(215ad) Integrated Bioenergy Farming System Using Communal Waste WATER – A NOVEL Approach To Carbon Mitigation

Increasing demand and depleting resources leads to the search of new and clean energy source, on the other hand treatment and reuse of waste water generated becomes a big challenge. Researchers around the world are working to sort out this problem and to find suitable solution. This paper discusses about the possibilities in integrated energy farming for small communities using communal waste water as a source to produce alternate bioenergy. Communal waste water can be categorized into back and grey water. Black water is the waste water generated from toilets, it contains very high amount of organic load with high BOD and COD, as a result it can be used to produce Biogas and thereby electricity using biogas. Grey water contains low amount of BOD, generally inorganic load is higher in grey water. This waste water was secondarily treated (primary settling and secondary biological processing via trickling filter). This secondarily treated grey water is rich in nitrogen, phosphorus and other nutrients; hence it needs a tertiary treatment to eliminate these compounds. In this study tertiary treatment was carried out using the microalgae Botryococcus braunii grown in laboratory, the microalga Botryococcus braunii contains high amount of oil which can be used for production of biodiesel. Experiments were carried out in laboratory scale Erlenmeyer flasks which was filled with secondarily treated grey water inoculated with microalgae Botryococcus braunii. The pH of the grey water was maintained under 8.0 in room temperature, 12 h light/12 h darkness cycles were maintained, light intensity has been maintained higher than 1.2 ± 0.2 klux. The compounds initially present in treated grey water like nitrogen and phosphorus is reduced considerably and it is used for landscaping purpose. The results show that the oil productivity of algae using communal waste water was higher than that of fresh water. This study reveals that an integrated energy farming system can be a potential source for energy in small communities.