| 河流汇合处水体磷素形态特征及紫外光照的影响：以渠江-嘉陵江、涪江-嘉陵江交汇为例 |
| 摘要点击 1698 全文点击 1151 投稿时间：2014-05-09 修订日期：2014-07-18 |
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| 中文关键词 磷素形态 相对分子质量分级 紫外光照 河流 交汇 |
| 英文关键词 phosphorus forms relative molecular weight fractionation UV irradiation river confluence |
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| 中文摘要 |
| 以渠江-嘉陵江、涪江-嘉陵江交汇处水体为研究对象，探究了河流交汇处水体磷素形态特征及紫外光照的影响. 水体磷形态分析结果表明，研究的所有水体中总磷浓度均超过水体富营养化阈值（0.2 mmol·m-3），支流汇入干流前后，研究水体中总磷（TP）主要由总溶解性磷（TDP）组成，而溶解性无机磷（DIP）是TDP的主要组成部分. 两支流汇入嘉陵江后，干流水体中各形态磷浓度均较干流汇合前升高，颗粒态磷（PP）增幅最大，达到129%. 按水体相对分子质量（Mr）分级结果表明，溶解态高相对分子质量组分（0.5×103~10×103）中的磷为溶解性磷（DP，<0.22 μm）主要成分，达到47%~61%，渠江和涪江两支流汇入干流后，嘉陵江水体不同相对分子质量组分中的磷含量并未发生较大变化. 通过紫外光照后，游离态组分（<0.5×103 ）中的磷含量明显增加，增幅在10%~29%，其余两组分中磷含量均降低，和涪江-嘉陵江汇合处样本相比，渠江-嘉陵江汇合处水体胶体态组分（Mr 10×103~0.22 μm）中磷含量降幅大于前者. 通过紫外光照实验，证明了紫外光照是影响水体中磷素地球化学过程的重要环境因素. |
| 英文摘要 |
| The confluences water of Qujiang-Jialing River and Fujiang-Jialing River was investigated in this paper for understanding the characteristics of phosphorus (P) forms and the effects of ultraviolet (UV) irradiation. Through analysis of P speciation, the results showed that the concentration of total P was above the Eutrophication threshold (0.2 mmol·m-3) in this study. Meanwhile, total dissolved P (TDP) and dissolved inorganic P (DIP) were the predominant forms of total P (TP) and TDP respectively at all sampling sites, which was independent of confluences. After confluences of Fujiang-Jialing River and Qujiang-Jialing River, the concentration of all forms of P in main stream increased, among which particulate P (PP) showed the greatest increase of up to 129%. Furthermore, water was fractionated by relative molecular weight (Mr) of composition, and the results showed the predominant forms of dissolved P (DP,<0.22 μm) was in the soluble high Mr fraction (0.5×103-10×103), which was ranged from 47%-61% of DP. After confluences, no significant changes of P contents in different Mr fraction of water were observed in the main stream (Jialing River). Moreover, UV irradiation experiment was conducted, and it suggested that P in free forms of water (<0.5×103) increased by 10%-29%, as compared with the decreasing P in the other two Mr fractions of Mr 10×103-0.22 μm and 0.5×103-10×103. Additionally, in comparison with confluence site samples of Fujiang-Jialing River, the decreasing trend of P in colloid fraction (10×103-0.22 μm) was higher in Qujiang-Jialing River. Thus, it confirmatively indicated that UV was an important environmental factor influencing the geochemical fate of P in aquatic system. |
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