Fuzzy Sludge Quality Index on the Basis of Fertilizer Potential After Primary Clarifier

The sludge is generated from the two treatment units of Sewage Treatment Plant (STP) like primary and secondary clarifier. In the activated sludge process, the sludge produced after secondary clarifier can be recycled and wasted sludge can be used as fertilizer after sludge treatment. The chemical sludge produced from primary clarifier is not suitable to be used as fertilizer because of the use of chemical coagulants for coagulation process. As considering this problem, a pilot plant study was done using natural coagulants to produce pure bio sludge. A methodology is also developed for ranking of different STPs on the basis of fertilizer potential of sludge from primary clarifier by developing Fuzzy Sludge Quality Index (SQI). A case study of three STPs which are located in Pimpri Chinchwad Municipal Corporation, Pimpri, Pune, Maharashtra, India is also incorporated in this study.