酪氨酸氯化过程中光谱变化特征及消毒副产物的生成规律

考察酪氨酸在不同投氯量条件下氯化后的余氯,紫外吸光度值和荧光光谱,以及消毒副产物对羟基苯乙腈(4-HBC)的生成特性。结果表明,随着投氯量的增加,余氯呈现先增加再减小再增加的趋势。在投氯量为0～0.5 mmolCl2/L时,增加投氯量可提高氯化后溶液的UV254、UV274和UV280值以及4-HBC的生成量,表明低投氯量时氯化可提高溶液中不饱和键的含量;而投氯量为0.5～1 mmol Cl2/L时,增加投氯量降低UV254、UV274和UV280值以及4-HBC的生成量,表明过量的氯亦可破坏溶液中的不饱和键。荧光光谱测试实验亦发现:在投氯量为0.05 mmol Cl2/L时,酪氨酸溶液氯化后的荧光峰强度明显增加,表明氯化可生成荧光强度较高的产物。过量的氯(0.5～1 mmol Cl2/L)则可破坏溶液中的荧光结构,降低荧光峰强度直至未检出。

Spectrum changes and disinfection by-product formation during chlorination of tyrosine

The changes of residual chlorine,UV absorbance values,fluorescence spectrum and 4-hydroxybenzyl cyanide(4-HBC) concentration after chlorination of tyrosine solution were investigated.The results showed that residual chlorine firstly increased with increasing chlorine doses,then decreased with increasing chlorine doses,and finally increased again.The values of UV254,UV274,UV280 and formation of 4-HBC increased with increasing chlorine doses from 0 to 0.5 mmol Cl2/L,and then decreased sharply with increasing chlorine doses from 0.5～1 mmol Cl2/L.The changes of UV absorbance values suggested that low dose of chlorine induced formation of unsaturated bonds in chlorinated tyrosine solution,while high dose of chlorine decreased the unsaturated bonds.By measuring fluorescent spectroscopy of chlorinated tyrosine,fluorescence intensity of the band maximum was found to increase sharply with the addition of sodium chlorine at 0.05 mmol Cl2/L,indicating that chlorination with low doses can produce substances with stronger fluorescence intensity than tyrosine.However,the fluorescence intensity decreased to non-detected with the increase of chlorine doses from 0.5～1 mmol Cl2/L,suggesting that chlorine at high doses would decrease the fluorescent structure of tyrosine.