Treatment Of Simulated Radioactive Waste Water Containing Iodine,Cesium And Strontium By Reverse Osmosis

In recent years,with the increasing depletion of traditional energy and the increasingly serious problem of environmental pollution,in order to meet their own development needs,countries around the world attach great importance to the development and utilization of new energy represented by nuclear energy.However,the development of nuclear power has brought a lot of clean energy,at the same time,several nuclear accidents have also brought great disasters to human beings and the environment.Radioactive iodine,cesium and strontium were detected in these nuclear accidents,especially in the water environment after the Fukushima nuclear accident in Japan.Therefore,the removal of radionuclides from water is one of the hot issues in the field of environment in recent years.A preliminary study on the removal of iodine,cesium and strontium from simulated radioactive wastewater by reverse osmosis?RO?technology was carried out.The removal efficiencies of iodine,cesium and strontium were investigated by changing the operating time,inlet pressure,initial concentration of radionuclides in the raw water and concentration of coexisting ions Cl^-,SO₄^2-,Ca²⁺,Mg²⁺,and the change of pH value were analyzed.The experimental results showed that the concentration of iodine,cesium and strontium in the water produced by RO film was basically constant during continuous operation,and didn't change greatly with the operation time.In addition,the decontamination factors?DF?of iodine,cesium and strontium were positively correlated with inlet pressure in the study range.When inlet pressure was between0.70 to 0.80 MPa and initial concentration of iodine ion was about 15.0 mg/L,its DF value could reach 916.In the same pressure range,when the initial concentration of strontium and cesium ion was about 5.00 mg/L,the DF value of strontium could reach5413,while that of cesium was only 45.At the same time,it was found that the initial concentration of nuclides in raw water was positively correlated with DF.When inlet pressure was between 0.45 to 0.50 MPa and the initial concentration of iodine increased from 1.21 mg/L to 15.2 mg/L,the DF value increased by 0.28 times,and when the initial concentration of strontium increased from 1.21 mg/L to 15.2 mg/L,the DF value increased by 2.19 times.The co-existing ions in raw water had a negative effect on the removal of radionuclides.Cl^-had a higher effect on the removal of iodine than SO₄^2-,and Ca²⁺had a higher effect on the removal of strontium than Mg²⁺.Therefore,salt should be avoided from entering the raw water in practical engineering.Finally,the pH values in the water treated by RO process were above6.10 and below 7.00,showing weak acidity.In conclusion,RO membrane had good application potential in removal of iodine and strontium,but poor in removal of cesium.