Microbial diversity (multi-primer) analysis Metagenome

Anaerobic fermentation of sludge is constrained by low short-chain fatty acids (SCFAs) yields and limited organic matter dissolution. This study presents a novel approach that integrates low-temperature heat treatment with biostimulant pretreatment to enhance the recovery of SCFAs from waste activated sludge. Experimental results indicate that applying 90 heat treatment and 1.2 g/g TSS D-limonene without pH adjustment led to an SCFA yield of 2664 mg/L, representing a 2.3-fold increase over the control group. Under conditions with initial pH set to 12, the SCFA yield peaked at 2977 mg/L by the seventh day. Mechanistic analysis revealed that the combined pretreatment effectively disrupted extracellular polymeric substances and cell walls, facilitating SCFAs production. Microbial community analysis demonstrated an enrichment of Proteobacteria, Actinobacteria, and chain-elongating bacteria, enhancing the conversion of low-value organic matter into high-value products. This study provides a new basis for efficient recovery of organic matter by sludge anaerobic fermentation.