Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, China.
Chemosphere. 2019 Jul;226:587-596. doi: 10.1016/j.chemosphere.2019.03.193. Epub 2019 Apr 1.
A substantial amount of ash is produced after the incineration of sewage sludge which is difficult to manage. Its potential use as a cost-effective adsorbent for heavy metals is beneficial to both waste management and wastewater treatment. In this study, the adsorption kinetics, isotherms as well as the factors influencing the adsorption performance were assessed through batch sorption experiments. The results show that incinerated sewage sludge ash (ISSA) was effective in adsorbing Pb(II) from aqueous solution in a wide pH range (3.00-6.00) due to the combined contributions of ion exchange, precipitation and complexation, which was confirmed by systematic investigation through XRD, SEM-EDX, FTIR, XPS and a sequential extraction procedure (SEP) for Pb(II). Nonetheless, the adsorption of Pb(II) by ISSA would be adversely affected by high ionic strength. The sorption process was fast, and the equilibrium data could be well described by the Langmuir model, the maximum uptake capacity for Pb(II) increased with temperature and the calculated adsorption capacities at 298, 308 and 318 K for Pb(II) were 58.28, 60.06 and 62.42 mg/g, respectively. These findings indicate the ISSA can be recognized as a high-performance adsorbent for Pb(II) removal in wastewater treatment applications.
焚烧污水污泥会产生大量难以处理的灰烬，而将其用作重金属的廉价吸附剂，既有利于废物管理，又有利于废水处理。本研究通过批量吸附实验评估了吸附动力学、等温线以及影响吸附性能的因素。结果表明，由于离子交换、沉淀和络合的综合作用，在较宽的 pH 范围（3.00-6.00）内，焚烧污水污泥灰（ISSA）可有效吸附水溶液中的 Pb(II)，这一点通过对 ISSA 进行 XRD、SEM-EDX、FTIR、XPS 和 Pb(II)的顺序提取程序（SEP）的系统研究得到了证实。尽管如此，高离子强度会对 Pb(II)的吸附产生不利影响。吸附过程很快，平衡数据可以很好地用 Langmuir 模型描述，Pb(II)的最大吸附容量随温度升高而增加，在 298、308 和 318 K 下计算出的 Pb(II)吸附容量分别为 58.28、60.06 和 62.42 mg/g。这些发现表明，ISSA 可以被认为是废水处理中去除 Pb(II)的高性能吸附剂。
