RCE Greater Nairobi - 2022

Energy Generation from effluent waste at Dandora Sewerage Treatment Plant, Nairobi. Kenya
Basic Information
Title of project : 
Energy Generation from effluent waste at Dandora Sewerage Treatment Plant, Nairobi. Kenya
Submitting RCE: 
RCE Central Kenya
Contributing organization(s) : 
Kenyatta University
Focal point(s) and affiliation(s)
Mercy Achieng omollo
Organizational Affiliation: 
Kenyatta University
Format of project: 
Language of project: 
Date of submission:
Friday, October 28, 2022
Geographical & Education Information
Africa and Middle East
Address of focal point institution for project: 
P.o Box 43844-00100
Nairobi, Kenya.
Target Audience:
Socioeconomic and environmental characteristics of the area : 
The project is located in Ruai. According to Kenya Population and Housing Census (2019), the project area (Ruai) has a total population of 72,134 with a total of 22,755 households. Roughly 79% of the total population of the area uses toilet facilities that are connected to the county council wastewater sewer lines. The area is associated with low-income earners who depend largely on firewood, paraffin, and charcoal as their main source of energy with a pantry relying on LPG. Lack of access to clean sources of energy is a major impediment to development through health-related complications such as respiratory infections and air pollution.
Description of sustainable development challenge(s) in the area the project addresses: 
The main challenges in the area is lack of access to clean sources of energy. High level energy are cleaner and comes at a higher cost and can only be used by households with high income levels. Because of their low socio-economic status the household here depend on firewood, paraffin and charcoal as energy sources and sometimes illegal connections to the grid which imposes health risks.

The other challenge is that currently the biogas being generated at Dandora is released onto the atmosphere that increasing the concentration of methane gas which is a green house gas. This is contributing to climate change effect.
January, 2007
The study focuses on methane generation from effluent waste. Methane generated can be used as a source of green energy for household purposes as an alternative to other renewable and non-renewable energy sources; and also, to keep the environment clean by minimizing the greenhouse effect.

Sewage (Effluent waste) management is a serious problem in Kenya causing pollution in the air, land, and water bodies. With the help of advanced technology, these effluents can be treated anaerobically resulting in the production of biogas which can generate energy. In Kenya anaerobic digestion has been used for the treatment of sewage in major towns including the Dandora sewerage treatment plant (DSTP) in Nairobi. Dandora sewerage treatment plant is one of the largest such treatment plants in Kenya due to the high population in Nairobi County, urbanization, and the huge amount of waste generation both in solid and liquid forms.

As of last year, the total average industrial and domestic effluent waste inflow at the Dandora sewerage treatment plant was 140,000m3/day, this amount is increasing progressively with the increasing population growth. By 2025 this amount may increase to approximately 250,000m3/day (Gebbie, 2013). This rapid increase in the average effluent inflow at Dandora is directly proportional to the increases in biogas production. Methane in biogas is a major atmospheric pollutant and it’s estimated that its global warming potential (GWP) is 21 times more than that of carbon dioxide (CO2). Biogas produced at this treatment plant is currently unquantified and released uncaptured into the atmosphere, thus increasing the potential for air pollution and global warming. Therefore, this study intends to determine the potential of the production of methane gas that can then be used as renewable energy at the community level for lighting and cooking.
Main Objective
To minimize the effects of methane pollution on the environment as a result of anaerobic processes at the Dandora Wastewater Treatment Plant.
Specific objectives are as follows:
(i) To quantify the amount of methane produced in the Dandora Sewerage Treatment Plant (DSTP)
(ii) To determine the degree to which conversion of methane gas to energy can reduce GHG emissions to the atmosphere
Activities and/or practices employed: 
Operational data was collected from 2007 on the inflow and outflows at Dandora Sewerage Treatment Plant. The data was then analyzed using MS excel to compute the trends of Biological Oxygen Demand & Chemical Oxygen Demand loadings and removals and thus biogas and methane generated and energy translation of the same thereof. To meet the 1st objective which was to compute the amount of biogas that could be generated at DSTP, the study adopted standard design parameters used in the design criteria of the ponds by Duncan Mara. It is important to note that for the study to establish the amount of methane that can be generated at DSTP, computations were undertaken for Series 1(2ponds), Series 2 (3ponds), Series 3 (3ponds), and Series 4-8 (3ponds). Quantifying the amount of biogas that can be generated at the DSTP was done by developing a relationship between the BOD removal across anaerobic treatment lagoons as a function of volumetric loading rates. This figure then helped in arriving at the computations of methane generation at DSTP. An assumption was made based on Mara 2003 that 90% of BOD5 removed was converted to biogas and that methane makes 70% of biogas. To meet the second objective which was to determine the degree to which conversion of methane gas to energy can help reduce GHG emissions into the atmosphere, the IPCC Guidelines (1996) and IPCC Good Practice Guidelines (GPG) (2000) were relied on. These were as well guided by assumptions that the Heat Value of biogas is 25 MJ/m3, an availability factor of 25% and that all biogas (Methane) captured will be pumped to a central energy generation location.
Size of academic audience: 
The findings from the two-level computations gave the amount of methane that can be generated at DSTP at 2,811m3 of methane per day, which is equivalent to a total of 1,026,292m3 annually. This is the amount of methane that is released directly into the environment thus contributing to global warming and climate change. The methane can however be captured and stored and distributed to the local community as energy for lighting and cooking. The findings of the study has shown that the methane generated would give out energy equivalent to 25,657,317MJ annually, this is equivalent to 7,127MWh of power. This is likely to support 42933 persons in a year or at least 117 persons around the project area daily. Generating methane at DSTP would be of great service and benefit to the climate change adaptation in Kenya and the whole world. Emission reduction of 6260 tCO2-e can then be achieved and this will contribute significantly to the Kenyan target of reducing greenhouse emissions by 32% (45MtCOeq) as per Kenya’s National Determined Contributions of 2020. This study, therefore, finds huge potential in the reduction of GHGs by generating methane at DSTP.
Lessons learned: 
These findings give an impetus to the government of Kenya and other relevant stakeholders to develop green energy from methane generated at the treatment plant thereby reducing GHGs emitted to the atmosphere in line with Kenya's NDC commitment to abating the climate change menace.
Relationship to other RCE activities: 
UN Sustainable Development Goals (SDGs)
(https://sustainabledevelopment.un.org/sdgs) and other themes of Education for Sustainable Development (ESD)
SDG 1 - End poverty in all its forms everywhere 
SDG 3 - Ensure healthy lives and promote wellbeing for all at all ages 
SDG 7 - Ensure access to affordable, reliable, sustainable and modern energy for all 
SDG 8 - Promote sustained, inclusive and sustainable economic growth, full and productive employment, and decent work for all 
SDG 13 - Take urgent action to combat climate change and its impacts 
I acknowledge the above: