用改进型CAJRIX离子交换技术去除水中镉、铜离子的研究

Removal of Cd^(2+) and Cu^(2+) Ions in Water Solution by the Modified CARIX Ion-Exchange Technology

本文报道用离子交换技术去除镉、铜的新工艺,在传统的CARIX工艺中碳酸钙是便宜的再生添加剂,但再生效率较低,使用较困难.本文报道用镁型化合物作为再生添加剂加入饱和的二氧化碳溶液中,将弱酸性阳离子交换树脂转变为镁型。在不同条件下选用Mg(OH)_2、碱式碳酸镁、白云石等作添加剂。实验结果表明,出水中镉、铜含量可达到废水排放允许标准。

This paper reports a new 'technology of ion exchanges in removing Cd2+ and Cu2+ from the dilute solutions of cadmium sulfate and copper sulfate. Its advantages are derived from the use of carbon dioxide and magnesium compounds as regenerate. As carbon dioxide is a non-polluting chemical, it could diminish saline loads in water bodies. The experimental results show that a partial conversion of the resin to magnesium is achieved and the eftect of desalination is satisfied. In addition, the concentration of magnesium ions in the regenerant is higher than that of carbonic acid and calcium ions during regeneration. It increases effective cation exchange capacity of the weakly acid cation exchange resins.