Wu Chung-Hsin, Lin Cheng-Fang, Horng Pay-Yu
Department of Environmental Engineering and Health, Yuanpei University of Science and Technology, Hsinchu, Taiwan, ROC.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2004;39(1):237-52. doi: 10.1081/ese-120027381.
In this study, water treatment sludges were sintered under various experimental conditions to generate Al-containing adsorbents. The adsorption of Cu2+ and Pb2+ onto sintered oxide was examined and sorption results were further modeled using a surface complex model. The specific surface area of the sintered adsorbent was substantially reduced from 30 m2/g (dried sludge) to 2 m2/g (sinter sludge). The pH-adsorption-edges of both Cu2+ and Pb2+ were shifted towards a higher pH than the edges of the unsintered adsorbent, revealing reduced affinity of the sintered adsorbent for metal ions. Metal leaching was measured by the TCLP procedure, and the results indicated that the amount of metal leaching by the sintered adsorbent was negligible. The effect of background electrolytes on Cu2+ and Pb2+ sorption was negligible. Triple-layer model (TLM) simulation revealed that Cu2+ and Pb2+ sorption on sintered adsorbent involves inner-sphere interactions and the dominant surface metal species are monodentates of Me2+ and MeOH+. The intrinsic adsorption constants of Cu2+ and Pb2+ on dried sludge, adsorbent sintered at 1000 degrees C, and adsorbent sintered at 1100 degrees C were also examined.
在本研究中，对水处理污泥在各种实验条件下进行烧结，以生成含铝吸附剂。考察了烧结氧化物对Cu2+和Pb2+的吸附情况，并使用表面络合模型对吸附结果进行了进一步模拟。烧结吸附剂的比表面积从30 m2/g（干污泥）大幅降低至2 m2/g（烧结污泥）。Cu2+和Pb2+的pH吸附边界均向比未烧结吸附剂更高的pH值移动，这表明烧结吸附剂对金属离子的亲和力降低。通过TCLP程序测量了金属浸出情况，结果表明烧结吸附剂的金属浸出量可忽略不计。背景电解质对Cu2+和Pb2+吸附的影响可忽略不计。三层模型（TLM）模拟表明，Cu2+和Pb2+在烧结吸附剂上的吸附涉及内球相互作用，主要表面金属物种为Me2+和MeOH+的单齿配体。还考察了Cu2+和Pb2+在干污泥、1000℃烧结吸附剂和1100℃烧结吸附剂上的固有吸附常数。
