基于DEA模型的区域生态环境建设绩效评价——以江苏省苏州市为例

选取生态系统服务价值、生态绿当量、人均生态足迹赤字和环境质量综合指数作为区域生态环境质量表征指标,借助DEA模型对区域生态环境建设过程中劳动力投入、资金投入、技术投入和资源投入的绩效进行评价,结果表明:(1)苏州市10年来生态环境建设总体而言绩效良好,DEA有效年份占30%,弱有效年份占20%,无效年份占50%,并且无效年份的效率指数都在0.97以上;(2)导致苏州市最近5年生态环境建设DEA无效的原因主要是乔资源投入不足,生态用地成为区域生态环境建设刚性约束;(3)通过调整生态环境建设要素投入比例,各种生态环境指标值都将有所提高,区域生态环境质量也将显著改善;(4)地区生态环境建设绩效下降还受地区人口数量增加、人均生态占用增长、生态环境累积效应影响.最后从促进区域社会经济与生态环境协调发展的角度提出相关建议.     

灌溉和降雨条件下生态沟渠氮、磷输出特征研究

为了研究长沙县金井河流域农业源头生态沟渠氮和磷的输出特征,对灌溉和降雨条件下及不同季节生态沟渠水体氮、磷的变化特征进行监测研究。研究结果表明：灌溉和降雨期间,生态沟渠中总氮的输出最大值为270 mg/L,其输出的主要形态为氨态氮和硝态氮,总磷的最大值达032 mg/L。灌溉后,生态沟渠氮、磷的输出均呈单调递减变化,在灌溉初期均最高。降雨后,总氮、总磷沿程变化趋势均呈递减变化;生态沟渠对水体总氮、总磷去除率分别达64%、70%;各断面氮、磷的输出随着时间的增加呈先增加后降低的趋势,其中总氮、氨态氮含量在雨后第3 d达到最高,总磷含量在雨后第2 d达到最高。在不同季节中水体氮、磷的变化以冬季总氮、氨态氮和磷浓度最高     

Effects of rainfall on surface environment and morphological characteristics in the Loess Plateau

Environmental Science and Pollution Research - Slope failure is a one of major process that causes severe landform variation and environment variation, and slope failure has become a major hidden...     

铜铈复合氧化物催化降解甲基橙

采用水热法制备的铜铈复合氧化物能够直接催化降解甲基橙,探究了铜铈摩尔比、pH、投加量对催化降解效果的影响。研究发现,pH=3.5、Cu/Ce=1、投加量1.0 g·L-1时,甲基橙的降解效果最佳。在0.5~1.0 g·L-1之间时,随着投加量的增加,甲基橙的脱色速率加快,脱色率也有所增加。随着溶液中的pH逐渐下降,甲基橙脱色率有所增加,pH=3.5时,甲基橙脱色率最高;而进一步降低pH至3.0时,脱色率反而下降,可能是强酸腐蚀了金属氧化物表层,降低了甲基橙的降解效果。甲基橙主要因其被降解而脱色,促使甲基橙脱色的活性物质为·OH,且与体系中的分子氧有关,反应过程消耗一定的H+。     

不干胶废弃物热解与燃烧动力学特性

采用热重分析方法对不干胶废弃物(PSAs)进行了热解和燃烧失重分析,并采用Doyle法拟合计算了PSAs热解和燃烧动力学参数。结果表明:当温度低于200℃或高于600℃,PSAs的热解和燃烧失重过程具有性;300~600℃时,PSAs热解过程具有3个失重峰,而其燃烧过程具有2个失重峰。动力学分析结果表明:PSAs的热解是由多阶段复杂的热裂解反应组成,其热解过程可用4个一级反应来描述,随着升温速率的提高热解阶段第1峰区表观活化能降低;而第2、3峰区以及半焦深度裂解阶段的第4峰区活化能逐渐升高;PSAs燃烧过程可用3个一级反应来描述,随着升温速率的提高,PSAs燃烧过程的表观活化能均逐渐降低,并且燃烧表观活化能均低于热解表观活化能。     

我国粉煤灰生态环境标准体系现状及建议

对我国粉煤灰管理相关的现行法律法规、部门规章和文件及有关标准进行了梳理,结果显示,现行生态环境标准中尚无专门针对粉煤灰的污染环境防治技术标准,粉煤灰的环境管理中适用的是一般工业固体废物相关标准,且标准数量较少,覆盖面不全。粉煤灰在产生、收集、运输环节还缺乏污染环境防治技术标准,也缺乏针对粉煤灰各综合利用方式的污染环境防治技术标准,不利于粉煤灰的综合利用和污染防控。目前,粉煤灰生态环境标准体系需要在全过程管理环节以及促进综合利用、污染防治、风险防控、信息化建设等方面进一步完善。

     

天津污灌区土壤中多环芳烃的提取、净化和测定

研究了天津污灌区严重污染土壤中 1 6种多环芳烃的提取和测定方法 .考察了加速溶剂提取的提取条件、样品净化方法和GC MS测定条件 .结果表明 ,在 1 4 0℃用1∶1二氯甲烷和丙酮提取 5min ,硅胶柱净化后用GC MS测定可以得到很好的效果 .方法回收率在 5 7%— 1 4 0 %之间 ,检测限为 3 5× 1 0 - 4— 1 1× 1 0 - 3 mg·l- 1,且重现性较好 .天津代表性污灌水稻土中 1 6种PAHs的实测浓度为 0 0 7— 1 2 7mg·kg- 1.     

天津污灌区苯并（a）芘、荧蒽和菲生态毒性的风险表征

运用概率风险评价方法表征和比较了天津污灌区3种多环芳烃对生物影响的风险性。根据各物质的环境暴露浓度和相应急性毒性值的累计概率分布曲线估计了各物质相对风险性的大小。采用联合概率曲线方式比较了不同暴露概率水平条件下3种多环芳烃的相对风险。结果表明，该地区目前菲的总体风险性高于另两种化合物，苯并（a)芘的总体风险性最低。而低暴露风险条件下（受威胁生物不超过20％），苯并（a)芘的风险较大，菲次之，荧蒽风险相对较低。     

Uptake of PAHs by cabbage root and leaf in vegetable plots near a large coking manufacturer and associations with PAHs in cabbage core

Samples of ambient air (including gaseous and particulate phases), dust fall, surface soil, rhizosphere soil, core (edible part), outer leaf, and root of cabbage from eight vegetable plots near a large coking manufacturer were collected during the harvest period. Concentrations, compositions, and distributions of parent PAHs in different samples were determined. Our results indicated that most of the parent PAHs in air occurred in the gaseous phase, dominated by low molecular weight (LMW) species with two to three rings. Specific isomeric ratios and principal component analysis were employed to preliminarily identify the local sources of parent PAHs emitted. The main emission sources of parent PAHs could be apportioned as a mixture of coal combustion, coking production, and traffic tailing gas. PAH components with two to four rings were prevailing in dust fall, surface soil, and rhizosphere soil. Concentrations of PAHs in surface soil exhibited a significant positive correlation with topsoil TOC fractions. Compositional profiles in outer leaf and core of cabbage, dominated by LMW species, were similar to those in the local air. Overall, the order of parent PAH concentration in cabbage was outer leaf > root > core. Partial correlation analysis and multivariate linear stepwise regression revealed that PAH concentrations in cabbage core were closely associated with PAHs present both in root and in outer leaf, namely, affected by adsorption, then absorption, and translocation of PAHs from rhizosphere soil and ambient air, respectively.     

Arsenic species in the well water and sediments of the blackfoot disease area in Taiwan

The blackfoot disease (BFD) observed in southwestern Taiwan is due to drinking high arsenic concentrations in well water. This paper presents some results concerning the distributions of arsenic species in water and sediments collected in the BFD (well, river and coastal) area and the background (lake and ocean) area for comparison. The results show that the concentrations of arsenate (870 ± 26 ug/L) and arsenite (70.2 ± 2.6 ug/ L) in well waters, and the contents of arsenic (1640 ug/g) with high percentage of easily reducible (Fe and Mn oxides, 91.7%) and exchangeable and carbonate (4.6%) phases in well sediments were much higher than those in river, lake and coastal samples. Low arsenic (3.46–31.8 ug/g) with high percentages (73.8–97.3%) of detritus and minerals phase with low percentages (0.4–9.8%) of total carbonate and exchangeable phases were found in the river and coastal samples in the BFD area as well as the lake and ocean samples in background area. It might suggest that the higher concentrations of toxic As(III) in well water and arsenic with higher values of easily reducible, carbonate and exchangeable phases in the well sediments, combined with the higher values of dissolved organic carbon, humic and fulvic acids and aromatic carbon as well as the higher fluorescence indensity in the well water are the key factors to cause the BFD in Taiwan.