附着生物对富营养化水体氮磷的去除效果

REMOVAL EFFECTS OF PERIPHYTON ON NITROGEN AND PHOSPHORUS IN THE EUTROPHIC WATER BODY

以太湖梅梁湾"863示范工程"水草恢复区原位湖水以及该区渔网围隔上的附着生物为材料,通过室内静态培养试验,研究了附着生物对富营养化湖水的氮、磷去除效果。结果表明,附着生物对水体中的氮有显著的去除效果,半个月内,附着生物对水体中总氮的累积去除率可达60%,在有附着生物的水体中总氮浓度从5 mg/L左右下降到2 mg/L左右;附着生物对水柱中氮的累积去除率和水柱中氮的浓度、附着生物的生物量以及附着生物作用时间密切相关。从培养过程中水体磷的浓度变化来说,培养初期,水体中磷的浓度比较高,附着生物对其有一定的去除作用;培养后期,水柱中磷的浓度比较低,附着生物不但不去除水中的磷,而且还向水柱中释放磷,这可能与附着生物向水体分泌碱性磷酸酶密切相关。

To research purifying effects of periphyton on nitrogen and phosphorus of the eutrophic water body,static incubation test was adopted by utilizing situ water and periphyton attached to the fishing nets paling in＂863 demonstration project＂submerged macrophyte restoration area of Meiliang Bay of Lake Taihu. The results showed that removal effect of periphyton on nitrogen was significant. Cumulative removal ratio of nitrogen was up to 60% ,the nitrogen concentration decreased from 5 to 2 mg/L or so within two weeks. Cumulative removal ratio of nitrogen was closely related with nitrogen concentration, working time and biomass of periphyton. In the first cultivation stage,as relatively high concentration of phosphorus,phosphorus from water column was removed to a certain extent by periphyton. The end of the incuba- tion,as low concentration of phosphorus periphyton releases phosphorus to water column instead of removal phosphorus from water,this may closely relate to the alkaline phosphatase secreted by periphyton in water body.