壳聚糖螯合吸附剂的制备及其在尾矿坝中的应用

Preparation of Chitosan Chelate Adsorbent and Its Application in Tailings Dam

尾矿坝的废水中含有大量的Ca^(2+),易与碳酸根离子、氢氧根离子形成淤堵物质,堵塞尾矿坝的排渗管,严重时导致溃坝。为处理废水中的钙离子,以壳聚糖为原料,采用乙二胺四乙酸(EDTA)进行接枝共聚反应,制备了一种离子吸附剂。采用傅里叶变换红外光谱仪对样品进行结构分析,确定了该离子吸附剂含有大量EDTA基团。通过模拟实验和络合滴定实验研究了原料配比、样品用量及吸附时间对吸附量的影响。结果表明,该吸附剂的饱和吸附量达到4.3 mmol/g,有着很好的吸附效果。研究为尾矿坝废水中的Ca^(2+)安全处理提供理论依据。

A large number of calcium ions in the wastewater form blockages with carbonate and hydroxide ions to block the drainage pipe and lead to dam-failure in tailings dam.To remove Ca(II)in wastewater,we prepared a ion adsorbent by grafting copolymerization of ethylenediamineteraacetic acid(EDTA)onto chitosan(CS),and characterized its structures by Fourier transform infrared spectroscopy.The result shows that the new ion adsorbent contains a large number of EDTA groups.The effects of mole ratio of CS to EDTAD,CS-EDTAD dosages and adsorption times on Ca(II)adsorption were determined by simulation experiment and complexometry experiment.The results show that the saturated adsorption of Ca(Ⅱ)reaches 4.3 mmol/g,and the new ion adsorbent has a better adsorption capacity.The study provides a theoretical basis for safe treatment of Ca(II)in wastewater from tailings dam.