富营养化水体中芦苇和菖蒲浮床氮净化能力比较研究

A Comparative Study on Nitrogen Removal from Polluted Water by Floating Beds Planted with Phragmites australis and Acorus calamus

以小兴凯湖水为原水配制不同富营养化程度的污水，比较了芦苇和菖蒲浮床系统对TN的去除效果，分析了植物根系特征和植物吸收氮总量与氮去除效率和速率之间的关系，研究氮去除的主要途径和主要影响因素。结果表明，芦苇和菖蒲浮床对TN均有较强的净化能力，在TN浓度分别为9．63、4．58mg·L^-1的污水中，芦苇浮床对TN的平均去除率分别为91．5％和84．2％，菖蒲浮床的去除效率分别为89．9％和82．8％，植物吸收对氮去除的贡献率为36．4％～77．1％。两种污水中，芦苇浮床在生长末期前2d对TN的平均去除速率分别为4．20、1．77mg·L^-1·d^-1，显著高于菖蒲浮床的1．75、1．04mg·L^-1·d^-1。两种植物的根系总长度、表面积和体积3个指标均与TN去除速率呈正相关关系（R≥0．826，P〈0．01），根系发达程度是影响TN去除速率的主要因素。

Lab-scale experiments were carried out to compare the efficiency of nitrogen（ N ） removal by floating beds planted with common reed （Phragmites australis ） and calamus （A corns c alnmus ） in eutrophic water man-made from water of Khanka Lake. The rhizome charac- teristics and the efficiency and rate of nitrogen removal by Phragmites australis and Acorns calamus were examined to study nitrogen removal mechanisms and major influencing factors. Results demonstrated that floating beds planted with Phragmites australis （ 3 replicas ） and A - corns calamus （3 replicas ） had water purifying ability. The average TN removal percentage was 91.5% and 84.2% for the reed beds and 89.9% and 82.8% for the calamus beds at 9.63 mg·L^-1 （feed A） and 4.58 mg·L ^-1 （feed B） of TN concentrations in the feed water, respec- tively. Plant uptake contributed to 36.4%~77.1% of TN removal. The mean TN removal rate by the reed beds at late growth stage was 4.20 mg.L^-1·d^-1 and 1.77 mg.L^-1·d^-1, while that of the calamus beds was 1.75 mg.L^-1·d^-1 and 1.04 mg.L^-1·d^-1, respectively, for feed A and feed B. Significant cmxelations（ R ≥ 0.826 and P〈0.01 ） were found between TN removal rates and total length, surface area and volume of plant roots. The plant roots is found to be the determinant factor of nitrogen removal efficiency in floating beds. Keywords： eutrophication; nitrogen; purification capacity; Phragmites australis ; A corus calamus