Quantification of polychlorinated biphenyl contamination using human placenta as biomarker from Punjab Province,Pakistan

Environmental Science and Pollution Research - The present study biomonitored the placental polychlorinated biphenyl (PCB) concentrations in women from Punjab Province, Pakistan, that provides the...     

政府环境报告基层实施:现状、问题及其对策

政府环境报告基层实施是利用县级人大与公众直接联系的"基层"优势加强对政府环境责任监督的有效手段。实践中,报告主体及对象级别各异,报告内容繁简不一,总体情况为越是基层贯彻实施政府环境报告的力度越弱,存在报告形式不明确、信息公开不到位、常态化监督机制和政府责任缺失等问题。因此,必须在认清立法目的的基础上合理运用法律解释明确报告的法律属性,规范报告内容、扩大公开范围,利用"基层"优势与公众加强联系,并在准确定位环保法的前提下构建人大监督的刚性约束。     

高速公路交通救援资源派遣方法适用性研究

为降低高速公路交通事故人员伤亡和财产损失、提高指挥调度中心救援效率,将适合高速公路交通救援资源派遣的匈牙利法、直接成本法和机会成本法,分别从基于资源派遣方法的数学特征、高速公路交通救援点配置情况和交通事故救援实施3个方面对各方法的适用性进行研究,并结合指挥调度中心现有资源派遣实际,制定出交通救援资源派遣规则。以南京市周边高速公路网为例,根据适用条件选用合适的交通救援资源派遣方法和派遣规则,进行救援资源的派遣决策,为指挥调度中心高效地派遣交通救援资源提供了理论依据和合适方法。     

小尺寸装药直径及约束条件对Jo-9c爆压影响的实验

采用锰铜压阻法对Jo-9c在小尺寸装药条件下的爆压进行实验测定,得出不同装药条件下的爆压值,并对数据进行分析,得到约束条件和装药直径对爆压的影响规律.     

纤维素季铵盐处理活性染料废水

研究了纤维素通过季铵化反应制备的纤维素季铵盐(quaternized celluloses,QCs)高分子混凝剂对染料废水的脱色效果及机理,实验了它和无机助凝剂的联合使用分别对不同pH值条件下的活性染料废水脱色效果的影响。结果表明,在pH值为8至12范围内,QCs的投加对活性染料废水的脱色作用非常显著,无机助凝剂的投加对其脱色率的影响相对较小,但可以提高其脱色反应速度和脱色率。活性染料废水的脱色率可达98.53%,色度可达4倍以下。     

Levels,profile and distribution of Dechloran Plus (DP) and Polybrominated Diphenyl Ethers (PBDEs) in the environment of Pakistan

No scientific data is available on emerging contaminants including Polybrominated Diphenyl Ethers (PBDEs) and Dechloran Plus (DP) levels in the environment in Pakistan. Levels of PBDEs and DP were determined in the soil, sediment and atmospheric samples along the stretch of River Ravi in Punjab Province. Average concentrations of ΣPBDEs in atmosphere, soils and sediments were 36 pg m⁻³, 40 ng g⁻¹ and 640 ng g⁻¹. BDE-209 was the most abundant PBDE congener, showing that deca-BDE accounts for most of the total PBDE emitted in the environment of Pakistan. Total DP levels were calculated as 88 pg m⁻³, 0.8 ng g⁻¹ and 1.9 ng g⁻¹ in air, soil and sediment samples, respectively. The lower average fractions of anti-DP showed significant differences to those of the technical mixtures, indicating the lack of DP production source in Pakistan.     

Distribution of heavy metals in agricultural soils near a petrochemical complex in Guangzhou, China

The aim of the study was to investigate influence of an industrialized environment on the accumulation of heavy metals in agricultural soils. Seventy soil samples collected from surface layers (0-20 cm) and horizons of five selected pedons in the vicinity area of petrochemical complex in Guangzhou, China were analyzed for Zn, Cu, Pb, Cd, Hg and As concentrations, the horizontal and vertical variation of these metals were studied and geographic information system (GIS)-based mapping techniques were applied to generate spatial distribution maps. The mean concentrations of these heavy metals in the topsoils did not exceed the maximum allowable concentrations in agricultural soil of China with the exception of Hg. Significant differences between land-use types showed that Cu, Pb, Cd, Hg and As concentrations in topsoils were strongly influenced by agricultural practices and soil management. Within a radius of 1,300 m there were no marked decreasing trends for these element concentrations (except for Zn) with the increase of distance from the complex boundary, which reflected little influence of petroleum air emission on soil heavy metal accumulation. Concentrations of Zn, Cu, Pb, Cd, Hg and As in the five pedons, particularly in cultivated vegetable field and orchard, decreased with soil depth, indicating these elements mainly originated from anthropogenic sources. GIS mapping was a useful tool for evaluating spatial variability of heavy metals in the affected soil. The spatial distribution maps allowed the identification of hot-spot areas with high metal concentration. Effective measures should be taken to avoid or minimize heavy metal further contamination of soils and to remediate the contaminated areas in order to prevent pollutants affecting human health through agricultural products.     

Biodegradation of Chlorimuron-ethyl by the Bacterium Klebsiella jilinsis 2N3

Enrichment culturing of sludge taken from an industrial wastewater treatment pond led to the identification of a bacterium (Klebsiella jilinsis H. Zhang) that degrades chlorimuron-ethyl with high efficiency. Klebsiella jilinsis strain 2N3 grows with chlorimuron-ethyl as the sole nitrogen source at the optimal temperature range of 30–35°C and pH values between 6.0–7.0. In liquid medium, the degradation activity was further induced by chlorimuron-ethyl. Degradation rates followed the pesticide degradation kinetic equation at concentrations between 20 and 200 mg L^?1. Using initial concentrations of 20 and 100 mg L^?1, the degradation rates of chlorimuron-ethyl were 83.5 % and 92.5 % in 12 hours, respectively. At an initial concentration higher than 200 mg L^?1, the degradation rate decreased slightly as the concentration increased. The 2N3 strain also degraded the sulfonylurea herbicides ethametsulfuron, metsulfuron-methyl, nicosulfuron, rimsulfuron, and tribenuron-methyl. This study provides scientific evidence and support for the application of K. jilinsis in bioremediation to reduce environmental pollution.