摘要
Abstract
[Objective]This paper aims to investigate the mechanism by which submerged plant coverage improves water quality.[Methods]Targeting Jincheng Lake 4#,the"Daphnia magna-guided underwater ecological restoration technology"was applied to reconstruct the aquatic ecosystem.Key measures included pretreatment at water replenishment points,sediment activation and improvement,introduction of Daphnia magna,establishment of submerged plant communities and aquatic animal communities.After implementation,a one-year dynamic monitoring program was conducted.Three sampling points(inlet,mid-lake,outlet)were set to measure total nitrogen(TN),total phosphorus(TP),chemical oxygen demand(COD),ammonia nitrogen,chlorophyll-a(Chla),and secchi depth(SD).Correlations between these parameters and submerged plant coverage were analyzed.[Results]Submerged plant coverage demonstrated a significant positive correlation with water quality improvement.As coverage increased,TN,TP,COD,and ammonia nitrogen concentrations decreased from 3.64 mg/L,0.42 mg/L,64 mg/L,and 2.850 mg/L to 0.92 mg/L,0.03 mg/L,16 mg/L,and 0.052 mg/L,respectively,achieving removal rates from 74.7%to 98.2%.TN,TP,COD,and ammonia nitrogen water quality stabilized at class Ⅲ standards of Environmental Quality Standards for Surface Water(GB 3838-2002)when coverage reached 90%.Water SD showed a significant negative correlation with Chla.As Daphnia magna biomass increased,Chla levels rapidly declined,enhancing transparency and providing optimal light conditions for submerged plant growth,thereby promoting higher coverage.[Conclusion]Restoring submerged plant coverage is central to ecological rehabilitation in artificial lakes.Coverage≥90%ensures water SD≥2.5 m and stable water quality indicators such as TN,TP,COD,ammonia nitrogen can meet class Ⅲstandards.关键词
水生态系统构建/人工湖/沉水植物覆盖度/食藻虫/水质净化Key words
water ecosystems construction/artificial Lake/coverage of submerged plant/Daphnia magna/water purification分类
环境科学
