不同水生经济植物对南四湖富营养化水体的净化效果

在南四湖湖区浅水域、废弃池塘、塌陷地水域和入湖河口水域4个生态区种植菰茭草、芦苇、蒲草、湖菱、莲藕和芡实6种水生经济植物，分别测定了其对富营养化水体中的总氮（TN）、总磷（TP）、氨氮（NH3-N）和化学耗氧量（COD）的净化效果。结果表明:6种水生经济植物均可显著降低水体中TN、TP、NH3-N和COD含量，具有较好的净化能力。同一生态区域条件下，菰茭草处理对这4种污染物的去除率均大于湖菱处理。同一水生经济植物（菰茭草、湖菱）相比，随着生态区域污染物含量降低，其对这4种污染物的去除率则呈下降趋势，且菰茭草处理的去除率显著高于湖菱处理。从对废弃池塘水体中污染物的去除率来看，对TN的去除率表现为菰茭草＞湖菱＞芦苇＞莲藕＞蒲草＞芡实，对TP的去除率表现为菰茭草＞莲藕＞芡实＞蒲草＞芦苇＞湖菱，对NH3-N的去除率表现为菰茭草＞芦苇＞莲藕、湖菱＞蒲草＞芡实，对COD的去除率表现为蒲草＞菰茭草＞芦苇＞莲藕、湖菱＞芡实。菰茭草对这4种污染物均表现出较高的去除率，净水效果最优，芦苇、莲藕、湖菱和蒲草次之，芡实最差。因此，菰茭草可作为南四湖流域及类似湖泊、水域富营养化水体水质净化的先锋植物。 

Effects of Different Aquatic Economic Plants on Water Purification in Lake Nansi Eutrophication

Zizania latifolia，Phragmites australis，Acorus calanus，Trapa japonica，Nelumbo nucifera and Euryales semen were cultured in Lake Nansi shallow water，waste ponds，the water of subsided land and estuarine waters into the lake for phytodecontamination.Contents of total nitrogen（TN），total phosphorus（TP），ammonia（NH3-N）and chemical oxygen demand（COD）in the domestic wastewater were tested during growth of these six plants.Results showed that，six aquatic economic plants could significantly reduce TN，TP，NH3-N and COD contents，with better purification capability.At the same ecoregions，removal rates of four pollutants applied with Zizania latifolia were higher than those applied with Trapa japonica.Compared with the same aquatic economic plants（Zizania latifolia and Trapa japonica ），removal rates of four pollutants were declining along with pollutant content of ecoregions was reduced，and removal rates of Zizania latifolia treatment was significantly higher than those of Trapa japonica treatment.From quality of removal rate，performance of removal TN，Zizania latifolia>Trapa japonica> Phragmites australis > Nelumbo nucifera > Acorus calanus > Euryales semen，for performance of removal TP，Zizania latifolia>Nelumbo nucifera>Euryales semen>Acorus calanus>Phragmites australis>Trapa japonica，for performance of removal NH3-N，Zizania latifolia>Phragmites australis>Nelumbo nucifera，Trapa japonica>Acorus calanus>Euryales semen，for performance of removal COD efficiency，Acorus calanus>Zizania latifolia>Phragmites australis>Nelumbo nucifera，Trapa japonica>Euryales semen.Zizania latifolia was more capable of removing TN，TP，NH3-N and COD than Phragmites australis，Nelumbo nucifera，Trapa japonica，Acorus calanus and Euryales semen.Therefore，Zizania latifolia was cultured as pioneer plants for water purification in eutrophication water of Lake Nansi and similar lakes.