关键词: 废物处理, 辐射, 优化设计, 微波预处理, 剩余污泥, 乙酸

Abstract: The current microwave pretreatment of waste activated sludge is limited to sludge hydrolysis ratio and the effect to anaerobic digestion, soluble COD is often used to evaluate pretreatment effect, and volatile fatty acids recovery from sludge is rarely reported. In order to determine the optimal process conditions of volatile fatty acids recovery from waste activated sludge using microwave pretreatment process, the factors and their levels were established by single factor experiment first, and response surface methodology of four factors and three levels was used based on the center combination design. The four factors included heating temperature, heating time, dosage of H₂O₂, and dosage of acetic acid. The optimal process conditions were as follows:microwave heating temperature of 180℃, microwave heating time of 21min, H₂O₂ dosage of 0.18g/(gSS), acetic acid dosage of 49mg/(gSS). Under these conditions, the maximum predicted acetic acid concentration was 581mg/L, the relative deviation was 0.033—0.074 between the predicted values and the experimental values. The results showed that this method could effectively improve volatile fatty acids recovery from sludge, the predicted values were in accordance with the experimental values, and this method could provide theoretical and practical guidance for in situ carbon source production from sludge.

Key words: waste treatment, radiation, optimal design, microwave pretreatment, waste activated sludge, acetic acid