Zhang Fu-Shen, Itoh Hideaki
Division of Environmental Research, EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
Chemosphere. 2005 Jul;60(3):319-25. doi: 10.1016/j.chemosphere.2004.12.019.
An effective adsorbent for arsenic removal from aqueous system was synthesized by loading iron(III) oxide on municipal solid waste incinerator melted slag. The loading was accomplished via chemical processes and thermal coating technique. The key point of the technique was the simultaneous generation of amorphous FeOOH sol and silica sol in-situ and eventually led to the formation of Fe-Si surface complexes which combined the iron oxide with the melted slag tightly. The surface morphology of the iron oxide-loaded slag was examined and the loading mechanisms were discussed in detail. The adsorbent was effective for both arsenate and arsenite removal and its removal capabilities for As(V) and As(III) were 2.5 and 3 times of those of FeOOH, respectively. Both affinity adsorption and chemical reactions contributed to arsenic removal. The effects of solution pH, contact time, arsenic concentration and adsorbent dosage on arsenic removal were examined and the optimum removal conditions were established. Furthermore, leaching of hazardous elements such as Cr(VI), As, Se, Cd and Pb from the adsorbent at a pH range of 2.5-12.5 was below the regulation values. Accordingly, it is believed that the iron oxide-loaded slag developed in this study is environmentally acceptable and industrially applicable for wastewater treatment.
通过将氧化铁负载在城市固体废弃物焚烧炉熔渣上，合成了一种用于从水体系中去除砷的有效吸附剂。负载过程通过化学方法和热涂覆技术完成。该技术的关键在于原位同时生成无定形FeOOH溶胶和硅溶胶，最终导致形成将氧化铁与熔渣紧密结合的Fe-Si表面络合物。研究了负载氧化铁的熔渣的表面形态，并详细讨论了负载机理。该吸附剂对砷酸盐和亚砷酸盐的去除均有效，其对As(V)和As(III)的去除能力分别是FeOOH的2.5倍和3倍。亲和吸附和化学反应都有助于砷的去除。考察了溶液pH值、接触时间、砷浓度和吸附剂用量对砷去除的影响，并确定了最佳去除条件。此外，在pH值为2.5 - 12.5的范围内，吸附剂中Cr(VI)、As、Se、Cd和Pb等有害元素的浸出量低于规定值。因此，认为本研究开发的负载氧化铁的熔渣在环境上是可接受的，并且在工业上可应用于废水处理。
