Mitigating Climate Change Through Energy Recovery at Dandora Wastewater Treatment Plant, Nairobi County, Kenya

The world is experiencing an increase in the rate of greenhouse gases emissions accumulating in the atmosphere due to natural and anthropogenic causes. These gasses absorb and emits radiation within the thermal infrared range thus contributing to the Green House effect. The building up of greenhouse gasses beyond the natural acceptable levels can change the earth's climate thus contributing to climate change. To mitigate climate change, there is need to cease the increase of greenhouse gases either by not adding them into the air and or increasing the earths’ ability to withdraw them out of air. This study looked into mitigating climate change through energy recovery at Dandora wastewater treatment plant in Nairobi. The study employed both primary and secondary data. Operational data on the raw sewer chemical oxygen demand and biological oxygen demand levels was collected from the plant between 2007 and 2013. MS excel was used to analyze the data in order to cipher the trends of biological oxygen demand & chemical oxygen demand loadings and removals and thus estimation of biogas and methane likely to be generated and energy recovery thereof. The relationship between these two variables were tested through a Correlation coefficient test. The two-level computations estimated the daily biogas generation at the treatment plant as 2738m3. The study estimates methane generated to be equivalent to 68398MJ/Day of energy. Considering the calorific value of LPG of 46MJ/kg, this is equivalent to 495 cylinders daily serving 2974 households daily. The findings indicate that recovery of energy from the Plant mitigates climate change through reduction of emissions by 16 tCO2-e per day. The energy recovered had a positive correlation with the emission reduction at a high value of r= 0.99. The study concludes that energy recovery from wastewater treatment plant reduces emission thus mitigates climate change.