水生植物对水体水质的净化作用分析

随着中国工业化进程的推进,近年来,水生植物对水体水质的净化作用的研究需求越来越急切。水生植物对水体水质起主要净化作用,本文主要通过对水生植物的概念,水生植物对水体水质净化作用的应用,以及水生植物对水体水质的净化原理三个方面的阐述,从而对水生植物对水体水质的净化作用进行分析。     

利用水生植物原位修复污染水体

在实验围隔系统中,夏季利用凤眼莲、冬季利用耐寒型沉水植物伊乐藻等恢复水生生态系统,研究水生植物对水体氮、磷营养盐、透明度等理化性质的影响.结果表明：水生植物处理围区营养盐水平均显著低于围区对照和大湖水体.最初15 d,凤眼莲生长速度快,覆盖面积从100 m²增加到470 m²;44 d后,覆盖面积达到65％,处理围区的水质最佳,总氮(TN)、铵态氮(NH₄⁺ -N)、亚硝态氮(NO₂^- -N)、高锰酸钾盐指数(COD_Mn)和叶绿素a浓度最低,透明度达到1.7～1.8 m(水底).10月份后,处理围区水体总磷(TP)维持在0.1 mg·L^-1左右.处理围区透明度提高后,伊乐藻逐渐成为优势种(覆盖面积达到总水域的1/3),在净化水质、维持水质理化性质稳定和提高透明度方面作用显著.表明水生植被恢复可以有效降低水体营养盐,控制浮游植物增长,是改善富营养湖泊水质的重要措施.     

三种水生植物对苯的净化作用及条件优化

为了探讨水生植物对含苯污染水体的修复效果,采用L₂₇(3¹³)正交设计法,研究了3种水生植物普生轮藻（Chara vulgaris L.）、豆瓣菜（Nasturtium officinale R.Br.）和菹草（Potamogeton crispus L.）对水体中苯的净化作用。结果表明,在实验条件下,3种植物对苯的最大去除率分别达到35.26%、69.71%和55.45%。温度、作用时间、生物量及温度与时间、温度与生物量的交互作用对普生轮藻去除苯的作用影响显著。温度和生物量对豆瓣菜去除苯的作用影响显著。作用时间对菹草去除苯的作用影响显著。3种植物均可作为良好的水质净化材料。普生轮藻和豆瓣菜适合在夏秋季选用,而菹草则适合冬春季选用。     

红枫湖富营养化水体生态修复中水生植物化学成分

高原山区深水型湖泊水深大、水位变化剧烈,不利于水生植物生长,通常的浅水湖泊生态修复技术难以应用.本文选取贵州红枫湖这一典型的高原深水湖泊作为试验点,在右二湖湾以浮岛为载体引种多种水生植物,并对植物根茎叶中的氮、磷及重金属成分进行了分析.结果表明:各水生植物氮含量为菹草＞鲁梅克斯＞聚合草,磷含量为菹草＞伊乐藻＞鲁梅克斯,氮、磷元素去除效果较好的植物为菹草、伊乐藻、鲁梅克斯;试验植物对重金属Cu、Cd、Pb、Zn和Hg均具有一定的耐受性,植物内不同重金属的累积浓度为Zn＞Pb＞Cu＞＞Cd＞Hg,重金属富集系数根＞叶＞茎,Zn/Cd比值为叶＞茎＞根;总体上,黑麦草、鲁梅克斯和菹草重金属的富集系数较高;植物中总氮(TN)与总磷(TP)含量呈显著正相关,重金属与营养元素之间不存在明显的相关性.试验表明,陆生植物依靠浮岛载体能在水面较好地生长,可应用于深水型湖泊污染水体生态修复.在实际应用时,需结合水体污染特点和植物吸收特性选择最佳植物组合类型.     

水生植物修复铁污染水体的效果及作用机制

为解决铁离子污染导致水体发黄问题,采用水培试验,分析了水禾、粉绿狐尾藻、圆币草、黄花水龙、大藻和圆叶节节菜等6种水生植物对铁离子污染水体的修复能力,研究了铁离子浓度、pH和植物生物量对水禾修复效果的影响,并探讨了曝气对水禾除铁的强化作用.结果 表明:6种水生植物均不同程度地促进了水中二价铁和全铁的去除,不同植物对铁的去...     

淡水水生植物化感作用研究进展

水生植物的化感作用对淡水生态系统中水草的可持续管理和湖泊富营养化的生态控制具有非常重要的意义。本文综述了淡水水生植物化感作用的发展历史和研究现状,讨论了水生植物化感作用研究过程中所涉及的实验方法、生物测试方法、化感物质分离方法以及影响水生植物化感研究的环境因素。抑藻圈试验、藻类生长试验和浮萍生长试验是常用的生物测试方法;采用共生培养或单独培养的方法,从种植水中分离、鉴定化感物质,对证实复杂水环境中水生植物化感作用的存在,研究它们化感物质的释放途径和作用机理都具有十分重要的作用。     

利用水生植物清除水体中放射性物质的研究：（Ⅲ）水生植物对Sr^90、Y^91、Cs^137、Ce^144的积累、释放及Ca对Sr^90吸收的影响

5种水生植物对所用4种放射性同位素都有一定的清除能力,其清除能力的大小不仅取决于生物的种类,而且还取决于生物本身代谢率的高低。试验结果：去污率高的可达80％,积累系数最高可达1,500;水体中含Ca量的多少对生物吸收积累放射性物质的多少有一定的影响;生物在积累放射性物质之后,转移到无放射性物质的水体中将释放出原积累的一部分放射性物质。     

利用植物多级净化广州污染河涌水体及景观修复设想

对广州市水系污染状况及其综合治污的重要性和必要性进行了分析,对以往靠比较单一的污水处理厂处理污水效果较差的原因从多个角度进行了探究.对于采取建立利用植物多级处理、净化水污染物的立体处理系统的原理、必要性及可行性进行了分析;针对广州市土地紧张,在水厂内难以建立大型植物氧化塘的特点,提出了在各个河涌建立各级以高等植物为主的植物净化系统等措施,对主要技术措施进行了论述,并对其所能达到的改善水生态系统、实现良好的景观效益和生态效益方面进行了深入的探讨.     

4种水生植物对富营养化水体氮磷去除效果的研究

以灯心草、水田芥、菹草和轮藻为试验对象,研究了其在两种不同程度富营养化水体中的生长状况及对水体中总氮(TN)、总磷(TP)、氨氮(NH4+-N)和化学耗氧量(COD)的净化效果。结果表明,在轻度富营养化水体中水田芥效果最好,培养20 d后的水田芥对总氮、总磷、氨氮和化学耗氧量的吸收率分别为75.28%、93.00%、76.35%和83.74%,其它3种水生植物对水体也都有较好的净化效果;在重度富营养化水体中灯心草效果最好,培养20天后的灯心草对总氮、总磷、氨氮和化学耗氧量的吸收率分别为89.30%、83.11%、83.41%和78.56%,但水田芥和轮藻的净化效果相对较差。     

乡土水生植物对富营养化水体的净化效果研究

为了解乡土水生植物净化富营养化水体的效果,研究了广东地区5种乡土水生植物对2种富营养化水体总氮(TN)、总磷(TP)的净化效果和植物的生长状况。结果表明,与无植物空白相比,5种乡土植物使低、高浓度水体的TN去除率分别提高了3.8%～13.3%和13.2%～17.1%,TP去除率分别提高了15.2%～22.1%和11.3%～57.6%,其中野荸荠(Eleocharis plantagineiformis)适用于净化低氮水体;酸模叶蓼(Polygonumlapathifolium)适用于高氮水体;三白草(Saururuschinensis)适用于低磷水体;菱角(Trapa komarovii)适用于低氮或高磷水体;水龙(Ludwigia adscendens)对2种水体均有较好的净化效果,对高磷水体效果极佳。5种乡土植物在低、高浓度水体中均旺盛生长,水龙的生物量净增长率分别达375.5%和539.8%,表现最优,其次为菱角;水葫芦(Eichhorniacrassipes)则在高浓度水体中腐烂死亡,加重了水体污染。水龙、菱角对污染物的吸收作用较强,对P的吸收能力显著优于其他植物(P0.05)。因此,5种乡土植物均可作为广东地区富营养化水体修复的备选植物,其中水龙和菱角的开发潜力最大。     

八种水生植物对重金属富集能力的比较研究

通过野外采样和系统分析方法,研究了芜湖市四褐山工业区附近水域中Cu、Pb、Cd、Zn和Mn5种重金属的含量及其在8种水生植物体内的积累特性。结果表明,工业区水体污染严重,重金属含量严重超标,分别为标准值的9、10.1、400、3和438倍;8种水生植物的重金属积累量均较大,其中以水鳖根、茎叶的Cu、Pb、Cd、Zn含量最高,分别为水体中重金属浓度的9.12和2.59倍、33.41和5倍、0.8和0.3倍、26.9和9.1倍,明显高于其它7种水生植物;8种水生植物不同器官对Cu、Pb、Zn的富集系数均>1,富集能力较强。其中,香蒲对Pb、Cd的吸收能力表现为茎叶>根。结果表明,在Cu、Pb和Zn等重金属复合污染水域的植物治理中,浮萍、香蒲、水鳖、中华慈姑、芦苇、空心莲子草等植物有着较大的发展潜力和应用前景。     

Energy content of water- and bog-plant associations in the region of Valdivia (Chile)

Summary Mapping the vegetation of the littoral zone of different types of aquatic habitats in the region of Valdivia (Chile) submerged Egerietum densum, the emergent Sagittario-Alismetum and the Scirpetum californiae were found. In the littoral zone of the banados (i.e. lakes) formed by inundation after subsidence the submerged Egerietum densum, the floating-leaved Polygono-Jussiaetum and the emergent Juncetum procerii; the analyzed pond of Mehuin contained the Callitrichetum stagnalis chilensis and the artificial ponds close to La Union the Lemno-Azolletum. The caloric values of 18 hydrophytes showed a decline from the large emergent hydrophytes (3 818 cal/g) to the submerged (2 907 cal/g) and there was also a decrease from the free-floating (3 652 cal/g) to the floating-leaved (3 364 cal/g) and to the submerged plants. In the most eases high caloric values correspond to a high content of lignin (large emergent hydrophytes) or lipids (floating-leaved plants).We thank Mrs. Bölke and Mr. Delgado for technical help and the Universidad Austral de Chile, Valdivia for fluancial support.     

Comparative Characterization of the Pigment Complex in Emergent, Floating, and Submerged Leaves of Hydrophytes

The content of chlorophylls (Chls) and carotenoids was studied in the leaves of 42 species of boreal aquatic plants with different degree of submergence (emergent, floating, and submerged) and isopalisade, dorsoventral, and homogenous types of mesophyll structure. Hydrophytes were shown to have a low Chl content (1–2 mg/g fr wt) and low Chls/carotenoids ratio (2.3–3.5) as compared to terrestrial plants. The pigment content per dry wt unit and unit leaf area was dependent on the type of mesophyll structure. It was a consequence of the changes in the parameters of leaf mesophyll structure characterizing the density of photosynthetic elements. In a sequence emergent floating submerged forms, the content of Chls and carotenoids decreased, and the photosynthetic capacity decreased due to a reduction in the chloroplast number per unit leaf area. Adaptation of submerged leaves to low illumination and slow CO₂ diffusion changed the functional properties of chloroplasts. An increase in the pigment content in the chloroplasts of submerged leaves (7 × 10^–9 mg Chl, 2 × 10^–9 mg carotenoids) as compared to emergent and floating leaves was accompanied by a decline in the photosynthetic capacity per Chl comprising 1.6 mg CO₂/(mg Chl h) versus 3.9 and 3.8 mg CO₂/(mg Chl h) in emergent and floating leaves, respectively.     

水生植物在瘦西湖公园中的应用

介绍了瘦西湖公园的概况和目前水生植物在公园中的应用情况,指出了目前园林中应用水生植物时存在的不足,提出了令后的改进措施和努力方向。     

毛竹林和阔叶林凋落物互置对土壤氮矿化的影响及微生物贡献

凋落物输入方式的改变导致凋落物数量和质量发生变化,进而对森林土壤氮矿化产生影响。选择未被入侵的次生阔叶林和毛竹入侵后形成的毛竹纯林为对象,对地表凋落物进行保留、去除与置换处理,采用室内培养法同时添加抗生素(链霉素和放线菌酮)分析真菌和细菌在土壤氮素矿化中的贡献。结果表明：(1)去除凋落物处理使阔叶林土壤净氨化速率增加27.0%,净硝化速率降低11.4%;毛竹林土壤净氨化速率增加23.4%。(2)置换凋落物处理使阔叶林土壤净氨化速率增加43.8%,净硝化速率降低33.5%;毛竹林土壤净硝化速率增加73.1%。(3)添加抗生素后,凋落物置换处理与对照相比,置换凋落物后阔叶林土壤真菌和细菌在净氨化中发挥主要作用;真菌在两种林分土壤净硝化中发挥主要作用,细菌在阔叶林土壤净硝化中发挥主要作用。(4)结合测定的凋落物化学性质可知,置换凋落物后引起真菌和细菌在土壤氮素矿化中贡献发生变化,是由于输入凋落物中木质素和纤维素含量的变化。综上,凋落物去除和置换改变了土壤氮素矿化速率,置换凋落物后改变了真菌和细菌对土壤氮素矿化的贡献。解析凋落物质量在土壤氮素矿化中的作用及微生物群落的相对贡献,有助于阐明毛竹入...     

Drainage ditching at the catchment scale affects water quality and macrophyte occurrence in Swedish lakes

1. We have limited knowledge of the effects of land use in general and of drainage ditching in particular on macrophyte communities in lakes. I quantified catchment land use, including drainage ditching, as well as water quality and the number of macrophyte species in 17 Swedish lakes in summer 2005. 2. Land use within 1 km of the studied lakes was analysed in a geographic information system. The following variables were included: areas of forests, mires, agricultural land and urbanization, length of drainage ditches (classified according to the use of the land they drained), and shortest distance from lake to an urban area. To extract and analyse general trends in the data sets, redundancy analysis was used. 3. Water quality was explained mainly by three land‐use related variables: the lengths of agricultural, forest and mire ditches. The length of agricultural ditches was positively correlated with lake water conductivity, total dissolved solids, Ca, N and total organic carbon (TOC). The lengths of forest and mire ditches were positively correlated with lake water characteristics, especially TOC. 4. The number of species representing different macrophyte life forms was explained by three environmental variables: conductivity, and lengths of forest and agricultural ditches. The numbers of isoetids, nymphaeids, elodeids and total obligate hydrophytes were negatively correlated with length of forest ditches. In contrast, the number of lemnids and helophytes was positively correlated with conductivity and length of agricultural ditches. Furthermore, the number of isoetids was exponentially related (negatively) to lengths of agricultural and forest ditches, indicating a threshold response to drainage ditch length. 5. The results suggest that effects on water quality and macrophyte communities result from drainage ditching in the lake catchments rather than from land use itself. Given the total area of drainage‐ditched land worldwide (millions of ha in Scandinavia alone), drainage ditching should be considered when evaluating environmental impacts on lake water quality and macrophyte occurrence and when determining reference conditions for catchment land use.     

利用水生植物净化河涌污水能力的比较研究

以8种水生植物为材料,在单一、复合种植的组合条件下,对污染物的去除效率及各植物的生长发育状况进行研究.结果表明：总磷、总氮、氨氮、浊度等水质指标的去除速率随着处理时间延长而逐渐升高,而CODMn的去除效果为开始较高,然后有所降低,后期又提高的波动现象.整体上除个别植物种类外,所有组合单元的处理效果均优于对照.经过植物净化处理,原污水的TP含量约为重污染水Ⅴ类水的4倍、TN含量为Ⅴ类水的5~6倍、水中上述污染物有30％~33．3％的种植组合达到Ⅲ类水的水平,其中20％~25％的组合达到了Ⅱ类水的水平.其他20％~30％的种植组合能使TP、TN污染物含量减少2~3倍,污染水水质相当或接近于Ⅴ类水的水平.原污水氨氮含量为Ⅴ类水的6~7倍,经过植物各组合的处理,58．3％组合的水平在Ⅲ类水以上,其中50％的组合达到Ⅱ类水的水平.其他约35％的组合使氨氮含量减少4~5倍,接近Ⅴ类水的水平.在植物形态学指标方面,除个别大薸单元出现负增长及植株坏死外,其余植物根、茎、叶有一定增长,表明植物能适应这样的污水而生长;植物复合种植比单一种植单元的处理表现出更高的净化水平及稳定性,应得到重视;挺水植物比漂浮植物和沉水植物的净化能力强,在水处理实践中可优先考虑.     

Structure of the Photosynthetic Apparatus in Leaves of Freshwater Hydrophytes: 2. Quantitative Characterization of Leaf Mesophyll and the Functional Activity of Leaves with Different Degrees of Submersion

The structure of leaf photosynthetic elements was investigated on 42 boreal plant species characterized by different degrees of submergence (helophytes, neustophytes, and hydatophytes). Six main types of mesophyll structures were identified. Quantitative characteristics for the mesostructure of the photosynthetic apparatus in these groups were determined, such as the size and abundance of cells and chloroplasts in the mesophyll and epidermis, the number of plastids per cell in each tissue, the total surface area of the mesophyll cells, epidermal cells, and chloroplasts per unit leaf area. Analysis showed that quantitative characteristics of the photosynthetic apparatus in hydrophytes are determined by two factors: (a) the degree of leaf submergence and (b) the type of mesophyll structure. With an increasing degree of immersion in water, the mesophyll types change in a sequence isopalisade dorsoventral homogeneous. The leaves become thinner, their weight per unit area diminishes, cells and chloroplasts become less numerous (on a per unit leaf area basis), but their dimensions become larger. Adaptation to aquatic medium is also manifested in the increasing contribution of the epidermal tissue to the overall photosynthesis: in submerged leaves, the epidermis accounts for more than 50% of the photosynthetic activity. The occurrence of six structural types of leaves contrasting in their characteristics was confirmed by discriminatory analysis according to the qualitative parameters of mesophyll.     

自然曝气生物滤床对二级污水处理厂尾水中抗生素的去除效果及影响因素研究

采用自然曝气生物滤床工艺处理污水处理厂尾水中抗生素,对生物滤床中抗生素的去除特点和影响因素进行研究。研究结果发现,自然曝气生物滤床能够有效地去除四环素类抗生素(58±2)%、喹诺酮类抗生素(48±20)%和大环内酯类抗生素(18±11)%。微生物降解和物理吸附是生物滤床去除抗生素的主要途径,而这两种途径的协同作用则延长了生物滤床的运行周期。结果还表明,水力负荷对抗生素的去除效率影响较大,当水力负荷为4.8～6.4m/d时,生物滤床对抗生素有较好的处理效果。此外,水质参数(水温、pH、COD浓度和硝化作用等)在一定程度上也可以影响生物滤床对抗生素的处理效果。