氟利昂替代品降解产物——三氟乙酸对水环境的潜在影响

三氟乙酸 (简称 TFA)是氟利昂替代品的主要降解产物之一 ,该物质会造成大气环境的恶化 ,雨水会将其从大气中去除。三氟乙酸化学性质极其稳定 ,在水中全部溶解。在自然条件下 ,三氟乙酸不降解、不光解、不被土壤吸附、不被微生物分解 ,易于在水体中积累 ,特别是在没有流入和流出的水体及季节性湿地中蓄积。全球雨水中的三氟乙酸 2 0 1 0年预计可达到 1 0 0～ 1 60 ng/L,部分地区地表水可达到 1 60 ng/L。     

三重串联四极杆气相质谱联用仪测定饮用水源地水体中的多氯联苯

建立了以液-液萃取、三重串联四极杆气相质谱多反应监测法同时测定饮用水源地水体中18种多氯联苯的方法,给出了测量线性范围,线性关系良好,相关系数大于0.998。水中加标浓度为1.00、5.00、10.0ng/L时,平均加标回收率分别为75.6%～96.0%、90.6%～105%和92.4%～102%,相对标准偏差分别为19.8%～11.8%、4.2%～12.9%和4.3%～9.9%,检出限为0.29～0.57ng/L。结果表明,在测定水体中痕量多氯联苯方面,三重串联四极杆气相质谱相对于气相色谱-电子捕获检测和气相色谱质谱-选择离子检测具有更高的灵敏度和准确度,具有更广泛的应用。     

电子垃圾回收地得克隆的污染水平及分布特征

对浙江某电子垃圾回收地水体、沉积物、土壤以及大气中得克隆（DP）的污染水平及分布特征进行了调查。结果表明，水、沉积物、土壤和大气样品中均检测出了 DP，分别为0．843～1．56 ng/L，0．185～7．03 ng/g干重，0．115～26．4 ng/g干重和11．2 pg/m3；该区域 DP分布特征表明电子垃圾的拆解和焚烧是环境中 DP的重要来源。     

惠州农业土壤、灌溉水和农产品中有机氯农药的残留

用气相色谱法(GC-ECD)对惠州市51个农业土壤样品、12个灌溉水样品和21个农产品样品中的HCHs和DDTs残留量进行了测定.HCHs平均含量分别为土壤1.66μg/kg、灌溉水5.86ng/L、农产品24.74μg/kg;DDTs平均含量分别为土壤4.98μg/kg、灌溉水2.06ng/L、农产品41.72μg/kg,土壤中有机氯农药通过多种方式进入到水体及农产品中.从HCHs和DDTs异构体组成可以看出,环境中绝大多数农药残留是由于历史上使用造成的,个别地区可能还有新的污染输入.同其它地区相比,惠州农业土壤和灌溉水中的有机氯农药残留水平较低,但农产品尤其是蔬菜中DDTs富集程度较高.     

柱前衍生化-固相萃取-气相色谱法快速测定水中五氯酚

建立了柱前衍生化-固相萃取-气相色谱法快速测定水样中五氯酚的方法。结果表明,目标化合物在气相色谱条件下可以实现很好的基线分离,五氯酚在质量浓度0. 05~50. 0μg/L范围内呈现良好的线性关系,相关系数r=0. 998,方法检出限为0. 006μg/L,测定下限为0. 024μg/L,相对标准偏差均10%。该方法具有较高的精密度和准确度,且简便高效,适用于水体中五氯酚的测定。     

固相萃取- GC/MS法测定水中有机氯农药

建立了固相萃取-气相色谱／质谱联用测定水中痕量六六六、滴滴涕和环氧七氯的方法。采用C18固相萃取柱富集水样，二氯甲烷／丙酮混合溶剂洗脱，加入菲-d10作为内标，利用气相色谱／质谱联用仪选择离子监测模式检测，内标法定量，定性、定量准确，线性响应良好，干扰小，按采样1 L计算，方法检出限为4．26ng／L～19、2ng／L，RSD在0、4％-6、3％之间，平均加标回收率在77．7％～118％之间，实际样品测定结果表明方法能满足环境水体中痕量有机氯农药的监测要求。     

环境水系统中氯氟烃替代品降解产物TFA的测定

三氟乙酸为氯氟烃替代品的降解产物,对植物和土壤微生物群落的生长有一定抑制作用.建立测定TFA质量浓度的实验方法,将样品中的三氟乙酸与甲醇在硫酸溶液中衍生化为三氟乙酸甲酯(MTFA),利用三氟乙酸甲酯的易挥发性,以顶空进样进行富集浓缩.使用质谱定性手段确定出峰时间,再通过电子捕捉检测器ECD对实际样品进行分析.仪器检测限为30μg/L,方法检出限约为30ng/L,加标回收率60%～90%.     

气相色谱-高分辨双聚焦磁质谱测定水中超痕量多氯萘

采用固相萃取法处理水样，气相色谱-高分辨双聚焦磁质谱法测定水中超痕量多氯萘，同位素内标法定量，并对样品前处理条件和仪器条件进行优化。试验表明：方法在0．500 ng/L～500 ng/L范围内线性良好；当取样体积为1 L时，方法检出限为0．005 ng/L～0．01 ng/L；对实际水样进行2个质量浓度水平的加标回收试验，平行测定6次的 RSD为2．7％～8．7％，回收率为70．2％～110％。方法适用性试验表明，水样中复杂的基质对测定无影响。     

影响顶空-气相色谱法测定水中吡啶准确度的关键因素探讨

通过试验,讨论盐析效应、顶空的平衡温度和平衡时间、水样的p H值、色谱条件等对顶空-气相色谱法测定环境水体中吡啶准确度的影响。优化上述条件后,方法在0 mg/L~3.95 mg/L范围内线性良好,检出限可达0.016 mg/L,测定下限为0.064 mg/L。用该方法对地表水和生活污水做3个质量浓度水平的加标回收试验,测定6次结果的RSD为1.7%~5.7%,回收率为93.9%~113%。     

乌鲁木齐地表水饮用水源地水体有机氯农药健康风险评价

为了解乌鲁木齐市地表饮用水源地水体中有机氯农药(OCPs)对人体产生的潜在健康危害风险,从一号冰川、英雄桥、乌拉泊水库的9个采样点采集水样,采用液液萃取-气相色谱/质谱法对其中的有机氯农药残留状况进行了测定,水样中9种有机氯化合物的总质量浓度为15.1 ng/L～41.2 ng/L。应用美国国家环保局(US EPA)推荐的健康风险评价方法,对乌鲁木齐市地表饮用水源地水体中有机氯农药通过食用途径进入人体的危害进行了风险计算和初步评价。结果表明,各监测断面的致癌风险和非致癌风险低于ICRP和USEPA推荐的最大可接受风险水平,初步认为目前乌鲁木齐市地表饮用水源地水体中有机氯农药不会对人体产生明显的健康危害。     

水质中高浓度挥发酚的预测

提出一种以溴水预测法确定高浓度挥发酚稀释倍数 ,为高浓度水样提供了一种科学准确的操作分析方法。简单快速 ,并能确保高浓度挥发酚水样分析的可靠性与成功性 ,具有很大的应用和推广价值     

Crown density assessments, control surveys and reproducibility

This study aims to evaluate the quality of crown density data, based on independent, pairwise tree assessments. The data originates from monitoring of forest health (crown condition) in Norway; 250 plots, comprising 12 000 individual trees of Norway spruce, have been reassessed by a single observer during 1990–95. Of the trees, 2300 were controlled more than twice, providing the possibility of evaluating the quality of assessed temporal changes of crown density. True errors (standard deviation) are estimated to be about 10% for single trees and 5% for plot means, while the real standard deviation of the differences were slightly higher. The errors of the temporal changes of crown density were of similar magnitude. Systematic differences in crown density were found between sites and plot types, partly resulting from observer bias. However, the results suggest that observer bias is really the result of each observer's personal style in assessment.     

淡水环境沉积物中微塑料的密度分离方法研究

微塑料污染已广泛覆盖了全球海洋和淡水环境的表层水体、深层水体以及沉积物,沉积物中的泥沙和其他杂质颗粒会严重影响对沉积物中微塑料的实验分析.因此,将微塑料从沉积物中分离出来至关重要,而目前我国微塑料分离方法暂无统一的系统程序和检测标准.该研究在岷江成都段选取4个采样点采集沉积物样品,通过对比研究基于密度分离法的3种分离方...     

A Fast Method for Monitoring Foliage Density in Single Lower-canopy Trees

A subjective visual assessment of foliage density is the mostwidely used rapid method of determining forest health. Forthese assessments to be ecologically meaningful they must bereliable (have low inter- and intra-observer variability) andreadily relate to a measure of physiological or physicalstress. A simple rapid method for assessing percent foliagedensity in lower stature trees is described. This method haslow inter-observer variability (standard deviation betweenobservers=8.6%) and therefore, minimizes the risk ofconfounding the effects of different observers with genuinechanges in density. The percentage changes in this measure offoliage density correlate well with percentage changes inbiomass, allowing a ready interpretation of observed changes.The technique does not specifically identify the cause of themeasured changes, however, with appropriate additionalmeasures this problem may be overcome.     

Anuran Development, Density and Diversity in Relation to Agricultural Activity in the Holland River Watershed, Ontario, Canada (1990–1992)

Significantly lower anuran species diversity and density was recorded in a vegetable growing area relative to upstream and downstream sites in the Holland River watershed, Ontario, Canada. Egg hatching success and tadpole deformity rates of American toads (Bufo americanus americanus), green frogs (Rana clamitans melanota) and northern leopard frogs (Rana pipiens) eggs in water from field sites and control water were assessed. Compared to the control and the upstream site, the total abnormality rate (unhatched eggs plus deformed tadpoles) was higher for American toads in water from the agricultural and downstream sites. Total abnormality was higher in green frog eggs in water from the agricultural site and a downstream site. Trace concentrations of organophosphorus pesticides were detected most often in agricultural zone water and sediments than in upstream and downstream sites. Organochlorine pesticide residues, especially in agricultural zone samples, exceeded the no effect level guidelines for the protection of aquatic life. Ammonia, phosphorus, particulates, BOD and TKN were highest in the agricultural zone. Significant correlations between these parameters and anuran development suggest nutrient run-off as a causal or contributing factor in lower anuran diversity, density and reproductive success of American toads and green frogs in the site dominated by agriculture.     

生物监测中叶绿素a浓度与藻类密度的关联性研究

通过测定叶绿素a浓度、藻类密度和藻类分类计数等,获取"水华"水体生物监测数据。统计分析结果表明,叶绿素a浓度和藻类密度在蓝藻"水华"(微囊藻为优势种)暴发期间存在显著相关,并拟合出了回归直线。且叶绿素a浓度和藻类密度的自然对数比值也与藻类发生和兴衰存在着规律性联系。     

太湖流域近地表主要温室气体本底浓度特征

根据2003年1月-2005年6月太湖流域近地表大气中主要温室气体CO2、CH4和N2O本底浓度的监测资料,研究了该流域近地表大气主要温室气体浓度的变化特征.结果表明,在观测时段内,该流域近地表大气CO2浓度呈上升趋势;CH4浓度呈逐年递减趋势;N2O浓度呈先减后增趋势.3种气体主要与人类活动、工农业生产和交通运输业发展有关,CO2浓度的季节变化明显,冬春季高,夏秋季低,最高值在12月,最低值在8月;CH4浓度由春至夏升高,由夏至秋至冬递减,最高值在7月,最低值在2月;N2O浓度没有明显的季节变化,它们主要受源汇强度变化影响.CO2浓度的日变化基本呈双峰态,是源汇强度变化和边界层稳定程度相互作用的原因,CH4浓度无明显日变化规律,N2O浓度日变化中的最高值总体呈现是夏、秋、春至冬逐渐延迟的状态.     

Modelling the Removal of Gaseous Pollutants and Particulate Matters from the Atmosphere of a City by Rain: Effect of Cloud Density

In this paper, an original nonlinear mathematical model for the removal of gaseous pollutants and particulate matters from the atmosphere of an industrial city by rain is proposed and analyzed. It is assumed that five interacting phases in the atmosphere of the city exist, i.e., cloud droplets phase, raindrops phase, gaseous pollutants phase, particulate matters phase, and the phase of absorbed gaseous pollutants in raindrops. It is assumed further that these phases undergo nonlinear interactions in the atmosphere, while gaseous pollutant interacts with cloud droplets as well as with raindrops but particulate matters interact only with raindrops. The gravitational settling and reversible reaction processes have also been considered appropriately in the model. By analyzing the model, it is shown that both the gaseous pollutants and particulate matters may be removed from the atmosphere under certain conditions, provided the rates of formation of cloud droplets and raindrops are sufficiently large. It is noted that under unfavorable atmospheric conditions, rain does not occur and pollutants are not removed from the atmosphere.     

杭州城区PM2.5和PM10污染特征及其影响因子分析

利用2013年12月—2014年11月杭州城区空气质量监测站PM_(2.5)、PM_(10)浓度值结合气象、道路、人口数据以及站点周边绿地信息分析PM_(2.5)、PM_(10)浓度时空特征及其影响因子。结果表明,杭州城区各监测站PM_(2.5)和PM_(10)晴天日浓度变化趋势基本一致,PM_(2.5)比PM_(10)污染严重;晴天日PM_(2.5)、PM_(10)浓度值与对应的温度(-0.463,-0.281)、风速(-0.305,-0.332)呈负相关,与湿度(0.257,0.239)呈正相关;晴天有风时,杭州市区PM_(2.5)、PM_(10)污染北部重于南部,东部重于西部,浓度极高值集中在风速小于5 m/s时段,且风速越小浓度值越高;温度为12℃左右,湿度在60%~80%时,颗粒物污染最严重;交通高峰时各监测站PM_(2.5)、PM_(10)污染程度存在明显差异。相关性分析表明,PM_(2.5)、PM_(10)污染程度与道路密度成正比,与缓冲区内绿地覆盖面积成反比。PM_(2.5)污染程度与人口密度成正比,PM_(10)污染与人口密度成反比。     

近地面NO_2浓度卫星遥感估算问题

对卫星遥感监测大气NO_2的差分算法涉及的科学问题进行了综述,包括去除大气散射和地表反射噪声影响、大气拉曼散射引起的Ring效应校正、不同大气成分分离和观测垂直归一化等问题。国际上通过剔除平流层NO_2获得对流层柱浓度产品,文章绕开平流层NO_2获取问题,提出了结合大气化学模式模拟的垂直廓线直接估算近地面NO_2浓度技术方法,以更好地满足环境空气质量的观测需求,阐述了几个影响NO_2反演精度的相关问题。