外源废水输入对福州东湖湿地水体污染元素浓度和分布特征的影响

Effects of External Wastewater Input on the Concentration and Distribution Characteristics of Polluting Element in Fuzhou Donghu Wetland Water Body

滨海湿地作为一种特殊的湿地类型,对人类活动和环境污染响应十分敏感。近年来,外源废水输入导致滨海湿地水体污染严重,对生态环境和人类健康产生威胁。该研究以福州东湖湿地为研究对象,分析上游径流、生活污水、工业废水、养殖塘废水、退塘还湿以及天然湿地等外源水输入对福州东湖水体Cr、Cu、Zn、As、Pb和Mn浓度及分布特征的影响,并对养殖塘水体与沉积物中污染元素浓度进行分析和生态风险评估。研究结果表明,福州东湖湿地水体中Cr、Cu、Zn、As、Pb、Mn的质量浓度分别为(0.50±0.20)、(3.87±1.54)、(34.48±1.71)、(4.72±0.48)、(0.77±0.38)、(151.96±58.81)μg/L,各污染元素浓度符合地表水Ⅱ类水标准。工业废水和养殖塘废水输入是福州东湖水体中污染元素的主要来源,其中工业废水的Mn浓度、养殖塘废水的Cr、Cu、Pb和Mn浓度较高。由于养殖饵料与消毒剂的添加,部分养殖塘沉积物Cr和Mn存在轻度或偏中度污染,呈现轻度生态风险。为防止水质进一步恶化,应改良工业废水处理设施,优化农业养殖模式,控制周边地区污染源。

As a special type of wetland,coastal wetland is sensitive to human activities and environmental pollution.In recent years,the input of external wastewater has caused serious water pollution in coastal wetland water,posing a threat to the ecological environment and human health.This study takes the Fuzhou Donghu Wetland as the research object.We analyze the influence of upstream runoff,domestic wastewater,industrial wastewater,aquaculture ponds wastewater,returning ponds to wetland areas and natural wetland areas on the content and distribution characteristics of Cr,Cu,Zn,As,Pb and Mn in the Fuzhou Donghu Wetland water body,and conduct ecological risk assessment of the typical polluting elements content of the aquaculture pond water and sediments.The results of the study showed that the concentrations of Cr,Cu,Zn,As,Pb and Mn in the Fuzhou Donghu wetland water body are(0.50±0.20),(3.87±1.54),(34.48±1.71),(4.72±0.48),(0.77±0.38),(151.96±58.81) μg/L,respectively.The concentration of each metal meets the surface water Class Ⅱ water standard.The input of industrial wastewater and aquaculture ponds wastewater are the main source of polluting elements in the Fuzhou Donghu.The concentration of Mn in industrial wastewater and the concentration of Cr,Cu,Pb and Mn in aquaculture ponds wastewater are relatively high.The contents of Cr and Mn in the sediments in some aquaculture ponds are slightly or moderately polluted,and present a slight ecological risk,caused by the addition of breeding bait and disinfectant.In order to prevent further deterioration of water quality,some measures should be taken to improve industrial wastewater treatment facilities and agricultural breeding models,to control the pollution sources in the surrounding areas.