【作者】 胡绵好；

【导师】 奥岩松； 杨肖娥；

【作者基本信息】 上海交通大学 ， 蔬菜学， 2008， 博士

【摘要】 水问题是全球所面临的最热点环境问题之一,而由氮磷等营养盐所引起的水体富营养化不仅是水体污染最为普遍的现象,还是国内外水污染治理的难题。生态浮床技术是采用现代农艺和生态工程措施综合集成的水面无土种植植物技术,是富营养化水体原位修复的经济有效的、可行的绿色方法。本文以浙江本著的水生植物为研究对象,利用生态浮床技术深入研究了不同经济植物对富营养化水体的净化能力、环境因子包括pH和曝气、温度、浮床附生藻类等对浮床水生经济植物改善富营养化水体水质的影响、水生经济植物吸收NH₄⁺-N和NO₃^--N的动力学以及富营养化水体中水生经济植物氮代谢酶特性与不同形态氮去除的关系、以及结合当前植物修复研究的最新趋势,从根际氮循环细菌的种群数量及其作用来揭示不同水生经济植物修复富营养化水体的差异。研究结果丰富了植物营养生态学、污染生态学和微生物生态学知识,为植物和微生物资源的开发和利用及其对富营养化水体的修复进程提供了必需的知识基础和理论指导。主要研究内容和结果如下:①不同经济植物对富营养化水体净化能力的比较研究为建立净化富营养化水体的生态工程,本试验选择水芹、水蕹菜、韭菜、葱、豆瓣菜、芹菜等6种经济植物,比较研究了其对不同N水平的富营养化水体的净化能力。结果表明:每种经济植物对水体总氮、总磷均有一定的去除作用,特别是豆瓣菜、水芹和水蕹菜,其在20d处理时,对高N水平的富营养化水体中总氮的去除率分别为92.5%,95.6%,98.2%。研究还表明,各植物处理的水中COD_cr的浓度变化呈先降低后升高再降低的变化趋势,但韭菜和葱处理,水中辛味加重;除韭菜和葱外,其他经济植物处理的水中BOD₅和Chla浓度变化均随处理时间的延长而降低。各项指标综合分析表明,对不同N水平的富营养化水体处理中,水蕹菜处理效果最好,水芹、豆瓣菜次之,芹菜居中,韭菜最差。②pH和曝气处理对水生经济植物改善富营养化水体水质的影响pH和曝气处理对水生经济植物净化富营养化水体影响的研究结果表明,不同pH处理6d后,植物系统中TN、COD_Mn、BOD₅的去除效果在pH8.9处理下最好, TP的去除效果在pH6.7处理下最好, Chla的去除效果在pH5.0处理下最好;而无植物（对照）系统中,TN、TP去除效果在pH8.9下最好,BOD₅去除效果在pH6.7下最好,COD_Mn、Chla去除效果在pH5.0下最好。植物和无植物系统中,曝气处理6d对TN去除率明显小于不曝气处理（P <0.001）,除豆瓣菜系统中,曝气还对COD_Mn去除产生一定的影响,但对TP和Chla的去除无影响。结果还表明,植物修复系统和无植物系统中,不同pH处理下,水体中NH₄-N、NO₃-N、NO₂-N的去除效果均在pH8.9处理下最好,且在pH8.9和曝气联合作用下水体中NH₄-N、NH₄-N、NO₃-N、NO₂-N的去除率也最高。③水生经济植物-浮床附生藻类对富营养化水体水质改善的协同效果通过有光、避光控制,研究了水生经济植物与浮床附生藻类协同作用对富营养化水体水质的改善影响,结果表明,试验后水体中的藻类减少,但浮床上的附生藻类增多,且主要以小球藻（Chlorella.vulgaris）、小球衣藻（Chamydomonas. microsphaera）等绿藻为主。P-PFB和NP-PFB处理对水体中TN、TP、COD_Mn、BOD₅的去除率比P和NP处理高,且P和P-PFB处理系统水体中TN、TP的去除率明显高于NP和NP-PFB系统。处理20d,P-PFB处理对水体中TN的去除率达76.8%以上,对TP的去除率在89.9%以上;而P处理对TN的去除率最高仅为61.1%;对TP的去除率最高为85.4%。P-PFB处理对水体中COD_Mn、BOD₅的去除率达94.0%以上,而P处理对COD_Mn、BOD₅的去除率最高为89.5%。P和P-PFB处理系统中NH₄-N、NO₂-N、Chla、DP浓度均随处理时间的延长而降低,且P-PFB处理下降较避光处理明显;而DO浓度随着处理时间的延长而升高,且P-PFB和NP-PFB处理明显高于P和NP处理。NP-PFB和NP处理的富营养化水体中NH₄-N、NO₃-N、NO₂-N、DP浓度均比P和P-PFB处理高。结果还表明,WD和W地上部分N的净积累量分别为0.5908和0.3675mg·plant^-1·d^-1,P的净积累量分别为0.1530和0.0665mg·plant^-1·d^-1;而WD-PFB和W-PFB处理其地上部分N的净积累量为0.2566和0.1162mg·plant^-1·d^-1, P的净积累量为0.0548和0.0181mg·plant^-1·d^-1。④富营养化水体中水生经济植物氮代谢酶特性与不同形态氮去除的关系水芹和豆瓣菜对不同氮形态吸收的动力学差异和富营养化水体中水生植物体内氮代谢酶特性与不同形态氮去除关系的研究结果表明,两种水生植物对NH₄-N,NO₃^-N吸收适合Michaelis-Menten酶动力学模型。其中,水芹对NH₄⁺吸收的最大速率(V_max)和米氏常数（K_m）均明显大于对NO₃^-吸收的V_max和K_m值,而豆瓣菜对NH₄⁺吸收的V_max大于对NO₃^-吸收的V_max,但吸收的K_m值却明显小于对NO₃^-吸收的K_m值。而且,水芹对低浓度的铵态氮和硝态氮的吸收能力较豆瓣菜要强。水芹和豆瓣菜体内GS活性与富营养化水体中TN、NH₄-N去除存在极显著的相关性（r >0.91）,而GOGAT和NR活性与水体中TN、NH₄-N、NO₃-N、NO₂-N去除呈指数衰减变化趋势,但无明显的相关性。⑤不同温度处理对水生经济植物净化富营养化水体能力的影响利用生态浮床系统研究了温度变化对水芹和豆瓣菜生长及其净化富营养化水体能力的影响,结果表明,10℃处理下的浮床植物下部叶片发黄、茎细且植株生长缓慢,且35℃处理的浮床植物叶片发黄更加严重,茎干更细（徒长现象严重）,且浮床豆瓣菜叶片上还有大量的蚜虫发生。而22℃处理下,植株生长正常及其高度介于10℃和35℃处理之间。22℃处理的浮床植物体内TN、TP的净积累量明显高于10℃和35℃处理,且35℃处理的又明显高于比10℃处理。不同温度处理下,浮床豆瓣菜体内TN和TP净积累量明显高于浮床水芹的（P <0.05）。不同温度处理,无植物浮床系统对TN去除效果为:10℃<22℃<35℃,而植物浮床系统则是:10℃<35℃<22℃,但各浮床系统对COD_Mn、BOD₅去除效果为:10℃<22℃<35℃;10℃和22℃处理的豆瓣菜浮床系统对TN的去除率高于水芹浮床系统,而35℃处理的却明显低于水芹浮床系统;22℃与35℃处理下,水芹浮床系统对TN的去除率没有明显的差异,但对BOD₅的去除率却明显低于豆瓣菜浮床系统。不同温度处理,各浮床系统中NH₄-N浓度下降高低为:22℃>35℃>10℃,NO₃-N、NO₂-N浓度下降高低为:35℃>22℃>10℃,且植物浮床系统中NH₄-N、NO₃-N、NO₂-N浓度的下降明显多于无植物浮床系统。处理5d后,10℃和22℃处理的豆瓣菜浮床系统中NH₄-N的浓度明显低于水芹浮床系统,但35℃处理的两个植物系统中NH₄-N浓度下降均无显著差异;22℃和35℃处理的豆瓣菜浮床系统中NO₃-N浓度高于水芹浮床系统,但两植物浮床系统间NO₂-N浓度下降无明显差异;各浮床系统中pH高低为35℃>22℃>10℃,豆瓣菜浮床系统中pH明显高于水芹浮床系统,但两植物浮床系统中pH均明显低于无植物浮床系统。但处理3d后,10℃处理的各浮床系统中DO浓度高于22℃和35℃处理,且10℃和35℃处理的豆瓣菜浮床系统中DO浓度较无植物和水芹浮床系统要高,但22℃处理的无植物浮床系统中DO浓度比植物浮床系统要高。⑥浮床系统中水生经济植物根际氮循环细菌及其作用的研究利用生态浮床系统,研究了浮床水生经济植物单作和混作对氮的去除效果及其根际周围硝化与反硝化菌种群数量以及硝化与反硝化作用速率的变化规律,结果表明,浮床水生经济植物混作系统对氮的去除效果优于植物单作和无植物系统,而植物系统又优于无植物系统,除8d处理外,各系统中氮的去除率由小到大分别为无植物系统<豆瓣菜系统<水芹系统<混作系统。水生经济植物单作与混作根际硝化细菌种群数量和硝化作用速率、反硝化细菌种群数量和反硝化作用速率均具有明显的差异;处理16d,硝化细菌种群数量多少及其作用速率大小为:水芹系统<混作系统<豆瓣菜系统<无植物系统;而反硝化细菌种群数量多少及其作用速率大小为:无植物系统<混作系统<豆瓣菜系统<水芹系统。更多还原

【Abstract】 Water pollution is one of the major environmental problems through the world, and water eutrophication resulting from nitrogen and phosphorus enrichments not only is universal phenomenon in water pollution, but also is the most difficulty problem for water remediation. Ecological floating bed technology is a surface soilless planting technology of modern agronomic and ecological engineering measures integrated comprehensively, and is a cost-effective and feasible method of the green for eutrophic water remediation in situ. Purification capacity to eutrophic water bodies by the different economic plant, impact of environmental factors （including pH and aeration, temperature and floating bed epiphytic algae） on eutrophication water quality improvement by economic aquatic plants, the absorption kinetics of NH₄+ and NO3- by aquatic plants and the relation between nitrogen metabolism enzyme characteristics in plants and different forms nitrogen removal in eutropihc water were carried out using ecological floating bed system in this paper. With the current trend of the latest research on phytoremediation, this paper was to reveal the difference between different aquatic plants in eutrophic water body remediation, from the nitrogen cycle bacteria population and their action in rhizosphere. The results enriched the knowledge of plant nutritional ecology, pollution ecology and microbial ecology, and provided a necessary foundation of knowledge and theoretical guidance for the development and utilization of plant and microbial resources in the restoration of eutrophic water bodies. Research and the main findings are as follows:①Comparative studies on the purification ability to eutrophic water bodies by different economic plantsFor building the ecological engineering to purify the eutrophic water, six economic plants, which are water dropwort, water convolvulus, leek, shallot, watercress, and celery, respectively, were selected, and their purification ability in different N level eutrophic water were studied. The results showed that each species had great ability to remove total nitrogen （TN） and total phosphorous （TP）, especially watercress, water dropwort, and water convolvulus, their removal rate to TN and TP in high N level eutrophic water afer 20 days’treatment is 92.5%, 95.6%, and 98.2%, respectively. The change trend of COD_cr concentration decreased firstly and increased later and decreased finally in the different N level eutrophic water bodies with different economic plants, but the acrid smell in the water aggravated during leek and shallot treatment. The changes of Chla and BOD₅ decreased with time continuing in the different N level eutrophic water with other economic plants treatment, except for leek and shallot. The integrated analysis of all indices indicated that in the different N level eutrophic water, the purification effect of water convolvulus was the best, water dropwort and watercress take second place, celery place in the center, leek was worst.②Effect of pH and aeration on eutrophication water quality improvement by economic aquatic plantEffect of pH and aeration on eutrophication water quality improvement by aquatic plants on floating bed was investigated in the greenhouse in this paper. The results showed that at different pH treatments for 6d, removal efficiencies for TN, COD_Mn, and BOD₅ were highest at pH8.9, TP removal was highest at pH6.7, Chla removal was highest at pH5.0 in the plant system. However, removal efficiencies of TN and TP were highest at pH8.9, BOD₅ removal was better at pH6.7, removal for Chla and COD_Mn was highest at pH5.0 in the no plant system. TN removal with aeration treatment was much smaller than that with no-aeration （P <0.001） in the planted and unplanted system. COD_Mn removal was affected, but removal of TP and Chla was not impacted by aeration, except for in the watercress system. In addition, removal efficiencies of NH₄-N, NO₃-N, and NO₂-N were highest at pH8.9 and pH8.9+aeration.③Eutrophication water quality improvement by the synergistic effects of economic aquatic plant and periphyte on floating bedsEffect of the synergistic effects of economic aquatic plant and periphyte on floating bed on the improvement of eutrophication water quality was investigated under light and non-light control using floating culture system in the greenhouse. The results showed that the amount of green algae in the water body decreased, but the periphytes on floating bed increased with treatment of growing plants （water dropwort and watercress） under light or without light conditions for 20 days. The dominant periphyte species were Chlorella.vulgaris and Chamydomonas, Microsphaera, at the end of the experiments. The removal rate of TN、TP、COD_Mn、BOD₅ in the P-PFB and NP-PFB treatment systems were higher than that of P and NP treatments, and higher removal rates for TN and TP were noted in planted treatment than in unplanted treatment. After 20 days’s treatment, removal rates of TN and TP were above 76.8%, 89.9%, respectively, in the P-PFB treatment systems, while were only 61.1%, 85.4%, respectively, for the P treatment systems. Removal rates of COD_Mn and BOD₅ were above 94.0% in the P-PFB treatment systems, whereas was only 89.5% in the P treatment systems. The concentrations of NH₄-N, NO₂-N, DP and Chla in the eutrophic water bodies decreased with increasing treatment time in all treatments in the plant floating bed, whereas the reduction of their concentrations in the P-PFB treatment system were markedly greater than that of P treatment system. However, the change of DO concentration increased with increasing treatment time, and DO concentration in the P-PFB and NP-PFB treatment systems was higher than in the P and NP treatment systems. The concentrations of NH₄-N, NO₃-N, NO₂-N, and DP in the eutrophic water bodies in the NP-PFB and NP system were higher than in the P-PFB and P treatment systems. The results also indicated that the nitrogen accumulation in the shoots of WD and W were 0.5908 and 0.3675mg·plant^-1·d^-1, and phosphorus accumulation were 0.1530 and 0.0665mg·plant^-1·d^-1, respectively. While the nitrogen accumulation were 0.2566 and 0.1162mg·plant^-1·d^-1, and phosphorus accumulation were 0.0548 and 0.0181mg·plant^-1·d^-1, respectively, in the shoots of WD-PFB and W-PFB treatment.④Relationship between nitrogen metabolism enzyme characters in economic aquatic plants and different forms nitrogen removals in eutrophic water bodiesAbsorption kinetics of different forms nitrogen by water dropwort and watercress was studied firstly, and then the relationship between nitrogen metabolism enzyme characteristics in two aquatic plants and different forms nitrogen removal in eutrophic water was carried out by floating bed plant system. NH₄-N and NO₃-N uptake of two aquatic plants was fitting Michaelis-Menten kinetics model. Among them, the V_max and K_m of NH₄+ absorption were significantly greater than the V_max and K_m of NO₃- absorption for water dropwort, and the V_max of NH₄⁺ absorption was greater than the V_max of NO₃- absorption, but the K_m is obviously less than the K_m of absorption of NO₃- for watercress. In addition, the uptakes of NH₄-N and NO₃-N for water dropwort were stronger than that of watercress at low concentrations. GS activity of water dropwort and watercress was significant correlation with TN and NH₄-N removal in water bodies （r> 0.91）. GOGAT and NR activity in two aquatic plants were exponential decay with TN, NH₄-N, NO₃-N, NO₂-N removal, but had no significant correlation.⑤Effects of different temperature on the purification ability to eutrophic water by aquatic plantsThe effects of different temperature on the purification ability to eutrophic water by two aquatic plants in the ecological floating bed system were studied. The results showed the lower leaves of floating bed plants grew yellow, and the stems grew small and slow at 10℃treatment, and the leaves grew yellow seriously and the stems became smaller at 35℃, and aphids had occurred on the leaf of watercress. At 22℃treatment, the plant grew normally and the height of plants was between 10℃and 35℃. Moreover, the TN and TP net accumulations in plants at 22℃treatment were significantly higher than 10℃and 35℃treatments, and at 35℃treatment also was higher than at 10℃treatment. The TN and TP net accumulation in the watercress were significantly higher than that of the water dropwort at different temperature treatments （P <0.05）.At different temperature treatments, no plants floating bed system （NPFBS） for the removal of TN: 10℃<22℃<35℃, and plants floating bed system （PFBS） was: 10℃<35℃<22℃, however, COD_Mn and BOD₅ removal efficiency in floating bed system （FBS）: 10℃<22℃<35℃, and TN removal in the watercress floating bed system （WFBS） was higher at 10℃and 22℃treatments, and is obviously lower at 35℃than in the water dropwort floating bed system （WDFBS）. At 22℃and 35℃treatments, TN removal was no obvious difference in the WDFBS, but BOD₅ removal was obviously lower than in the WFBS. NH₄-N concentration decreased level in the FBS: 22℃>35℃>10℃; NO₃-N, NO₂-N concentration level for the decline: 35℃>22℃>10℃, and NH₄-N, NO₃-N, NO₂-N concentrations decreased significantly in the PFBS more than in NPFBS. At 10℃and 22℃treatments for 5d, NH₄-N concentration in the WFBS was significantly lower than in the WDFBS, but the decrease of NH₄-N concentration was no significant difference for the two plants at 35℃. NO₃-N concentrations in the WFBS at 22℃and 35℃were higher than in the WDFBS, but the decrease of NO₂-N concentration was no significant difference between two plants floating bed systems （TPFBS）. pH level in the FBS was 35℃>22℃>10℃, pH in the WFBS was significantly higher than that in the WDFBS, but pH in the TPFBS was significantly lower than that of NPFBS. However, for 3 d treatment, DO concentration in the FBS was higher at 10℃than that of 22℃and 35℃, and it was higher in the WFBS at 10℃and 35℃than that of NPFBS and WDFBS. DO concentration in the NPFBS at 22℃was higher than that of PFBS.⑥Nitrogen cycle bacteria and their action in the rhizosphere of economic aquatic plants in the floating bed systemThe nitrogen removal effect in water and the changes of the nitrification and denitrification bacteria population and their action in the rhizosphere with plant monoculture and mixture were studies in the ecological floating bed system. The result indicated that nitrogen removal in the plant mixture was better than in plant monoculture and non plant systems, and plant system was better than no plant systems, nitrogen removal in the order were no plant system （NPS）< watercress system （WS） < water dropwort system （WDS）< mixture system （MS）, except for 8 d treatment. There were significant difference in the nitrifying bacteria population and nitrification rates, and denitrifying bacteria population and denitrification rates of the rhizosphere between monoculture and mixture. Furthermore, the number of nitrifying bacteria population and its rate: WDS<MS<WS<NPS, and the numbers of denitrifying bacteria population and its rate: NPS <MS<WS<WDF for 16 d treatment.更多还原