近海CDOM光反应变化及SPM对其影响的研究

Photoreaction Changes of CDOM in Offshore and Study on Effects of SPM on Photoreaction

对经0.22 mm PES滤膜的东海海水进行长达126 h的紫外照射实验,研究有色溶解有机物(CDOM)的光化学反应特征。结果表明在紫外照射下,类色氨酸组分发生明显降解,而类酪氨酸组分则逐渐增多,光反应过程均符合一级动力学方程,反应速率分别为-0.011和0.019。悬浮颗粒物(SPM)是海水的重要组成部分,文章首次报道并量化东海海域海水在不同SPM含量下CDOM光化学反应中荧光性质的变化。实验表明SPM对类色氨酸光化学降解有显著阻碍作用,且在0~150 mg/L范围内SPM浓度越高类色氨酸光降解速率越慢。但SPM对类酪氨酸的影响较为复杂,在100 mg/L及以下时,SPM对类酪氨酸荧光增加有促进作用,而当含量为150 mg/L时,SPM会抑制类酪氨酸荧光增加。

The photochemical reaction characteristics of colored dissolved organic matter(CDOM)were studied by 126 h UV irradiation on the East China Sea water filtered through 0.22 mm PES membrane.The results showed that under the ultraviolet irradiation,the tryptophan-like component was obviously degraded while the tyrosine-like component was gradually increased.The photoreaction process accorded with the first-order kinetic equation,and the reaction rates were-0.011 and 0.019 respectively.Suspended particulate matter(SPM)is an important component of seawater.The article first reported and quantified the changes in fluorescence properties of seawater in the East China Sea at different SPM levels.Experiments show that SPM has a significant inhibitory effect on the photochemical degradation of tryptophan-like,and the higher the SPM concentration in the range of 0-150 mg/L,the slower the gradation rate of tryptophan-like.However,the effect of SPM on tyrosine-like is more complicated.At 100 mg/L and below,SPM can promote the increase of tyrosine-like fluorescence,while when it is 150 mg/L,SPM inhibits the increase of tyrosine-like fluorescence.