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Item Phenotypic and genotypic characterisation of an unique indigenous hypersaline unicellular cyanobacterium, Euhalothece sp.nov(Elsevier, 2018) Mogany, Trisha; Swalaha, Feroz Mahomed; Allam, Mushal; Mtshali, Phillip Senzo; Ismail, Arshad; Kumari, Sheena K.; Bux, FaizalA novel halotolerant species of cyanobacterium of the order Chroococcales was isolated from hypersaline estuary in Kwa-Zulu Natal, South Africa. A comprehensive polyphasic approach viz., cell morphology, pigment com-position and complete genome sequence analysis was conducted to elucidate the taxonomic position of the isolated strain. The blue-green oval to rod-shaped cells were 14–18 μm in size, and contained a high amount of phycocyanin pigments. The strain was moderate thermotolerant/alkalitolerant halophile with the optimum conditions for growth at 35 °C, pH 8.5 and 120 g/l of NaCl. Based on 16S rRNA gene sequence phylogeny, the strain was related to members of the ‘Euhalothece’ subcluster (99%). The whole genome sequence was de-termined, and the annotated genes showed a 90% sequence similarity to the gas-vacuolate, spindle-shaped Dactylococcopsis salina PCC 8305. The size of the genome was determined to be 5,113,178 bp and contained 4332 protein-coding genes and 69 RNA genes with a G + C content of 46.7%. Genes encoding osmoregulation, oxi-dative stress, heat shock, persister cells, and UV-absorbing secondary metabolites, among others, were identified. Based on the phylogenetic analysis of the 16S rRNA gene sequences, physiological data, pigment compositions and genomic data, the strain is considered to represent a novel species of Euhalothece.Item Synthesis of biodiesel from Scenedesmus sp. by microwave and ultrasound assisted in situ transesterification using tungstated zirconia as a solid acid catalyst(Elsevier, 2014-05-20) Guldhe, Abhishek; Singh, Bhaskar; Rawat, Ismail; Bux, FaizalOleaginous Scenedesmus sp. was cultivated phototrophically in an open pond for biofuels production. The culture was harvested and subsequently dewatered and dried. The chemical properties of the Scenedesmus sp. lipids were determined as per standard ASTM methods. Biodiesel was synthesized by in situ transesterification from dried biomass using microwave and sonication techniques with tungstated zirconia (WO3/ZrO2) as a solid acid catalyst. In situ transesterification allowed minimizing the requirement of solvents by merging the two steps (i.e. extraction of lipid and conversion to biodiesel) to a single step. The use of a solid catalyst effectively reduces the purification cost of biodiesel due to ease of separation and potential for reuse. The conversion of Scenedesmus sp. lipids to biodiesel was determined by GC. Box–Behnken design was used for optimization of the variables to optimize the biodiesel yield and conversion. The efficiency of the two processes was compared.Item Thermal behavior and pyrolytic characteristics of freshwater Scenedesmus sp. biomass(Taylor and Francis, 2015) Ranjith Kumar, R.; Ramesh, D.; Mutanda, Taurai; Rawat, Ismail; Bux, FaizalThermal behavior and pyrolytic characteristics of Scenedesmus sp. biomass was investigated under five different heating rates of 5, 10, 20, 30, and 40°C/min by using thermogravimetric analysis. The calorific value and carbon content of the tested biomass sample was 17.65 kJ g−1 and 46.60%, respectively. The data generated for thermogravimetric analysis showed that three stages of thermal decompositions occurred for selected biomass materials for all of the tested heating rates. The maximum volatile matter was evolved in the second stage of thermal decomposition, with temperatures between 273 and 399°C. The maximum thermal decomposition temperature increased from 294 to 330°C as the heating rates increased from 5 to 40°C/min. The average apparent activation energy of selected biomass determined by Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) methods were found to be closer values 203 kJ mol−1.Item The optimization of biomass and lipid yields of Chlorella sorokiniana when using wastewater supplemented with different nitrogen sources.(Pubmed, 2014-09) Ramanna, Luveshan; Guldhe, Abhishek; Rawat, Ismail; Bux, FaizalThe potential of nitrogen sources supplementing domestic wastewater for the cultivation of microalgae was assessed. Urea, potassium nitrate, sodium nitrate and ammonium nitrate were evaluated for their effect on cultivation and lipid production of Chlorella sorokiniana. Urea showed the highest biomass yield of 0.220 g L−1 and was selected for further experimentation. Urea concentrations (0–10 g L−1) were assessed for their effect on growth and microalgal physiology using pulse amplitude modulated fluorometry. A concentration of 1.5 g L−1 urea produced 0.218 g L−1 biomass and 61.52% lipid by relative fluorescence. Physiological stress was evident by the decrease in relative Electron Transport Rate from 10.45 to 6.77 and quantum efficiency of photosystem II charge separation from 0.665 to 0.131. Gas chromatography analysis revealed that C16:0, C18:0, C18:1, C18:2 and C18:3 were the major fatty acids produced by C. sorokiniana. Urea proved to be an effective nitrogen supplement for cultivation of C. sorokiniana in wastewater.Item Assessment of brewery effluent composition from a beer producing industry in KwaZulu-Natal, South Africa(PSP, 2014) Enitan, Abimbola Motunrayo; Swalaha, Feroz Mahomed; Adeyemo, Josiah; Bux, FaizalThe objective of the study was to assess the physico-chemical composition and process variations of the effluent from a brewery industry located in KwaZulu - Natal, South Africa during the months of September 2011 to May 2012. The parameters monitored for the quantitative analysis of brewery wastewater include the total and soluble chemical oxygen demand (TCOD and SCOD), biological oxygen demand (BOD5), total solids (TS), volatile solids (VS), total suspended solids (TSS), volatile suspended solids (TSS), pH, ammonia (NH3), total oxidized nitrogen, nitrate, nitrite, phosphorus, electrical conductivity (EC), crude protein and alkalinity content. On the average, the TCOD and SCOD concentrations of the brewery effluent were 5340.97 and 3902.24 mg/L, respectively, with average pH values of 4.0 to 6.7. The BOD and the solids content of the effluent from the brewery industry were high indicating that the effluent is of biodegradable type. This suggests that the effluent is very rich in organics, and its discharge into the water bodies or the municipal treatment plant can cause environmental pollution or damage the treatment plant. In addition, there were variations in the effluent composition throughout the period of monitoring which might be due to the activities that take place during the production process and the effects of peak periods of beer production. Thus, there is a need for an on-site effluent treatment plant in order to reduce the high pollution of the effluent prior to its discharge to the municipal wastewater treatment plants.Item Evaluation of phytotoxicity effect on selected crops using treated and untreated wastewater from different configurative domestic wastewater plants(Taylor and francis Online, 2016) Ravindran, B.; Kumari, Sheena K.; Stenström, Thor-Axel; Bux, FaizalThis study investigated the phytotoxicity effect of untreated and treated wastewater collected from two different configurations of domestic wastewater treatment plants in South Africa. The phytotoxicity effect on vegetable seed growth was studied in terms of germination index (GI), relative seed germination (RSG) and relative root elongation (RRE) using four commercial crop varieties, viz., tomato (Lycopersicon esculentum), radish (Raphanus sativus), carrot (Daucus carota) and onion (Allium cepa). According to phyototoxicity limits, 80% germination and above is regarded as non-toxic and less than 50% GI is regarded as highly toxic and not suitable for agricultural purposes. In our study, seeds were irrigated with concentrations of 25%, 50%, 75%, 100% of treated effluent (TE) and untreated effluent (UTE). The TE results were best with the highest GI (%) recorded as tomato, 177; carrot, 158.5; onion, 132; and lettuce, 124. The results of this study indicate that TE showed no phytotoxicty effects and recorded above 80% GI. The UTE irrigated crops reached a GI of only 50% and above which is clear evidence of the beneficial effect of waste water treatment. The overall results confirmed that treated wastewater has a beneficial effect on agricultural crops and can be used as a liquid fertilizer.Item Anaerobic digestion model to enhance treatment of brewery wastewater for biogas production using UASB reactor(Springerlink, 2015) Enitan, Abimbola Motunrayo; Adeyemo, Josiah; Swalaha, Feroz Mahomed; Bux, FaizalBiogas produced from an upflow anaerobic sludge blanket (UASB) reactor is a clean and an environmentally friendly by-product that could be used to meet partial energy needs. In this study, a modified methane generation model (MMGM) was developed on the basis of mass balance prin-ciples to predict and increase methane production rate in a UASB reactor during anaerobic fermentation of brewery wastewater. Model coefficients were determined using the da-ta collected from a full-scale reactor. The results showed that the composition of wastewater and operational conditions of the reactor strongly influence the kinetics of the digestion process. Simulation of the reactor process using the model was used to predict the effect of organic loading rate and temperature on methane production with an optimum methane production at 29 °C and 8.26 g COD/L/day. Methane produc-tion rate increased from 0.29 to 1.46 L CH4/g COD, when the loading rate was increased from 2.0 to 8.26 g COD/L/day. The results showed the applicability of MMGM to predict usable methane component of biogas produced during anaerobic digestion of brewery wastewater. This study would help industries to predict and increase the generation of renewable energy by improving methane production from a UASB reac-tor. To the best of our knowledge, MMGM is the first reported developed model that could serve as a predictive tool for brewery wastewater treatment plant available in the literature.Item Continuous biohydrogen production from starch wastewater via sequential dark-photo fermentation with emphasize on maghemite nanoparticles(Elsevier, 2015) Nasr, Mahmoud; Tawfik, Ahmed; Ookawara, Shinichi; Suzuki, Masaaki; Kumari, Sheena K.; Bux, FaizalHydrogen production from starch wastewater via sequential dark-photo fermentation process was investigated. Two anaerobic baffled reactors (ABRs) were operated in parallel at an OLR of 8.11 ± 0.97 g-COD/L/d, and a HRT of 15 h. ABR-1 and ABR-2 was inoculated with pre-treated sludge and sludge immobilized on maghemite nanoparticles, respectively. Better hydrogen yield of 104.75 ± 12.39 mL-H2/g-COD-removed was achieved in ABR-2 as compared to 66.22 ± 4.88 mL-H2/g-COD-removed in ABR-1. The effluent of ABR-2 was used for further hydrogen production by photo fermentation in ABR-3. An overall hydrogen yield of 166.83 ± 27.79 mL-H2/g-COD-removed was achieved at a total HRT of 30 h. 16S rRNA phylogeny showed that Clostridium and Rhodopseudomonas palustris species were dominant in ABR-1, ABR-2 and ABR-3, respectively.Item Effect of thermal pre-treatment on inoculum sludge to enhance bio-hydrogen production from alkali hydrolysed rice straw in a mesophilic anaerobic baffled reactor.(Taylor & Francis, 2013) Bux, Faizal; Kumari, Sheena K.; Tawfik, Ahmed; El-berry, HaithamThe effect of thermal pre-treatment on inoculum sludge for continuous H2 production from alkali hydrolysed rice straw using anaerobic baffled reactor (ABR) was investigated. Two reactors, ABR1 and ABR2, were inoculated with untreated and thermally pre-treated sludge, respectively. Both reactors were operated in parallel at a constant hydraulic retention time of 20 h and organic loading rate ranged from 0.5 to 2.16 g COD/L d. The results obtained indicated that ABR2 achieved a better hydrogen conversion rate and hydrogen yield as compared with ABR1. The hydrogen conversion rates were 30% and 24%, while the hydrogen yields were 1.19 and 0.97 mol H2/mol glucose for ABR2 and ABR1, respectively. Similar trend was observed for chemical oxygen demand (COD) and carbohydrate removal, where ABR2 provided a removal efficiency of 53±2.3% for COD and 46±2% for carbohydrate. The microbial community analysis using 16S rRNA phylogeny revealed the presence of different species of bacteria, namely Clostridium, Prevotella, Paludibacter, Ensifer, and Petrimonas within the reactors. Volatile fatty acids generated from ABR1 and ABR2 were mainly in the form of acetate and butyrate and a relatively low fraction of propionate was detected in ABR1. Based on these results, thermal pre-treatment of inoculum sludge is preferable for hydrogen production from hydrolysed rice straw.Item Application of radio-immunoassays to assess the fate of estrogen EDCs in full scale wastewater treatment plants(Taylor and Francis, 2013) Bux, Faizal; Surujlal-Naicker, SwastikaWastewater effluents have been documented as major contributors of hormone endocrine disrupting compounds (EDCs) in to the aquatic ecosystem. The need for rapid, simple and cost effective methods to detect these EDCs has increased. The use of Radio-immunoassays (RIA) were assessed to determine the fate of estradiol in a laboratory batch test and the three natural estrogens (estrone (E1), estradiol (E2) and estriol (E3)) in wastewater treatment plants (WWTPs) with different types of configurations. Precision of the RIAs were done using intra-assay and inter-assay validations. The E2 intra-assay variation was <8% and inter-assay variation was <11% for standards 1 to 6. E1 RIA showed less than 8% for both the intra-assay and inter-assay variations. E3 RIA showed extremely good variations with both the intra and inter-assay variations being below <8% for all standards. The lab scale investigation showed a 94% reduction in E2 after 5 h and after 10 h both E2 and E1 were no longer detected. The simple activated sludge process, the biological nutrient removal (BNR) activated sludge process and the oxidation pond had final effluent concentrations of 10.75, 5.96 and 25.48 pg E2/mL respectively; 20.80, 9.30 and 46.55 pg E1/mL, respectively, and 0.12, 0.07 and 0.17 ng E3/mL, respectively. Thus far findings indicated that the RIA can be employed as a rapid technique for detection of natural estrogens in water. Results indicate that these potential problematic hormone EDCs are still present in final wastewater effluents that are discharged in to South African aquatic sources.