Contrasting effects of black carbon amendments on PAH bioaccumulation by Chironomus plumosus larvae in two distinct sediments: role of water absorption and particle ingestion

Two sediment matrices with different characteristics were amended with chars from different sources for bioaccumulation assay with filter-feeding Chironomus plumosus larvae. Chars greatly decreased porewater concentrations of PAHs (C_iw) measured using polyethylene devices in sediments. In organic rich sediment matrix-based systems where suspended char particles were absent, PAH concentrations in larvae (C_iB) were significantly correlated with C_iw, and there was no difference in water-based bioaccumulation factors (BAFs) between different treatments, suggesting that water absorption was the main contaminant uptake route for larvae. In organic poor sediment matrix-based systems where suspended char particles were present, poor Pearson correlation between C_iB and C_iw was found, but there was a significant linear increase of BAF values with char contents, which indicated that ingestion of suspended char particles could also be important for PAH bioaccumulation. Therefore, we need to rethink of the effectiveness and risks for the application of black carbon to sediment/soil remediation.     

Evolution of chemical composition of fogwater in winter in Chengdu, China

Two sampling sites representing the urban and suburban area of Chengdu, China were sampled and analyzed for selected chemicals to characterize the evolution of the chemical composition of fogwater. A trend of total organic carbon (TOC) > total nitrogen (TN) > total inorganic carbon (TIC) was observed for both sites. Variation of inorganic ions indicated that inorganic pollutants were not accumulated in the fog. Concentrations of n-alkanes (C11-C37) at the urban site ranged from 7.58 to 27.75 ng/mL while at the suburban site concentrations were 2.57-21.55 ng/mL. The highest concentration of n-alkanes was observed in the mature period of fog (393.12 ng/mL) which was more than ten times that in the fog formation period (27.83 ng/mL) and the fog dissipation period (14.87 ng/mL). Concentrations of Σ15PAHs were in the range of 7.27-38.52 ng/mL at the urban site and 2.59-22.69 ng/mL at the suburban site. Contents of PAHs in the mature period of fog (27.15 ng/mL) > fog dissipation period (11.59 ng/mL) > fog formation period (6.42 ng/mL). Concentrations of dicarboxylic acids (C5-C9) ranged from 10.92 to 40.78 ng/mL, with glutaric acid (C5) as the dominant dicarboxylic acid. These data provide strong indications of the accumulation of certain organic chemicals of environmental concern in fog and fog water, and provide additional insights about processes in urban and suburban air acting on organic chemicals with similar physical chemical properties.     

煤流化床气化的床内脱硫研究

在φ１００ｍｍ加压流化床气化装置上,进行了义马、大同、夏庄和南定４种煤及２种钙基脱硫剂的床内脱硫试验。结果表明,所选石灰石和白云做为床内脱硫剂是可行的,脱硫率随Ｃａ／Ｓ摩尔比增加而提高,比为３达最大值。操作压力对脱硫率的影响与床层温度和ＣＯ２分压是有关,反应处于脱硫剂煅烧不受压力影响,在非煅烧区脱硫率随压力而降低。原煤中全硫增加脱硫效率提高。本试验范围所得脱硫率５０－８５％。     

开阳磷矿10种木本植物叶片重金属富集特征

植物对重金属具有一定的吸附能力,植物修复是生态修复不可或缺的一部分,利用植物减缓和治理重金属污染具有重要意义.选取开阳磷矿马路坪矿区生命周期较长的木本植物及其土壤作为研究对象,探究木本植物受Cu、Zn、Pb、Cd、As等5种重金属污染土壤的效应,对植物重金属含量及其富集特性进行研究分析,筛选出累积重金属的植物,作为矿区...     

武汉市城区大气PM2．5的碳组分与源解析

大气细颗粒物（PM2．5）和碳组分（OC,EC）是影响大气能见度、气候变化以及人体健康的重要污染物,研究大气颗粒物及其中碳组分的污染特征及各类典型污染源对大气细颗粒物及碳组分的贡献,对于认识区域和城市大气污染状况,控制细颗粒物的污染,具有重要意义。2011年7月至2012年2月,利用大流量PM2．5采样器采集武汉市大气细颗粒物样品并对其碳组分进行测定。武汉市城区大气中PM215、OC和EC的质量浓度平均值分别为（127±48．7）、（19．4±10．5）和（2．9±1．48）μg·m-3。其PM2．5的浓度处于我国主要城市的中等偏高水平,而OC、EC的浓度则属中等偏下水平,但均高于国外城市。武汉市大气PM2,质量浓度的季节性变化呈现出秋季〉冬季〉夏季的趋势,是气象因素和污染源排放综合影响的结果。OC浓度和EC浓度具有较好的相关性（r2=0．69）,表明二者存在来源联系。OC／EC的比值为6．7,指示武汉市大气中OC和EC的来源受汽车尾气排放和生物质燃烧的共同影响。SOA的平均质量浓度值为12．5μg·m-3约占PM2．5平均质量浓度的9．8％,表明SOA对武汉市城区大气PM2．5具有重要贡献。结合PM2．5所含的水溶性离子、微量元素组成,利用正矩阵因子分析（PMF）模型对武汉市城区大气PM2．5来源进行解析,结果表明,其主要来源及贡献率分别为机动车源（27．1％）、二次硫酸盐和硝酸盐（26．8％）、工厂排放（26．4％）和生物质燃烧（19．6％）。     

河蚬(Corbicula fluminea)在生态毒理学研究中的应用与评价

河蚬是大型底栖双壳类生物,广泛分布于我国淡水水域。它具有个体小、分布广、来源方便、易于实验室驯养等特点,常被作为受试生物用于毒理学研究中,为评价污染物毒性作用提供有价值信息。从河蚬对各化学品的行为响应、耐受性以及生理生化指标响应三个方面详细阐述了其在生态毒理学中的研究现状。最后指出将河蚬应用于毒理学研究领域的过程中存在的待完善之处,并对其研究前景进行了展望。总结出其可用于中国淡水水质基准制定、化学品毒性评价以及生物监测领域,具有广阔的研究前景。     

Gangba sheep in the Tibetan plateau: Validating their unique meat quality and grazing factor analysis

Gangba sheep are known for having typical sensory characteristics attributed to free range conditions and grazing on wild plants. The genuine Gangba mutton was selected as the experimental group, and the commercial Tibetan mutton was selected as the control group, the nutritive composition of basic chemical components, amino acids and fatty acids in mutton were investigated to correlate its unique meat quality and eating satisfaction. The results showed that fatty acids were significantly higher (P<0.05) in Gangba mutton than in commercial mutton, and the higher content of flavoring amino acids (glutamic acid and aspartame) were primarily responsible for the taste attributes umami of meat juices. Moreover, the trace elements analysis in mutton and grazing factors (forage, water source and soil) were conducted, to explain the source of essential trace elements in mutton. The concentrations of essential trace elements show that the Gangba mutton was a valuable source for highly available Cu and Zn in human nutrition, and well managed with few detected of toxicity metal. The concentrations of essential trace elements in mutton are closely related to the trace elements in environmental grazing factors. In conclusion, the congenital grazing conditions (a highly mineralized water resource, natural forages and clean soils) were shown to contribute to the unique meat characteristics of Gangba sheep.     

Seasonal and spatial distribution of 4-tert-octylphenol, 4-nonylphenol and bisphenol A in the Huangpu River and its tributaries, Shanghai, China

The seasonal variations and spatial distributions of 4-tert-octylphenol (OP), 4-nonylphenol (NP) and bisphenol A (BPA) in surface waters, suspended solids and surface sediments in the Huangpu River and its tributaries (Suzhou River and Yunzao Brook) were firstly investigated. The mean concentrations of OP, NP and BPA in the three rivers were 10.59, 120.96 and 22.93 ng L^?1 in surface waters, 199.87, 2,300.87 and 84.11 ng g^?1 in suspended solids and 9.49, 119.44 and 7.13 ng g^?1 dry weight in surface sediments, respectively. The concentrations of NP and OP were higher in summer than in winter in the suspended solids and surface sediments, while the reverse was true in surface waters. Similarly, the levels of BPA were lower in summer than in winter in surface sediments, while the opposite was true in surface waters and suspended solids. These seasonal variations might be attributed to temperature and stream flows. High levels of OP, NP and BPA were found in surrounding river intersections, residential and industrial areas. Their concentrations decreased gradually with increasing distance from those areas, while the lowest levels were measured in near less urbanized and agricultural areas. These phenomena might indicate that the stream current and pollutant source were the major factors that affect the spatial distributions of OP, NP and BPA in the three rivers. Ecological risk assessment indicated that NP was the only one of the three pollutants with the potential to influence local aquatic organisms. The results of this study provide scientific support for control of these pollutants.     

Atmospheric Mercury Pollution in Beijing

The atmospheric mercury pollution in Beijing is a serious problem. Atmospheric mercury has three sources： natural emission, anthropogenic emission and previously deposited mercury reemission or recycling, composing elemental mercury, divalent mercury and particulate-phase mercury. Many studies showed that mercury in Beijing＇s air was higher than the general level of mercury concentration in the atmosphere. Mercury emission sources were discussed. Industrial emissions, coal burning, vehicle exhaust emissions and waste incineration were thought to be the main sources of atmospheric mercury pollution in Beijing. And also meteorology has an effect on atmospheric mercury concentration in Beijing. Measures have been taken to control the emission of mercury into the air in recent years.     

浏阳河土地利用变化对非点源污染负荷的影响

以红壤丘陵区典型流域——浏阳河流域为研究区域,利用1986、2000、2005年3个时段的土地利用数据,分析土地利用方式的变化,并结合土壤普查图和降雨数据,在RS和GIS的支持下,利用长期水文影响评价(L-THIA)模型,评估区域长期水文响应,采用相似流域的营养盐输出系数估算非点源污染负荷。结果表明,从1986～2005年期间,林地和草地有向城镇、农村居民点用地和农业用地转化的趋势,其中农业用地由13.75%增加到20%左右,城镇用地和农村居民用地分别由原来的1.34%和0.10%变为2.56%和0.80%,期间非点源污染敏感区面积不断扩大,污染负荷不断增加,TN由1986年的675.56 t增加到2005年的1 001.02 t,TP从15.52 t增加到了23.41 t。