MA-2000型测汞仪直接测定环境水体中的汞

介绍了MA-2000型测汞仪测定环境水体中的汞，以氯化亚锡为还原剂，0．001％半胱氨酸为汞固定剂，在一定浓度范围内被测汞蒸汽在波长253．7nm紫外光下的吸收值与汞蒸汽浓度成正比。方法检出限0．006ng，精密度和准确度均满足水质监测实验室质量控制的要求。     

成都地区蔬菜中重金属污染分析与评价

通过对成都地区的9种蔬菜152个样品的可食部分中重金属元素的分析研究，查明了蔬菜中重金属汞、砷、铅、锡的含量及分布特征。结果表明，锡和铅是成都地区蔬菜中的主要污染元素，在检测的蔬菜样品中，锡和铅的超标率分别为29．4％和22％，最高超标分别为5.60倍和2.86倍，汞和砷无超标现象。     

原子荧光光谱仪同时测定样品中的砷和汞

用原子荧光光度计,采用顺序注射自动进样技术同时测定不同样品中的砷和汞,并进行了仪器工作条件的优化,砷、汞的检出限分别可达0．2μg/L和0．015μg/L,样品的加标回收率砷为92％～103％,汞为98％～104％,完全能够满足环保行业不同样品砷和汞的含量的检测。该方法具有一次性处理样品,同时测定样品中砷和汞含量的优点,操作简单、快速,节省试剂。     

微波消解-原子荧光光谱法同时测定土壤中痕量砷和汞

建立了微波消解—原子荧光光谱法同时测定土壤中痕量砷和汞的方法。通过对消解体系以及灯电流、载气流量、屏蔽气流量等仪器参数进行优化,确定了最佳实验条件。在优化的实验条件下,采用原子荧光光谱法同时测定砷和汞的检出限分别为0.02μg/L和0.01μg/L,线性范围分别为0～40μg/L和0～4μg/L,两元素的加标回收率在92%～102%之间,相对标准偏差砷为0.9%～3.1%,汞为1.5%～3.4%,完全适用于土壤环境样品的检测。     

西宁地区环境有害元素砷汞含量及其防治对策

对西宁地区自然环境（土壤、水体、农作物）中有害元素的调查分析表明,砷、汞含量水平相对较低,总体环境状况良好,局部土壤砷和汞的污染主要由人为活动（工业性大气降尘和农药、化肥施用等）所致。结合环境污染特点,探讨了砷、汞污染防治对策     

宁波市鄞州区农业土壤重金属含量变化及评价

为发展无公害农产品基地提供科学依据，2005年对浙江省宁波市鄞州区100个农业土壤样品中重金属含量进行了测定和评价。结果表明：耕层全砷、镉、铬、汞和铅的平均含量分别为8．1mg·kg^-1,0．163mg·kg^-1、100．1mg·kg^-1、0．257mg·kg^-1和3．6mg·kg^-1，与1983年宁波市的耕层土壤背景值相比，分别增加了12．5％、32．5％、61．2％、0．8％和55．2％，土壤已受到镉、铅和汞的轻微污染，而汞的污染已得到遏制。从总体上来说，鄞州区农业土壤环境质量良好，区内有98个点（占总样点数的98％）符合无公害农产品产地土壤环境质量要求，但有2个点（占总样点数的2％）分别受到镉和汞的污染。     

九寨沟白水河污染特征研究

通过对2012年4月～2013年3月九寨沟白水河不同断面水样分析,研究了《地表水环境质量标准》（GB3838—2002）中表1“地表水环境质量标准基本项目”的含量变化,并对铬、镉、硒、铜、汞、锌、铅、砷、氨氮、高锰酸盐指数进行污染状况评价。结果显示：镉、铜、汞、锌、铅均未检出;对铬、砷、硒、氨氮、高锰酸盐指数等有检出项目进行单项污染指数和内梅罗综合污染指数评价,水样中铬、砷、硒、氨氮、高锰酸盐指数全年监测平均浓度分别为0．294μg／L、0．024μg／L、0．084μg／L、0．187mg／L、0．695mg／L,用国家水质环境标准的一级标准,所有监测点位（PN〈1）未超标。从单因子污染指数来看,高锰酸盐指数在4月、7月、10月P,〉1,属于轻度污染,初步推断人为活动所致。通过本文的研究发现九寨沟水质依然较好,未受到污染。     

沈阳市道路绿化带土壤污染现状调查分析

选择沈阳市内不同道路绿化带土壤进行现状调查与分析,分别在5个区域,各布设3个采样点,分析测定土壤中的p H,阳离子交换量,汞、砷、铅、镉等元素以及DDT、六六六有机项目的含量。结果表明,总体上北部地区镉、汞、铅、DDT、六六六含量都较低,而南部地区含量则较高;各种元素中铅浓度相对较高。     

土壤中痕量砷的调查与研究

通过对6个典型区域和农村主要地区进行调查，共采集具有代表性的土壤样品330个。采用王水体系消解-原子荧光光度法测定土壤样品中砷的含量，结果表明：砷标准样品在10．0-60．0μg·L-1范围内，线性相关系数为0．9995；取0．5g样品消解，方法检出限为0．007mg·kg-1；以20．0μg·L-1的标准溶液连续测量11次，相对标准偏差为0．2％；调查的6个典型区域的180个点位和农村主要土壤耕层的150个土样中，砷含量在1．02-32．87mg·kg-1之间，根据《土壤环境质量标准》（GB15618--1995）三级标准评价，土壤中砷的含量均未超过国家标准。     

正交试验-硝酸微波消解-冷原子吸收法测定土壤中汞

应用硝酸微波消解土壤样品-冷原子吸收法测定土壤中的汞。通过正交试验，优化了土壤中汞的微波消解条件。并对干扰消除、方法精密度、加标回收、检出限进行了试验研究。在0～10μg／L范围内线性关系良好，方法测定下限为0．20μg／L，土壤中汞的检出限为0．005μg／g。该优化条件对汞含量为0．02—0．46μg／g的土壤样品，汞提取完全。建立了一种简便、成本低、干扰少、灵敏度高的方法。     

微波消解—ICP-MS法测定鲤鱼和河蚌中汞和砷

采用微波消解样品,电感耦合等离子体质谱检测,以Rh作为内标物进行基体干扰校正,同时测定了鲤鱼和河蚌中Hg和As的含量。结果表明:建立的方法简便、快速、准确,标准曲线的线性关系均大于0.9990,样品加标回收率在97.9%～104%之间。     

王水消解-冷原子荧光法测定土壤中的微量汞

建立了一种用王水水浴消解土壤样品一冷原子荧光测定土壤中的微量汞的分析方法。在优化实验条件下，方法的检出限为0.010 2ug／L；土壤中汞的回收率为95％-109％；测定下限为0.01ug／g。该方法具有操作简便、快速、准确、灵敏度高、重复性好等优点。     

Contaminants evaluation of Marais des Cygnes National Wildlife Refuge in Kansas and Missouri,USA

At the new Marais des Cygnes National Wildlife Refuge in Linn County, Kansas, and Bates County, Missouri, USA, we evaluated long-lived contaminants before acquisition of the land for the refuge. We sampled sediments at 16 locations and fish at seven locations. The samples were analyzed for metals and for chlorinated hydrocarbon compounds. Selected sediment samples also were analyzed for aliphatic hydrocarbons. Arsenic concentrations in sediment samples from six locations were elevated compared to US norms, but arsenic was not detected in any fish composite. Mercury concentrations in largemouth bass from two locations were comparable to the 85th percentile concentrations in nationwide fish collections. Most sediment concentrations of other metals were unlikely to have detrimental effects on biota. No chlorinated hydrocarbons were detected in any sediment sample. Chlordane compound concentrations in fish composites from two sites at the eastern end of the sampling area were 0.127 and 0.228 μg/g wet weight, respectively, which are high enough to cause concern. Most aliphatic hydrocarbons detected were found at low concentrations and probably were natural in origin. We concluded that there are no serious contaminants concerns within the project area, but past use of arsenical pesticides may mean a legacy of elevated soil arsenic levels in parts of the area and some use of banned pesticides such as chlordane and DDT likely is still occurring near the refuge.     

Solar oxidation and removal of arsenic from water: An experimental study

Arsenic poses a significant threat to both human health and the environment. Arsenic removal through solar oxidation has been investigated in a batch process. Arsenic was artificially added to both deionized and tap water to conduct the experiments. Clean, colorless, transparent, Polyethylene Terephthalate (PET) bottles were used for Solar Oxidation and Removal of Arsenic (SORAS) experiments. Various parameters including concentration of arsenic, iron, and photo-catalyst were varied during the experiments. The maximum arsenic removal efficiency obtained was 94% and 88% for deionized water and tap water respectively when ferrous ammonium sulphate and lemon juice were used. Maximum efficiency of 88% and 82% was obtained for deionized and tap water respectively when locally available ferrous alum and glacial acetic acid were used. The change in volume of the photo-catalyst (lemon juice and glacial acetic acid) also did not affect the SORAS process significantly. Therefore, the recommended volume for the photo-catalyst was 1–2 ml/L. SORAS can very well be used for areas contaminated with arsenic having concentrations less than 100 μg/L.     

Iron and aluminium based adsorption strategies for removing arsenic from water

Arsenic is a commonly occurring toxic metal in natural systems and is the root cause of many diseases and disorders. Occurrence of arsenic contaminated water is reported from several countries all over the world. A great deal of research over recent decades has been motivated by the requirement to lower the concentration of arsenic in drinking water and the need to develop low cost techniques which can be widely applied for arsenic removal from contaminated water. This review briefly presents iron and aluminium based adsorbents for arsenic removal. Studies carried out on oxidation of arsenic(III) to arsenic(V) employing various oxidising agents to facilitate arsenic removal are briefly mentioned. Effects of competing ions, As:Fe ratios, arsenic(V) vs. arsenic(III) removal using ferrihydrite as the adsorbent have been discussed. Recent efforts made for investigating arsenic adsorption on iron hydroxides/oxyhydroxides/oxides such as granular ferric hydroxide, goethite, akaganeite, magnetite and haematite have been reviewed. The adsorption behaviours of activated alumina, gibbsite, bauxite, activated bauxite, layered double hydroxides are discussed. Point-of-use adsorptive remediation methods indicate that Sono Arsenic filter and Kanchan™ Arsenic filter are in operation at various locations of Bangladesh and Nepal. The relative merits and demerits of such filters have been discussed. Evaluation of kits used for at-site arsenic estimation by various researchers also forms a part of this review.     

Assessment of contamination from arsenical pesticide use on orchards in the Great Valley region, Virginia and West Virginia, USA

Lead arsenate pesticides were widely used in apple orchards from 1925 to 1955. Soils from historic orchards in four counties in Virginia and West Virginia contained elevated concentrations of As and Pb, consistent with an arsenical pesticide source. Arsenic concentrations in approximately 50% of the orchard site soils and approximately 1% of reference site soils exceed the USEPA Preliminary Remediation Goal (PRG) screening guideline of 22 mg kg(-1) for As in residential soil, defined on the basis of combined chronic exposure risk. Approximately 5% of orchard site soils exceed the USEPA PRG for Pb of 400 mg kg(-1) in residential soil; no reference site soils sampled exceed this value. A variety of statistical methods were used to characterize the occurrence, distribution, and dispersion of arsenical pesticide residues in soils, stream sediments, and ground waters relative to landscape features and likely background conditions. Concentrations of Zn, Pb, and Cu were most strongly associated with high developed land density and population density, whereas elevated concentrations of As were weakly correlated with high orchard density, consistent with a pesticide residue source. Arsenic concentrations in ground water wells in the region are generally <0.005 mg L(-1). There was no spatial association between As concentrations in ground water and proximity to orchards. Arsenic had limited mobility into ground water from surface soils contaminated with arsenical pesticide residues at concentrations typically found in orchards.     

Arsenic distribution in Florida urban soils: comparison between Gainesville and Miami

Arsenic contamination is of concern due to its effect as a carcinogen. Understanding the distribution of arsenic in urban soils is important for establishing baseline concentrations from which anthropogenic effects can be measured. The soil cleanup target level (SCTL) for arsenic in Florida (0.8 and 3.7 mg kg(-1) in residential and commercial areas, respectively) is lower than in most states and is near the arsenic background concentrations in Florida soils. The objective of this study was to characterize the distribution of arsenic in the soils of two Florida cities, Gainesville and Miami. More than 200 soil samples were collected from three land-use classes in each city (residential, commercial, and public land), digested with USEPA Method 3051a, and analyzed with graphite furnace atomic absorption spectrophotometry. Arsenic concentrations varied greatly in Gainesville, ranging from 0.21 to approximately 660 mg kg(-1) with a geometric mean (GM) of 0.40 mg kg(-1) (after discarding outliers), which was significantly lower than the GM of 2.81 mg kg(-1) in Miami, although Miami samples ranged only from 0.32 to approximately 110 mg kg(-1). Arsenic concentrations in 29 and 4% of the Gainesville soil samples and 95 and 33% of the Miami samples exceeded the Florida residential and commercial SCTL, respectively. This study is the first to provide information on arsenic distribution in urban soils of Florida, and the data are useful for assessing arsenic contamination and determining the need for remediation.     

烟气中汞现场监测氧化吸收条件优化研究

以高锰酸钾溶液作为烟气中汞元素的氧化吸收液,通过单因素试验研究了氧化吸收液浓度、反应时间、初始汞浓度、反应温度、pH值对KMnO₄对Hg⁰吸收效率的影响,阐明方法适应性,并将现行采样方法进一步优化。结果表明,15min后,氧化吸收基本平衡,KMnO₄浓度为5mmol/L,反应温度为60℃时KMnO₄氧化吸收最佳。强酸和强碱环境的吸收效率均高于中性条件,初始汞浓度变化对KMnO₄吸收效率的影响不大,抗冲击负荷的能力较强,最优实验条件下,氧化吸收效率提高显著,具有统计学意义。