人工湿地生态安全评价指标体系的构建

由于人工湿地涉及的资源范围广、要素多、联系复杂,因此人工湿地生态安全评价指标体系的构建过程中指标的选取与量化具有模糊性和不确定性。本文利用层次分析法理论建立了人工湿地生态安全评价指标体系,通过专家打分,并采用层次分析法计算出各评价指标的权重,从而定量分析了各指标对人工湿地生态安全影响的重要性。该研究可为人工湿地生态安全评价提供参考依据。     

洞庭湖区湿地生物多样性保护及其可持续利用

洞庭湖区是我国最大的淡水湖泊湿地之一，复杂多样的湿地类型和生态环境蕴含了丰富的生物资源，但长期以来由于人类不合理的开放利用，导致了洞庭湖区湿地面积和景观结构发生了很大变化，湿地生态功能也遭到严重破坏，生物多样性不断减少，本文分析了洞庭湖区湿地生物多样性现状及保护的意义，湿地生物多样性面临的威胁，并提出了洞庭湖区湿地生物多样性保护及其可持续利用的主要对策。     

松北区湿地生态系统健康评价及恢复对策

运用湿地健康评价指标体系,对松北区湿地健康进行了评价。采用专家咨询法及层次分析法确定各指标权重,用模糊综合评价法对松北区湿地生态系统健康评价,并对结果进行了诊断分析及预警分析。针对评价结果进行松北湿地生态系统健康影响因素分析,得出影响因子既有湿地自身生态过程,也有人类活动作用,人类活动的影响最大。针对生态健康影响因素提出了松北区湿地健康的恢复对策。     

洞庭湖区湿地生态系统存在的问题及其对策研究

洞庭湖是我国最大的淡水湖泊湿地景观生态系统之一,湿地资源丰富.由于泥沙淤积,洞庭湖区调蓄容积减少、洪水位不断抬升、江湖关系改变.在加重湖区的防洪负担、造成严重的洪涝灾害的同时,也降低了湖泊水体对各种污染物的稀释自净能力和水环境承载能力,导致湖泊湿地生态系统严重退化.本文分析了洞庭湖区湿地生态系统的功能,找出了导致洞庭湖区湿地生态系统退化的原因,并针对原因提出了一系列对策,以期恢复其原有功能.     

盐城海滨湿地生态风险评价

分析盐城海滨湿地的主要生态环境问题,筛选自然灾害,综合污染,互花米草作为主要风险源,以盐城海滨湿地保护的目标种丹顶鹤和其他珍稀鸟类及生境作为评价受体进行研究,以物种重要性指数、生物多样性指数和自然度指数计算生态指数;依据生态指数和生态脆弱度指数来计算生态损失度指数;最后以生态损失度指数,自然灾害指数,综合污染指数,互花米草入侵指数来构建盐城海滨湿地生态风险评价的指标体系,并进行盐城海滨湿地的生态风险评价。     

双台子河口湿地植被修复生境健康评价方法研究

以2014—2015年双台子河口滨海湿地植被修复20个站位调查资料为基础,对湿地修复结构指标、功能指标和环境指标进行研究,结合湿地生态系统健康理论,构建湿地生态环境健康评价指标体系。运用层次分析法(AHP)确定权重,对各个指标赋予权重,将健康评价分为3个等级,确立了生态健康评价方法,对近岸破损湿地翅碱蓬修复生境进行评价。进一步引用评价净影响值(EI)方法判断生境修复前、后的健康对比状态,从而确定翅碱蓬对该破损湿地的修复效果显著。从景观生态学和健康评价角度分析来看,建立此评价方法是可行的,可为今后湿地的管理与保护提供科学依据。     

基于层次分析法的洞庭湖生态安全评估

采用"驱动力-压力-状态-影响-风险"模型,选取14项指标,构建洞庭湖生态安全评价指标体系.利用层次分析法确定各指标的权重,运用生态安全度计算模型,对2000,2005,2007年洞庭湖生态安全状况进行分级评价.结果表明,与20世纪80年代相比,2000年洞庭湖区评价级别处于安全状态;2007年处于一般状态,生态安全状态水平下降,状态得分值仅为基准年的57.2%.对状态做进一步分析可知,TP和Chl.a是造成洞庭湖水生态状况恶化的主要原因.     

湿地生态完整性评价方法研究进展

系统介绍了目前湿地生态完整性评价方法,包括湿地评价技术、水文地貌分类法、生物完整性指标法、生境适宜性指标法、指示生物法、环境清单法和河流保护评价系统等,讨论了每种方法的优缺点,并指出由于传统湿地监测需要花费大量的时间与财力,加之许多湿地地理位置较为偏远,因此建立湿地快速评价指标体系的评价方法成为当今主要发展趋势.     

基于GIS的海岛生态脆弱性评价研究与实践——以海坛岛为例

基于生态敏感度、生态弹性度和生态压力度,构建了海岛生态脆弱性评价的指标体系,采用综合指数法和GIS相结合的方法对海坛岛的生态脆弱性进行了定量评价,并绘制了生态脆弱性等级分布图,分析了生态脆弱度的空间差异和不同区域生态脆弱性的主导成因.评价结果与该区域的生态环境状况较为一致,对于海坛岛的生态保护和资源利用具有一定的指导意...     

黄河三角洲湿地生态保护红线区选划研究

滨海湿地具有非常重要的生态服务功能,针对其独特的地理区位和资源特征,划定区域湿地生态保护红线,对于生态红线制度的落实和滨海湿地开发利用管理具有重要意义.本研究以黄河三角洲湿地为例,基于陆海统筹原则,建立滨海湿地区域生态保护红线区选划评价指标体系,采用GIS空间分析方法实现对湿地生态服务功能重要性和生态环境敏感/脆弱性的评价,划定黄河三角洲湿地生态保护红线范围,并提出分级管控要求.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.