陆生经济植物浮床去除富营养化水中氮素研究

通过玻璃缸静态培养试验,探讨陆生经济植物芹菜(Apium graveolens L).、茼蒿(Chrysanthemum coronarium L).和大蒜(Alliumsativum L).作为人工生物浮岛栽培植物,去除富营养化水体中氮的可行性和净化效果。采用常规耗竭法进行吸收动力学试验,研究植物根系对不同形态氮的吸收特性,为浮床植物遴选提供理论依据。结果表明:芹菜、茼蒿和大蒜在水中生长状况良好,试验前后生物量相对增长了121.24%~330.12%;三种经济植物浮床系统净化效果显著,对水中TN的去除率为44.94%~82.84%,高于空白对照系统(25.15%)。三种植物浮床系统对TN去除效果差异极显著(P0.05),根据这三种植物根系对不同形态氮在不同浓度水平下的吸收特性研究发现,其吸收规律均符合Michaelis-Menten动力学方程,但不同种类植物根系吸收特性存在差异,从而影响不同形态氮的去除效果。其中芹菜对NH4+-N的吸收潜力最大,对NO3--N的亲和力最大,大蒜对NO3--N的吸收潜力最大,对NH4+-N亲和力最大,茼蒿对两种形态氮的吸收能力较差。

Nitrogen Removal from Eutrophic Water by Terrestrial Economic Plants Floating-bed System

Feasibility and purification effect of nitrogen removal from severely eutrophic water by floating culture with celery,Chrysanthemum coronarium and garlic were investigated via static culture tests in aquarium.Experiments on absorption kinetics were performed by normal depletion method to study nitrogen uptake characteristics of three terrestrial vegetables.Results showed these vegetables were in good growth condition and relative growth of biomass were 121.24%~330.12%.Three vegetable floatingbed system purification effect to wastewater were distinct,and purification efficiency to TN in water were 44.94%~82.84% which were higher than that of control group system of 25.15%.There were significantly different compared with three vegetable floatingbed system.Different nitrogen forms absorption rate under different concentrations for the roots of three vegetables were found to follow Michaelis-Menten model.But different vegetables had different root absorption characteristics,which had influence on removal of nitrogen from water.Celery had the largest absorption potentiality on NH4+-N,and ions affinity was the largest on NO3--N.Garlic had the largest absorption potentiality on NO3--N,and ions affinity was the largest on NH4+-N.Chrysanthemum coronarium had poor absorptive capacity of nitrogen.