生物淋滤法对疏浚淤泥中镉去除率及性质的影响

针对疏浚淤泥黏粒含量高、呈弱碱性的特性,采用疏浚淤泥和城市污水厂污泥共同驯化培养硫细菌接种液,研究生物淋滤过程对高污泥浓度的疏浚泥浆中镉的去除率、脱水性能和沉降性能的影响.结果表明:底物硫粉和FeSO4·7H2O共同用于生物淋滤能有效脱除淤泥中镉,同时可显著改善淤泥的脱水和沉降性能.当硫粉浓度为5g/L, FeSO4·7H2O浓度为15g/L,接种量为20%时,淋滤效果最好,淤泥中镉去除率达到88.68%,在此条件下,淤泥的离心脱水率和滤饼含水率分别为75%和33.47%,最终沉降距离最大.

Effects of bioleaching on removal rate of cadmium and dewatering property from dredged sludge

With the characteristics of highly clay content and weakly alkaline, dredged sludge was mixed with the sludge from domestic wastewater treatment plant to domesticate for sulfur bacteria liquid. The effects of bioleaching test on the cadmium removal rates, dewatering and sediment properties were demonstrated. The results revealed that Cd could be effectively removed by cooperation of substrate sulfur powder and FeSO4?7H2O, and the sludge properties of dewatering and sediment were significantly improved. The removal rate of Cd was 88.68 % when the concentration of sulfur powder and FeSO4?7H2O were 5 g/L and 15 g/L and the inoculation was 20%. The centrifugal dewatering rate and moisture content of the sludge cake were 75% and 33.47%, respectively. Under the same condition, sludge had the maximum sediment distance.