生物淋滤法对污水污泥中重金属去除效果研究

摘要

Chemical forms of heavy metals from concentrated sludge from certain sewage treatment plants in Taiyuan were analyzed by Sequential Extraction Technique. All the heavy metals measured did not exceed the standard of alkalescent soil; only the content of Zn and Cu exceeded the standard of acidic soil. The unsteady chemical forms of element Zn took a high percentage in sludge, other metals were more steady. On the basis of the results, influence on removal effect with different inoculum sizes and sulfur concentration by bioleaching was investigated. The results show that efficiency was optimum with inoculum sizes of 3 % and sulfur concentration of 3 g/L.%利用Tessier五步法,对某污水处理厂初沉池和二沉池混合的浓缩污泥进行重金属形态分析和测定,结果显示,所测定的重金属均未超过我国污泥农林利用碱性土壤标准,只有Cu和Zn超过了污泥农林利用酸性土壤标准；污泥中Zn不稳定形态所占比例较高,其余重金属稳定性较好.在此基础上,研究了用生物淋滤法去除Cu、Zn时,不同接种量和不同底物投加量的溶出率.结果表明,当接种量体积分数为3％、硫的质量浓度为3 g/L时去除效果最好.本研究结果为城市污泥农用前降低重金属毒性奠定了基础.