典型城市湖泊沉积物污染特征与清淤深度  

Pollution characteristics and dredging depth of the sediment in a typical urban lake

作　　者：侯晓辉 曹昕熹 刁艳芳 李桂荣 贾胜勇[2] HOU Xiaohui;CAO Xinxi;DIAO Yanfang;LI Guirong;JIA Shengyong(Henan Water&Power Engineering Consulting CO.,Ltd,Zhengzhou 450016,China;School of Ecology and Environment,Zhengzhou University,Zhengzhou 450001,China;School of Water Conservation Science and Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]河南省水利勘测设计研究有限公司,郑州450001 [2]郑州大学生态与环境学院,郑州450001 [3]郑州大学水利科学与工程学院,郑州450001

出　　处：《环境工程学报》2023年第12期3890-3896,共7页Chinese Journal of Environmental Engineering

基　　金：河南省重点研发与推广专项(科技攻关)(212102310071,232102320104,212102110112)。

摘　　要：城市湖泊外源污染阻断后,沉积物污染物向上覆水体扩散成为水质主要威胁,探明城市湖泊沉积物污染分布特征和来源是实现湖泊清淤的前提。以龙亭湖和包公湖沉积物为对象,分析了沉积物OM、TN和TP分布特征并进行源解析,基于有机指数和有机氮指数探讨了其清淤深度。结果表明,龙亭湖和包公湖表层(深度20~30 cm)沉积物污染严重且分布差异显著,OM (93.08~8.67 mg·g^(-1),120 cm深度变化)和TN (5.42~0.26 mg·g^(-1),40 cm深度变化)随深度显著降低,TP (1.04~0.55 mg·g^(-1),110 cm深度变化)纵向分布变化不显著。龙亭湖沉积物OM来源与取样位置相关,且沉积物形成早期存在大量外源OM输入(C/N>14);包公湖取样点OM以陆源输入占主导(C/N=5.008~52.808)。基于此,提出有机指数≥0.5或有机氮指数≥0.133的沉积物层及以上部分应清除,龙亭湖和包公湖所选点位最大清淤深度分别为100和70 cm,湖泊取样点底泥清淤削减量分别达到33.33%~100%和33.33%~53.84%。该研究结果对城市湖泊水质长效保持提供实践参考。When the external pollution of urban lakes is blocked,the sediment pollutants diffusion to the overlying water becomes a major threat to water quality.It is a prerequisite for lake dredging to clarify the vertical distribution characteristics and source of sediment pollutants.Longting Lake and Baogong Lake sediment were investigated in the present study,the vertical distribution of organic matter(OM),total nitrogen(TN)and total phosphorus(TP)were analyzed,and pollutant source analysis was conducted.Based on the organic index and organic nitrogen index,the dredging depth was further explored.The results showed that surface sediments(20~30 cm depth)of the two lakes were seriously polluted and represented significant differences in distribution.The concentration of OM(93.08~8.67 mg·g^(-1) varied in 120 cm depth sediment)and TN(5.42~0.26 mg·g^(-1) varied in 40 cm depth sediment)significantly decreased with the increase of depth,but the TP(1.04~0.55 mg·g^(-1) varied in 110 cm depth sediment)changed slightly.The OM source in Longting Lake sediment was mainly related to the location site,and a large amount of external OM input occurred in the early stage of sediment formation(C/N>14).The OM source in Baogong Lake sediment was mainly attributed to terrestrial input(C/N=5.008~52.808).The present study proposed that the sediment layers with an organic index≥0.5 or an organic nitrogen index≥0.133 should be removed.Relying on the results,the maximum dredging depth of the sampling points in Longting Lake and Baogong Lake was 100 and 70 cm,respectively.The reduction rates of sediment dredging at the sampling points reached 33.33%~100%and 33.33%~53.84%,respectively.This study has important practical significance for long-term maintenance of urban lake water quality.

关 键 词：湖泊沉积物 污染物纵向分布 上覆水体 污染物来源 清淤 

分 类 号：X52[环境科学与工程—环境工程]