Pembuatan Biogas Dari Sampah Buah-Buahan Melalui Fermentasi Aerobik Dan Anaerobik

Abstract

Solid wastes and energy crisis are created by high growing rate of people. An alternative solving for both problems is biogas technology. Municipal waste can be proceed into biogas and fertilizer by biogas technology. In general, the process of conventional biogas technology has long time about 40 days (in tropical countries) and 100 days (in subtropical countries). The main goal of the research was to shorten the retention time of biogas production by combining its aerobic and anaerobic processes with optimized environmental condition (temperature) and substrate composition (C:N ratio) in anaerobic phase. Hydrolysis and acidogenesis were set in aerobic phase, while asetogenesis was set in anaerobic phase. Fruits waste were set into pre-treatment, minimized waste size between 1-2 cm2 and water addition (1: 1). The mixed ingredients was added by E~ microorganism culture and took into digester to start aerobic process. After 5 days, the process was stopped then substrate took to anaerobic digester to produced biogas (methano~enesis). Anaerobic process was set at different temperatures (30,35 and 40 C) and C:N ratios (20,25 and 30). The beginning of water content and C:N ratio of substrate were 86,24 % and 70,32: 1. Respectively, in aerobic process substrate was degraded by microorganism into simple compound. This process can be analyzed by C:N ratio change of total solid (TS), total volatile solid (TVS), chemical oxygen demand (COD), volatile fatty acid (VF A) and acidity degree (pH). Methanogenesis (anaerobic process) was monitored by the volume of biogas produced and analyzed COD, VF A and pH. The optimum of production rate and volume ofbiogas produced was achieved by treatment in 35°C temperature and 30: 1 C:N ratio, which biogas has produced 26,5 ml in the ftrst day and 42,5 ml biogas in the end of biogas production with the highest production rate was 9,6 mVday. It showed that activity of methanogenic microbe was optimum in that treatment condition.