新疆奎屯地区高砷地下水DOM三维荧光特征

新疆奎屯地区是中国大陆第一个地方性砷（As）中毒病区，为了解析该地区高As地下水中溶解性有机物（DOM）的组分和来源，探索其在As迁移转化过程中的作用，利用三维荧光光谱结合平行因子分析法对奎屯地区水样进行研究.结果表明：该地区地下水As含量范围在1.30~400.68μg/L，平均值为61.18μg/L，有68.99%的地下水为高As地下水.地下水中DOM含有3种组分：类腐殖质C1（260（325） nm/425nm），占2.78%；类色氨酸C2（275nm/350nm），占18.74%；微生物源的还原性醌类C3（260（375） nm/475nm），占54.12%.研究区水体DOM的荧光指数在1.2~1.52之间，均值为1.36，水中DOM以陆源为主.该地区地下水整体呈现还原-弱碱性环境，地下水中As的释放过程主要有铁氧化物矿物还原和脱硫酸作用，水中的DOM参与了铁、硫酸盐的还原反应过程，类色氨酸C2主要在微生物呼吸过程中充当电子供体角色，还原性醌类C3担任了电子飞行过程中的电子穿梭体，增强了As从含水层沉积物中释放到地下水的迁移性能.

The 3D-EEM characteristics of DOM in high arsenic groundwater of Kuitun,Xinjiang

Kuitun area in Xinjiang is the firstly reported endemic arsenic poisoning area in mainland China. Based on 3D-EEM and parallel factor analysis (PARAFAC) for high arsenic groundwater samples collected from Kuitun Xinjiang, the role of arsenic migration and transformation dissolved organic matter (DOM) characteristics and sources in the area was explored. The results indicated that the arsenic content of groundwater was in the range of 1.30~400.68μg/L, with an average of 61.18μg/L, and high arsenic groundwater accounted for 68.99% among all the samples. Three fluorescence components in the groundwater were identified as DOM including humic-like components C1 (260(325)nm/425nm),the microbial tryptophan C2 (275nm/350nm), and a humic-like (microbial reduced quinones) component C3 (260(375)nm/475nm), accounting for 2.78%, 18.74% and 54.12% respectively. The DOM fluorescence index of the water in Kuitun area was between 1.2~1.52, with a mean of 1.36, the DOM was mainly generated from terrestrial sources. The groundwater is weak alkaline-reduced environment. The release process of arsenic in groundwater is mainly the reduction of iron oxide minerals and desulfurization acid. DOM in water is involved in the reduction reaction process of iron and sulfate. The microbial tryptophan C2 acts as an electron donor during microbial respiration. The microbial reduced quinones C3 acts as an electron shuttle in the process of electron flight, enhancing the arsenic migration properties from aquifer deposits to groundwater.