Volume No. 11 Issue No.: 1 Page No.: 170-179 July-September 2016

 

COMPUTATION OF METHANE GENERATED BY ANAEROBIC CO-DIGESTION OF FOOD WASTE AND SEWAGE SLUDGE

 

Kamat S. S.* and Khambete K. A.

Department of Civil Engineering, S. V. National Institute of Technology, Surat (INDIA)

 

Received on : April 20, 2016

 

ABSTRACT

 

Municipal Solid Waste (MSW) has always been a rising concern, with the advancement of technology and urban civilization. Moreover, the depleting resources of fossil fuels and the consequent growth of pollution is also an important aspect to be considered for achieving the goals of environmental sustainability. The kitchen waste, comprising of the left-over food waste can serve as a tremendous source of bio-energy which can serve dual purposes. It has been found that the effective load of kitchen waste on MSW can be reduced to a large extent, as well the energy in the form of biogas, can be utilized for the domestic purposes. It has found by survey that organic fraction comprises of 40-60% of the MSW. However, it becomes largely inconvenient for the local bodies to actually manage and segregate this kitchen waste for a considerably large population. Moreover, the amount to biological sludge generated in the municipal wastewater treatment plants, is difficult to manage, As a result, it becomes fairly advantageous to opt for a compact system to carry out the anaerobic co-digestion of food waste and sewage sludge. Biogas is produced when the bacteria degrades the organic matter in the absence of air i.e. anaerobically. Anaerobic process is a biological process that occurs naturally with the classification of three main reactions viz. hydrolysis, acidogenesis and methanogenesis. In this study, the process monitoring has been given due importance because it is important to regularly monitor the pH and alkalinity requirements of the system. Moreover, any kind of increase in the inhibitory substances can affect the process. Based on the Chemical Oxygen Demand (COD) profile, certain conclusions were being made. It was found that after the 25th day, there was uniform reduction in COD, however it was a steep fall of curve which indicated that the reaction is proceeding in the methanogenesis phase. From the 57th day onwards, it was observed that there is gradual exponential reduction of the COD profile, which was a clear indication of the dominance of the methanogens. Based on the COD balance concept, the amount of methane generated was predicted.

 

Keywords : Co-digestion, COD, Methane, pH, Municipal Solid Waste

 

 

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