Li Xiaobo, Wu Shuibo, Hu Baoan, Gu Ping
School of Environmental Science & Engineering, Tianjin University, Tianjin 300072, China.
Wei Sheng Yan Jiu. 2008 Mar;37(2):168-71.
To study the leaching toxicity of the ferric salt and aluminum salt containing arsenic-bearing sludge coming from the high arsenic drinking water treated by coagulation/microfiltration process and its disposal method.
The Chinese standard method and TCLP method issued by USEPA were used to test the leaching toxicity of arsenic-bearing sludge and its Portland cement solidification tests were conducted. Minor ferric salt containing arsenic-bearing sludge was added into road-application concrete for its utilization.
The arsenic concentrations in TCLP leaching solutions of ferric salt and aluminum sludge were 118 microg/L and 420 microg/L, respectively, which were higher than 9.5 microg/L and 11.8 microg/L of the Chinese standard method. However, all of them were less than identification standard for hazardous wastes of China. When arsenic-bearing sludge was solidified with cement, its leaching toxicity reduced about 90%. The unconfined compression strengths of solidification products were 3.25MPa and 0.76MPa which could meet the requirement for the landfill and sludge reclamation. The compression strengths of road-application concrete were upgraded about 12% when minor parts of ferric salt arsenic-bearing sludge was added.
Ferric salt and aluminum salt arsenic-bearing sludge do not belong to the hazardous waste with leaching toxicity. Cement solidification is an efficient method for the disposal of arsenic-bearing sludge. The mix of arsenic-bearing sludge with road-application concrete could provide a method for the efficient utilization of arsenic-bearing sludge. At the same time, the possible environmental problems should be avoided.
研究混凝/微滤法处理高砷饮用水产生的含铁盐和铝盐的含砷污泥的浸出毒性及其处置方法。
采用中国标准方法和美国环保署发布的TCLP方法测试含砷污泥的浸出毒性，并进行其波特兰水泥固化试验。将少量含铁盐的含砷污泥添加到道路应用混凝土中进行利用。
铁盐和铝污泥的TCLP浸出液中砷浓度分别为118μg/L和420μg/L，高于中国标准方法的9.5μg/L和11.8μg/L。然而，它们均低于中国危险废物鉴别标准。用水泥固化含砷污泥时，其浸出毒性降低约90%。固化产物的无侧限抗压强度分别为3.25MPa和0.76MPa，可满足填埋和污泥回收的要求。添加少量含铁盐的含砷污泥时，道路应用混凝土的抗压强度提高约12%。
含铁盐和铝盐的含砷污泥不属于具有浸出毒性的危险废物。水泥固化是处置含砷污泥的有效方法。含砷污泥与道路应用混凝土混合可为含砷污泥的有效利用提供一种方法。同时，应避免可能出现的环境问题。
