不同水生植物对富营养化水体的净化动态及其机理研究

Study on the purification dynamics and mechanism of different aquatic plants on eutrophic water

为研究不同水生植物对富营养化水体的净化动力及其机理,以黄花水龙、苦草、凤眼莲和纸莎草4种水生植物为试验材料,用天然富营养水溶液培养40 d,其间研究了植物生物量和水溶液中营养元素以及生理指标的变化。结果显示:水生植物的生物量和生长速率影响其对水体的净化效果和净化动力;不同类型的水生植物对水中氮和磷的吸收和去除效果不同。生长速率大的水生植物对水体的净化能力比较强,如凤眼莲和黄花水龙生长最快,其对氨态氮(NH_(4)^(+)-N)的去除率在第8 d达到最大,为87%和92%,而苦草生长相对较慢,其对NH_(4)^(+)-N的去除率第20 d才达到最大,为75%;另外,水生植物体内过氧化物酶(POD)和硝酸还原酶(NRA)活性也会影响其对水中氮和磷的去除动力和去除效果。本研究可以为治理水体富营养化提供科学依据。

To study the purification kinetics and the mechanism of eutrophic water bodies by different aquatic plants,four aquatic plants,namely Jussiaea stipulacea,Vallisneria natans,Eichhornia crassipes and Cyperus papyrus,were used as experimental materials and cultured in natural eutrophic water solution for 40 days.During the period,the changes of plant biomass,nutrient elements in water solution,and physiological indicators of the plants were studied.The results showed that the growth rate of aquatic plants affected their purification power.Different types of aquatic plants have different absorption and removal effects on nitrogen and phosphorus in water.Aquatic plants with high growth rates had strong ability to purify water bodies.For example,E.crassipes and J.stipulacea had strong high growth rate which resulted in high removal rates of ammonia nitrogen(NH_(4)^(+)-N)with maximum on the 8th day,reaching 87%and 92%,respectively.However,V.natans grew relatively slowly which resulted in low removal rate of NH_(4)^(+)-N,reaching its maximum of 75%on the 20th day;In addition,the activities of peroxidase(POD)and nitrate reductase(NRA)in aquatic plants could also affect their removal kinetics and effectiveness of nitrogen and phosphorus in water.This study can provide scientific basis for controlling eutrophication in water bodies.