Yang Zhenzhou, Tian Sicong, Ji Ru, Liu Lili, Wang Xidong, Zhang Zuotai
Beijing Key Laboratory for Solid Waste Utilization and Management and Department of Energy and Resource Engineering, College of Engineering, Peking University, Beijing 100871, PR China.
School of Environmental Science and Engineering, Southern University of Science and Technology of China, Shenzhen, 518055, PR China; School of Environment, Tsinghua University, Beijing 100084, PR China.
Waste Manag. 2017 Oct;68:221-231. doi: 10.1016/j.wasman.2017.06.039. Epub 2017 Jun 24.
The present study systemically investigated the effect of a water-washing process on the removal of harmful chlorides, sulfates, and heavy metals in the air pollution control (APC) residue from municipal solid wastes incineration (MSWI), for sake of a better reuse and disposal of this kind of waste. In addition, the kinetic study was conducted to reveal the releasing mechanism of relevant element in the residue. The results show that, over 70wt.% of chlorides and nearly 25wt.% of sulfates in the residue could be removed by water washing. Based on an economical consideration, the optimal operation conditions for water washing of APC residue was at liquid/solid (L/S) ratio of 3mL:1g and extracting time of 5min. As expected, the concentrations of Co, Cr, Fe, Ni, V and Cu in the washing effluent increased with time during the washing process. However, the extracting regime differs among different heavy metals. The concentrations of Ba and Mn increased firstly but declined afterwards, and concentrations of Pb and Zn gradually declined while Cd and As kept constant with the increase of extracting time. It is worth mentioning that the bubbling of CO into the washing effluent is promisingly effective for a further removal of Pb, Cu and Zn. Furthermore, kinetic study of the water washing process reveals that the extracting of heavy metals during water washing follows a second-order model.
本研究系统地研究了水洗过程对城市固体废物焚烧（MSWI）空气污染控制（APC）残渣中有害氯化物、硫酸盐和重金属去除的影响，以便更好地对这类废物进行再利用和处置。此外，还进行了动力学研究，以揭示残渣中相关元素的释放机制。结果表明，水洗可去除残渣中70wt.%以上的氯化物和近25wt.%的硫酸盐。基于经济考虑，APC残渣水洗的最佳操作条件为液固（L/S）比3mL:1g，萃取时间5min。正如预期的那样，水洗过程中洗涤废水中Co、Cr、Fe、Ni、V和Cu的浓度随时间增加。然而，不同重金属的萃取规律不同。Ba和Mn的浓度先升高后下降，Pb和Zn的浓度逐渐下降，而Cd和As的浓度随萃取时间的增加保持不变。值得一提的是，向洗涤废水中通入CO对进一步去除Pb、Cu和Zn有显著效果。此外，水洗过程的动力学研究表明，水洗过程中重金属的萃取遵循二级模型。
