Seed Sludge Effect on Anaerobic Treatment of Organic Solid Waste and Its Microbial Community

Abstract

In this study, two anaerobic bioreactors started up to investigate the effects co-disposal of different seed sludges with the organic fraction of municipal solid wastes (OFMSW) on the anaerobic treatment. All of the reactors were operated with leachate recirculation. One of these was loaded only with OFMSW (control reactor-Run 1); the second reactor (Run 2) was loaded with Bio-One™ and OFMSW; the third reactor (Run 3) was loaded with anaerobic sludge and OFMSW; and the fourth reactor (Run 4) was loaded with Karahayıt sludge and OFMSW. Besides chemical characterization such as chemical oxygen demand (COD), volatile fatty acids (VFA) molecular microbiology techniques such as polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and sequencing were applied to leachate samples. After 90 days of anaerobic incubation, it was observed that the COD and VFA concentrations in the leachate samples of the anaerobic sludge-added reactor (run 3) were better than in the other reactors. All the representative DGGE sequences were found to be closely related to 16S rDNAs of methanogens, such as Methanosarcinales, Methanomicrobiales and Methanobacteriales order.