污泥生物沥浸处理对病原物的杀灭效果影响

Elimination of Pathogens in Municipal Sludge and Tannery Sludge by Bioleaching Approach

生物沥浸能够去除污泥中的重金属，同时可能对污泥中的病原物有一定的杀灭作用．通过测定沥浸过程中异养细菌总数及沥浸前后总大肠菌群和粪大肠菌群的变化，研究了生物沥浸作用去除城市污泥和制革污泥中的病原物的作用．结果表明，经过6～7d的生物沥浸处理，城市污泥中的异养细菌总数从1．38×10^8个／mL降为4．43×10^6个／mL，制革污泥中的异养细菌总数从9．23×10^5个／mL降为4．26×104个／mL；总大肠菌群（TC）和粪大肠菌群（FC）的去除率达到99％以上；但蛔虫卵的死亡率并无明显变化．大肠菌群纯培养试验表明，沥浸过程中病原物的消减作用主要是由于沥浸作用产生的低pH环境，而与污泥中SO4^2-和重金属浓度的升高无关．

Heavy metals could be removed from sludge by bioleaching approach, and pathogens in sludge may also be eliminated by the approach. Elimination efficiencies of pathogens in municipal sludge and tannery sludge during bioleaching were studied through batch trials. The results revealed that, after 6 - 7 days of bioleaching compared with the control without bioleaching, the amounts of bacteria in municipal sludge decreased from 1.38×10^8 cells/mL to 4.43×10^6 cells/mL, and the amounts of bacteria in tannery sludge decreased from 9.23 × 10^5 cells/mL to 4.26 × 10^4 cells/mL. The amounts of sludge bacteria in the control were maintained at the similar level before and after bioleaching. Elimination efficiencies of total coliforms （TC） and fecal coliforms （FC） in bioleached sludge exceeded 99% . But bioleaching approach couldn＇t eliminate ascarid eggs, as indicating similar levels for survival ascarid eggs before and after sludge bioleaching. Axenic culture of coliforms revealed that the low pH caused by the bioleaching was responsible for pathogens elimination instead of the increases of the concentrations of SO4^2- and heavy metals.