National Institute for Environmental Studies, Water and Soil Environment Division, Ibaraki 305-8506, Japan;
Ebara Corp., Technologies, R. & D. Division, Kanagawa 251-8502, Japan;
Department of Environmental Systems Engineering, Nagaoka University of Technology, Niigata 940-2188, Japan;
Ebara Corp., Technologies, R. & D. Division, Kanagawa 251-8502, Japan;
农业部沼气科学研究所;