초록
The effects of anaerobic co-digestion of waste-mixed sludge with fruit and vegetable waste (FVW) on the methane generation of a mesophilic digester was investigated. Organic loading rates (OLR) were 1.46kgVS/m<SUP>3</SUP>day, 2.1kgVS/m<SUP>3</SUP>day and 2.8kgVS/m<SUP>3</SUP>day. Increase in the OLR due to FVW co-digestion caused modification of the internal environment of the digester, mainly in terms of N-NH<SUB>4</SUB> (mg/L). Corresponding microbial populations were investigated by metagenomic high-throughput sequencing. Maximum specific bio-methane generation of 435 NLCH<SUB>4</SUB> per kgVS feed was achieved for an OLR of 2.1kgVS/m<SUP>3</SUP>day, which corresponded to a biomethane generation per kgVS removed of about 1700 NLCH<SUB>4</SUB>. In these conditions the methanogenic pathway was dominated by aceticlastic Methanosaeta and hydrogenotrophic/aceticlastic Methanoscarcinae. Ammonia concentration in the digester resulted a key parameter for enhancing syntrophic acetate oxidation, enabling a balanced aceticlastic and hydrogenotrophic/aceticlastic methanogenic pathway.