Satoto E. Nayono, Josef Winter, Claudia Gallert
A highly polluted liquid (" press water" ) was obtained from the pressing facility for the organic fraction of municipal solid waste in a composting plant. Methane productivity of the squeezed-off leachate was investigated in batch assays. To assess the technical feasibility of " press water" as a substrate for anaerobic digestion, a laboratory-scale glass column reactor was operated semi-continuously at 37 °C. A high methane productivity of 270m-3 CH4ton-1 CODadded or 490m-3 CH4ton-1 VSadded was achieved in the batch experiment. The semi-continuously run laboratory-scale reactor was initially operated at an organic loading rate of 10.7kg CODm-3d-1. The loading was increased to finally 27.7kg CODm-3d-1, corresponding to a reduction of the hydraulic retention time from initially 20 to finally 7.7days. During the digestion, a stable elimination of organic material (measured as COD elimination) of approximately 60% was achieved. Linearly with the increment of the OLR, the volumetric methane production of the reactor increased from 2.6m3mreactor-3d-1 to 7.1 m3mreactor-3d-1. The results indicated that " press water" from the organic fraction of municipal solid waste was a suitable substrate for anaerobic digestion which gave a high biogas yield even at very high loading rates. © 2009 Elsevier Ltd.
Department of Civil Engineering, Yogyakarta State University, Campus UNY, Karangmalang Yogyakarta 55281, Indonesia; Institute of Biology for Engineers and Biotechnology of Wastewater, University of Karlsruhe, 76131 Karlsruhe, Am Fasanengarten, Germany
