【作者】 高冲；

【导师】 杨肖娥；

【作者基本信息】 浙江大学 ， 植物营养学， 2008， 硕士

【摘要】 水体富营养化是当今世界面临的一个重要问题,而造成水体富营养化的主要原因就是水中的氮磷含量过高。许多研究已经表明利用一些大型植物富集氮、磷是治理、调节和抑制湖泊富营养化的有效途径之一。本论文研究了一种粮药兼用植物——薏苡对富营养化水体中氮磷吸收去除效果及其环境影响因子,为实际应用薏苡处理富营养化水体提供科学依据。取得的主要结果如下:1.薏苡对氮磷的吸收动力学特征与水稻存在显著差异。薏苡吸收铵态氮、硝态氮和磷的最大吸收速率分别为0.0298、0.0302、0.0.0043mmol·g^-1FW·hr^-1,米氏常数分别为0.2080、0.6599、0.0308mmol·L^-1;而水稻吸收铵态氮、硝态氮和磷的最大吸收速率分别为0.0266、0.0270、0.0023 mmol·g^-1FW·hr^-1,米氏常数分别为0.3391、0.6051、0.0515 mmol·L^-1,说明薏苡比水稻更能广泛适应在不同浓度氨氮、磷和较高浓度硝态氮的水体环境。2.利用室内模拟和野外大田试验研究了薏苡对富营养化水的净化效果。结果发现,在室内模拟条件下,经过30天的处理,薏苡对于水体中总氮的去除率能够达到84.59%,氨氮可以达到89.46%,硝态氮达到82.66%,对总磷、可溶性磷的去除率分别为66.36%和51.09%,COD_Mn的去除率为37.54%,pH也由8.25降到了7.51;大田试验结果表明,薏苡对二级污水中氮磷和COD_Cr的去除都有很好的效果。3.采用模拟试验研究了pH、温度和溶解氧对薏苡去除人工模拟富营养化水中氮磷的影响。一组试验在保持不同温度下即10℃、20℃、30℃进行;一组试验每两天调节一次水体pH,使其分别保持在4、5、6、7、8、9;第三组试验分别采用充气和不充气,以控制水中的溶解氧。结果发现,经过24天的处理,温度为30℃时对总氮的去除率达到了67.06%,氨氮的去除率达到68.74%,硝态氮达到了65.66%,总磷也达到了57.52%,都远远大于在10℃和20℃条件下对氮磷的去除率。在pH4和pH5条件下对总氮的去除率可达到77.75%和78.30%,总磷的去除率达到70.02%和73.52%,高于其他的pH条件。溶解氧对薏苡去除水体中氮磷的效果的影响小于温度和pH,但是充气条件下薏苡对水体中氮磷的去除率仍要比不充气的高。这些结果表明,较低pH、较高温度有和增加溶解氧浓度有利于薏苡对水体氮磷的去除,该植物可作为夏秋季富营养化水体修复的候选植物。更多还原

【Abstract】 Water eutrophication is a serious environmental problem in the world.The major factors causing water eutrophication include load of nitrogen（N）and phosphors（P）. Many researches have proved that using some large plants to remove nitrogen and phosphorus is an effective way to treat,adjust and control the eutrophication. Therefore,Coix Lachrymajobi.L,a kind of plant can be used as both food supplies and Chinese medicine,was selected to study the possibility to purify eutrophicated water,as well as the effects of environment factors such as pH,temperature and dissolved oxygen on its remove abilities of nitrogen and phosphorus from eutrophicated water.The results of this study,could provide scientific bases for controlling the lake eutrophication.The main results obtained can be summarized as follows:1.Obvious differences of the maximum rates of ammonium,nitrate and phosphorus uptake as well as the Km value of absorption between Coix and rice was observed.The maximum rate of ammonium,nitrate and phosphorus uptake by Coix were 0.0298,0.0302,0.0043rnmol·g^-1FW·hr^-1,respectively;the Km value of the nutrient absorption of Coix were 0.2080,0.6599,0,0308mmoi·L^-1.However,the maximum rate of ammonium,nitrate and phosphorus uptake by rice were 0.0266、0.0270、0.0023 mmol·g^-1FW·hr_-1,respectively;the Km value of absorption of rice were0.3391、0.6051、0.0515 mmol·L^-1.It indicated that Coix is more suitable for improve eutrophicated water with more widely range of NH₄⁺ and phosphorus.2.The effectiveness of Coix for purifying eutrophicated water was studied with simulation experiment and field experiment.The result from simulation experiment showed that the remove rate of total nitrogen,ammonium,nitrate,total phosphorus, dissolved phosphorus and COD_Mnby Coix can reach 84.59%,89.46%,82.66%, 66.36%,51.09%,37.54%respectively,and the pH level of the water decreased from 8.25 to 7.51.The result of constructed wetland experiment achieved the accordant result,and the remove rate of nitrogen,phosphorus and COD_crfrom secondary effluent was also ideal. 3.The removal abilities of nitrogen and phosphorus from eutrophicated water by Coix were studied under different pH,temperatures and dissolved oxygen.In one experiment Lachryma-jobi.L were grownunder 10℃,20℃,30℃,respectively,in another set of experiment the plants were treated with different pH of 4,5,6,7,8,and 9,in the last experiment the plants were grown in aerating water and normal water. From the temperature experiment we can see that the removal rates of total nitrogen, ammonium,nitrate and phosphorus were respectively 67.06%,68,74%,65.66%, 57.52%,which were much higher than those treated under 20℃and 10℃.The results from pH effect experiment showed that the removal rate of total nitrogen reached 77,75%and 78.30%and that of total phosphorus reached to 70.02%and 73.52%at pH 4 and 5.And the removal rates of nitrogen and phosphorus at other pH values were lower,Dissolved oxygen was not so efficiency as pH and temperature in affecting removing nitrogen and phosphorus.These results indicate that more efficient removal of N and P by Coix lacryma-job occurred at relative low pH,high temperature,and high dissoived oxygen.Therefore,this plant could be used for phytoremediation of eutrophic water at summer and autumn seasons.更多还原