低剂量放射性稀土废渣产品对污水的净化效果研究

Use of low radioactive rare-earth waste for sewage treatment

以低剂量放射性稀土废渣为原料(含232Th,比活度5000～8000Bq/kg),用水泥、砂子、工业废渣(如:电石渣等)做20倍稀释后制成特种水泥产品,其放射性剂量符合GB6566-86放射卫生防护标准。试验结果表明:含有低放稀土废渣的水泥产品能有效降低污水的COD,COD的降解率随时间的延长而增加;在酸性介质条件下,含有低放稀土废渣的水泥产品对大肠杆菌的去除效果表现较好;分别在单独曝气、曝气加低放稀土废渣产品的条件下处理污水时,COD的下降值与时间的关系经计算机模拟符合Logistic模型,所得的两条“S”曲线表明曝气条件下再加低放稀土废渣产品对污水的处理有协同作用。

Low radioactive rare-earth waste(containing 232 Th,specific activity5000～8000Bq/kg)were diluted20times by cement,sand and carbide ash and were made into special cement.The radioactivi-ty of this special cement complied with the healthy protection standard for radioactive materials(GB6566-86).Test results showed that this special cement could lower COD,the degradation rate in-creased as time went on.In acidic medium,this special cement could remove E.Coli effectively.Ap-plying aeration and adding lumps of cement ,the degradation of COD versus time complied with Logis-tic model through fitting by computer.The two ″S″curves indicated that aeration adding lumps of ce-ment had synergistic action on sewage treatment.