和田市城市发展与大气污染耦合关系

探索环境承载力低的和田市城市发展与大气污染之间的耦合关系,对于促进城市与生态环境和谐发展具有重要意义。基于和田市2001～2016年城市发展和大气环境污染时间序列统计数据,利用专家咨询法选取10项城市化水平指标和4项大气环境污染指标,分别计算城市化水平综合指数与大气环境污染综合指数,并基于环境库兹涅茨曲线(EKC)理论探讨其拟合模型。结果表明:和田市2001～2016年人口城市化指数由0.004 8升至0.931 1、土地城市化指数由0.000 1升至0.879 1、经济城市化指数由0.000 2升至0.714 2、社会城市化指数由0.003 2升至0.898 0,城市化综合指数由0.251 0升至0.883 7,其城市综合发展能力由一般达到较好或优良水平;和田市2001～2016年大气环境污染综合指数由15.088 3下降至10.290 2,降尘和PM_(10)为大气污染主要贡献因子。各单项污染指数变化情况为:SO_2由0.483 3升至0.766 7,NO_2由0.400 0升至0.650 0,PM_(10)由5.910 0降至2.750 0,降尘由8.295 0降至6.102 5;城市化综合指数与大气污染综合指数拟合曲线呈环境库兹涅茨曲线(EKC)特殊形式倒"N"型曲线。     

太湖水质变化与经济发展关系研究—基于环境库兹涅茨曲线(EKC)方法

本文利用1979-2010年五项太湖水质指标时间序列数据,通过拟合太湖水质环境库兹涅茨曲线对太湖水质与经济发展之间关系进行了实证分析。研究结果表明:总磷、总氮和高锰酸钾指数与经济发展之间存在典型的倒"U"型曲线关系,叶绿素a和化学需氧量与经济发展之间的关系则可以用倒"N"型三次曲线的右半部分刻画。二十世纪末以来开展的一系列太湖流域污染治理措施对水质环境库兹涅茨曲线拐点的出现甚至提前起到很大的作用。     

我国工业“三废”的环境库兹涅茨曲线实证研究

选取我国1996~2008年共13年的人均GDP与工业"三废"排放量的统计数据,借助SPSS系统软件,建立计量经济学模型,分析了工业"三废"排放量的环境库兹涅茨曲线特征及其成因。研究发现:我国工业固体废物排放量的环境库兹涅茨曲线呈现出一条递增的直线;工业废水排放量的环境库兹涅茨曲线呈现出一条"倒N型"("U型"+"倒U型")曲线;工业废气排放量环境库兹涅茨曲线近似"倒U型"曲线的左半段。也就是说,除工业废水排放量回归曲线出现拐点外,工业固体废物产生量与工业废气排放量仍处于上升期。     

江苏省SO_2排放环境库茨涅茨关系研究——基于半参数面板数据模型分析

以江苏省为研究区域,通过验证环境库兹涅茨曲线的存在来分析经济增长、城市化对SO_2排放的影响.采用1991~2013年江苏省市级面板数据,结合参数及半参数固定效应回归同时对经济增长/城市化与SO_2排放关系开展研究.研究发现了经济增长与SO_2排放之间存在着倒U型曲线关系,但是对于城市化与SO_2排放,二者的倒U型曲线关系并不存在.经济增长与SO_2排放之间环境库兹涅茨关系的存在表明了经济的持续发展能够协调并解决其与SO_2排放之间的困境.同时,这些研究发现有助于推动社会经济发展与环境污染关系的研究.     

乌鲁木齐城市化进程与大气污染关系研究

以乌鲁木齐市为研究区,选取乌鲁木齐市2004—2013年11项城市化指标以及3项大气污染指标,得出城市化水平综合指数以及大气污染水平综合指数。将城市化综合水平作为解释变量,SO2、NO2、PM10污染综合指数、大气污染综合指数分别作为被解释变量,分析城市化水平与大气污染状况,分别对其进行二次曲线回归分析以及三次曲线回归分析,得出乌鲁木齐市2004—2013年城市化进程与大气污染之间的演化规律。     

时空效应下PM2.5的环境库兹涅茨曲线——基于动态空间面板视角

经济发展与环境保护的平衡一直是人们关心的话题,为分析空气质量水平与经济发展程度之间的关系,即环境库兹涅茨曲线,本研究利用2013—2017年中国省级PM_(2.5)污染数据,运用动态空间面板数据模型,从而控制相邻省份的空气质量水平与本地上期污染水平,实证分析中国PM_(2.5)环境库兹涅茨曲线的存在性及空间溢出性.结果表明:①PM_(2.5)的环境库兹涅茨曲线在省级基础上表现为倒U形,即随着初期经济水平的发展,大气污染会不断增加,在经济发展到一定水平后,大气污染开始降低;②东部、中部省份的空气污染表现与全国一致,而西部省份尚无显著趋势,只有第一产业产量与空气污染水平呈负相关;③中国整体的PM_(2.5)污染具有显著的空间溢出性;④对二氧化硫和氮氧化物进行环境库兹涅茨曲线研究,发现全国平均而言还处在大气污染的上升阶段.研究表明,中国各地区处在大气污染发展路径的不同阶段上,而且空气污染的治理模式应采取区域联合分块治理的策略.     

博乐市城市化与大气污染之间关系研究

以博乐市为研究区域,选取2005～2016年博乐市11项城市化指数以及3项大气环境污染指数,并获取城市化发展综合指数以及大气污染物水平综合指数。计算过程中,把城市化发展指数作为自变量,SO_2、NO_2、PM_(10)污染物指数、大气污染物综合指数单独作为因变量,解析城市化发展综合水平与大气污染综合指数的关系,并分别对其进行二、三次回归模型的深入分析。结果表明:博乐市2005～2016年城市化发展指数与大气污染物综合指数出现"N型"库兹涅斯(ECK)曲线关系。由于研究周期不长,因而可能只得出真正的ECK曲线的一部分,博乐市城市化发展综合水平与大气污染物综合水平之间的演变规律有待进一步深化探索。     

基于环境库兹涅茨模型的河南省经济与环境关系分析研究

文章在综述国内外学者对环境库兹涅茨曲线研究的基础上,选取河南省1997年-2011年的经济与环境数据,建立了计量模型,分析了经济增长与多个环境指标之间的关系。实证研究表明,河南省经济增长与环境状况之间尚未呈倒“U”曲线特征,工业“三废”处于倒“U”型的上升阶段,工业COD和工业SO2分别呈现倒“N”型和“N”型的波浪形状。河南省总体环境压力依然较大,对河南省环境保护工作提出了政策建议。     

深圳市经济增长与工业污染物排放量关系研究

根据环境库兹涅茨曲线假设,选取深圳市1996 - 2010年的经济与环境数据,构造了环境污染指标与人均GDP之间的计量经济模型.研究结果表明:工业化学需氧量排放量、工业SO2排放量、工业烟尘排放量、工业固体废物排放量符合“倒U型”曲线假说,环保投资和强有力的环境管理促进了深圳市跨越环境库兹涅茨曲线转折点;各环境指标的排污费用总和与人均GDP的关系表现出“倒U型”曲线.综合来看,目前深圳市整体的环境污染情况已经趋于好转.     

新疆重点城市空气质量与经济库兹涅茨曲线的分析研究

根据新疆重点城市2005年-2013年经济状况与环境空气质量监测数据,借助SPSS数据统计软件分析人均GDP与空气质量各污染物监测值的相关关系,通过环境库兹涅茨曲线估计,得出新疆重点城市经济发展与环境污染之间的关系.结果表明,新疆重点城市随着经济的发展,PM10呈现倒"N"型,SO2呈现"U"型,NO2未呈现倒"N"或倒"U"型KEF;同时表明,PM10和SO2得到了有效的治理,NO2未得到有效的治理,需进一步加大对PM10和NO2治理的投入,以满足新的环境空气质量标准的要求.     

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.     

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

ＲｅｍｏｖａｌｏｆｈｅａｖｙｍｅｔａｌｓｆｒｏｍｓｅｗａｇｅｓｌｕｄｇｅｂｙｌｏｗｃｏｓｔｉｎｇｃｈｅｍｉｃａｌｍｅｔｈｏｄａｎｄｒｅｃｙｃｌｉｎｇｉｎａｇｒｉｃｕｌｔｕｒｅＷｕＱｉｔａｎｇ，ＮｙｉｒａｎｄｅｇｅＰａｓｃａｓｉｅ，ＭｏＣｅｈｕｉＦ...     

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.     

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.