Effect of eutrophication on the distribution of arsenic species in eutrophic and mesotrophic lakes.
Effect of eutrophication on the distribution of arsenic species in eutrophic and mesotrophic lakes.
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DOI：
10.1016/j.scitotenv.2008.10.024
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发表时间：
2009-02
期刊：
影响因子：
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通讯作者：
H. Hasegawa;M. Rahman;T. Matsuda;T. Kitahara;T. Maki;K. Ueda
中科院分区：
文献类型：
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作者：
H. Hasegawa;M. Rahman;T. Matsuda;T. Kitahara;T. Maki;K. Ueda
研究了富营养化对日本木场湖和琵琶湖砷形态的影响。采用氢化物发生-原子吸收光谱法结合紫外辐射法测定了砷的无机态、甲基态和紫外不稳定态。在这两个湖泊，无机物种（As（V+III））占主导地位的其他形式的砷全年。甲基胂中的主要成分为二甲基胂酸（DMAA），单甲基胂酸（MMAA）的含量低于检测限。对水柱中砷浓度的测量表明，大部分DMAA分布在真正溶解的部分（<10 kDa），而紫外线不稳定部分分布在颗粒（>0.45 µm）和胶体（10 kDa-0.45 µm）部分。富营养化千叶湖砷的形态随季节波动较大。在5 ~ 10月，随着DMAA浓度的增加，出现了紫外不稳定组分，而在1月，随着DMAA浓度的降低，紫外不稳定组分消失。在中营养型的琵琶湖，砷的紫外线不稳定的馏分没有影响到那些在富营养化的木叶湖。另一方面，琵琶湖的DMAA浓度高于木叶湖。研究结果表明，富营养化促进了复杂有机砷化合物的生物合成，自然沃茨中生物过程的平衡会影响砷的形态分布。
Effects of eutrophication on arsenic speciation were studied in eutrophic Lake Kiba and mesotrophic Lake Biwa, Japan. By combining hydride generation atomic absorption spectrometry with ultraviolet irradiation, inorganic, methyl and ultraviolet-labile fractions of arsenic were determined. In both Lakes, inorganic species (As(V+III)) dominated over other forms of arsenic all the year round. Most of methylarsenic fraction was dimethylarsinic acid (DMAA), and the concentration of monomethylarsonic acid (MMAA) was below the detection limit. Measurements of size-fractioned arsenic concentrations in water column indicate that most of the DMAA was distributed in truly dissolved fraction (<10 kDa), while ultraviolet-labile fractions were distributed in particulate (>0.45 µm) and colloidal (10 kDa–0.45 µm) fractions. Arsenic speciation in eutrophic Lake Kiba fluctuated greatly with season. The ultraviolet-labile fractions were observed with the increase of DMAA from May to October, and they disappeared with the decrease of DMAA in January. In mesotrophic Lake Biwa, the ultraviolet-labile fractions of arsenic were not influenced as much as those in eutrophic Lake Kiba. On the other hand DMAA concentration was higher in Lake Biwa compared to that in Lake Kiba. The results suggest that the biosynthesis of complex organoarsenicals was enhanced by eutrophication, and the arsenic speciation would be influenced by the balance of biological processes in natural waters.