大薸对水体氮磷去除效果的初步研究

通过大薸在模拟富营养化水体中的培养试验，研究其在不同程度富营养化水体中对N、P的去除效果。结果显示：在总氮（TN）、总磷（TP）初始浓度分别为245～941 mg/L和044～153 mg/L的3种富营养化水体中，大薸均可正常生长。经过21 d的生长，大薸鲜重达16433～1934 g，干重达857～1053 g，大薸鲜重的特定生长率为044%～119%/d，大薸干重的特定生长率为046%～14%/d，大薸的分株速率为133%～362%/d。3种富营养化水体中的N、P去除量分别为6920～31860 mg和1560～6600 mg，大薸的N、P吸收量分别为3520～20821 mg和899～4837 mg，且随水体初始N、P浓度的升高而增加。大薸吸收对水体N去除的贡献率为5326%～6524%，对水体P去除的贡献率分别为5958%～7419%。由此可以看出，大薸对氮磷具有较好的去除效果，在富营养化水体中种植大薸可起到改善水质的作用

EFFECTS OF PISTIA STRATIOTES L.ON REMOVAL RATE FOR NITROGEN AND PHOSPHORUS IN POLLUTED WATER BODY

Stimulated experiments were carried out to study nitrogen and phosphorus uptake and removal ability of Pistia stratiotes L.in eutrophic waters.The results showed that Pistia stratiotes L.grew normally in different degrees of eutrophic waters with initial concentrations of 2.45-9.41 mg/L TN and 0.44-1.53 mg/L TP.Accumulated Pistia stratiotes L.fresh weight and dry weight increased to 164.33-193.4g and 8.57-10.53 g for the period of study,the specific growth rate of fresh weight and dry weight were 0.44%-1.19%/d and 0.46%-1.4%/d,the ramet rate of Pistia stratiotes L.was 1.33%-3.62%/d.The removal of nitrogen and phosphorus were 69.20-318.60 mg and 15.60-66.00 mg and nitrogen and phosphorus uptaken by Pistia stratiotes L.were 35.2-208.21 mg and 8.99-48.37 mg,respectively.Meanwhile,accumulated assimilation of nitrogen and phosphorus increased with increasing initial nitrogen and phosphorus concentration in eutrophic waters.The removal contribution rate of nitrogen was 53.26-65.24% and that of phosphorus was 59.58%-74.19% in different degrees of eutrophic waters,respectively.Therefore,Pistia stratiotes L.had good removal efficiency,and planting Pistia stratiotes L.in eutrophic waters could improve water quality.