Treatment of Polluted River Water Using Pilot-Scale Constructed Wetlands

No abstract available.     

水体中重金属离子的形态及其对生物富集影响

详细介绍了水体中重金属离子形态的划分方法 ,阐述了重金属形态与生物富集的关系及其影响因素 ,指出该研究领域目前亟待解决的问题     

Diazinon Determination Using High Performance Liquid Chromatography: A Comparison of the ENVI-Carb Column with the Immunoaffinity Column for the Pretreatment of Water and Soil Samples

An immunoaffinity chromatography column was developed to remove diazinon from water and soil samples. In this paper, two types of absorbent columns, the immunoaffinity chromatography column and the ENVI-Carb column, were compared. To accomplish this, each of these columns was used to treat water and soil samples that had been spiked with diazinon at concentrations of 2.5 or 5 ng/mL (or ng/g). High performance liquid chromatography was then used to analyze the treated samples. The ENVI-Carb column recovered 87.99%–95.95% of the diazinon from water and soil with CVs of 5.08%–8.06%. The recoveries observed when the immunoaffinity chromatography column was used were slightly lower (52.61%–81.58%); however, it effectively clean up the soil samples.     

Assessing Contaminant Sensitivity of Endangered and Threatened Aquatic Species: Part II. Chronic Toxicity of Copper and Pentachlorophenol to Two Endangered Species and Two Surrogate Species

Early life-stage toxicity tests with copper and pentachlorophenol (PCP) were conducted with two species listed under the United States Endangered Species Act (the endangered fountain darter, Etheostoma fonticola, and the threatened spotfin chub, Cyprinella monacha) and two commonly tested species (fathead minnow, Pimephales promelas, and rainbow trout, Oncorhynchus mykiss). Results were compared using lowest–observed effect concentrations (LOECs) based on statistical hypothesis tests and by point estimates derived by linear interpolation and logistic regression. Sublethal end points, growth (mean individual dry weight) and biomass (total dry weight per replicate) were usually more sensitive than survival. The biomass end point was equally sensitive as growth and had less among-test variation. Effect concentrations based on linear interpolation were less variable than LOECs, which corresponded to effects ranging from 9% to 76% relative to controls and were consistent with thresholds based on logistic regression. Fountain darter was the most sensitive species for both chemicals tested, with effect concentrations for biomass at 11 g/L (LOEC and 25% inhibition concentration [IC25]) for copper and at 21 g/L (IC25) for PCP, but spotfin chub was no more sensitive than the commonly tested species. Effect concentrations for fountain darter were lower than current chronic water quality criteria for both copper and PCP. Protectiveness of chronic water-quality criteria for threatened and endangered species could be improved by the use of safety factors or by conducting additional chronic toxicity tests with species and chemicals of concern.     

生活饮用水中氯苯类化合物测定的顶空-毛细管柱气相色谱法

目的建立生活饮用水中氯苯类化合物含量测定的顶空-毛细管柱气相色谱法。方法采用Agilent顶空气相色谱、中等极性毛细柱（DB 225,30 m×0.25 mm×0.25μm）、程序升温的方式。结果 11种氯苯类化合物分离良好,检测限在0.005～1.300 g/L之间,方法线性为0.996～0.999之间,相对标准偏差2%～13%,回收率在70%～130%之间。结论该方法简单、灵敏、准确。     

毛细管气相色谱法测定水中2,4,6-三氯酚和五氯酚

目的:建立测定水中2,4,6-三氯酚和五氯酚的气相色谱测定方法。方法:水中的微量2,4,6-三氯酚和五氯酚经液-液萃取后,用DB-1701毛细管色谱柱,在程序升温条件下进行GC分析,以保留时间定性,外标法定量。结果:2,4,6-三氯酚的线性范围为0.005μg/L~1.0μg/L,最低检出浓度为0.0030μg/L,五氯酚的线性范围为0.01μg/L~2.0μg/L,最低检出浓度为0.0048μg/L,相关系数均≥0.9990,水样加标回收率为73.0%~91.0%,RSD为4.6%~7.9%。结论:方法仅用8.5 m in完成饮用水中2,4,6-三氯酚和五氯酚的测定,操作简便、灵敏度高。     

水中6种有机磷农药的毛细管柱气相色谱测定法

目的建立一种同时测定环境水中敌敌畏、乐果、马拉硫磷、甲基对硫磷、对硫磷、毒死蜱6种有机磷农药的方法。方法采用液-液萃取和RTX-50毛细管柱气相色谱火焰光度检测器(FPD)法进行测定。结果本法测定前述6种有机磷农药的分离度均大于1.5,线性范围为2.0～16.0μg/ml,相关系数≥0.9992,检出限为0.0092～0.076ng,RSD为1.5%～7.1%,平均加标回收率为93.0%～98.7%,在21min内6种有机磷完全分离。结论本法与GB13192—1991《水质有机磷农药的测定》方法比较,其检测限、精密度、准确度均显出明显优势,能满足《生活饮用水卫生规范》的要求和日常分析的需要。     

水中12种有机磷农药的毛细管气相色谱测定法

目的建立同时测定水中多种有机磷农药的气相色谱测定方法。方法水中的微量有机磷化合物经液-液萃取后,用DB-1701毛细管色谱柱,同时在程序升温和恒线速度氮载气条件下进行气相色谱分析,以保留时间定性,外标法定量。结果该方法12种有机磷农药的线性范围为0.2～50.0μg/L,相关系数≥0.9991,最低检出浓度为0.009～0.04μg/L,水样加标回收率为78.4%～93.9%,RSD为3.4%～7.5%。结论该方法一次性完成水中12种有机磷化合物的分离和测定,分析时间仅为32.5min,操作简便、灵敏。     

水中三氯杀螨醇和拟除虫菊酯的气相色谱测定法

目的建立同时测定水中三氯杀螨醇和7种拟除虫菊酯的气相色谱(GC)测定方法。方法水中的微量三氯杀螨醇和拟除虫菊酯经液-液萃取后,利用DB-1型毛细管色谱柱,在程序升温条件下进行GC分析,以保留时间定性,外标法定量。结果三氯杀螨醇、联苯菊酯、甲氰菊酯、氯氟氰菊酯、氯菊酯、氟氯氰菊酯、氯氰菊酯、氰戊菊酯的线性范围分别为0.24～31.1、0.21～27.2、0.20～26.0、0.21～26.5、0.20～25.7、0.21～26.4、0.22～29.0、0.22～27.4μg/L,相关系数≥0.9990,最低检测浓度分别为0.20、0.33、0.30、0.13、0.36、0.26、0.33、0.30μg/L,该方法的平均加标回收率为86.0%～111.7%,RSD为3.8%～11.8%。结论该方法操作简便、灵敏度高,适合于生活饮用水中三氯杀螨醇和7种拟除虫菊酯的同时测定。     

Persistent DDE in the Mesopotamian Wetlands of Southern Iraq

Screening of potential pollutants in surface sediments revealed that almost all persistent organochlorine pesticides were not detected in the newly flooded Mesopotamian wetlands of southern Iraq. This observation suggests that there has been minimal input of organochlorine pesticides recently except for p,p′-DDE which was the only pesticide residue detected (0.29–2.33 μg/kg). It was found in all samples indicating its ability to persist under severe drying of previously exposed surface sediments, high temperature, and intensive solar radiation. p,p′-DDE appears to have a negative relationship with wetland biota, such as zooplankton.     

Effects of Pulsed Contaminant Exposures on Early Life Stages of the Fathead Minnow

Water quality standards for protecting aquatic life are based primarily on laboratory tests that use constant exposure concentrations. Typical effluent and nonpoint source exposure concentrations fluctuate in frequency, magnitude, and duration, which may result in different toxicological impacts. Current information indicates that pulsed or fluctuating exposures are generally more toxic than continuous exposures, when averaged over the applicable time period. However, few studies have evaluated chronic or sublethal effects of pulsed exposures, particularly those applicable to wastewater discharge situations. To address this issue, several pulsed exposure toxicity tests were conducted using modified fathead minnow (Pimephales promelas) early life stage (7 d) tests and several chemicals representative of those commonly encountered in wastewater effluents including copper, nitric acid, cadmium, and sodium chloride. Results suggest that survival and/or growth effects depend on the combination of frequency, magnitude, and duration, as well as the type of chemical. Nitric acid and sodium chloride pulsed treatments did not exhibit growth effects independent of survival effects, but both metals did elicit only growth effects in some treatments. Growth effects were related to pulse frequency and duration for copper and pulse duration and magnitude for cadmium. A 12-h exposure of approximately five times the 7-d continuous exposure IC₂₅ concentration of either metal quickly elicited mortality responses. Prolonged (>24 h) lag effects on survival were not observed in any of the experiments, regardless of the contaminant tested. Our results suggest that current water quality criteria may be underprotective if based on an average concentration over a 2-4 d exposure. For these contaminants, a short-term increase in concentration may elicit effects even though the average concentration is within nontoxic ranges for the organism.     

Contaminant dispersion in the vicinity of a worker in a uniform velocity field

The transportation of gaseous contaminant from a low and moderate low impulse (momentum<1 m s(-1)) source to the breathing zone was studied in a uniform air stream flow. Results of the effects of the direction and the velocity of principal air flow, convection due to a human body, arm movement of a human being and the type of source on the concentration profiles are presented. Three important results were obtained. Firstly, for a given low and moderate impulse low impulse contaminant source in the near field of a worker, his/her orientation relative to the principal air flow direction is the most important factor in reducing occupational exposure, with an air velocity of about 0.3 m s(-1). Secondly, the effect of convection resulting from body heat on air flow was lower than expected. Thirdly, arm movements influence contaminant dispersion, and should be included when models assessing exposure are developed. The present data can also be used to validate existing computational fluid dynamic (CFD) models.     

二次加压供水卫生管理指数的建立与应用

本文通过对国内１２０起二次加压供水污染事故的分析，总结出造成污染事故发生的主要原因为：基础设施设计及安装不合理（Ｘ１）、水箱存在被污染的隐患（Ｘ２）、卫生管理不善（Ｘ３）。进一步推导出二次加压供水污染的危险性指数，即二次加压供水卫生管理指数：Ａｉ＝０．７１Ｘ１＋０．０５Ｘ２＋０．２４Ｘ３，并提出了使用该指数的方法。应用此指数对某市二次加压供水进行了卫生学评价，表明该市二次加压供水卫生管理提数为１．     

Laboratory-based Evaluation of the Protection Provided Against Cold Water by Two Helicopter Passenger Suits

The thermal protection provided by two helicopter passengerimmersion suits was evaluated. Suit A was a standard ‘dry’suit and suit B was a ‘dry’ suit with inherent insulationprovided by inflation of the outer shell of the suit. Duringfour hour immersions in water at 4°C with simulated rain,wind and waves, suit B provided significantly (p < 0.01)better protection against the long-term effects of immersionthan suit A. The skin and core temperature of subjects fellat slower rates over the immersion period when they wore SuitB, they shivered less, had lower heart rates and were more comfortablein this suit. The problems of testing and selecting appropriateimmersion suits are discussed and it is concluded that testsof immersion suits should be as realistic as possible and, whenthis is so, ‘dry’ suits with inherent insulationwhich is unaffected by leakage are likely to perform betterin cold water than those without such insulation. Requests for reprints should be addressed to: M. J. Tipton, Institute of Naval Medicine, Gosport, Hampshire, UK