Biomethanation efficiency of para-grass in piggery wastewater in single stage and temperature phased anaerobic systems. (July 2018)

• Record Type: Journal Article
• Authors: Saritpongteeraka, Kanyarat; Dechrugsa, Sumeth; Kantachote, Duangporn; Chen, Wen-Hsing; Chaiprapat, Sumate
• Is Part Of: Biocatalysis and agricultural biotechnology. Number 15(2018)
• Page Start: 254
• Page End: 263
• Publication Date: 2018-07
• Subjects: AD anaerobic digestion -- ALK alkalinity -- CHONS carbon, hydrogen, oxygen, nitrogen and sulfur -- COD chemical oxygen demand -- CSTR continuously stirred tank reactor -- C:N carbon to nitrogen ratio -- DGGE denaturing gradient gel electrophoresis -- HAc acetic acid -- HPr propionic acid -- HRT hydraulic retention time -- HBu butyric acid -- HVa valeric acid -- i-Hbu iso-butyric acid -- i-HVa isovaleric acid -- MS mesophilic single stage reactor -- M2 mesophilic 2nd stage reactor in TPAD -- OLR organic loading rate -- PG para-grass -- PM pig manure -- SVFA short chain volatile fatty acids -- TPAD temperature-phased anaerobic digestion -- TS total solids -- TVFA total volatile fatty acid -- T1 thermophilic 1st stage reactor in TPAD -- VFA volatile fatty acid -- VS volatile solids -- Ya acidification yield -- Yh hydrolysis yield; Co-digestion -- Grass -- Manure -- Solid concentration -- Thermophilic -- Mass transfer; Agricultural biotechnology -- Periodicals; Enzymes -- Biotechnology -- Periodicals; 660.6
• DOI: 10.1016/j.bcab.2018.06.021
• Languages: English
• ISSNs: 1878-8181

Abstract

Abstract: Effects of para-grass (PG) addition to pig manure (PM) digester were evaluated at organic loadings 0.10–3.76 gVS/L.d by different PG mixing ratios 0–8% in mesophilic single-stage (MS) and temperature-phased anaerobic digestion (TPAD, comprising T1 and M2 reactors) systems. Results showed equivalent methane production between MS and TPAD until 4%PG mix. Highest biogas yields obtained were 271.7 and 264.0 m 3 /tondry for MS and TPAD, respectively. Even with intense VFAs accumulation, the acidification yield in T1 was less than M2 because of continuous conversion of VFAs to CH4 . Only at higher loading (8%PG), reactor staging by temperature was justified for this co-digestion as TPAD exhibited a superior performance and lesser mass transfer impediment. Para-grass addition to PM digester shifted the domination of bacterial strains whereas achaea were steady. Higher microbial diversity and some evolving hydrolytic bacteria observed in T1 could contribute to greater system stability at high solid loading. An addition of small front-end thermophilic tank should be considered when expansion of the existing MS system is planned to process higher solid. Graphical abstract: fx1 Highlights: Para-grass is an abundant resource as co-substrate to piggery wastewater digestion. Highest CH4 yield obtained was 264–271 m 3 /ton dry matter at 4% grass mix, HRT 20d. Temperature-phased showed an advantage over one stage AD above 4% grass mix in feed. High microbial diversity in TPAD contributed to stable operation at high solid load. Adding small thermophilic tank to existing mesophilic system can be more economical.