Co-treatment of organic fraction of municipal solid waste (OFMSW) and sewage by vermireactor

Abstract

Performance evaluation of vermireactors (Trials T1, T2, T3) for co-treatment of organic fractions of municipal solid waste (OFMSW) and sewage was conducted on three different earthworm species such as Eisenia fetida, Perionyx excavatus, and Perionyx sansibaricus. The results were compared with control reactor (T4) (without earthworms) for 120 days. Sewage was applied at hydraulic loading rate of 1m3/m2/day, and earthworm biomass of 500mg per 2kg of organic waste was used for the treatment purpose. A significant gain in earthworm biomass was noted, and maximum growth was observed in T1 followed by T2 than T3. The treatment process due to earthworms causes removal of total organic carbon (65–75%), CODtot (85–86%), BOD5 (84–87%), ammonia nitrogen (45–59%), and coliforms (99.9%), but increase in nitrate nitrogen (172.5–186.7%) and total phosphorous (161–201%) subsequently in treated effluent and nutrient enhancement in solid waste samples was observed. Scanning electron micrographs revealed the final products (vermicompost) exhibited a distinct physical appearance than initial solid waste samples characterized by predominantly spherical cell-like structure and significantly lower number of filamentous bacteria. Moreover, it can be concluded that these three earthworm species are suitable for onsite co-treatment of OFMSW and municipal sewage.