芬顿法和微波协同芬顿法在放射性TBP/OK废液处理中的对比分析

Comparison of Fenton Method and Microwave Synergistic Fenton Method in Radioactive TBP/OK Waste Liquid Treatment

铀提纯和乏燃料后处理过程中会产生放射性磷酸三丁酯(TBP)/煤油(OK)有机废液,为了避免因放射性有机废液常年累积而造成的安全隐患,亟需对其进行处理。分别研究了传统芬顿法和微波协同芬顿法对模拟放射性TBP/OK废液的处理效果,以及芬顿试剂的ρ(Fe^(2+))/ρ(H_(2)O_(2))、ρ(Fe^(2+))、初始pH和氧化时间等因素对化学需氧量(COD)去除率的影响程度。结果表明:单一芬顿法最佳的工艺条件为ρ(Fe^(2+))=20 mg/L,ρ(Fe^(2+))/ρ(H_(2)O_(2))=1∶10,初始pH=1.90,氧化时间=15 min,TBP/OK的COD去除率最高可以达到72.01%;其中,对COD去除率影响最大的因素为ρ(Fe^(2+))/ρ(H_(2)O_(2)),后依次为ρ(Fe^(2+))、初始pH和氧化时间;当同处于最佳反应条件下,微波协同芬顿法处理模拟放射性TBP/OK的效果优于传统加热+芬顿的方法,更优于单一芬顿法;在微波协同作用下,芬顿体系的COD去除率能够提升至95.80%,芬顿试剂的用量也从ρ(Fe^(2+))=20 mg/L、ρ(H_(2)O_(2))=200 mg/L降低至ρ(Fe^(2+))=10 mg/L、ρ(H_(2)O_(2))=100 mg/L。由此可见,微波的协同作用不仅进一步提高了芬顿氧化的效率,而且降低了芬顿试剂的用量。

Radioactive TBP/kerosene(OK)organic waste liquid is produced in the process of uranium purification and spent fuel retreatment.In order to avoid the safety risks caused by the accumulation of radioactive organic waste liquid over the years,it is urgent to treat it.In this paper,the conventional Fenton oxidation method and microwave synergistic Fenton method were used to treat simulated radioactive TBP/OK waste liquid,and the effects of mass fraction of Fenton’s reagentρ(Fe^(2+))andρ(H_(2)O_(2)),initial pH and oxidation time(t)on the removal of chemical oxygen demand(COD)was experimentally investigated.The results of the conventional Fenton oxidation method show that:at the optimal process conditions,ρ(Fe^(2+))=20 mg/L,ρ(Fe^(2+))/ρ(H_(2)O_(2))=1∶10,initial pH=1.90,t=15 min,the COD removal can reach up to72.01%;the most important factor is the ratio ofρ(Fe^(2+))/ρ(H_(2)O_(2)),followed byρ(Fe^(2+)),initial pH,and oxidation time.The microwave synergistic Fenton method is superior to the conventional heating Fenton method,and even better than the conventional Fenton oxidation method,when under the same optimal reaction conditions.As for the microwave synergistic Fenton method,the COD removal can be increased to95.80%.The dosage of Fenton reagent is also reduced fromρ(Fe^(2+))=20 mg/L,ρ(H_(2)O_(2))=200 mg/L toρ(Fe^(2+))=10 mg/L,ρ(H_(2)O_(2))=100 mg/L.It can be seen that the microwave synergistic Fenton method not only further improves the COD removal,but also reduces the dosage of Fenton reagent.