Department of Civil and Environmental Engineering, Seoul National University, San 56-1, Daehak-dong, Gwanak-gu, Seoul, 151-742, Republic of Korea.
J Hazard Mater. 2012 Apr 30;213-214:147-55. doi: 10.1016/j.jhazmat.2012.01.074. Epub 2012 Feb 4.
This study focused on the environmental risk of steel making slag itself, arsenic removal mechanism and re-leaching possibility of arsenic to aqueous state after the adsorption. The purpose of the study is to promote the use of steel making slag as a low-cost adsorbent for arsenic in aqueous system. Calcium was easily dissolved out from the slag and become the dominant substance in the leachate. Some of the calcium could form amorphous calcium carbonate in alkaline condition, and arsenic in the aqueous solution would be removed by being co-precipitated with or adsorbed onto the amorphous calcium carbonate. Most of the amorphous calcium carbonate containing arsenic would be bound to amorphous iron oxide of the slag. When the slag was used as an adsorbent for arsenic removal, a little amount of toxic chemicals were leached from the slag itself under pH 0.8 to 13.6. Also, 70-80% of arsenic laden on the slag was bound to amorphous iron oxide which would not easily desorb unless given a reducing and complexing condition. Showing 95-100% removal efficiency near initial pH 2, the slag, therefore, could be used as an appropriate adsorbent for eliminating arsenic in acidic aqueous solution.
本研究重点关注炼钢渣本身的环境风险、砷的去除机制以及吸附后砷重新浸出到水溶液中的可能性。本研究旨在促进炼钢渣作为水溶液中砷的低成本吸附剂的使用。钙容易从渣中溶解出来，并成为浸出液中的主要物质。部分钙在碱性条件下可以形成无定形碳酸钙，水溶液中的砷会与无定形碳酸钙共沉淀或被其吸附而被去除。大部分含有砷的无定形碳酸钙会与渣中的无定形氧化铁结合。当渣被用作砷去除的吸附剂时，在 pH 值为 0.8 到 13.6 的条件下，渣本身会浸出少量有毒化学物质。而且，负载在渣上的 70-80%的砷与不易解吸的无定形氧化铁结合。在初始 pH 值为 2 附近，显示出 95-100%的去除效率，因此，渣可用作去除酸性水溶液中砷的合适吸附剂。
