Investigation of Sewage Sludge Anaerobic Digestion Performance Using Peracetic Acid as a Pretreatment

Sewage sludge is difficult to degrade in anaerobic digestion systems and pretreatments have been shown to speed up the hydrolysis stage. In this paper sludge anaerobic digestion experiments with peracetic acid as a pretreatment were carried out and the effects of acid pretreatment using peracetic acid on subsequent digestion were investigated. It has been proved that this treatment effectively leads to a solubilisation of organic material and thus leads to a increase of soluble chemical oxygen demand (SCOD) and volatile fatty acids (VFA) concentration. Besides, the SV of sludge was reduced and the settling characteristics of sludge were improved. But high dosage of peracetic acid lead to a decrease in biogas production and the proper dosage was 20 g/kg DS. It can be concluded that sludge anaerobic digestion with peracetic acid pretreatment is an effective method for biomass material transformation.