基于硝酸钠超临界水氧化技术处理磷酸三丁酯的实验研究

Experimental Study on the Treatment of Tributyl Phosphate by Supercritical Water Oxidation Technology Using Sodium Nitrate

放射性磷酸三丁酯是一种常见的放射性有机废物,其妥善处理对于核工业的可持续发展极为重要。采用连续式超临界水氧化设备,以硝酸钠为氧化剂对磷酸三丁酯的氧化分解进行了探究。结果表明:磷酸三丁酯降解产物无毒害物,气相产物为N_(2)、CO_(2),液相产物中含有NO_(3)^(-)、PO_(4)^(3-)及未反应的有机物,证实了以硝酸钠为氧化剂超临界水氧化技术处理磷酸三丁酯的可行性。通过对反应温度、反应压力、停留时间等因素对有机物去除率影响的研究,确定了磷酸三丁酯超临界水氧化反应的最优化反应条件:反应温度500℃、反应压力22.5 MPa、过氧系数1.5、停留时间55.7 s。在此条件下,有机物去除率达到95%以上。

Radioactive tributyl phosphate is a common radioactive organic waste,and its proper treatment is extremely important for the sustainable development of the nuclear industry.In this paper,the oxidative decomposition of tributyl phosphate was investigated using a continuous supercritical water oxidation plant with sodium nitrate as the oxidant.The results showed that the degradation products of tributyl phosphate were non-toxic,and the gas phase products were N_(2) and CO_(2),while the liquid phase products contained NO_(3)^(-),PO_(4)^(3-)and unreacted organic matter,which confirmed the feasibility of treating tributyl phosphate with sodium nitrate as the oxidant by supercritical water oxidation technology.By studying the effects of reaction temperature,reaction pressure and residence time on the removal rate of organic matter,the optimum reaction conditions for the supercritical water oxidation reaction of tributyl phosphate were determined as follows:reaction temperature 530℃,reaction pressure 22.5 MPa,peroxide coefficient 1.5 and residence time 55.7 s.The removal rate of organic matter reached 95%under above conditions.