微生物沥滤法去除城市污泥中重金属的试验研究

城市污泥的植物营养元素丰富,农业资源化利用潜力巨大,但污泥中重金属含量常常超标,所以采取一定措施对污泥中重金属加以去除十分必要。本研究以桂林城市污泥作为培养介质,利用以还原硫作为生长基质进行生命活动的氧化硫硫杆菌来沥滤去除污泥中重金属。结果表明,在基质投配比为5gL并附以15%的驯化污泥回流条件下,能将污泥驯化周期缩短为5d,Cu、Zn和Cd的去除率分别达到了70.8%、80.4%和78.9%。同时,污泥中剩余的重金属含量可满足污泥农用的国家标准。

EXPERIMENTAL RESEARCH ON HEAVY METAL REMOVAL FROM MUNICIPAL SLUDGE BY MICROBIAL LEACHING

Municipal sludge with plentiful nutrition for crop growing is potential fertilizer, but the concentrations of heavy metals are frequently higher than the control standard for pollutants in sludge from agricultural use.Therefore, it is necessary to take some measurements to remove heavy metals from sludge before its using as fertilizer.In order to remove heavy metals in sludge through microbial leaching of sulfur bacilli,the municipal sludge, taken from Guilin Sewage Treatment Plant,was used as cultivating medium and reductive sulfur as growing substrate for bacteria metabolism.When dosing ratio was 5 g/L and reflux rate of inoculation sludge was 15% in bioleaching test, the time of sludge acidification was reduced to 5 days.The removal rates of copper,zinc and cadmium were up to 70.8%,80.4% and 78.9%,respectively.Simultaneously, the residual concentrations of heavy metals could meet the national standard for agricultural usage.