低污染水生态净化组合技术应用

为有效提升低污染水体环境质量,采用生态净化组合技术,通过对环境基底改造、水质生物强化、水生植物恢复、水景观构建等处理技术的集成与优化,构建以活水为基础、以生态净化为核心、兼顾景观提升的低污染水体水环境组合整治系统. 结果表明,该组合技术成功恢复大型水生植物18种,水生植物覆盖率达90%,形成由挺水植物、浮水植物和沉水植物组成的良性水生态系统. 组合生态净化工程实施后,底泥pH由6.80~7.60升至7.30~7.90,E_h(氧化还原电位)由-210~-150 mV升至-62~31 mV,底质生境得到显著改善；水体透明度由15~35 cm显著升至83~145 cm,下层水体ρ(DO)由0.48~1.03 mg/L升至3.43~15.61 mg/L,ρ(TN)、ρ(NH₃-N)和ρ(TP)的削减率分别达到76%、85%和92%；水体浮游植物总数和总生物量分别减少了84.0%和90.6%,浮游植物群丛类型由富营养蓝藻(平裂藻)型转变为中-富营养混合型. 因此,水生态净化组合技术可有效净化低污染水的同时,还可提高水生态系统多样性. 

Applied Research on Combined Technique for Ecological Purification of Lightly Polluted River

To improve the quality of a water environment, a combined technique for ecological purification including polluted sediment restoration, water quality bio-fortification, macrophyte reestablishment and water landscape construction was used to treat lightly polluted water. A comprehensive water environment improvement project centered on ecological purification combined with high landscape promotion was conducted with running water. The results showed that the integrated technique successfully reestablished 18 species of macrophytes. The rate of macrophyte coverage reached 90%, forming a healthy water ecosystem with different plants such as emergent plants, floating-leaved plants and submerged plants. The pH and E_h of the sediments were enhanced from 6.8-7.6 to 7.3-7.9 and-210--150 mV to-62-+31 mV, respectively. The results indicated that the sediments were significantly improved by the use of the technique. The water transparency increased from 15-35 cm to 83-145 cm, and the ρ(DO) of the bottom water increased from 0.48-1.03 mg/L to 3.43-15.61 mg/L. Meanwhile, the removal rates of TN, NH₃-N and TP reached 76%, 85% and 92%, respectively. The quantity and biomass of phytoplankton decreased by 84.0% and 90.6%, respectively, and the association type changed from eutrophic-cyanophyta (Merismopedia) type to meso-eutrophic-mixed type. Thus, the combined ecological purification technique not only had a high effect in treating a lightly polluted river, but also increased the biodiversity of the water ecosystem.