Institute of Environmental Science & Engineering, School of Metallurgy and Environment, Central South University, Changsha, Hunan 410083, China.
Institute of Environmental Science & Engineering, School of Metallurgy and Environment, Central South University, Changsha, Hunan 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, Hunan 410083, China.
J Environ Manage. 2016 Oct 1;181:756-761. doi: 10.1016/j.jenvman.2016.07.031. Epub 2016 Jul 19.
Wastewater treatment sludge from a primary lead-zinc smelter is characterized as hazardous waste and requires treatment prior to disposal due to its significant arsenic and heavy metals contents. This study presents a method for the stabilization of arsenic sludge that uses a slag based curing agent composed of smelting slag, cement clinker and limestone. The Unconfined Compressive Strength (UCS) test, the China Standard Leaching Test (CSLT), and the Toxicity Characteristic Leaching Procedures (TCLP) were used to physically and chemically characterize the solidified sludge. The binder ratio was determined according to the UCS and optimal experiments, and the optimal mass ratio of m (smelting slag): m (cement clinker): m (gypsum sludge): m (limestone) was 70:13:12:5. When the binder was mixed with arsenic sludge using a mass ratio of 1:1 and then maintained at 25 °C for 28 d, the UCS reached 9.30 MPa. The results indicated that the leached arsenic content was always less than 5 mg/L, which is a safe level, and does not contribute to recontamination of the environment. The arsenic sludge from the Zn/Pb metallurgy plant can be blended with cement clinker and smelting slag materials for manufacturing bricks and can be recycled as construction materials.
来自原生铅锌冶炼厂的废水处理污泥被归类为危险废物，由于其砷和重金属含量高，在处置之前需要进行处理。本研究提出了一种利用基于冶炼渣、水泥熟料和石灰石的固化剂稳定砷污泥的方法。采用无侧限抗压强度（UCS）试验、中国标准浸出试验（CSLT）和毒性特征浸出程序（TCLP）对固化污泥进行物理化学特性分析。根据 UCS 和最佳实验确定了结合剂的比例，m（冶炼渣）：m（水泥熟料）：m（石膏污泥）：m（石灰）的最佳质量比为 70:13:12:5。当结合剂与砷污泥以质量比 1:1 混合并在 25°C 下保持 28 d 时，UCS 达到 9.30 MPa。结果表明，浸出的砷含量始终低于 5mg/L，属于安全水平，不会对环境造成再污染。来自 Zn/Pb 冶金厂的砷污泥可以与水泥熟料和冶炼渣材料混合制造砖块，并可作为建筑材料回收利用。
