Anaerobic digestion of wastewater and solid waste using raw clays as supports

Abstract

The efficiency of certain raw clays from Spanish deposits (talc, bentonite, sepiolite) as supports in the anaerobic digestion of wastewater and solid waste was studied. The results were compared with those obtained using the commercial support biolite. The best results were obtained using sepiolite and biolite. The good results obtained with sepiolite may be attributable to its ability to release magnesium ions continuously. Sepiolite was chosen as the support material in a fluidized bed digester with solid wastes and domestic sewage. Gas production of 15 litres/d was obtained for 30.53 g/litre organic matter treated. Biogas production was ten-fold higher when sepiolite was present than in its absence.