| 浙北下渚湖湿地上覆水-底泥界面磷素特征与水质响应研究 |
| 摘要点击 1207 全文点击 1761 投稿时间：2008-07-10 修订日期：2008-09-05 |
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| 中文关键词 下渚湖湿地 磷素 底泥 上覆水 静态模拟 |
| 英文关键词 Xiazhuhu wetland phosphorus sediment overlying water static wetland microcosm |
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| 中文摘要 |
| 健康湿地是面源污染生态修复的有效途径.以浙北下渚湖湿地为研究对象,同步开展上覆水及底泥磷素野外调查;模拟湿地枯水季节设计微型静态湿地水柱试验,揭示上覆水-底泥界面磷素交换规律、磷库特征及其潜在水质响应机制.结果表明，下渚湖湿地底泥总磷(TP)含量范围为0.187～0.591 mg·g-1,属于中度富磷;全年水体TP浓度为0.022～0.718 mg·L-1;水体磷素,即TP、溶解性磷(DP)及颗粒磷(PP)浓度大小的季节性特征为冬季>夏季>春季>秋季.在上覆水磷素浓度梯度(0.0～10.5 mg·L-1)胁迫下,微型静态湿地水柱模拟表明，湿地底泥吸附上覆水磷素依次呈现缓冲吸附过程、快速吸附过程、及慢速吸附过程等3个特征性过程.在上覆水DP为1.0 mg·L-1的胁迫下,枯水季节湿地底泥磷库增量分配代表性比例分别为:弱结合态磷0.0%、铁/锰结合态磷(Fe-P)19.9%、碱可提取磷66.3%［其中铝结合态磷(Al-P)58.0%;碱可提取有机磷(OPAlk)8.3%］、钙结合态磷(Ca-P)1.9%及闭蓄态磷(Res-P)11.3%.在枯水期可以通过补充铝盐的技术手段增加下渚湖湿地底泥对水体磷素的净化容量. |
| 英文摘要 |
| Healthy wetland system is regarded as an effective way for biological remediation of non-point source pollutants. A case field investigation on phosphorus (P) status of overlying water and sediment was carried out for Xiazhuhu wetland located in Northern Zhejiang Province, China. A static wetland microcosm experiment was conducted to understand the characteristics and mechanisms related to P exchanging, P forms changing, and water quality impact across the interface of water and sediment. Field investigation showed that total P (TP) concentrations of sediments were found from 0.187 mg·g-1 to 0.591 mg·g-1, and TP in overlying water reached from 0.022 mg·L-1 to 0.718 mg·L-1 where the seasonal concentration variations of TP, dissolved P (DP), and particulate P (PP) were commonly found in order as winter>summer>spring>fall. Fed by synthetic solution containing P levels of 0.0～10.5 mg·L-1, a 35-day-lasting microcosm study showed that P retention by sediments could be divided into three basic phases in order, i.e., buffer reaction, rapid adsorption, and slow adsorption. Under a typical stress concentration of 1.0 mg·L-1 in overlying water, the increment of P tanks in different forms was found as NH4Cl-P (0.0%), Fe-P/Mn-P (around 20%), NaOH-TP (around 66%, mainly as the form of Al-P), Ca-P (1.9%), and Res-P (11.3%), on the condition of Xiazhuhu wetland under low water season. Application of Al to wetland would increase the capacity of sediment P retention in Xiazhuhu wetland. |
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