Application of Supporting Media for Improvement of Anaerobic Digestion Performance and Biogas Production

Abstract

In this study, effects of supporting media as attached carrier for microorganisms to improve biogas production were evaluated in laboratory-scale batch reactor. A batch anaerobic test was to compare 3 types of suitable supporting media (bamboo tube, PVC tube and nylon fiber) and digestion of free-cell digester as the control experiment with 40 days retention time. The related parameters were determined, namely, pH value, chemical oxygen demand (COD), total solid (TS), volatile solid (VS), alkalinity (Alk.) and carbon and nitrogen (C/N) ratio. It was found that the application of bamboo tube, PVC tube and nylon fiber showed the biogas yield higher than the control experiment. The results showed that bamboo tube as supporting media showed the best methaneyield and the highest of biogas production (12.19 mLCH₄/gdCOD_removed and 22.4 L, respectively). Biogas production and methane yield of control experiment set were minimum 16.92 L and 7.8 mLCH₄/gdCOD_removed, respectively. The removal efficiencies of COD in all experiment set were 89.54%, 85.24%, 70.87% and 69.24% for bamboo tube, nylon fiber and PVC tube as supporting media and free-cell digester, respectively. The study results could support the supporting media for attachment of microorganisms to be used to improve and enhance the biogas production and methane yield in anaerobic digestion.