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1.
分析了洪泽湖湿地生态系统属性及其在南水北调工程实施后的演变趋势,利用野外实验研究,在生境改变条件下,适用于不同湿地退化状况的人工辅助恢复技术;在实验监测的基础上,对洪泽湖几种典型湿地生态系统的生态功能进行了定量评价,为生态恢复工程的设计提供必要的技术支持。  相似文献   

2.
湿地环境保护的思考   总被引:2,自引:0,他引:2  
简述了中国湿地的现状,介绍了湿地的生态功能、经济功能和社会功能,进而指出了当前中国对湿地环境保护方面存在的众多问题。当前,中国的湿地生态环境受到了越来越严重的威胁,保护好湿地生态环境,实现人与自然的和谐相处。是关系到人类自身可持续发展的大事。  相似文献   

3.
湿地生态地球化学研究进展   总被引:5,自引:0,他引:5  
湿地生态地球化学研究是湿地研究的核心内容之一, 是研究其物理过程、化学过程和生物过程及其相互关系以及这些过程与湿地功能的关系.回顾了近年来国内外湿地生态地球化学方面的研究成果,介绍了它的概念,并评述了湿地的生态功能、元素地球化学、生物地球化学、湿地模型和3S技术等新技术在湿地研究中的应用等方面的研究进展.提出了中国湿地生态地球化学研究的优先领域,应加强湿地基础理论研究及在湿地的演化、生态过程、界面过程、预测与评价、信息系统等方面的研究.  相似文献   

4.
从建湖县“九龙口”省级风景名胜区湿地的实际出发,分析了湿地生态保护的必要性,根据保护原则,提出了相应的保护措施。  相似文献   

5.
人工湿地在污水处理中的研究进展   总被引:1,自引:0,他引:1  
人工湿地作为一种新型的生态处理工艺,在生活污水处理方面得到了广泛的应用,因此,总结了人工湿地的发展及应用情况,重点回顾了一些改进方法,包括进水方式、湿地植物选择、人工基质及其在寒冷地区的应用。  相似文献   

6.
监测了南京市的主要水系:长江、秦淮河和玄武湖水体表层的沉积物中Hg、Cd、Pb、Cu、As、Cr和zn等7种元素含量,分析了元素的富集程度,采用Hakanson潜在生态危害指数法对其生态危害程度进行了评价。结果表明:长江和玄武湖水系沉积物中,7种元素含量属于低潜在生态风险,秦淮河沉积物则呈较高潜在生态风险;7种元素的富集系数均为,秦淮河〉玄武湖〉长江,长江Cd元素的富集系数最大,为3.18,秦淮河和玄武湖两水系都是Hg的富集系数最大,分别为11.78和3.33;就元素的生态风险而言,长江水体表层沉积物中,7种元素属低潜在生态风险,玄武湖表层沉积物中,除Hg属中潜在生态风险外,其余6种元素属低潜在生态风险,秦淮河表层沉积物的7种元素生态风险由高到低,依次为Hg〉Cd〉Cu〉As〉Zn〉Pb〉Cr,Hg和cd分别属高潜在生态风险和较高潜在生态风险,其余5种元素属低潜在生态风险。  相似文献   

7.
刍议长三角地区的生态建设   总被引:1,自引:0,他引:1  
长三角地区城市化和工业化带来区域经济迅猛发展的同时,也导致了长三角生态系统组分比例失调、结构缺损、功能丧失、环境容量萎缩等生态问题.湿地兼有自然"肾"、"肺"双功能.利用长三角地区湿地生态系统的独特性和内在优势,加强湿地生态建设、生态保护、生态恢复与生态重建,拓展环境容量,可保障该区域可持续发展的实现.从地质地貌、自然史发展、自然经济学和区域发展等角度探讨了长三角地区湿地的生态服务价值的现存价值和理论价值,分析讨论了长三角自然湿地、城市区湿地和农业区湿地的生态建设思路.  相似文献   

8.
《环境污染与防治》2006,28(2):142-142
我国长江流域湿地保护正在受到关注。2005年11月8日,《湿地公约》缔约方常务委员会召开的第九届缔约方大会,授予中国科学院测量与地球研究所蔡述明湿地保护科学奖。洪湖生态环境因工业发展和人口增加曾一度严重恶化。中国国家林业局和湖北省人民政府根据蔡述明反映的洪湖生态受到破坏的情况,立即采取行动,采纳了蔡的7条建议,投入9000多万元整治洪湖,使洪湖生态面貌较快得到改善。  相似文献   

9.
白鳍豚(Yangtge River Dolphin),中国国家一级保护动物,拉丁学名:Lipotes vexillifer。2006年,来自中国、美国、英国、日本、德国和瑞士等国近40名科学家,对宜昌-上海长江中下游的干流1700km江段进行了考察,未发现一头白鳍豚。  相似文献   

10.
在已建成的石驳岸河道中构建生态岛,不但可以改善生态景观效果,还可以提高水体净化能力。将生态岛和湿地技术结合起来,设计了2种生态岛类型:以泥土为基质的常规型生态岛和以砂石为基质的湿地型生态岛,并对2种生态岛的水体交换能力和水体净化效果进行了研究,结果表明:在水体波动条件下,无植物、栽培鸢尾和芦苇的3个湿地型生态岛的水体交换率最高分别达到90.6%、31.0%和84.0%,分别比常规型生态岛高7.8倍、2.6倍和6.8倍;对总磷、总氮、氨氮的平均去除率分别达到37.4%、41.7%和31.6%,比常规型生态岛提高了15.2%、11.7%和8.4%,因此,湿地型生态岛比常规型生态岛具有更好的水体交换能力和水体净化能力。  相似文献   

11.
The stereoselectivity of R,S-venlafaxine and its metabolites R,S-O-desmethylvenlafaxine, N-desmethylvenlafaxine, O,N-didesmethylvenlafaxine, N,N-didesmethylvenlafaxine and tridesmethylvenlafaxine was studied in three processes: (i) anaerobic and aerobic laboratory scale tests; (ii) six wastewater treatment plants (WWTPs) operating under different conditions; and (iii) a variety of wastewater treatments including conventional activated sludge, natural attenuation along a receiving river stream and storage in operational and seasonal reservoirs. In the laboratory and field studies, the degradation of the venlafaxine yielded O-desmethylvenalfaxine as the dominant metabolite under aerobic and anaerobic conditions. Venlafaxine was almost exclusively converted to O-desmethylvenlafaxine under anaerobic conditions, but only a fraction of the drug was transformed to O-desmethylvenlafaxine under aerobic conditions. Degradation of venlafaxine involved only small stereoisomeric selectivity. In contrast, the degradation of O-desmethylvenlafaxine yielded remarkable S to R enrichment under aerobic conditions but none under anaerobic conditions. Determination of venlafaxine and its metabolites in the WWTPs agreed well with the stereoselectivity observed in the laboratory studies. Our results suggest that the levels of the drug and its metabolites and the stereoisomeric enrichment of the metabolite and its parent drug can be used for source tracking and for discrimination between domestic and nondomestic wastewater pollution. This was indeed demonstrated in the investigations carried out at the Jerusalem WWTP.  相似文献   

12.
Polychlorinated-dibenzo-p-dioxins and -dibenzofurans (PCDD/Fs) were measured in soils and sediments from the Yellow Sea region. Korean soils and sediments mostly contained detectable PCDD/Fs and showed a widespread distribution among locations. Soil and sedimentary PCDD/Fs from China were comparable to or less than those in Korea. The patterns of relative concentrations of individual congeners in soils were different between the two countries, but similar in sediments. Sources of PCDD/Fs in China and Korea were found to be independent of each other and their distributions reflected matrix-dependent accumulation. Spatial distribution indicated some point sources in Korea while Chinese sources were more widespread and diffuse. PCDD/Fs measured in the coastal areas of the Yellow Sea were comparable to or less than those previously reported in for eastern Asia. However, ∑TEQs in soils and sediments were near to or, in some cases exceeded environmental quality guidelines.  相似文献   

13.
剩余污泥浓缩脱水投药量优化和模型建立   总被引:1,自引:1,他引:0  
李振华 《环境工程学报》2011,5(12):2797-2800
应用高分子阳离子絮凝剂(CPF-100)和聚丙烯酰胺(PAM)对污水厂剩余污泥进行浓缩脱水实验,研究表明:CPF-100的浓缩脱水效果优于PAM;当CPF-00投加量为1.16‰时,污泥沉降性能改善程度为37.51%;且在CPF-100投加量逐渐增大的初始阶段,污泥沉降性能改善程度随投加量的增加而增大,但CPF-100投加量也不宜过大,当CPF-100投加量超过1.16‰后,反而会使浓缩脱水效果变差。同时,建立了污泥沉降性能改善程度与絮凝剂CPF-100投加量、沉降时间之间的数学模型,其能较好地反映污水厂剩余污泥的浓缩脱水效果。  相似文献   

14.
骆马湖富营养化和生态状况调查与评价   总被引:5,自引:0,他引:5  
为了了解骆马湖水质状况,在2005年对骆马湖富营养化状态和生态特性进行了调查,并结合“十五”期间的监测资料进行了分析。2005年骆马湖水体中总氮和总磷的平均值超《地表水环境质量标准》(GB3838-2002)中Ⅲ类,超标情况分别为0.78倍和0.54倍,达到湖库特定项目Ⅳ类水标准,骆马湖处于轻度富营养化状态。对骆马湖生态特征分析表明,由于该湖泊的形态以及“藻型浊水状态”和“泥沙型浊水状态”交替出现,遏制了湖水从高营养盐含量向全面富营养化状态演变,保障了底栖动物的良好生长环境,从而形成了骆马湖独特的环境生态平衡。  相似文献   

15.
The chlorination and condensation of acetylene at low temperatures is demonstrated using copper chlorides as chlorinated agents coated to model borosilicate surfaces. Experiments with and without both a chlorine source and borosilicate surfaces indicate the absence of gas-phase and gas-surface reactions. Chlorination and condensation occur only in the presence of the copper catalyst. C2 through C8 organic products were observed in the effluent; PCDD/F were only observed from extraction of the borosilicate surfaces. A global reaction model is proposed that is consistent with the observed product distributions. Similar experiments with dichloroacetylene indicate greater reactivity in the absence of the copper catalyst. Reaction is observed in the gas-phase and in the presence of borosilicate surfaces at low temperatures. The formation of hexachlorobenzene is only observed in the presence of a copper catalyst. PCDD/F were only observed from extraction of the borosilicate surfaces. A global reaction model is proposed for the formation of hexachlorobenzene from dichloroacetylene.  相似文献   

16.
Abstract

The degradation of profluralin [N‐(cyclopropylmethyl)‐α,α,α‐trifluoro‐2,6‐dinitro‐N‐propyl‐]p‐toluidine] and trifluralin (α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine) was studied under aerobic and anaerobic soil conditions. Three soils (Goldsboro loamy sand, Cecil loamy sand, Drummer clay loam) were each treated with 1 ppmw herbicide; anaerobic conditions were maintained by flooding. Soil samples were extracted monthly and subjected to TLC analysis. No degradation was detected in sterile controls. Aerobic degradation of both herbicides was greatest in the Cecil loamy sand soil over the entire incubation period. Degradation of profluralin in Cecil soil under aerobic conditions was 86 percent after 4 months with three products detected; 83 percent of the trifluralin was degraded with two products detected. Anaerobic degradation accounted for 72 percent of the profluralin and 78 percent of the trifluralin after 4 months. Degradation of both herbicides increased with incubation time for the first 3 months and decreased slightly thereafter. Generally there was more extensive degradation (percent and in number of products formed) of profluralin than trifluralin under the conditions tested. More degradation products were detected for both herbicides under aerobic conditions than under anaerobic conditions.  相似文献   

17.
A biomass-generated soot was sequentially treated by HCl-HF solution, organic solvent, and oxidative acid to remove ash, extractable native organic matter (EOM), and amorphous carbon. The compositional heterogeneity and nano-structure of the untreated and treated soot samples were characterized by elemental analysis, thermal gravimetric analysis, BET-N2 surface area, and electron microscopic analysis. Sorption properties of polar and nonpolar organic pollutants onto the soot samples were compared, and individual contributions of adsorption and absorption were quantified. The sorption isotherms for raw sample were practically linear, while were nonlinear for the pretreated-soot. The removal of EOM enhanced adsorption and reduced absorption, indicating that EOM served as a partitioning phase and simultaneously masked the adsorptive sites. By drastic-oxidation, the outer amorphous carbon and the inner disordered core of the soot particles were completely removed, and a fullerene-like nanoporous structure (aromatic shell) was created, which promoted additional π-π interaction between phenanthrene and the soot.  相似文献   

18.
A new approach for the identification of suspect trace organic contaminants in drinking and surface waters is presented. Samples were initially analyzed using a target determination method for two contamination tracers, carbamazepine (CBZ) and atrazine (ATZ). This method used offline solid-phase extraction and online solid-phase extraction techniques coupled to liquid chromatography-triple quadrupole mass spectrometry to accelerate the sample preparation process and improve method performance. CBZ and ATZ were found respectively in 31% and 56% of the samples, and concentrations were usually <20 ng L−1. These samples were re-analyzed with a similar method on a quadrupole time-of-flight mass spectrometer to identify suspect contaminants by means of exact mass measurements and isotope patterns. A database of 264 common organic contaminants was built and used in conjunction with a Molecular Feature algorithm to identify the presence of these substances in drinking and surface water collected from different sources at various locations across Canada. Several organic contaminants were identified in the samples, but only the presence of caffeine, desethylatrazine, simazine and venlafaxine could be verified by comparison to pure standards. The presence of desethylatrazine was also confirmed by MS/MS experiments. These results suggest that target analysis for tracers of organic contamination may be a helpful tool to prioritize samples which should be further screened for suspect contaminants. This study also shows that the combination of separation techniques (offline and online SPE, LC) contribute to advance the applicability of high-resolution mass spectrometry for the identification of trace organic contaminants by accelerating the preparation step, reducing complexity and increasing analyte concentrations for optimal detection.  相似文献   

19.

The bioavailability of pollutants, pesticides and/or their degradation products in soil depends on the strength of their sorption by the different soil components, particularly by the clay minerals. This study reports the sorption-desorption behavior of the environmentally hazardous industrial pollutants and certain pesticides degradation products, 3-chloroaniline, 3,4-dichloroaniline, 2,4,6-trichloroaniline, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol on the reference clays kaolinite KGa-1 and Na-montmorillonite SWy-l. In batch studies, 2.0 g of clay were equilibrated with 100.0 mL solutions of each chemical at concentrations ranging from 10.0 to 200.0 mg/L. The uptake of the compounds was deduced from the results of HPLC-UV-Vis analysis. The lipophilic species were best retained by both clay materials. The most lipophilic chemical used in the study, 2,4,6-trichloroaniline, was also the most strongly retained, with sorption of up to 8 mg/g. In desorption experiments, which also relied on HPLC-UV-Vis technique, 2,4,6-trichloroaniline was the least desorbed from montmorillonite. However, on kaolinite all of the compounds under study were irreversibly retained. The experimental data have been modelled according to the Langmuir and Freundlich isotherms. A hypothesis is proposed concerning the sorption mechanism and potential applications of the findings in remediation strategies have been suggested.  相似文献   

20.
PCDD and PCDF were found in urban air particulates from St. Louis and Washington, D.C., and in sediments from the Great Lakes and Siskiwit Lake, Isle Royale. The similarity between the PCDD and PCDF found in air particulates and sediment samples and the presence of PCDD and PCDF in sediment from Siskiwit Lake (a location which can receive only atmospheric inputs) suggest that these compounds are emitted to the atmosphere from combustion sources. The historical input of PCDD and PCDF to dated sediment cores shows a strong increase since 1940, and this suggests that the incineration of chlorinated organic compounds is an important source of PCDD and PCDF to the environment.  相似文献   

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