Anaerobic digestion of municipal organic waste by using Hydrilla verticillata (Linnaeus f.) Royle as a co-substrate

Abstract

 This article studied effects of temperature and co-digestion ratios on biogas production under anaerobic condition. The substrate was collected two major sources: 1) municipal organic waste from Sakon Nakhon Rajabhat University and 2) Hydrilla verticillata (Linnaeus f.) Royle from Nong Han Lake. The substrate was operated to obtain the initial pH range between 4.73–5.62 and the BOD:N:P ratio100:4.25–6.27:0.4–1.23 in order to support biodegradation process sufficiently. The BOD:COD of MOW and Aquatic plant was 0.67 and 0.88 respectively. The ratio could imply significant improvement of accumulative biogas production at ratio 1:1–4:1 (MOW:Aquatic plant) at ambient and mesophilic condition. The ratio could imply significant improvement of accumulative biogas production at ratio 4:1 (MOW:Aquatic plant) at mesophilic and thermophilic conditions. The biogas composition concentration could produce the highest rate of CH4 at 215 M at ambient temperature (18–31○C), 212 M at mesophilic at ratio 4:1. The H2 could occur maximum at 201M in ratio 3:2 at ambient temperature and 72 M in ratio 2:3 at mesophilic. However, the operation under thermophilic incubation appeared to retard the biogas production.