都龙矿区三岔河污染底质砷、铬吸附特性的研究

通过对矿区选矿废水污染河流的底质进行采样分析,探讨了底质颗粒物粒径与砷、铬含量的关系及其砷、铬的吸附特性与吸附贡献率的关系.结果表明,底质中砷污染十分严重,而铬污染程度较轻.在垂直方向上底质中砷的分布无明显差别,但铬的分布差异性显著.砷、铬含量随着污染底质颗粒的变小而增加,呈负相关关系,且砷达到显著性水平.底质中砷、铬吸附贡献率具有相似的特性,2条贡献率曲线呈"双峰型",最大吸附贡献率出现在粒径为250～500 μm和710 μm～2 mm处.粒径500～710 μm处有一低谷,质量分数对铬吸附贡献率的影响达到极显著水平,相关系数0.999.为了使河流免遭二次污染,组织人力物力清理河流底质是十分必要的.     

湿法烟气脱硫专家帮助和故障诊断系统的开发

介绍了专家系统在火电厂湿法烟气脱硫系统中的作用,利用ACCESS建立了湿法烟气脱硫专家系统的知识库;以Visual Basic 6.0语言为开发工具,对湿法烟气脱硫专家系统软件进行了开发,该软件具有专家帮助功能、故障诊断功能、工艺仿真功能、知识库管理功能等。     

广州市主要污染物总量减排环境绩效评价

“十一五”期间,广州市主要污染物COD和SO2排放总量持续下降,经初步核算,2010年COD和S02排放量分别比2005年下降2．7万吨和6．5万吨,减排比例分别达到19．7％和43％,总量减排工作顺利完成。减排对环境改善明显,珠江广州河段主要污染指标浓度值均有所下降,COD年均浓度从2005的20．7毫克／升下降至2010年的13．6毫克／升,下降幅度达34．3％,整体水环境质量得到根本好转;空气环境质量优良率逐年上升,大气主要污染指标年均浓度值基本呈现逐年下降的态势,SO2从2005年年平均浓度为0．053毫克／立方米下降至2010年的0．033毫克／立方米,下降幅度达37．7％,空气质量持续得到好转。     

横坡与顺坡垄作径流氮磷输出及其富营养化风险对比研究

以沂蒙山区典型的坡耕地为例,通过2种雨强(40 mm·h-1和70 mm·h-1)下的野外原位模拟降雨试验,分析了横坡与顺坡垄作地表径流溶解态无机氮Inorganic-N(NO3--N、NH4+-N)以及溶解态磷(DP)的输出特征,并利用Inorganic-N/DP、NO3--N/DP和NH4+-N/DP等3种氮磷比对...     

电子废弃物的分类建议

电子废弃物的分类对于环境管理而言至关重要,发达国家依据自己的国情出台了电子废弃物分类细则。中国目前对于电子废弃物的详细分类还未出台相关的法律法规,本文针对中国电子废弃物回收处理系统提出全程管理分类模式。     

基于投入产出法的中国虚拟水国际贸易分析

文章引入虚拟水和虚拟水贸易的概念,基于投入产出方法,对中国虚拟水贸易进行研究分析。选取2002年、2005年和2007年相关数据,计算中国17个行业及全国的虚拟水进出口量,分析中国虚拟水进出口情况,指出中国是一个虚拟水净出口国,并且虚拟水净出口量始终处于增长状态,主要出口到美洲、欧洲和亚洲。在中国虚拟水贸易中,对虚拟水净出口贡献较大的行业为服装皮革羽绒及其制品业、纺织业、木材加工及家具制造业和农业,而对虚拟水净进口有贡献的行业为能源行业、金属矿采选业、化学工业、仪器仪表及文化办公用机械制造业,由于净出口行业基本上为耗水量比较大的行业,净进口行业耗水量相对较小,这就导致了中国虚拟水始终处于净出口状态。这些都为行业战略调整提供了一定的依据。     

沂蒙山区不同覆被棕壤理化特征对径流溶解态氮磷输出的影响

以沂蒙山区的棕壤为例,利用野外原位模拟降雨试验,在分析荒草地、侧柏林、金银花、山楂园和花生地等5种典型覆被下棕壤坡地径流溶解态氮(DN)、磷(DP)输出特征的基础上,探讨了不同土地覆被类型下棕壤主要理化性质差异对径流DN、DP输出的影响.结果表明,在降雨强度(70 mm·h-1)、地形和植被覆盖度等条件较为一致的情况下...     

城市绿地系统生态服务效能评价及优化研究——以淮安生态新城为例

通过运用生态服务效能指数的概念,选择5种指标因子(吸收二氧化硫量、吸收热量、蒸腾水量、涵养水源量、滞尘降尘量)构建了淮安生态新城绿地系统生态服务效能评估模型,并运用全排列多边形图示指标法,针对"现状条件"、"概念规划"、"控制性详细规划"、"理想状态"4种情景下的绿地系统进行了生态服务效能评价与预测.结果表明,4种不同的土地利用方式下,绿地系统生态服务效能综合指数分别为0.24、0.56、0.70和0.89,生态服务效能逐步改善.研究结果进一步表明,在"概念规划"和"控制性详细规划"两种情景下,应使城市绿地系统面积大于1200hm2,采用复合式绿地结构并调整林地与草地面积的比例达到7∶3,同时应保证本地植物指数大于70%,研究结果可为生态城市建设提供一定的参考.     

Assessment of source water contamination by estrogenic disrupting compounds in China

Detection of estrogenic disrupting compounds (EDCs) in drinking waters around China has led to rising concerns about health risks associated with these compounds. There is, however, a paucity of studies on the occurrence and identification of the main compounds responsible for this pollution in the source waters. To fill this void, we screened estrogenic activities of 23 source water samples from six main river systems in China, using a recombinant two-hybrid yeast assay. All sample extracts induced significant estrogenic activity, with E2 equivalents (EEQ) of raw water ranging from 0.08 to 2.40 ng/L. Additionally, 16 samples were selected for chemical analysis by gas chromatography-mass spectrometry. The EDCs of most concern, including estrone (E1), 17βup-estradiol (E2), 17αup-ethinylestradiol (EE2), estriol (E3), diethylstilbestrol (DES), estradiol valerate (EV), 4-t-octylphenol (4-t-OP), 4-nonylphenols (4-NP) and bisphenol A (BPA), were determined at concentrations of up to 2.98, 1.07, 2.67, 4.37, 2.52, 1.96, 89.52, 280.19 and 710.65 ng/L, respectively. Causality analysis, involving comparison of EEQ values from yeast assay and chemical analysis identified E2, EE2 and 4-NP as the main responsible compounds, accounting for the whole estrogenic activities (39.74% to 96.68%). The proposed approach using both chemical analysis and yeast assay could be used for the identification and evaluation of EDCs in source waters of China.     

Cationic content effects of biodegradable amphoteric chitosan-based flocculants on the flocculation properties

A series of biodegradable amphoteric chitosan-based flocculants (3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CTA) modified carboxymethyl chitosan, denoted as CMC-CTA) with different substitution degrees of CTA were prepared successfully. The content of carboxymethyl groups in each CMC-CTA sample was kept almost constant. The solubility of the various flocculants showed that, higher cationic content of flocculants caused a better solubility. The flocculation experiments using kaolin suspension as synthetic water at the laboratory scale indicated that the substitution degree of CTA was one of the key factors for the flocculation properties. With the increase of cationic content, the flocculants were demonstrated better flocculation performance and lower dosage requirement. Flocculation kinetics model of particles collisions combining zeta potential and turbidity measurements was employed to investigate the effects of the cationic content of the flocculants on the flocculation properties from the viewpoint of flocculation mechanism in detail. Furthermore, flocculation performance using raw water from Zhenjiang part of Yangtze River at the pilot scale showed the similar effects to those at the laboratory scale.