| 摘要: |
| 我国南方重金属超标水灌溉已成为农田生态系统重金属输入最主要来源。【目的】从源头治理农田灌溉水的重金属Cd污染。【方法】选取梭鱼草、狐尾藻、轮叶黑藻共3种湿地植物作为材料，构建了沉砂池+生态塘+表面流湿地+吸附池系统，探究了系统底泥含Cd量及有机质量的变化与3种湿地植物体内的Cd质量浓度变化趋势及富集转运系数。【结果】①该湿地系统底泥中含Cd量随水流方向呈现递减趋势，各个采样点Cd质量浓度随时间推移而增加，底泥中含Cd量变化范围为1.15~38.58 mg/kg。②底泥有机质量随水流沿程呈缓慢下降趋势，下降幅度最高为13.9 g/kg。3种湿地植物中，梭鱼草地下部含Cd量较高，最高达125.88 mg/kg，地上部最高达9.16 mg/kg，狐尾藻、轮叶黑藻体内质量浓度最高分别达到32.55、6.94 mg/kg。③梭鱼草的富集与转运系数范围分别为8.24~34.96、0.036~0.176，说明梭鱼草中大部分Cd固定于根部，向上转运较少。【结论】3种植物中梭鱼草具有较高的农田灌溉水中Cd净化潜力。 |
| 关键词: 生态塘； 有机质； 镉； 湿地植物； 富集系数； 转运系数； 人工湿地 |
| DOI：10.13522/j.cnki.ggps.2019023 |
| 分类号: |
| 基金项目: |
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| Effect of Plant Pond and Constructed Wetland System on Irrigation Water Purification and Rice Cadmium Control |
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LIU Shoutao, YANG Ruijia, HE Zhongxiang, PENG Ou,LIU Yuling, DONG Sijun, PENG Jing, LIU Xiaoli, TIE Baiqing
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1. College of Resources and Environment of Hunan Agricultural University, Changsha 410128, China; 2. The Engineering Technology Research Center of Water Pollution Purification of Irrigation Water Source, Changsha 410128, China; 3. Key Laboratory of Southern Original Agro-environmental Pollution Prevention and Control, Ministry of Agriculture, Changsha 410128, China)
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| Abstract: |
| Irrigation of heavy metals exceeding water in southern China has become the most important source of heavy metal input in farmland. 【Objective】It has great practical to control heavy metal Cd pollution from irrigation water in southern China. 【Method】In this study, three wetland plants, barracuda, Myriophyllum sp., and Hydrilla verticillata, were used to build a grit chamber + ecological pond + surface flow wetland + adsorption pool system to explore the changes of Cd content and organic matter in the sediment of the wetland systems. The trend of Cd concentration in plant tissues and the BF, TF coefficient were also studied. 【Result】The Cd content in the sediment of the wetland system had a decreasing trend with the flow direction. The concentration of Cd at each sampling sites increased with sampling over time, and the Cd content in the sediment ranged from 1.15 to 38.58 mg/kg. The organic matter content of the sediment gradually decreased with the flow direction and the highest decrease was 13.9 g/kg. Among the three wetland plants, the highest Cd content in the belowground and aboveground parts of the barracuda was 125.88 mg/kg and 9.16 mg/kg. The highest concentrations in the foxtail algae and Hydrilla verticillata reached 32.55 mg/kg, 6.94 mg/kg, respectively.The BF and TF coefficient of Barracuda were 8.24~34.96 and 0.036~0.176, respectively, indicating that most of the Cd in the barracuda was accumulated at roots rather than transport. 【Conclusion】Among the three plants, the barracuda has high Cd purification potential in farmland irrigation water. The research results can provide data support for Cd polluted irrigation water purification in southern China. |
| Key words: Ecological pond; organic matter; cadmium; wetland plant; enrichment factor; transport coefficient; constructed wetland |
