天津城市生态系统健康分析与评价

从城市生态系统健康的概念出发，选择活力、组织结构、恢复力、生态系统功能的维持、人群健康状况5个要素作为城市生态系统健康依据，建立了城市生态系统健康评价指标体系；运用主成分分析法确定出主要指标及权重；借鉴城市生态系统健康评价模型，对天津城市生态系统健康进行定量评价。结果表明：2001-2005年，天津城市生态系统总体处于亚健康状态；天津市城市生态系统中恢复力、生态系统功能的维持和人群健康为优势要素，活力和组织结构为限制要素。最后针对天津生态系统健康存在的问题。提出了相应的对策措施。     

南充市城市生态系统健康评价

城市生态系统是一个综合性、复杂性的大系统,涉及到城市自然环境、社会经济、人群健康状况、资源状况、环境状况和城市基础设施等各个方面,健康的城市生态系统是人类所向往的目标.从生态系统健康的内涵出发,依据城市生态系统的特殊性,建立了城市生态系统健康评价指标体系;运用AHP法确定了城市生态系统健康评价各指标要素之间的权重;采用模糊数学法的原理建立城市生态系统健康评价模型.将该模型方法应用于南充市城市生态系统健康评价,通过评价得出:南充城市生态系统健康状况为"亚健康"状态,其隶属度为0.329.     

基于未确知测度的城市生态系统健康评价

在参考相关研究成果的基础上建立评价指标体系及分类标准,采用熵权法求得各评价指标的权重,应用未确知测度方法构建评价模型,并运用该模型对六盘水市城市生态系统健康进行评价分析。结果显示:六盘市城市生态系统健康活力要素处于疾病状态,组织结构要素处于不健康状态,恢复力要素处于亚健康状态,生态系统服务功能要素为疾病状态,人群健康要素处于不健康状态,城市生态系统健康综合评价属于不健康状态。通过研究,掌握了六盘水市的城市生态系统健康现状,为六盘水市的可持续发展提供了科学参考。     

六盘水市城市生态系统健康动态评价研究

城市生态系统健康直接关系到城市的可持续发展,针对目前评价缺乏统一标准的问题,从城市生态系统健康的概念和内涵出发,参考国内外生态城市、园林城市等,根据国际、国内有关标准,选取自然子系统、社会子系统和经济子系统建立评价指标体系,运用均方差法和属性理论构建评价模型,并对六盘水市2001-2010年城市生态系统健康评价进行实例研究。评价结果表明,六盘水市城市生态系统健康逐渐好转,从疾病状态发展到亚健康状态,总体呈上升趋势。但前景不容乐观,第三产业占GDP比重、城市生活垃圾无公害化处理率、工业固体废物综合利用率、万人拥有大专学历人数、万元GDP物耗、单位GDP水耗、单位GDP能耗一直维持在很低的水平,是胁迫六盘水市城市生态系统健康发展的主要因子。通过评价研究,了解了六盘水市城市生态系统健康的基本状况,为六盘水市的规划建设提供了参考。     

城市生态系统健康评价方法及其应用研究

通过定性和定量分析建立了一套相对完整的评价指标体系,采用因子分析法赋予指标权重,应用模糊数学方法构建评价模型,并对重庆市城市生态系统健康状态进行了实例研究.结果表明,重庆生态系统健康在结构功能方面属于病态;可持续利用能力和动态变化方面属于亚健康状态,城市生态系统健康综合状况属于亚健康状态.以北京、天津、上海作为参比城市进行了对比评价,得出北京、天津和上海也均处于亚健康状态的结论;但4个城市生态系统整体健康状况排序为:上海、北京、天津、重庆.通过此评价,明确了重庆城市生态系统健康的状况及其影响因子,了解了重庆与其它3个直辖市的健康差距,为重庆城市生态规划与保护提供科学依据.     

基于MIEP模型的城市生态安全评价——以宁波市为例

基于城市生态安全内涵,运用PSR(压力-状态-响应)模型建立了宁波市生态安全评价指标体系,并以最大信息熵原理(MIEP)为基础,自组织特征映射神经网络(SOFM)为算法,借助MATLAB数学软件为计算平台,从复杂系统结构演化的角度提出了城市生态安全评价模型.最后,用MIEP模型对宁波市2002—2011年的城市生态安全进行评价.结果表明,2002—2011年宁波市生态安全水平逐年提高,2002—2009年处于临界安全状态,2010、2011年处于较安全状态.由于MIEP模型能较好地体现城市生态安全的时空演变动力学特性,连接权值的获取避免了人为设定的主观性,故在城市生态安全评价中有较明显的优势,且在预测上有一定的潜力.     

基于熵值法和GM(1,1)模型的重庆城市生态系统健康评价

应用信息熵值反映数据本身的效用值来计算指标权重系数,建立熵权综合评价模型,对重庆城市生态系统健康进行了评价.根据评价结果和灰理论数学建模特点,建立GM(1,1)灰色预测模型,对重庆市生态系统健康进行了动态预测分析.结果表明:2005~2009年期间,重庆城市生态系统健康总体水平良好,其中各要素指数评价大小依次是活力指数、恢复力指数、组织结构指数、服务功能指数、人群生活指数;2010~2015年期间,重庆城市生态系统健康综合评价值将以e0.1268的增速保持良好发展态势.此外,建立以熵权综合评价为基础的GM(1,1)灰色预测模型对城市生态系统健康进行评价,能够得出更客观、更全面的评价结果.     

基于未确知测度模型的生态系统健康评价

文章基于未确知测度模型对城市健康水平进行评价分析,建立以人群健康、城市福祉、人居健康、环境健康、生境健康和环境影响六大要素评价指标体系,通过建立多指标综合测度矩阵,对包头市2001-2005年评价样本进行宏观分析,得出城市的发展建设过程中存在的问题,并提出改善城市生态系统健康水平对策。     

基于信息熵和GM(1,1)的上海市城市生态系统演化分析与灰色预测

城市生态系统是典型的"自然-社会-经济系统",城市的可持续发展依托于城市生态系统结构和功能的不断协调与完善.新一轮"城市化"进程中,城市生态系统将面临生态用地减少、环境衰退等诸多挑战,生态环境和经济发展之间的矛盾可能日益突出.因此,把握城市生态系统的演化方向,对于促进城市可持续发展和生态文明建设意义重大.本研究以"国际化大都市"上海市为研究对象,运用"耗散结构理论"和"信息熵"分析模型,构建包括支持型输入熵、压力型输出熵、氧化型代谢熵、还原型代谢熵4方面的"上海市城市生态系统演化指标体系",以统计资料和政府公报为数据来源,对上海市2003—2013年的城市生态系统演化进行了熵变分析;基于集成层次分析法(AHP)和熵权法(EVM)"综合赋权"的"综合发展度"和"协调发展度"模型对城市生态系统可持续发展状况进行了评价;采用"相关分析法"对城市生态系统熵变与可持续发展协同演化过程进行量化分析;并引入GM(1,1)灰色预测模型对上海市城市生态系统(2014—2020)年的演化趋势和方向做出了预测.研究得出以下结论:12003—2013年,上海市城市生态系统"熵流、熵产生和总熵变",均整体呈波动下降趋势.上海市城市生态系统有序度不断提高,总体朝健康态势发展.22003—2013年,上海市城市生态系统总体可持续发展态势良好,不断向健康可持续方向演进;环境与经济整体效益不断提高,但环境与经济发展之间的协调能力近年来有所下降.3上海市城市生态系统(2014—2020)期间的演化趋势预测:城市生态系统整体继续向健康、有序方向演进.城市生态系统可持续发展整体保持协调发展态势,但未来发展协调度可能从"初级协调"衰退为"勉强协调".最后,基于指标"熵权"和熵变时序提出了上海市城市生态系统的针对性优化措施:积极扶持城市生态农业发展,扩大进出口贸易规模,促进娱乐教育文化服务产业增长;进一步提高居民生态环保意识,提倡低碳生活;加强工业"三废"的达标排放,提高资源利用率,巩固城市绿化率,加大环保投资规模.本研究旨在为上海市城市生态系统健康可持续发展和优化调控提供一定的科学参考.     

北京市城市生态系统健康评价

文章从城市生态系统健康的内涵出发,在总结城市生态系统健康评价研究进展的基础上,运用模糊数学评价法对2001～2005年北京市城市生态系统健康进行定量诊断分析。结果表明,近5a来,北京市城市生态系统健康状况逐年提高,但尚未达到健康的理想水平,未来还有很大的发展空间。城市生态系统健康状况各要素中恢复力、生态系统服务功能、人群健康状况为优势要素,活力和组织结构是胁迫城市健康发展的不利因素。在此基础上提出改善城市生态系统健康状况的对策和措施。     

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.     

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.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.     

Seed selections for crystallization of calcium phosphate for phosphorus recovery

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.