Biogas Generation from Sludge Co-digested with Pine Needles

Abstract

The purpose of this research is to study co-digestion of sewage sludge and pine needles. When we talk about the major problems we are facing now days, we come across one of the most debatable problem of depletion of non- conventional energy sources. So, one should divert the attention to one of the economic alternative energy source, Biogas. Anaerobic digestion of sewage sludge and pine needles will alleviate a number of environmental concern associated with them. Biogas or Anaerobic digestion technology has become a reliable source of renewable energy in state of Himachal Pradesh, facing a large climatic variation. Anaerobic digestion can help to reduce the load on the landfill by recycling the organic material of sludge and reduce the number of pathogens. Co-digestion will help to maintain a nutrient balance in both substrate and increase the performance of biogas digester in low temperature range. The substrate were studied for their physico-chemical characteristics, such as pH, Total solids, Volatile Solids, Total Organic Carbon, Total Kjeldahl Nitrogen, organic matter and C/N. The Cellulose, Hemicellulose and Lignin content of pine needles were also determined. The batch study was done in two different anaerobic digesters AD1 and AD2 of 45 L which consist of sludge and mixture of sewage sludge and pine needles for a retention time of 70 days during winter season and its continuation in the summer season for 55 days .Initial and final values of slurry before and after degradation process of various physico-chemical parameters like pH, Total solids, Volatile Solids, Alkalinity, Chemical Oxygen Demand were analyzed. The result from the study shows that adding pine needles to the sewage sludge significantly increased the biogas production caused by balanced C/N ratio of the digester.