Resource Recovery from Wastewaters for Sustainable Development

Abstract

Blackwater is the largest source of organic matter which is available in India. The newlinetotal blackwater generation from Class I cities (498) and Class II (410) towns in India newlineis around 35,558 and 2,696 MLD respectively while, the installed sewage treatment newlinecapacity is just 11,553 and 233 MLD (Kaur R. et al. 2012; Kamyotra J.S. and newlineBhardwaj R.M. 2011). Current conventional methods for wastewater treatment are not newlinesustainable and have many constraints as they do not focus on exploitation of valuable newlineresources from wastewater. There are no measures being taken for the recovery of newlinevaluable nitrogen (N) and phosphorus (P) from the wastewater. Very few treatment newlineplants have been supplemented with technologies to recover energy and nutrient for newlineagriculture. In this study, resource recovery such as energy and fertilizer production newlinewas successfully carried out using sustainable environmental technologies. Energy in newlinethe form of biogas was generated by adopting anaerobic digestion technology. newlineBiomethane potential of the septage and sewage sludge was investigated and found newlinethat biogas potential was very low due to high dilution of the sample. To make the newlineprocess efficient, septage and sewage sludge were subjected to anaerobic co-digestion newlinealong with food waste (FW). Co-digestion was carried out in various mixing ratios of newline1:1, 1.5:1, 2:1, 1:1.5 and 1:2 of FW and septage. Results indicated that mixing ratio of newline1:2 (FW and septage) produce the maximum biogas when compared with other ratios. newlineThe septage is naturally rich in many of the trace nutrient elements required for newlinemicroorganisms to produce maximum biogas from substrate. Experiments were newlineperformed to find whether septage fulfils the requirement of trace elements during its newlineanaerobic co-digestion with the FW. It was evident that the septage addition improved newlineanaerobic digestion of FW even when certain trace elements like Zn, Co, Fe were newlinelimiting. newlineThe co-digestion of sewage sludge with FW also indicated that mixing ratio of 1:2 newline(FW and septage) was optimum for maximum biogas