纳滤和反渗透法处理含Ag-110m的放射性废水

Treatment of Radioactive Wastewater Containing Ag-110m by Nanofiltration and Reverse Osmosis

Ag-110m是核电厂放射性废水中主要γ放射性核素,其放射性活度占核电厂总液态放射性流出物的份额高达57%,是放射性废水处理当中的关键核素。Ag-110m无法通过离子交换树脂净化处理,在国内多家核电厂均存在Ag-110m的处理问题。本研究从解决Ag-110m的处理问题出发,以国内某核电厂真实放射性废水源项为基础,开展纳滤、反渗透、纳滤和反渗透联用处理Ag-110m可行性研究。研究结果表明,3种处理方法均能实现对放射性废水中Ag-110m的有效去除,去除率由高到低依次为:纳滤和反渗透联用≈反渗透>纳滤。在3种处理方法中,纳滤虽对Ag去除率最低,但仍可达99%,经纳滤处理后的放射性废水中Ag-110m放射性活度浓度低于15 Bq/L,满足核电厂的废水排放限值要求。并且纳滤具有处理效率高、对进水水质要求低、使用寿命长的特点,从实际应用方面分析,采用纳滤处理核电厂放射性废水中Ag-110m是最为高效、经济的处理方式。

Ag-110m is the main gamma radionuclide in radioactive wastewater of nuclear power plants,and its radioactive activity accounts for 57%of the total liquid radioactive effluents of nuclear power plants.Ag-110m is a key nuclide in radioactive wastewater treatment.Ag-110m can not be purified by ion exchange resin.Ag-110m processing problems exist in many nuclear power plants in China.In order to solve the problem of Ag-110m treatment,based on the real radioactive wastewater source of a nuclear power plant in China,the Ag-110m treatment feasibility study of nanofiltration,reverse osmosis,combined nanofiltration and reverse osmosis was carried out.The results showed that the three treatment methods could effectively remove Ag-110m from radioactive wastewater,and the removal rates from high to low were as follows:combined nanofiltration and reverse osmosis≈reverse osmosis>nanofiltration.Among the three treatment methods,although nanofiltration has the lowest removal rate of Ag,it can still reach 99%.The radioactive activity concentration of Ag-110m in the radioactive wastewater treated by nanofiltration is lower than 15 Bq/L,which meets the wastewater discharge limit requirements of nuclear power plants.Moreover,nanofiltration has the characteristics of high treatment efficiency,low requirements on inlet water quality and long service life.From the practical application analysis,nanofiltration is the most efficient and economical treatment method for treating Ag-110m in radioactive wastewater of nuclear power plants.