酸化预处理对剩余活性污泥厌氧消化及其脱水性能的影响研究

摘要

Waste activated sludge（WAS） is difficult to degrade in anaerobic digestion systems and it is discovered that pre-treatment can speed up the hydrolysis process.This paper studies the effects of HCl acid pre-treatment（pH 6–1） on subsequent digestion and dewatering of WAS.The optimal technical parameters were obtained by considering the HCl dose and digestion characteristics of sludge.The optimal effect was achieved when pH equals to 2.The biogas produced by digesting sludge for 13 days equals to the volume by WAS without acid pre-treatment for 21 days.In semi-continuous digestion experiments（hydraulic retention time 12 day at 35℃）,the methane yield increased 14.3% compared to untreated WAS and the Salmonella was eradicated in the digestion.Dewatering investigations suggested that the acid pre-treated WAS required 40% less cationic polymer addition to achieve the same cake solid content.%剩余活性污泥在厌氧消化系统中难以降解,而研究发现预处理能加速其水解的过程。本文研究了盐酸酸化预处理（pH为6～1）对剩余活性污泥后续消化及脱水性能的影响。综合考虑盐酸的投加量和污泥消化性能的改善情况得出最佳工艺参数：酸化至pH为2时,综合效果最佳。此时污泥消化13天的沼气产量相当于未经酸化处理污泥消化21天的沼气产量。在半连续流消化反应试验（35℃,水力停留时间为12天）中,预处理后的污泥产甲烷量较未经预处理的污泥提高了14.3%,同时沙门氏菌全部灭活。脱水实验研究发现,酸化预处理能节约后续污泥脱水过程中40%的阳离子絮凝剂投加量以达到同样的泥饼含固率。