【作者】 许丽；

【导师】 黄光团；

【作者基本信息】 华东理工大学 ， 环境科学与工程， 2011， 硕士

【摘要】 本试验研究了香根草对不同程度富营养化水体的修复效果,香根草对不同浓度重金属Cu的吸收效果以及聚天冬氨酸(PASP)对香根草去除氮、磷及重金属Cu效果的影响。香根草对含高浓度氮、磷的水体有很好的适应能力,在不同程度富营养化水体中均表现出较好的生长态势,植株鲜重的增长率、组织内的氮磷含量与水体的富营养化程度呈正相关。对氮、磷去除机理的研究发现：NH4+-N去除的主要途径不是植物吸收,而是以水体中微生物的硝化作用为主；香根草的存在为亚硝化细菌、硝化细菌提供了附着基质和栖息场所,为N02--N的去除提供了有利的条件；N03--N的去除主要依靠香根草的同化吸收；总磷(TP)的去除主要是植物吸收、微生物转化以及磷的吸附沉降共同作用的结果。香根草对NH4+-N的最大吸收速率(Vmax)和亲和力(1/Km)均大于对N03--N的最大吸收速率(Vmax)和亲和力(1/Km),具有优先吸收NH4+-N的趋势。PASP能够促进香根草的生长,加强植物的光合作用；PASP浓度为10 mg·L-1时,对去除总氮(TN)的促进作用较为明显；不同浓度的PASP对去除TP的促进作用都较为明显。香根草对重金属Cu2+有一定的耐性。随着Cu2+浓度的增加,香根草体内叶绿素含量减少且丙二醛含量均高于对照组,说明香根草受到了一定的毒害。香根草叶、根组织内的Cu含量与溶液中Cu2+浓度正相关,且根部是主要的富集器官。香根草对Cu2+的吸收过程为快速吸附—释放—缓慢代谢吸收。在低Cu2+浓度下,PASP可以促进香根草的生长,并能在一定程度上缓解Cu2+对香根草组织的伤害。添加PASP后,香根草根内的Cu含量有所增加,但叶中Cu含量没有明显变化。更多还原

【Abstract】 The study investigated the remediation effect of eutrophic water by Vetiveria zizanioides under different nutritional environment, the absorption effect of heavy metal copper by Vetiveria zizanioides under different Cu2+concentrations, and the effect of polyaspartic acid (PASP) on the removal of N、P and the absorption of heavy metal copper.Vetiveria zizanioides had a good ability to adapt to high concentration of N, P. Vetiveria zizanioides grew well in different eutrophic waters. There was a positive correlation between fresh weight growth rate of plant, the content of N、P within the tissue of Vetiveria zizanioides and water eutrophication level. On the basis of mechanism study on nitrogen and phosphorus removal, it was found the NH4+-N was removed mainly by nitrification of microbe in waters, not by the adsorption of plant; Vetiveria zizanioides provided a good living environment for the nitrifying bacteria, and thus it provided favorable conditions for the removal of NO2--N. NO3--N was removed mainly by the assimilation of Vetiveria zizanioides, and TP was removed mainly by the interaction of Vetiveria zizanioides absorption, microbial transformation and phosphorus sorption and settlement.NH4+-N would be absorpted by Vetiveria zizanioides at first priority, because the maximum absorption rate (Vmax) and affinity (1/Km) of NH4+-N were higher than those of NO3---N.PASP could promote the growth of Vetiveria zizanioides and enhance photosynthesis of plants. The removal of TN was enhanced remarkably at 10 mg·L-1 of PASP. The removal of TP was considerably enhanced by PASP under different concentrations.Vetiveria zizanioides had better tolerance to heavy metal copper. With the increase of Cu2+concentration, the content of chlorophyll within the tissue of Vetiveria zizanioides decreased, and the content of malonic dialdehyde was higher than that of control group, indicating that Vetiveria zizanioides had been poisoned to some extent. The content of copper in leaves and roots of Vetiveria zizanioides had a positive correlation with the concentration of Cu2+in solution, and copper mainly concentrated in the roots of Vetiveria zizanioides. The Cu2+absorption of Vetiveria zizanioides was the process of fast sorption-release-slow metabolism absorption. PASP could promote the growth of Vetiveria zizanioides at low Cu2+ concentration, and alleviate the damage of Cu2+to the Vetiveria zizanioides tissue to some extent. After adding PASP, the copper content of the Vetiveria zizanioides roots increased a little, but the copper content of the Vetiveria zizanioides leaves had no significant change.更多还原