special stabilized pedestal. The several possible types of broadband ASA via different Radio Frequency (RF) band, such as Ku-band transceiving, airborne satellite broadband antenna, L and Ku-band antennas for DVB-RCS and Internet Protocol Television (IPTV) solutions, Ka-band transceiving antenna system for DVB-RCS solutions, Antenna Systems for Aeronautical Satellite Broadcasting (ASB) are discussed.
Airborne satellite antenna steering and mounting systems
(IEEE, 2016) Ilcev, Stojce Dimov
This paper describes the steering and mount systems of Airborne Satellite Antenna (ASA) as a most important and sensitive part of both Aeronautical Mobile Satellite Communication (AMSA) and Aeronautical Mobile Satellite Broadcasting (AMSB) systems. In general, most of ASA solutions are small and easy to install onboard aircraft such as Low Gain Antenna (LGA). However, in particular, some of ASA systems are quite complex, relatively large and heavy, especially airborne High Gain Antenna (HGA) for Aircraft Earth Stations (AES), such as Inmarsat-H, High Speed Data (HSD), Swift64, SwiftBroadband and Digital Video Broadcasting-Return Channel via Satellite (DVB-RCS) antennas, so they need sophisticated steering and mounting systems. Over the past decade are developed the steering ASA broadband system, which main components are reduced considerably in both physical size and weight. These reductions are presented in this research that brings greater Effective Isotropic Radiated Power (EIRP) from satellite transponders coupled with GaAs-FET technology at the front end the satellite receiver. In this paper are also introduced existing types of mechanical, electrical, combined and other mount systems of ASA steering system. The ASA has to be always pointed towards the satellite in spite of aircraft motions. At this point, the mount airborne satellite system as one of the main requirements in designing the mobile satellite antenna systems from the technical and rational viewpoints is discussed.
Airborne satellite navigation and other integrated antenna systems
(IEEE, 2016) Ilcev, Stojce Dimov
This paper is introducing the airborne satellite navigation and other integrated antenna systems for both weather and special navigation systems. In general, most of navigation antennas are omnidirectional, small and easy to install onboard aircraft, such as Global Navigation Satellite Antennas (GNSA) and other integrated antenna systems. However, in particular, some new developments of navigation antennas are providing miniaturized Global Navigation Satellite System (GNSS) antenna array technologies that significantly reduce the size of the antenna elements and the array dimensions. The passive and active GNSA for mobile applications including aeronautical are presented, which include all existing types of GNSS solutions. The GNSS antennas are usually omnidirectional, so they don’t need to be always pointed towards the satellite in spite of aircraft motions. In this paper are presented commercial aspects of the aircraft GNSS antenna technologies, their importance and integration with a digital beam-steering antenna electronics package. In addition, the solutions of different cost effective integrated antenna systems with GNSS antennas, such as airborne WAAS, XM, Weather, Sirius, ISL, DME, ADF, VOR, LOC, GS and other antenna systems are discussed.
Alcohols conversion over transition metal based catalyts
(2018) Ndebele, Mthobisi Sbonelo; Isa, Yusuf Makarﬁ
Ethanol and butanol obtainable through fermentation of lignocellulose biomass have become promising alternative feedstock for production of fuels as they are biodegradable and sustainably regenerated via the photosynthesis cycle. The properties of hydrocarbons produced through alcohol conversion closely resemble those of gasoline. Catalytic systems are reported to play a vital role during alcohol conversion to hydrocarbons. In this study ethanol and butanol were used as a feedstock for production of hydrocarbons over Fe, Zn and Ni catalyst systems supported on zeolite ZSM-5 (Zeolite Socony Mobil-5) and activated carbon (AC). X- Ray Diffraction (XRD), Scanning Electron Microscope (SEM) coupled with Energy- dispersive X-ray spectroscopy (EDS) and Brunauer, Emmet, and Teller (BET) analyses were employed for catalyst characterization. XRD patterns confirmed the success of metal doping on ZSM-5 and activated carbon supports. Major peaks at 7.96° and 23.97° corresponding to ZSM-5 crystals were observed in ZSM-5, and AC was found to be amorphous. Impregnation with metals reduced the crystallinity of ZSM-5 supported catalysts. Whereas SEM analysis showed that catalysts supported on ZSM-5 exhibited irregular shapes and catalyst supported on activated carbon exhibited disordered structures. The BET analyses confirmed that the surface areas of promoted catalysts decreased after metal doping. Evaluation of the catalysts were carried out in a ½ inch stainless steel reactor at 400 °C and atmospheric pressure with a weight hourly space velocity (WHSV) of 2.5 h-1 (g feed)/ (g catalyst). The ZSM-5 support performed better than activated carbon support. More than 90% conversion was achieved over catalysts supported on ZSM-5. Production of hydrocarbons over catalysts supported on activated carbon were as a result of the active component. Conversion of feedstock was observed to produce more benzene, toluene and xylene (BTX) compounds with an increase in butanol content. 100% conversion was achieved with pure butanol and not more than 99.86% conversion was achieved with pure ethanol. Catalyst systems supported on HZSM-5 and activated carbon were successfully synthesised. Ethanol, butanol and ethanol-butanol mixtures were successfully converted to liquid hydrocarbons and the conversion was greater than 90%. On the promoted catalysts, production of BTX were suppressed and various metals were observed to perform differently.
Anaerobic co-digestion of agricultural biomass with industrial wastewater for biogas production
(2021-03-26) Armah, Edward Kwaku; Chetty, Maggie; Deenadayalu, Nirmala
With the increasing demand for clean and affordable energy which is environmentally friendly, the use of renewable energy sources is a way for future energy generation. South Africa, like most countries in the world are over-dependent on the use of fossil fuels, prompting most current researchers to seek an affordable and reliable source of energy which is also,a focal point of the United Nations Sustainable Development Goal 7. In past decades, the process of anaerobic digestion (AD) also referred to as monodigestion, has proven to be efficient with positive environmental benefits for biogas production for the purpose of generating electricity, combined heat and power. However, due to regional shortages, process instability and lower biogas yield, the concept of anaerobic co-digestion (AcoD) emerged to account for these drawbacks. Given the considerable impact that industrial wastewater (WW) could provide nutrients in anaerobic biodigesters, the results of this study could apprise decisionmakers and the government to further implement biogas installations as an alternative energy source. The study aims at optimising the biogas production through AcoD of the agricultural biomasses: sugarcane bagasse (SCB) and corn silage (CS) with industrial WW sourced from Durban, KwaZulu-Natal, South Africa. The study commenced with the characterisation of the biomasses under this study with proximate and ultimate analysis using the Fourier transform infrared spectroscopy (FTIR), the thermo gravimetric analysis (TGA), the scanning electron microscopy (SEM) and the differential scanning calorimetry (DSC). The untreated biomass was subjected to biochemical methane potential (BMP) tests to optimise and predict the biogas potential for the selected biomass. A preliminary run was carried out with the agricultural biomass to determine which of the WW streams would yield the most biogas. Among the four WW streams sourced at this stage, two WW streams; sugar WW (SWW) and dairy WW (DWW) produced the highest volume of biogas in the increasing order; SWW ˃ DWW ˃ brewery WW > municipal WW. Therefore, both SWW and DWW were selected for further process optimisation with each biomass. Using the response surface methodology (RSM), the factors considered were temperature (25-55 °C) and organic loading rate (0.5-1.5 gVS/100mL); and the response was the biogas yield (m3 /kgVS). Maximum biogas yield and methane (CH4) content were found to be 5.0 m3 /kgVS and 79%, respectively, for the AcoD of CS with SWW. This established the association that existed among the set temperatures of the digestion process and the corresponding organic loading rate (OLR) of the AcoD process operating in batch mode. Both CS and SCB have been classified as lignocellulosic and thus, ionic liquid (IL) pretreatment was adapted in this study to ascertain their potential on the biogas yield. Results showed that the maximum biogas yield and CH4 content were found to be 3.9 m3 /kgVS and 87%, respectively, after IL pretreatment using 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) for CS with DWW at 55°C and 1.0 gVS/100mL. The IL pretreatment yielded lower biogas but of higher purity of CH4 than the untreated biomass. Data obtained from the BMP tests for the untreated and pretreated biomasses were tested with the existing kinetic models; first order, dual pooled first order, Chen and Hashimoto and the modified Gompertz. The results showed that for both untreated and pretreated biomass, the modified Gompertz had the best fit amongst the four models tested with coefficient of correlation, R 2 values of 0.997 and 0.979, respectively. Comparatively, the modified Gompertz model could be the preferred model for the study of industrial WW when used as co-substrate during AcoD for biogas production. The study showed that higher biogas production and CH4 contents were observed when CS was employed as a reliable feedstock with maximum volume of the untreated and pretreated feedstock reported at 31 L and 20 L respectively.
Anaerobic co-digestion with industrial wastewater for biomethane production
(2020-10-20) Adedeji, Jeremiah; Chetty, Maggie
The increasing demand for energy has led to the utilization of fossil fuels more abundantly as a quick alternative for generation of energy. The use of these sources of energy however as led to the generation of greenhouse gases which tend to cause climate change, thus affecting the ecosystem at large. Thus, there have been the search for alternative sources which cannot be depleted but do generate minimal greenhouse gases. One of such alternate sources is industrial wastewater which have shown to have high concentration of nutrients in the form of organic contents which can be converted by micro-organisms into energy, usually known as biogas, comprising majorly of CH4, CO2 and H2. Another important factor is that industrial wastewaters are a renewable energy source which are continuously generated due to increasing urbanisation and population growth. In this study, the characteristics of three agro-industrial based wastewaters used shows their potential for application in anaerobic co-digestion”. Anaerobic co-digestion method was utilized to harness the synergetic effect of both sewage sludge and agro-industrial wastewater as co-substrate for the generation of biomethane. The result of the effect of varying mix-ratio of the substrates on biomethane production of sugar wastewater and dairy wastewater indicated that mix-ratio of 1:1 for sewage sludge to sugar wastewater operated at 35oC was suitable for optimum generation of biomethane of 1400.99 mL CH4/g COD added and COD reduction of 54%. The model generated using design expert was found to navigate the design space and could perfectly predict the yield of biomethane effectively for the sugar wastewater mix. The biomethane potential tests (BMP) experiment using varying inoculum-substrate ratio (ISR) showed that operating at mesophilic temperature of 25oC with ISR of 1:2 and 2:1 for sugar wastewater and dairy wastewater respectively does increase the methane production within the first three (3) weeks. The kinetic models that best fit the anaerobic co-digestion for sugar wastewater was the first order model while the simplified Gompertz model favoured the dairy wastewater perfectly. The biomethane potential tests indicate significant increase the biomethane production and as well reduction in the volatile solid and chemical oxygen demand (COD) content. In conclusion, both sugar and dairy wastewater can be recommended as co-substrates for anaerobic digestion of sewage sludge for increased and improved biomethane production while simultaneously reducing their COD content at the same time.
Anaerobic treatment of slaugterhouse wastewater: evaluating operating conditions
(WIT Press, 2019-12-11) Chollom, Martha Noro; Rathilal, Sudesh; Swalaha, Feroz Mahomed; Bakare, Babatunde F.; Tetteh, Emmanuel K.
The aim of the study was to elucidate the effect of process parameters on the performance of an upflow anaerobic sludge blanket reactor (UASB) that was treating slaughterhouse wastewater. The UASB reactor was operated continuously under mesophilic conditions to evaluate its performance with respect to the removal of organics and, at the same time, monitor biogas production. Organic loading rate (OLR) was varied while keeping the hydraulic retention time (HRT) constant. Chemical oxygen demand (COD) removal efficiency higher than 75% was achieved at an OLR of 9 kg.COD.m-3.d-1, with a HRT of 12 h. Bulking sludge problems were not observed during the reactor operation period. Stability of the treatment process was achieved by the natural buffering of the system due to the produced alkalinity and also due to the characteristics of the wastewaters which was found to be rich in proteins and fatty acids.