大型溞-苦草配合处理富营养化水体的研究

生态修复实践中两种以上生物联合处理富营养化水体的技术受到广泛关注。以大型溞(Daphnia magna)、苦草(Vallisneria natans)为浮游动物、沉水植物代表,建立溞-草配合处理系统,以苦草处理为对照组,富营养化水体为空白组,研究处理过程中水质指标、底泥指标、水草生物量变化。结果表明,溞-草系统水和底泥质量指标优于苦草组,水体总氮、总磷、氨氮最终去除率分别为87%、88%、96%,最大去除率分别为70%、70%、86%;底泥总氮去除率39%,总磷去除率38%,27 d即水清见底,苦草生长率达740%。而对照组水体总氮、总磷、氨氮最终去除率分别为35%、33%、57%,最大去除率分别为35%、30%、57%,底泥总氮去除率40%,总磷去除率32%,48 d内未见底,苦草生长率为470%。因此,大型溞促进悬浮物沉降、有利于苦草生长以及稳定系统,溞-草系统配合处理富营养化水体能力大于单一的水草系统,溞-草系统能更快地提高水体透明度,苦草生长率更大,更易保持稳定,实验结果为指导生态修复工程实践提供参考。

Study on water eutrophication treatment with Daphnia magna and Vallisneria natans control system

The technique of combining two or more kinds of organisms to treat eutrophic water in ecological restoration has drawn much attention. In this paper, Daphnia magna and Vallisneria natans were used as the representatives of the zooplankton and submerged macrophytes to establish the combined system of daphnia-grass, the treatment of Vallisneria natans was used as the control group, and the eutrophic water as the blank group. Then we researched the process of water quality indicators, sediment indicators and aquatic biomass changes.The results showed that the quality indexes of water and sediment in the system were superior to that of the bitter Vallisneria natans group. The final removal rates of total nitrogen, total phosphorus and ammonia nitrogen were 87%, 88% and 96%, and the maximum removal rates were 70%,70% and 86%respectively. The removal rate of total nitrogen in sediment was 39% and the removal rate of total phosphorus was 38%. After 27 days of water clearing, the growth rate of Vallisneria natans reached 740%. In the control group, the final removal rates of total nitrogen, total phosphorus and ammonia nitrogen were 35%, 33% and 57%, and the maximum removal rates were 35%, 30% and 57% respectively, and the removal rate of the total nitrogen and total phosphorus was 40% and 32%, respectively. The water was not clear enough to see the bottom after 48 days, and the growth rate of Vallisneria natans was 470%.Therefore, Daphnia magna promoted the settlement of suspended solids, which is conducive to the growth of Vallisneria natans and the stability of the system. The ability of daphnia-grass system to deal with eutrophic water is greater than single aquatic systems, and it can speed up the transparency of water, achieve a higher growth rate of Vallisneria natans and is easier to maintain the stability. All in all, the experimental results provide reference for guiding the ecological restoration engineering practice.