海带浸泡液中碘离子的新型氧化工艺的研究

采用亚硝酸钠-过氧化氢混合氧化剂将海带浸泡液中的碘离子氧化为碘酸根离子，并以其为氧化剂进一步氧化海带浸泡液中的碘离子生成单质碘，达到回收碘的目的。研究了利用混合氧化剂制备碘酸根离子的反应条件，得到最佳反应条件为：100 mL的含碘量为498 mg/kg的海带浸泡液需要加入混合氧化剂的量分别为50 μL 8%（质量分数）亚硝酸钠溶液、150 μL 30%（质量分数）过氧化氢（过氧化氢与碘离子物质的量比为3.5∶1）。将制得的碘酸根离子作为氧化剂氧化碘离子，考察了pH、碘离子与碘酸根离子物质的量比、反应时间对海带浸泡液中碘离子氧化率的影响。结果表明，在pH为2.0、碘离子与碘酸根离子物质的量比为5∶1、反应时间为30 min的最优条件下，碘的氧化率为94.96%。

Study on new oxidation process for iodine ion in kelp soaking liquid

I- in the kelp soaking liquid was oxidized into IO3- by the mixed oxidant NaNO2-H2O2，and with the oxidant IO3- ，I-in the soaking liquid was further oxidized into elemental iodine，to achieve the purpose of recycling iodine. The reaction conditions of using mixed oxidant to prepare IO3-  were studied.The optimum reaction conditions were as follows: the dosage of mixed oxidant was 50 μL，8%（mass fraction） NaNO2 solution and 150 μL，30%（mass fraction） H2O2 （the amount-of-sub- stance ratio of H2O2 to I- is approximately 3.5∶1)，in 100 mL of kelp soaking liquid with the iodine content of 498 mg/kg.The obtained IO3- was as the oxidant to oxidize I-.The effects of pH，amount-of-substance ratio of I- to IO3-  and reaction time on I- conversation rate were investigated.Results showed that when the pH was 2.0，the amount-of-substance ratio of I- to IO3-  was 5∶1，and the reaction time was for 30 min，the iodine oxidation rate was 94.96%.