The study of biogas production from anaerobic co-digestion chicken manure and hydrilla (hydrilla verticillata (L.f.) Royle)

Abstract

This work presented the production of biogas using anaerobic co-digestion between hydrilla verticillata (HV) from Songkhla Lake Basin and chicken manure (CM). From the study of compositions of both wastes, it was found that the COD of CM and HV were 11,200 and 14,400 mg/l and pH were 6.5 and 5.5, respectively. The biogas production using anaerobic single-digestion of untreated hydrilla verticillata (UHV) gave accumulative methane of 1,251 ml-CH4/g-VS and methane production of 78.28 L-CH4/kg-substrate was obtained. For hydrilla treated with 2% w/v NaOH (THV), the accumulative methane was 1,786 ml-CH4/g-VS and the obtained methane production was 91.87 L- CH4/kg-substrate which was 17.5 % increase when compared to the UHV. For the biogas production using anaerobic single-digestion of CM, it was found that the accumulative methane and methane production were 978 ml-CH4/g-VS and 78.28 L- CH4/kgsubstrate, respectively. These were lower than the studies using HV. The study of anaerobic co-digestion of HV and CM at three different ratios; 1:1, 2:1 and 3:1 was studied. It was found that the anaerobic co-digestion using THV and CM at ratio 3:1 and 2:1 gave the highest potential for biogas production. The accumulate methane of 3,202.20 and 2,079.19 ml- CH4/g-VS were obtained, respectively. The methane productions were 2.53 and 82.26 L-CH4/ton-substrate, for ratio 3:1 and 2:1, respectively which is no significant different at 95 % confidence interval.