黄河中上游能源化工区重点产业发展战略土地资源承载力评价

结合黄河中上游能源化工区重点产业发展战略土地资源影响特点,探索了战略环评土地资源承载力评价方法和思路. 以土地资源优势、劣势、机会和威胁(SWOT)分析和主成分分析(PCA)为研究手段,构建了涵括土地资源生态属性、经济属性及社会属性的土地资源综合承载力评价指标体系,研究了重点产业战略实施前后土地资源综合承载力空间变化,深入剖析了重点产业发展战略的环境合理性. 结果表明:黄河中上游能源化工区重点产业战略实施后,能源重化工产业重点布局、大规模发展区域综合土地资源承载力指数较现状降低10%以上,而非重点发展区域土地资源综合承载力有所提升,因此,重点产业发展中必须结合土地资源承载力现状,合理调整产业发展布局.      

区域土地资源承载能力研究模式雏议——以甘肃省定西县为例

本文从土地现实生产力分析和作物潜在生产力估算入手,借助IBM-PC计算机,通过土地资源生产力评价的 MFICA 模式和土地资源优化利用模型的建立,初步框算了定西县1990年、2000年,2025年以及2050年之后的区域农业生产力及其土地资源承载力,进尔阐释了该县土地资源承载力的演变及其土地-粮食-人口关系的可能发展趋势。为区域土地资源承载力研究提供了一条切实可行的途径。     

沈阳市相对资源承载力评价

采用相对资源承载力的研究方法,分别以全国和辽宁省为参照区,对2000—2010年沈阳市相对土地资源承载力、相对经济资源承载力和综合资源承载力进行计算,并揭示了它们的演变规律。结果表明：沈阳市综合资源承载力一直处于富余状态,相对经济资源承载力对综合资源承载力的贡献率大于相对土地资源承载力,经济资源优势明显,土地资源短缺仍然是影响沈阳市可持续发展的重要因素。     

土地资源承载力若干问题浅析

本文就当前土地资源承载力研究中所遇到的若干问题,从土地资源承载力定义的理解、土地生产力的计算、单产预测、土地资源评价和土地利用结构调整等5个方面进行了探讨。 如何定义和理解土地资源人口承载力是进行这项研究的关键。以研究土地资源人口承载力为目的的土地资源评价是进行土地生产力计算和土地利用结构调整必不可少的基础。根据统计资料预测的作物单产,不能反映出土地生产力,而使用农业生态地带法计算作物单产目前也存在着一些问题。     

承载力概念的源起与发展：基于资源环境视角的讨论

科学认识承载力概念的源起与发展对于资源环境承载力理论探讨与实践研究具有重要的科学价值和现实意义。论文立足资源环境视角,从基于种群个体最大生物量的生态承载力,到基于人口与资源关系的资源承载力和基于人口与环境关系的环境承载力,再到面向区域可持续发展的资源环境承载力,较为系统地阐释了资源环境承载力的概念源起与发展历程。通过追踪公开发表或可获取的英文文献,同时兼顾中文资料,综述表明：承载力概念最早诞生于1840年代的工程机械领域,之后,在生态学、地理学、资源科学与环境科学领域得到了持续但有争议的发展;资源环境承载力概念最早可见于20世纪初期的能量承载力和畜牧承载力研究,1940年代末期以土地承载力研究为标志的资源承载力研究诞生;直到20世纪末期,具有综合特征的资源环境承载力概念才在中国悄然兴起,严格意义上的资源环境承载力研究则始于21世纪初。目前,我国资源环境承载力研究总体处于发展阶段,以概念探讨和定性研究为主,尽管在政策层面已得到国家有关部门的高度重视。相对而言,国外相关研究却较少使用这一概念,相应研究报道并不多见。2010年以来,作为描述发展限制的一个重要判据,资源环境承载力研究的现实意义在中国越来越受到重视,国家重大研发计划已有多项部署。但承载力概念似乎也成为了“灵丹妙药”,存在研究泛化或概念泛化现象。鉴于此,有必要科学认识资源环境承载力概念的源起与发展,加强资源环境承载力的科学内涵与理论基础、技术方法与模型参数以及模式化、规范化与标准化等方面的研究工作,以求正本清源、学以致用。     

乌鲁木齐市相对资源承载力与可持续发展问题研究

文章采用相对资源承载力的研究思路和计算方法,以全国和新疆作为参照区域,分别计算了1996年-2008年时段内的各年乌鲁木齐市自然资源、经济资源的相对承载力和综合承载力,同时分析了它们的动态变化过程。研究结果表明,1996年以来乌鲁木齐市的相对自然资源(土地资源和水资源)承载力始终处于超载状态,相对经济资源承载力始终呈富余状态,并且继续攀升。1996年-2004年综合资源承载力处于富余阶段,2004年之后始终处于超载。经济资源对于综合资源承载力的贡献远远大于土地资源和水资源承载力的贡献,经济资源占绝对优势。土地资源的紧缺和水资源的缺乏将成为乌鲁木齐市社会经济可持续发展的重要限制因素,因此,实现人口、资源、环境与经济的相互协调,提高土地资源和水资源承载力以及转变经济增长模式、保持绿色GDP的增长是保证乌鲁木齐市可持续发展的最关键问题。     

三江平原水利规划环境资源承载力分析与评价

环境资源承载力分析是规划环评要解决的关键问题.文章主要分析三江平原水利规划的实施在水资源、土地资源和水环境承载力,以及在满足区域环境功能和资源可持续利用的前提下的区域支撑能力.水资源承载力从地表水和地下水两方面分析供水量与需水量的平衡关系;土地承载力从土地利用类型及占地面积分析土地资源利用分布的变化;水环境承载力分析生活污水、工农业生产废水入河排放量、COD和氨氮对三江平原地区河流水质及功能区水环境的影响.规划基准年为2005年,近期为2020年,远期为2030年.     

三江平原水利规划环境资源承载力分析与评价

环境资源承载力分析是规划环评要解决的关键问题.本文主要分析三江平原水利规划的实施在水资源、土地资源和水环境承载力,以及在满足区域环境功能和资源可持续利用的前提下的区域支撑能力.水资源承载力从地表水和地下水两方面分析供水量与需水量的平衡关系;土地承载力从土地利用类型及占地面积分析土地资源利用分布的变化;水环境承载力分析生活污水、工农业生产废水入河排放量、COD和氨氮对三江平原地区河流水质及功能区水环境的影响.规划基准年为2005年,近期为2020年,远期为2030年.     

土地资源承载力在规划环评中的应用研究

土地资源是人类社会发展的基础,开展土地资源承载力研究,并将其引入规划环评中,对于完善规划环评技术方法,更好的发挥其战略指导作用,协调土地资源开发与经济发展和环境保护之间的关系具有重要的意义。本文对土地资源系统进行分析,重新框定土地资源承载力的概念和内涵;建立规划环评土地资源承载力分析的理论模型,并基于DSR模式,构建出一套可操作性强的规划环评土地资源承载力分析指标体系;开展广州南沙区规划环评土地资源承载力分析的应用研究,提出规划调整建议。     

克拉玛依市水,土资源承载力与城市发展对策研究

在城市可持续发展的进程中，克拉玛依已具备了许多有利条件，但同时也存在一些限制性２。文章重点研究了克拉玛依水、土地资源的承载力与城市发展的关系，从水资源供需平衡，水资源承载力与城市发展规模控制、土地资源人口承载力、工业用地规模、居住用地规模、绿化用地规模和环境管理等方面提出了对策。     

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.     

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.     

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.     

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.     

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.