| 摘要: |
| 随着中国地表水环境质量持续改善,沉积物正逐渐成为水库内源污染物的源或汇。为探究岩溶峡谷型水库沉积物磷的赋存形态分布、污染风险及迁移转化规律。选取典型岩溶区峡谷型水库万峰水库为研究对象,通过改进的连续浸取法提取沉积物磷赋存形态,分析沉积物磷形态分布特征及其污染水平。结果表明：(1)沉积物总磷含量为79.37~438.04 mg/kg,其中无机磷占比为73.26%~78.84%,是沉积物磷的主要赋存形态。各形态无机磷含量大小为：铁铝结合态无机磷＞钙结合态无机磷＞潜在活性无机磷＞弱吸附态无机磷,铁铝结合态无机磷是无机磷的主要赋存形态。各形态有机磷含量大小为：弱吸附态有机磷＞铁铝结合态有机磷＞钙结合态有机磷＞潜在活性有机磷,弱吸附态有机磷是有机磷的主要赋存形态。(2)沉积物生物有效性磷含量为66.97~201.46 mg/kg,占总磷的值为55.6%~59.6%,均高于55%,表明万峰水库沉积物可能具有较高的内源磷释放风险。(3)沉积物磷污染指数均值为0.53,生物有效性指数均值为0.81。沉积物磷污染整体处于轻度污染、安全水平,但仍存在内源磷污染风险,未来万峰水库在控制外源磷输入的同时应加强内源磷的管理。(4)残渣态磷、弱吸附态无机磷、钙结合态无机磷、潜在活性无机磷、铁铝结合态无机磷对总磷空间分异有极强的影响力,是空间分异的主要驱动力。沉积物的厚度对于总磷具有多重作用,与其他因素的共同作用显著。沉积物中无机磷相互转化极其显著,而有机磷的矿化能力相对较弱。 |
| 关键词: 沉积物 磷形态 污染评价 生物有效性磷 岩溶峡谷型水库 |
| DOI： |
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| 基金项目:贵州省科技计划项目（No.贵州科学合作支撑[2023]一般214）；贵州省省级科技计划项目（No. 黔科合基础 [2020]1Y252） |
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| Distribution of phosphorus forms and pollution evaluation in the sediments of karst canyon type reservoirs |
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Yang Liuying1, Jiao Shulin2,3,4,3, Wang Lei1, Li Yinjiu1, Wei Zongxiao1, Li Juan1
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1.School of Geography and Environmental Science/Karst Research Institute,Guizhou Normal University,Guiyang;2.School of Geography and Environmental Science/Karst Research Institute,Guizhou Normal University,Guiyang,;3.China;4.The State Key Laboratory Incubation Base for Karst Mountain Ecological Environment of Guizhou Province,Guiyang,
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| Abstract: |
| As the surface water quality in China continues to improve, sediments are gradually becoming the source or sink of pollutants in reservoirs. To investigate the distribution, pollution risk, and transformation of phosphorus in sediments of Karst Canyon reservoirs, the typical Wanfeng Reservoir was selected as the research object. The improved sequential extraction method was used to extract the forms of phosphorus in sediment, and the distribution characteristics and pollution levels of different forms of phosphorus were analyzed. The results showed that: (1) The TP content in the sediment ranged from 79.37 to 438.04 mg/kg, with IP accounting for 73.26% to 78.84%, the main form of P in the sediment. The order of IP content in different forms was Fe/Al-Pi＞Ca-Pi＞NaHCO3-Pi＞H2O-Pi, with Fe/Al-Pi being the main form. The order of OP content in different forms was H2O-Po＞Fe/Al-Po＞Ca-Po＞NaHCO3-Po, with H2O-Po being the main form of OP. (2) The content of BAP in sediments ranged from 66.97 to 201.46 mg/kg, accounting for 55.6% to 59.6% of the TP, which is higher than 55%, indicating that Wanfeng Reservoir sediments may have a high risk of internal phosphorus release. (3) The average value of the sediment phosphorus pollution index was 0.53, and the average value of the bioavailability index was 0.81. The overall phosphorus pollution in the sediment was at a mild pollution level and considered safe. However, there is still a risk of internal phosphorus pollution, so it is necessary to strengthen the management of internal phosphorus in Wanfeng Reservoir while controlling external phosphorus inputs in the future. (4) Res-P, H2O-Pi, Ca-Pi, NaHCO3-Pi, and Fe/Al-Pi strongly influence TP"s spatial variation and are the main driving forces behind spatial differentiation. The thickness of sediment has multiple effects on TP and significantly interacts with other factors. The transformation of IP in sediments is significant, while the mineralization ability of OP is relatively weak. |
| Key words: sediment phosphorus forms pollution evaluation bioavailable phosphorus Karst Canyon reservoirs |
