城市污泥生物沥滤过程中抑制作用的研究

对好氧剩余污泥重金属生物沥滤过程中可能存在的抑制作用进行了系统研究.结果表明,丽华污泥(取自常州丽华污水处理厂)和城东污泥(苏州城东污水处理厂)及其上清液对氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)的生长及Fe2 氧化作用均具有强烈抑制作用,而乙酸和丙酸是引起上述抑制作用的主要因子.采用不同固体含量污泥悬液进行模拟培养试验,结果证明污泥中的乙酸和丙酸主要来源于浓缩池内污泥有机质的厌氧分解.在污泥生物沥滤过程中,乙酸和丙酸的存在对Zn的溶出效率没有不利影响,但污泥的酸化速率显著下降,丽华污泥和城东污泥中Cu的沥滤时间分别比对照延长6 d和2 d,严重影响生物沥滤工艺的总体效率.

Inhibitory effects involved in bioleaching of heavy metals from municipal sewage sludge

Inhibitory effects involved in bioleaching of heavy metals from aerobic wastewater sludge were systematically investigated in the present study. The results showed that acetic and propioinic acids were responsible for strong inhibition on bacterial oxidation of ferrous iron in both sludge filtrate medium and bioleaching process of Lihua and Chengdong sludges. Results from an incubation experiment at different solids content of sewage sludge indicated that acetic and propionic acids were evolved mainly from anaerobic digestion of organics in sludge in thickening tank in sewage treatment plants. During the bioleaching process sludge acidification was greatly delayed and bioleaching time for significant solubilization of Cu from Chengdong and Lihua sludges was extended by 2 and 6 days, respectively, although solubilization of Zn was not affected by the presence of both organic acids.