Optimization of Biogas Production from sewage sludge
- Authors: Belaid, Mohamed , Matheri, Anthony Njuguna , Lelosa, Itumeleng Constance , Muzenda, Edison , Ramatsa, Ishmael
- Date: 2019
- Subjects: Anaerobic digestion , Co-digestion , Mesophilic temperature
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/403887 , uj:33862 , Citation: Belaid, M. et al. 2019. Optimization of Biogas Production from sewage sludge.
- Description: Abstract: It is widely known that the degradation of waste activated sludge is a slow process with a low extent of degradation. Improvement methods with regards to bio-methane yield were investigated in this study using a laboratory batch anaerobic digester. Mono-digestion of sludge with a C: N ratio of 15.47 resulted in a lower accumulation of gas volume than co-digested sludge even though the pH decreased rapidly in both cases. The thermophillic anaerobic digestion of sludge and co-digested sludge also produced higher bio-methane yield than mesophillic digestion of waste water sludge. Gas accumulation volume in the digesters during thermophillic digestion increased from 50 Nml to 100 Nml, 200 Nml to 600 Nml and 600 Nml to 750 Nml for sludge, cow dung and sludge and sludge and food waste respectively as the temperature was increased from 37o C to 45o C.
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Biochemical methane potential analysis using cow dung, chicken manure and pig manure under mesophilic conditions
- Authors: Belaid, Mohamed , Matheri, Anthony Njuguna , Mdluli, Nomkhosi Princess , Muzenda, Edison
- Date: 2019
- Subjects: Anaerobic digestion , Mono-digestion , Co-digestion
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/403895 , uj:33863 , Citation: Belaid, M. et al. 2019. Biochemical methane potential analysis using cow dung, chicken manure and pig manure under mesophilic conditions.
- Description: Abstract: In this study, we compared methane production by anaerobic mono-digestion and co-digestion of cow dung, chicken manure and pig manure under mesophilic conditions at the temperature of 37 0 C using a ratio of 1:1. C/N ratio, pH, VS/TS and sulphur content were the parameters investigated. Results indicated that co-digesting of cow dung; pig manure and chicken manure enhanced biogas production and methane content. The results also imply that pig manure cannot be used alone to produce methane as it produced low methane. Chicken manure produced more on the first day (272 Nml) compared to pig manure (257.4 Nml) and cow dung (80.5 Nml). On the ninth day, chicken produced 884 .9 Nml and then on the tenth day it went up again to 1095.6 Nml, reached its peak on day 13 and stopped, chicken yielded better results compared to the cow dung and pig manure because chicken had a higher VS/TS percent which is desirable for methane production. Pig manure started producing methane on the first day which was 257.4 Nml and stopped on the second day with the volume of 262.3 Nml. Pig manure showed poor results compared to cow dung and chicken manure.
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Analysis of the biogas productivity from dry anaerobic digestion of organic fraction of municipal solid waste
- Authors: Matheri, Anthony Njuguna , Sethunya, Vuiswa Lucia , Belaid, Mohamed , Muzenda, Edison , Ntuli, Freeman
- Date: 2017
- Subjects: BMP , Biodegradable , Co-digestion
- Language: English
- Type: Article
- Identifier: http://ujcontent.uj.ac.za8080/10210/380169 , http://hdl.handle.net/10210/241025 , uj:24804 , Citation: Matheri, A.N. 2017. Analysis of the biogas productivity from dry anaerobic digestion of organic fraction of municipal solid waste.
- Description: Abstract: In this study, it was observed that in experimental work under laboratory scale using conventional biomethane potential (BMP) analyser under the mesophilic optimum temperature of 37 0C and pH of 7. Organic fraction municipality solid waste (OFMSW) inoculated with cow manure had higher biodegradability rate leading to high methane production under shorter hydraulic retention rate. The co-digestion of OFMSW and cow manure stabilises conditions in digestion process such as carbon to nitrogen (C: N) ratio in the substrate mixtures as well as macro and micronutrients, pH, inhibitors or toxic compounds, dry matter and thus increasing methane production. It was concluded that the organic waste generated in the municipality co-digested with manures to produce methane can be used as a source of sustainable renewable energy.
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Multi-criteria analysis of different technologies for the bioenergy recovery from OFMSW
- Authors: Matheri, Anthony Njuguna , Mbohwa, Charles , Belaid, Mohamed , Seodigeng, Tumisang , Ngila, Jane Catherine
- Date: 2016
- Subjects: Anaerobic digester , Design , Bioenergy recovery
- Language: English
- Type: Conference proceedings
- Identifier: http://ujcontent.uj.ac.za8080/10210/377197 , http://hdl.handle.net/10210/214131 , uj:21242 , Citation: Matheri, A.N. et al. 2016. Multi-criteria analysis of different technologies for the bioenergy recovery from OFMSW.
- Description: Abstract: In this study, the multi-criteria analysis model is demonstrated for evaluation and technologies from municipal solid waste (MSW) in City of Johannesburg (CoJ), South Africa. The technologies evaluation and alternation criteria for multi-criteria decision analysis (MCDA) area characterized by reviewing the literature and consulting experts in the renewable energy and waste management. MCDA was the approach employed by decision makers to make recommendation on technique employed to select the most suitable biogas digester technology for organic fraction of municipal solid waste (OFMWS) originating from the city’s landfills base on scalability, relative cost prices, available, temperature regulation, agitation, ease of construction, operation and maintenance. The result for digester type indicated that the “complete mix, continuously stirred anaerobic digester” (CSAD) was preferred with 79% preference to other anaerobic digester technologies for energy recovery.
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Modelling the kinetic of biogas production from co-digestion of pig waste and grass clippings
- Authors: Matheri, Anthony Njuguna , Belaid, Mohamed , Seodigeng, Tumisang , Ngila, Catherine Jane
- Date: 2016
- Subjects: Anaerobic , Co-digestion , Kinetics , Mesophilic temperature , Modified gompertz
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93635 , uj:20372 , Citation: Matheri, A.N. et al. 2016. Modelling the kinetic of biogas production from co-digestion of pig waste and grass clippings.
- Description: Abstract: This work investigated the use of laboratory batch anaerobic digester to derive kinetics parameters for anaerobic co-digestion of pig waste and grass clippings. Laboratory experiment data from 10 litres batch anaerobic digester operating at ambient mesophilic temperature of 37 0C and pH of 6.9 was used to derive parameters for modified Gompertz model. The carbon/nitrogen (C/N) ratio of Pig waste was found to be 16.16 and grass clippings to be 20.54. Through co-digestion in ratio of 1:1, the C/N ratio settled at 17.28. The actual biogas yield was found to be 7725 ml/g COD. In the model of biogas production prediction, the kinetics constants of A (ml/g COD), μ (ml/g COD. day), λ (day) was 7920.70, 701.35, 1.61 respectively with coefficient of determination (R2) of 0.9994. Modified Gompertz plot showed better correlation of cumulative biogas production and these results show biogas production can be enhanced from co-digestion of substrates.
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Waste to energy bio-digester selection and design model for the organic fraction of municipal solid waste
- Authors: Matheri, Anthony Njuguna , Mbohwa, Charles , Ntuli, Freeman , Belaid, Mohamed , Seodigeng, Tumisang , Ngila, Jane Catherine , Njenga, Cecilia Kinuthia
- Date: 2017
- Subjects: Anaerobic digestion , Bio-digester , Mesophilic temperature
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/250904 , uj:26157 , Citation: Matheri, A.N. et al. 2017. Waste to energy bio-digester selection and design model for the organic fraction of municipal solid waste.
- Description: Abstract: Please refer to full text to view abstract
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The role of trace elements on anaerobic codigestion in biogas production
- Authors: Matheri, Anthony Njuguna , Belaid, Mohamed , Seodigeng, Tumisang , Ngila, Jane Catherine
- Date: 2016
- Subjects: Anaerobic digestion , Co-digestion , Mesophilic temperature , Trace elements
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93628 , uj:20371 , Citation: Matheri, A.N. et al. 2016. The role of trace elements on anaerobic codigestion in biogas production.
- Description: Abstract: In this study, we investigated the concentration of trace elements in the digestates in a laboratory batch anaerobic digester. Many of these trace elements are important macro and micro nutrients. The availability of these nutrients for microbes responsible for anaerobic digestion and substrate toxicity have to be controlled in biogas production. The analyzed substrates were characterized at various concentrations in the following trace elements; potassium, phosphorus, manganese, copper, calcium, molybdenum, zinc, cobalt, iron, aluminum, silver, nickel and cadmium. Trace elements like copper, silver, nickel, cadmium, zinc have been reported to be inhibitory and toxic under certain conditions in biochemical reaction depending on their concentrations. These trace elements lower biogas production above threshold concentration due to accumulation of organic acid as a result of methanogenic bacterial inhibition. There was no deficit of nutrients detected in the anaerobic digesters analysis.
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Mesophilic anaerobic co-digestion of cow dung, chicken droppings and grass clippings
- Authors: Matheri, Anthony Njuguna , Belaid, Mohamed , Seodigeng, Tumisang , Ngila, Catherine Jane , Mbohwa, Charles
- Date: 2016
- Subjects: Anaerobic digestion , Co-digestion , Mesophilic temperature
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/214105 , uj:21240 , Citation: Matheri, A.N. et al. 2016. Mesophilic anaerobic co-digestion of cow dung, chicken droppings and grass clippings.
- Description: Abstract: The main focus of this study was mesophilic anaerobic co-digestion of cow dung, chicken droppings and grass clippings using pilot bio-digesters. The biochemical methane potential (BMP) works under batch anaerobic digester operating in ambient mesophilic temperature of 35 oC and 37 0C and pH of 7 to generate biogas. The carbon/nitrogen (C/N) ratio for cow dung and chicken droppings was found to be 17.70 and 63.67 respectively and grass clippings to be 20.54. Through co-digestion in a ratio of 1:1, the C/N ratio for cow dung and grass clippings settled at 19.19 while that for chicken droppings and grass clippings settled at 20.49. The conversion rate of the reaction and biogas production increased with the increase in temperature and hydraulic retention time until an equilibrium state was achieved. At the temperature 37 OC, it was observed to be the suitable mesophilic temperature for anaerobic digestion due to high dissociation and collision leading to high rate of biogas production.
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Water and Wastewater Digital Surveillance 1 for Monitoring and Early Detection of 2 the COVID-19 Hotspot: Industry 4.0
- Authors: Matheri, Anthony Njuguna , Belaid, Mohamed , Kinuthia, Cecilia Njenga , Ngila, Jane Catherine
- Date: 2022
- Subjects: Epidemiology , Monitoring , Pathogens
- Language: English
- Type: Journal articles
- Identifier: http://hdl.handle.net/10210/493539 , uj:45114 , Citation: Matheri, A.N., Belaid, M., Njenga, C.K. and Ngila, J.C., 2022. Water and wastewater digital surveillance for monitoring and early detection of the COVID-19 hotspot: industry 4.0. International Journal of Environmental Science and Technology, pp.1-18.
- Description: Abstract: There are a high number of COVID-19 cases per capita in the world that goes undetected including clinical diseases compatible with COVID-19. While the presence of the COVID-19 in untreated drinking water is possible, it is yet to be detected in the drinking-water supplies. COVID-19 viral fragments have been found in excrete, this call for wastewater monitoring and analysis (wastewater surveillance) of the potential health risk. This raises concern about the potential of the SARS-CoV-2 transmission via the water systems. The economic limits on the medical screening for the SARS-CoV-2 or COVID-19 worldwide are turning to wastewater-based epidemiology as great potential tools for assessing and management of the COVID-19 pandemic. Surveillance and tracking of the pathogens in the wastewater are key to the early warning system and public health strategy monitoring of the COVID-19. Currently, RT-qPCR assays is been developed for SARS-CoV-2 RNA specimen clinical testing and detection in the water system. Convectional wastewater treatment methods and disinfection are expected to eradicate the SAR-CoV-2. Chlorine, UV radiation, ozone, chloramine is been used to inactivate and disinfect the water treatment system against the SARS-CoV-2. Water management and design of the water infrastructure require major changes to accommodate climate change, water cycle, reimaging of digitalization, infrastructure and privacy protection. The water digital revolution, biosensors and nanoscale, contact tracing, knowledge management can accelerate with disruption of the COVID-19 outbreak (water-health-digital nexus).
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