改进型垂直流湿地应用于城市半封闭河道治理技术研究

随着城市河道截污、清淤、驳岸等水环境综合整治工程的推进,河道半封闭化和湖泊化已成为城市水环境新问题.通过对垂直流湿地的基本结构、布水集水系统、基质、湿地植物等进行改进,将其直接构建于城市半封闭河道中,应用于上海市徐汇区漕溪河富营养水体生态恢复工程.近5个月的运行结果表明,在每隔7～10天间歇性流量300～400m3/次的污水补水进量下,改进型垂直流湿地技术和其它生物修复、生态恢复技术结合,消除水体富营养现象,3～5天内大幅度消减水体CODCr、NH3-N、TP等,而且Chla、藻类数量等指标一直维持在较低水平,河道清澈见底.改进型湿地对河水处理效率和系统水力负荷密切相关,水力负荷越高,河道CODCr、NH3-N、TP等消减速度越快.改进型垂直流湿地是城市半封闭河道治理的有效技术措施,根据其运行特点,我们将此工艺定名为复合生态滤床.     

南京外秦淮河河岸带原生植被初步调查

对南京外秦淮河河岸带原生植被进行了初步调查.外秦淮河河岸带原生植被共有28科、50属、53种,其中漂浮植物4种,占7.55%,沉水植物1种,占1.89%,挺水和湿生植物13种,占24.53%,陆生草本和藤本植物24种,占45.28%,乔木和灌木11种,占20.75%.在概括外秦淮河自然环境和分析原生植被主要特征的基础上,提出在进行河岸带植被群落重建时应注重闸下段河岸带植被群落的重建,增加沉水植物、浮叶植物和观赏性植物的种植.另外,植被群落可按河道垂向的常水位以下区域、变化水位区域和洪水位以上区域来构建.     

壳聚糖对沉水植物轮叶黑藻抗污能力的影响

利用化学需氧量(CODCr)分别为318 mg·L-1、157 mg·L-1、30 mg·L-1的生活污水培养轮叶黑藻.在各浓度生活污水中添加浓度为0.1%的壳聚糖,同时设不添加壳聚糖的对照组.通过对轮叶黑藻生长指标和叶绿素、可溶性蛋白质含量及抗氧化酶活性的测定,研究壳聚糖对沉水植物轮叶黑藻抗污能力的影响.结果显示,壳聚糖可明显促进轮叶黑藻主茎、根、分枝的生长,添加壳聚糖的试验组植株的叶绿素、可溶性蛋白质的含量比对照组高,且差异显著.壳聚糖能诱导黑藻超氧化物歧化酶和过氧化物酶活性增高,减轻膜脂质过氧化反应.研究结果提示壳聚糖能够促进黑藻生长,提高黑藻的抗污能力.     

浮床种植观赏植物净化富营养化水体的试验

文章选择风车草、彩叶草和茉莉等观赏性植物对富营养化鱼塘水进行漂浮种植试验，观察植物的生长适应情况，评价供试植物对水样中COD、N、P等污染物的净化效果。结果表明，风车草和彩叶草可以正常生长，但茉莉的生长适应能力较差；3种植物对富营养化水样均有较好的净化效果，其中风车草效果最佳。     

其他

X799.303 200401808 植物在城市生活污水人工土快滤处理床的作用/ 朱夕珍(华南农业大学资源环境学院)…//农业环境科学学报/中国农业生态环保协会.-2003,22 (5).-582-584 环图X-15 采用人工土柱植物种植方法,研究了两种植物(水葫芦、万寿菊)在人工土快滤-植物复合床上对城市生活污水的处理作用。6个月的运行结果表明,种植植物后的人工土快滤系统对CODCr、     

人工污水释放对白骨壤模拟湿地系统土壤理化性质的影响

在温室中建立红树林植物白骨壤模拟湿地系统，分别用正常(NW)、5倍(FW)和10倍(TW)浓度的人工配置的污水每周定时定量对模拟系统污灌2次，用海水作对照(CL)，持续1a。研究污灌对模拟湿地系统土壤理化性质的影响。结果表明：经过1a的污水处理，白骨壤模拟湿地系统的土壤理化性质未发生显著改变，种植其上的白骨壤植物能维持正常生长。     

关于运用人工湿地处理城市污水的思考

目前许多城市污水处理能力还不能满足截污需要，为此，应当运用人工湿地污水处理技术进行治理。从生物净化原理看，人工湿地是一项新型的污水处理技术一株芦苇的根系连接起来长达１公里，能吸附污水中的氮和磷等多种物质。人工湿地生态系统水质净化技术的基本原理是：在一定的填料上种美人蕉、富贵竹、芦苇等特定的植物，将污水投入到人工建造的类似于沼泽的湿地上，进行水流结构、最适合植物微生物组合等方面的优化。当富营养化水流过人工湿地时，经沙石、土壤过滤，植物根际的多种微生物活动，包括好氧和厌氧过程和植物吸收，将水中的污染…     

碳纤维湿地式浮床对微污染水体的净化研究

首先研究了千屈菜(Lythrum salicaria Linn)、小香蒲(Typha minima Funk)以及黄菖蒲(Iris pseudacorus)3种较适合北方种植的耐寒植物在微污染水中的生长状况及对污水的净化效果,其次研究了碳纤维湿地式生态浮床系统对微污染水体中各指标的净化效果。结果表明,综合分析生长状况及对污水的净化效果,最适合用于浮床的植物依次是千屈菜、小香蒲、黄菖蒲。在水力停留时间1 d及气水比为2∶1的条件下,种植了千屈菜的碳纤维湿地式生态浮床对污水中的浊度、COD、NH4+-N以及TP都有很好的去除效果,平均去除率分别为96.47%、83.76%、90.48%及81.58%以上。但浮床系统对微污染水体中的TN去除效果不佳,平均去除率仅为15.80%。     

几种水草清污能力的测定

随着环境问题的日益严重，水污染问题引起了人们的注意，本采用对比实验的方法对几种水草在不同水质条件下净化作用（COD值）及其生理反应（叶绿素，SOC，蛋白质）进行比较测定，发现这几种水草都具有较强的清污能力，在污水中，苦草的耐污能力较强，微齿眼子菜急性耐污能力较强，菹草的耐污能力最好，且适合在冬季种植，同时，水草量的多少对水质的净化也有一定的关系，建议在治疗的同时，应该控制污水的直接排放。     

中小城市污水排水问题及对策研究

为解决中小城市污水排水问题,进一步加强城市排水管理,改善城市水环境,杜绝雨污混排,提高污水处理率,分析和探讨了中小城市在污水排水系统建设、管理、维护中存在的问题,针对排水法规不健全、污水管网不完善、雨污分流难、管理不到位等问题进行原因分析,提出加强排水制度建设、加快排水设施的建设、加强排水管理、加强宣传教育等措施.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Effect of sorbed and desorbed Zn(Ⅱ) on the growth of a green alga (Chlorella pyrenoidosa)

Toxic effect of Zn(Ⅱ) on a green alga (Chlorella pyrenoidasa) in the presence of sepiolite and kaolinite was investigated.The Zn-free clays were found to have a negative impact on the growth of C.pyrenoidosa in comparison with control samples (without adding any clay or Zn(Ⅱ)).When Zn(Ⅱ) was added,the algae in the presence of clays could be better survived than the control samples,which was actually caused by a decrease in Zn(Ⅱ) concentration in the solution owing to the adsorption of Zn(Ⅱ) on the clays.When the solution system was diluted,the growth of algae could be further inhibited as compared to that in a system which had the same initial Zn(Ⅱ) concentration as in the diluted system.This in fact resulted from desorption of Zn(Ⅱ) from the zinc-contaminated clays,although the effect varied according to the different desorption capabilities of sepiolite and kaolinite.Therefore the adsorption and desorption processes of Zn(Ⅱ) played an important part in its toxicity,and adsorption and desorption of pollutants on soils/sediments should be well considered in natural eco-environmental systems before their risk of toxicity to aquatic organisms was assessed objectively.