Effect of thermal activated peroxydisulfate pretreatment on short-chain fatty acids production from waste activated sludge anaerobic fermentation

The effect of thermal activation of peroxydisulfate (PDS) pretreatment on anaerobic fermentation (AF) of waste activated sludge (WAS) was investigated. WAS pretreatment was conducted at 35 °C and 55 °C with PDS dosage increasing from 0.1 to 0.9 mM/g TSS (total suspended solids). Experimental results showed that sludge solubilization and short chain fatty acids (SCFAs) production were significantly improved after pretreatment, while methanogenesis was severely inhibited. The maximum total SCFAs yield of 3183.51 mg COD/L occurred at 55 °C with 0.3 mM PDS/g TSS addition and day 9 of AF, which was 2.1, 1.3 and 1.1 fold of the blank, 55 °C and 35 °C + 0.3 mM PDS/g TSS pretreated samples, respectively. In addition, thermal activated PDS pretreatment could enhance the dewaterability of fermented sludge, which was advantageous for subsequent disposal of sludge.