| 引用本文: | 秦文凯,李一平,杜观超,陈红卫,高旭,李峰东,朱立琴.表面流湿地沉积物再悬浮及其对湿地净化效果的影响.湖泊科学,2019,31(6):1570-1581. DOI:10.18307/2019.0613 |
| QIN Wenkai,LI Yiping,DU Guanchao,CHEN Hongwei,GAO Xu,LI Fengdong,ZHU Liqin.The effect of surface sediment resuspension on constructed wetland purification. J. Lake Sci.2019,31(6):1570-1581. DOI:10.18307/2019.0613 |
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| 表面流湿地沉积物再悬浮及其对湿地净化效果的影响 |
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秦文凯1, 李一平1, 杜观超2, 陈红卫3, 高旭2, 李峰东2, 朱立琴4
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1.河海大学环境学院, 南京 210098;2.盐城市盐龙湖饮用水源管理处, 盐城 224014;3.盐城市节约用水办公室, 盐城 224001;4.河海大学马克思主义学院, 南京 210098
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| 摘要: |
| 选取典型表面流人工湿地——盐龙湖人工湿地为研究对象，通过对沉积物理化性质分析，湿地系统水动力模拟，风场与悬浮物（SS）再悬浮浓度关系的拟合及全年再悬浮对湿地净化效果的影响估算，探索表面流湿地沉积物在动力条件下的再悬浮特征及此过程中营养物质的再悬浮量.结果显示：0.3~0.5 m水深沉积物的理论起动流速在18.54~22.62 cm/s之间，模拟得到湿地运行过程中水体流速最大值为1.62 cm/s，会远小于理论起动流速值，因此湿地内部流动产生的底部扰动难以形成湿地底泥的大规模再悬浮现象.但湿地内部仍存在一定的底泥再悬浮效应，风场扰动是主要影响因素，风场作用受植物影响显著，萌发期（3-4月）和收割期（11月-次年2月）再悬浮贡献量大于生长期（5-8月）与成熟期（9-10月），并且当风速>4 m/s时再悬浮浓度明显增加.再悬浮浓度与运行水深也有关，0.3 m水深SS再悬浮浓度分别高出0.4 m和0.5 m水深12.48%和18.67%；高锰酸盐指数（CODMn）分别高出12.61%和19.52%；总氮（TN）分别高出248.12%和341.94%；总磷（TP）分别高出35.53%和43.48%.全年SS、CODMn、TN和TP再悬浮量分别达到2.8、0.47、0.15和0.011 kg/m2. |
| 关键词: 人工湿地 沉积物再悬浮 起动流速 扰动 营养物质释放 盐龙湖 |
| DOI：10.18307/2019.0613 |
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| 基金项目:国家重点基础研发计划（2017YFC0405203）、国家自然科学基金项目（51879082）和中央高校基本科研业务费专项资金（2018B48214，2017B20514）联合资助. |
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| The effect of surface sediment resuspension on constructed wetland purification |
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QIN Wenkai1, LI Yiping1, DU Guanchao2, CHEN Hongwei3, GAO Xu2, LI Fengdong2, ZHU Liqin4
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1.College of Environment, Hohai University, Nanjing 210098, P. R. China;2.Yancheng Yanlong Lake Drinking Water Source Management Office, Yancheng 224014, P. R. China;3.Yancheng City Water Conservation Office, Yancheng 224001, P. R. China;4.School of Marxism, Hohai University, Nanjing 210098, P. R. China
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| Abstract: |
| This paper chose the typical surface flow constructed wetland of Lake Yanlong as study site. Through analysis of sedimentary physical properties, the hydrodynamic simulation of wetland system, the relationship between wind and resuspension, the estimation of resuspension of sediments throughout the year, this paper explored the resuspension characteristics of surface wetland sediments under dynamic conditions and the amount of nutrients resuspended in the process. Results show that the incipient velocity is between 18.54 and 22.62 cm/s within the depth of 0.3-0.5 m, but the maximum flow rate of water in and out of the actual wetland operation is 1.62 cm/s. It is much smaller than the incipient velocity. Therefore, the bottom disturbance caused by the internal flow of the wetland is difficult to form a large-scale resuspension. However, there is still a sediment resuspension effect inside the wetland. Wind field are the main influencing factors, while the wind is significantly affected by plants. The resuspension contribution during the plant germination period (Mar.-Apr.) and harvesting period (Nov. to the next Feb.) is significantly greater than the growth period (May-Aug.) and maturity period (Sep.-Oct.). When the wind speed is >4 m/s, the amount of resuspension (AR) increases obviously. The AR is also related to the water depth. The AR of 0.3 m water depth is higher than the AR of 0.4 m and 0.5 m with 12.48% and 18.67%, respectively; chemical oxygen demand (CODMn) is higher than 12.61% and 19.52%; total nitrogen (TN) is higher than 248.12% and 341.94%; total phosphorus (TP) is higher than 35.53% and 43.48%. The annual nutrient resuspension contribution was 2.8 kg/m2 for SS,~0.47 kg/m2 for CODMn,~0.15 kg/m2 for TN, and~0.011 kg/m2 for TP. |
| Key words: Constructed wetland sediment resuspension incipient velocity disturbance nutrient release Yanlong Lake |
