大连近海沉积物多环芳烃污染特征及源解析

本文对大连近海海域15个表层沉积物样品中16种多环芳烃(PAHs)污染特征及来源进行研究。结果表明,沉积物中16PAHs总浓度为30.0410-9~89.2410-9,平均值为50.8410-9,其中工业区显著高于城市地区(p0.05),极显著高于农村地区(p0.01)。沉积物中PAHs含量与总有机碳(TOC)含量间存在显著正相关性(p0.05),表明沉积物有机质含量是影响PAHs含量的主要因素。主成分分析得出,大连近海海域PAHs污染源为石油泄漏造成的石油源、生物质及化石燃料燃烧形成的燃烧源和燃油燃烧形成的交通源。     

Modifying glass fiber surface with grafting acrylamide by UV-grafting copolymerization for preparation of glass fiber reinforced PVDF composite membrane

Experimental design and response surface methodology(RSM) were used to optimize the modification of conditions for glass surface grafting with acrylamide(AM) monomer for preparation of a glass fiber reinforced poly(vinylidene fluoride)(PVDF) composite membrane(GFRP-CM). The factors considered for experimental design were the UV(ultraviolet)-irradiation time, the concentrations of the initiator and solvent, and the kinds and concentrations of the silane coupling agent. The optimum operating conditions determined were UV-irradiation time of 25 min, an initiator concentration of 0–0.25 wt.%,solvent of N-Dimethylacetamide(DMAC), and silane coupling agent KH570 with a concentration of 7 wt.%. The obtained optimal parameters were located in the valid region and the experimental confirmation tests conducted showed good accordance between predicted and experimental values. Under these optimal conditions, the water absorption of the grafted modified glass fiber was improved from 13.6% to 23%; the tensile strength was enhanced and the peeling strength of the glass fiber reinforced PVDF composite membrane was improved by 23.7% and 32.6% with an AM concentration at 1 wt.% and 2 wt.%. The surface composition and microstructure of AM grafted glass fiber were studied via several techniques including Field Emission Scanning Electron Microscopy(FESEM), Fourier transform infrared spectroscopy-attenuated total reflectance(FTIR-ATR) and energy dispersive X-ray spectroscopy(EDX). The analysis of the EDX and FTIR-ATR results confirmed that the AM was grafted to the glass fiber successfully by detecting and proving the existence of nitrogen atoms in the GFRP-CM.     

我国农用地土壤环境基准与标准制定研究

在分析我国现行土壤环境质量标准不足的基础上,综述了国外制定农用地土壤环境筛选值的现状,在此基础上提出我国农用地土壤环境基准制定方法学的建议以及我国农用地土壤环境标准体系的框架建议,服务于我国农用地土壤的污染预防、风险筛选和污染农用地的安全利用、修复和风险管控。     

Safety performance evaluation of cable median barriers on freeways in Florida

Objective: This article aims to evaluate the safety performance of cable median barriers on freeways in Florida.

Method: The safety performance evaluation was based on the percentages of barrier and median crossovers by vehicle type, crash severity, and cable median barrier type (Trinity Cable Safety System [CASS] and Gibraltar system). Twenty-three locations with cable median barriers totaling about 101 miles were identified. Police reports of 6,524 crashes from years 2005–2010 at these locations were reviewed to verify and obtain detailed crash information. A total of 549 crashes were determined to be barrier related (i.e., crashes involving vehicles hitting the cable median barrier) and were reviewed in further detail to identify crossover crashes and the manner in which the vehicles crossed the barriers; that is, by either overriding, underriding, or penetrating the barriers.

Results: Overall, 2.6% of vehicles that hit the cable median barrier crossed the median and traversed into the opposite travel lane. Overall, 98.1% of cars and 95.5% of light trucks that hit the barrier were prevented from crossing the median. In other words, 1.9% of cars and 4.5% of light trucks that hit the barrier had crossed the median and encroached on the opposite travel lanes. There is no significant difference in the performance of cable median barrier for cars versus light trucks in terms of crossover crashes. In terms of severity, overrides were more severe compared to underrides and penetrations. The statistics showed that the CASS and Gibraltar systems performed similarly in terms of crossover crashes. However, the Gibraltar system experienced a higher proportion of penetrations compared to the CASS system. The CASS system resulted in a slightly higher percentage of moderate and minor injury crashes compared to the Gibraltar system.

Conclusions: Cable median barriers are successful in preventing median crossover crashes; 97.4% of the cable median barrier crashes were prevented from crossing over the median. Of all of the vehicles that hit the barrier, 83.6% were either redirected or contained by the cable barrier system. Barrier crossover crashes were found to be more severe compared to barrier noncrossover crashes. In addition, overrides were found to be more severe compared to underrides and penetrations.     

Profiling kidney microRNAs from juvenile grass carp (Ctenopharyngodon idella) after 56 days of oral exposure to decabromodiphenyl ethane

Grass carp(Ctenopharyngodon idella) is one of the most important species in China.Decabromodiphenyl ethane(DBDPE) is a brominated flame retardant that has been used widely in industry, and has been observed to accumulate in the tissues of fish from South China. Evidence has shown that DBDPE is toxic to aquatic animals, but the molecular response has been unclear. MicroRNAs(miRNAs) are small noncoding and negative regulatory RNAs that are 20–24 nucleotides in length, which are involved in a wide range of biological processes. We took advantage of deep-sequencing techniques to accurately and comprehensively profile the kidney mi RNA expression of grass carp after 8 weeks of oral exposure to DBDPE. After mapping sequencing data to the genome and Expressed Sequence Tags(ESTs) of grass carp, we identified 493 miRNAs in the sequenced grass carp samples, which included 51 new miRNAs. The results indicated that 5 miRNAs were significantly down-regulated and 36 miRNAs were significantly up-regulated(FDR 0.001,1.5-fold change) after DBDPE exposure. Real-time quantitative PCR(RT-q PCR) was performed on 4 miRNAs from the two samples, and the sequencing and RT-q PCR data were consistent. This study provides the first comprehensive identification of grass carp miRNAs, and the first expression analysis of grass carp miRNAs following DBDPE exposure.The results indicated that miRNAs have potential for use as biomarkers.     

区域大气环境容量及其区域配置研究

以重庆市涪陵区为例,在了解区域大气环境功能区划及区域大气环境质量现状的前提下,采用A-P值法,对涪陵区十三五期间大气环境容量进行研究,并对辖区内的污染负荷进行预测,在此基础上,对大气污染总量控制指标进行分配.研究结果表明,在涪陵区化工园区的二氧化硫排放量已达到或超过总量控制指标,需要制定削减计划,新兴工业园区污染物排放量虽远小于总量控制指标,但根据城市发展规划需进行结构优化与合理布局.     

电渗析技术在浓盐水回收项目的应用研究

电渗析技术作为一种新兴的膜分离技术,因高效率低能耗、对预处理要求低、对分离组分选择性高、原水回收率高、环境友好等优点,在国内外各行业获得广泛应用.江苏华晖环保科技有限公司改进了电渗析工艺参数,并在贵州开磷(集团)有限责任公司进行了推广应用,大大降低了出水中Cl-和Ca2+浓度,电导率由数千us/cm降到200 us/cm以下.电渗析技术可节约水资源,社会、环境、经济效益显著,对企业实现真正的“零排放”具有巨大的推动力.     

地理数据库的构建及其在水利工程环境影响评价中的应用研究

GIS技术为环境影响评价提供了高效的操作平台和有力的技术支撑,应用GIS技术建立的地理数据库,有助于科学地分析、预测和评估工程实施对周边环境可能造成的影响.文章简述了地理数据库的模块结构及构建流程,并结合贵州省夹岩水利枢纽及黔西北供水工程环境影响评价工作对地理数据库在图件制作、环境敏感目标识别、水文信息提取与分析、生态影响评价等方面的应用进行了介绍.最后指出GIS技术相对于传统评价技术的优点,并对其应用前景进行了展望.     

Lead (Pb) exposure and heart failure risk

Environmental Science and Pollution Research - Lead (Pb) is a heavy metal with widespread industrial use, but it is also a widespread environmental contaminant with serious toxicological...     

Characterization,source apportionment and risk assessment of PAHs in urban surface dust in Shenyang city,China

Environmental Geochemistry and Health - Characteristics, profile composition, ecological and human health risk of polycyclic aromatic hydrocarbons in surface dust collected from Shenyang city,...