微波消解—原子吸收/原子荧光光度法测定活性污泥中的Cd、Pb、Ni、Cu、Zn、Cr、K、As、Hg

通过实验,建立了活性污泥中金属和重金属的测定方法。活性污泥样品经硝酸—氢氟酸或硝酸—高氯酸微波消解处理后,Pb、Ni、Cu、Zn、Cr、K选用火焰原子吸收分光光度法测定,Cd用石墨炉原子吸收分光光度法测定,As、Hg用原子荧光光度法测定。该方法操作简单,结果准确,重现性好。样品加标回收率为93%-108%,相对标准偏差〈5%。     

土壤中锰、锌、铜、铬、镍、钴、钒、钛的ICP-AES测定

本实验对土壤中Mn、Zn、Cu、Cr、Ni、Co、V、Ti八种元素的测定条件及样品预处理方法进行了探讨。样品经HNO_3—HF—混合酸完全消解,于ICP上连续测定各元素含量。光谱干扰采用系数法扣除。本法与原子吸收法比较,具有线性范围宽,多元素同时测定,操作简便、快速等优点。用于土壤样品测定及经全国土壤背景值调查分析质控考核,结果令人满意。     

离子色谱法同时测定酸雨中的钠、铵、钾、镁、钙

阐述了离子色谱法测定酸雨中的钠、铵、钾、镁、钙含量的方法和步骤。结果表明,各元素的检出限均低于0.02 mg/L,加标回收率为90%~110%,相对标准偏差均低于1%,结果令人满意。该方法可同时测定酸雨中的5种阳离子,并且操作便捷,值得推广与应用。     

ICP-MS法测定水稻田表层土壤中重金属元素Zn、Cd、Pb、Cu、Cr、Mn的研究

报道了用ICP-MS法直接测定水稻田表层土壤中的重金属元素Zn、Cd、Pb、Cu、Cr、Mn含量的方法.土壤样品经HNO3-HF-HClO4彻底消化后,加入内标元素45Sc、115In、204Tl,采用内标法进行测定,有效地克服了基体效应、接口效应及仪器波动所产生的影响;通过优化仪器的工作参数,选择待测元素适当地测定同位素,有效克服了因质谱干扰所带来的影响.对污染土壤标准物质(编号GBW08305)进行测定,测定结果与标准值相吻合.该方法的加标回收率是98.0%～102.0%,相对标准偏差是2.2%～3.5%,具有线性范围宽、简单、快速、准确等特点.     

用几种溶样方法对典型土样中Pb、Cr、Ni、Cd、Mn、Cu、Zn的溶出情况比较

本文采用HNO_3、HCl-HNO_3、HNO_3-H_2SO_4-HClO_4,溶洋方法消解土样,用原子吸收法测定题述中的元素,并与HCl-HNO_3-HF-HClO_4全消解方法进行了比较.发现除用HF以外的其它酸溶法Pb、Cr的溶出较少溶出比分别低于55％和67％,主要原因是Pb、Cr包藏在土壤的矿物晶格中。     

土壤中Br、Cs、Hf、Rb、Sb、Sc、Ta、Th、U、Zr的中子活化分析

本文采用仪器中子活化法,相对法和单比较器KO法及干扰校正IKO法相结合的分析方案,测定了背景值土壤试样中题述元素,得到了良好的结果。 一、实验方法 (一)标准制备:本工作采用光谱纯化合物或高纯金属丝(或片)经溶解制成适当浓度的单元素或多元素溶液,然后定量滴在φ9×2mm的无灰滤纸片上,烘干并用高纯铝箔包装。 (二)样品制备:从干燥器中取出土壤样品分别称取约150mg样品用高纯铝箔包装。     

环境样品中铅、锑、汞、硒形态分析研究进展

综述了环境样品中铅、锑、汞、硒形态分析的研究进展，以及光谱法、色谱法、毛细管电泳及其联用技术在形态分析中的应用，展望了环境样品痕量元素形态分析的发展前景。     

高压密闭消解土壤砷、汞、铅、镉酸体系比较

采用高压密闭消解系统消解土壤,氢化物发生-原子荧光光谱法(HG-AFS)测定As和Hg,石墨炉原子吸收光度法(GF-AAS)测定Pb和Cd,对比了不同消解酸体系对国家土壤标准参考样中As、Hg、Pb、Cd的消解效果。结果表明,盐酸-硝酸体系对As、Hg、Pb和Cd的消解平均回收率分别为26.1%、100.6%、69.7%、87.3%;硝酸-高氯酸-氢氟酸体系中As、Hg、Pb和Cd消解平均回收率分别为109.9%、84.7%、87.5%、90.1%;硝酸-双氧水体系对Hg、Pb、Cd消解平均回收率分别为104.8%、95.1%、93.3%,对As的回收率虽只有69.2%,但数据精密度最好。此外,从简化试验步骤,减少误差,提高检测效率及减少试验危险性等方面综合评价,认为硝酸-双氧水消解体系是采用高压密闭系统消解土壤重金属的最理想酸体系。     

原子吸收光谱法测定酸雨中K、Na、Ca、Mg方法改进

用0．1％硝酸溶液配制混合标准溶液，不加抗干扰试剂，火焰原子吸收光谱法直接测定酸雨中K、Na、Ca、Mg，方法精密度、准确度满足酸雨监测的分析要求。     

大气降尘中铅、锌、铜、铁的原子吸收光谱法测定

研究了大气降尘中铅、锌、铜、铁等金属元素的原子吸收光谱测定方法,用氢氟酸消解法对降尘进行预处理,并对方法的精密度、准确度进行了检验,结果较为满意.该法简便、快速、灵敏.     

Mercury in Tree Swallow Food, Eggs, Bodies, and Feathers at Acadia National Park, Maine, and an EPA Superfund Site, Ayer, Massachusetts

We monitored nest boxes during 1997–1999 at Acadia National Park, Mt. Desert Island, ME and at an old-field site in Orono, ME to determine mercury (Hg) uptake in tree swallow (Tachycineta bicolor) eggs, tissues, and food boluses. Also, in 1998–1999 we monitored nest boxes at Grove Pond and Plow Shop Pond at a U.S. Environmental Protection Agency Superfund site in Ayer, MA. We recorded breeding success at all locations. On average among locations, total mercury (THg) biomagnified 2 to 4-fold from food to eggs and 9 to 18-fold from food to feathers. These are minimum values because the proportion of transferable methyl mercury (MeHg) of the THg in insects varies (i.e., 35%–95% of THg) in food boluses. THg was highest in food boluses at Aunt Betty Pond at Acadia, whereas THg in eggs was highest at the Superfund site. A few eggs from nests at each of these locations exceeded the threshold (i.e., 800–1,000 ng/g, wet wt.) of embryotoxicity established for Hg. Hatching success was 88.9% to 100% among locations, but five eggs failed to hatch from 4 of the 11 clutches in which an egg exceeded this threshold. MeHg in feathers was highest in tree swallows at Aunt Betty Pond and the concentration of THg in bodies was related to the concentration in feathers. Transfer of an average of 80%–92% of the Hg in bodies to feathers may have enhanced nestling survival. Residues of Hg in tissues of tree swallows in the Northeast seem higher than those of the Midwest.     

Concentration of Cd, Cu, Pb, Zn, Al, and Fe in soils of Manresa, NE Spain

The aims of this study were to determine the contents of cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn), aluminium (Al), and iron (Fe) (aqua regia-extractable) in 27 soil plots (54 samples) from Manresa, NE Spain, and to establish relationships between heavy metals and some soil properties. The main soil types were surveyed and the median concentrations (mg kg(-1)) obtained were Cd 0.28, Cu 20.3, Pb 18.6, Zn 67.4, Al 22,572, and Fe 21,551. Element concentrations for these soils were lower than the published values for the Valencia region (Spain) and Torrelles and Sant Climent municipal districts (Catalonia, Spain). In terms of soil properties, the results of this study suggest that, in Manresa soils, both trace element adsorption and retention are influenced by several properties such as clay minerals, carbonates, organic matter, and pH. All element contents were positively correlated with clay content. Pb and Zn were negatively correlated with pH and CaCO(3).     

Determination of Cu, Pb, Zn, Ni, Co, Cd, and Mn in road dusts of Samsun City

The dust samples from 52 different locations in central roads of Samsun City were collected in a study area of 40 km long for the purpose of determining total metal concentrations of dust samples by flame atomic absorption spectrometry. The concentrations of Cu, Pb, Co, Zn, Ni, Mn, and Cd were found in the ranges of 11.92–352.43, 5.47–223.57, 4.52–41.69, 40.85–173.10, 18.71–131.29, 133.19–179.13, and 0.02–6.16 mg/kg, respectively. The results showed that metal levels were higher around the industrial area than other locations. Principal component analysis was also carried out to ascertain the possible contributing factors towards the metal concentrations. Validation of the analytical results was tested by analysis of the BCR 032 Moroccan phosphate rock certified reference material.     

Concentrations of Arsenic, Cadmium, Copper, Lead, Selenium, and Zinc in Fish from the Mississippi River Basin, 1995

Fish were collected in late 1995 from 34 National Contaminant Biomonitoring Program (NCBP) stations and 12 National Water Quality Assessment Program (NAWQA) stations in the Mississippi River basin (MRB), and in late 1996 from a reference site in West Virginia. The NCBP sites represented key points (dams, tributaries, etc.) in the largest rivers of the MRB. The NAWQA sites were typically on smaller rivers and were selected to represent dominant land uses in their watersheds. The West Virginia site, which is in an Eastern U.S. watershed adjacent to the MRB, was selected to document elemental concentrations in fish used for other aspects of a larger study and to provide additional contemporaneous data on background elemental concentrations. At each site four samples, each comprising (nominally) 10 adult common carp (Cyprinus carpio, 'carp') or black bass (Micropterus spp., 'bass') of the same sex, were collected. The whole fish were composited by station, species, and gender for analysis of arsenic (As), lead (Pb), and selenium (Se) by atomic absorption spectroscopy and for cadmium (Cd), copper (Cu), and zinc (Zn) by inductively-coupled plasma emission spectroscopy. Concentrations of most of the elements examined were lower in both carp and bass from the reference site, a small impoundment located in a rural area, than from the NCBP and NAWQA sites on rivers and larger impoundments. In contrast, there were few overall differences between NCBP sites NAWQA sites. The 1995 results generally confirmed the continued weathering and re-distribution of these elemental contaminants in the MRB; concentrations declined or were unchanged from 1984-1986 to 1995 at most NCBP sites, thus continuing two-decade trends. Exceptions were Se at Station 77 (Arkansas R. at John Martin Reservoir, CO), where concentrations have been elevated historically and increased slightly (to 3.8-4.7 microg g-(1) in bass and carp); and Pb, Cd, and Zn at Station 67 (Allegheny R. at Natrona, PA), where levels of these metals were high in the past and increased from 1986 to 1995.     

A survey of Pb,Cu, Zn,Cd, Cr,As, and Se in earthworms and soil from diverse sites

Earthworms and soils were collected from 20 diverse sites in Maryland, Pennsylvania, and Virginia, and were analyzed for Pb, Cu, Zn, Cd, Cr, As, and Se. Correlation coefficients relating concentrations of the elements in earthworms to concentrations in soil were low (–0.20<r<+0.57). Species differences and ecological variables contributed to the variability in concentrations of these elements in earthworms. The maximum concentrations of Pb (2100 ppm), Zn (1600 ppm), Cd (23 ppm) and Se (7.6 ppm) detected in earthworms were in the range reported to be toxic to animals fed diets containing these elements; however, even in the absence of any environmental contamination, some species of earthworms may contain high concentrations of Pb, Zn, and Se. Earthworms of the genus Eisenoides, for example, were exceptional in their ability to concentrate Pb. When earthworms are used as indicators of environmental contamination, it is important to identify the species, to report the soil characteristics, and to collect similar earthworms from very similar but uncontaminated soil.     

Fluoride in groundwater, Varaha River Basin, Visakhapatnam District, Andhra Pradesh, India

Excess intake of fluoride through drinking water causes fluorosis on human beings in many States of the country (India), including Andhra Pradesh. Groundwater quality in the Varaha River Basin located in the Visakhapatnam District of Andhra Pradesh has been studied, with reference to fluoride content, for its possible sources for implementing appropriate management measures, according to the controlling mechanism of fluoride concentration in the groundwater. The area occupied by the river basin is underlain by the Precambrian Eastern Ghats, over which the Recent sediments occur. Results of the chemical data of the groundwater suggest that the considerable number of groundwater samples show fluoride content greater than that of the safe limit prescribed for drinking purpose. Statistical analysis shows that the fluoride has a good positive relation, with pH and bicarbonate. This indicates an alkaline environment, as a dominant controlling mechanism for leaching of fluoride from the source material. Other supplementary factors responsible for the occurrence of fluoride in the groundwater are evapotranspiration, long contact time of water with the aquifer material, and agricultural fertilizers. A lack of correlation between fluoride and chloride, and a high positive correlation between fluoride and bicarbonate indicate recharge of the aquifer by the river water. However, the higher concentration of fluoride observed in the groundwater in some locations indicates insufficient dilution by the river water. That means the natural dilution did not perform more effectively. Hence, the study emphasizes the need for surface water management structures, with people's participation, for getting more effective results.     

The impact of terrorism and FDI on environmental pollution: Evidence from Afghanistan,Iraq, Nigeria,Pakistan, Philippines,Syria, Somalia,Thailand and Yemen

In this study, the relationships among environmental pollution, terrorism, foreign direct investments (FDI), energy consumption and economic growth is investigated for Afghanistan, Iraq, Nigeria, Pakistan, Philippines, Syria, Somalia, Thailand and Yemen covering the 1975–2017 period utilizing Panel cointegration tests, ANOVA tests, long-run estimators and panel trivariate Causality tests. ANOVA results are in favor of evidence of homogeneity between the selected countries. Long-run estimators reveal that terrorism, FDI, energy consumption and economic growth have statistically significant effects on environmental pollution. Panel trivariate Causality test determines the causal relationship between the variables. Accordingly, one-way causal nexus from terrorism to Carbon dioxide (CO₂) emissions and from FDI inflows to CO₂ emissions are found in the short-run. In the long-run, with strong causality results, the evidence of bi-directional causality between CO₂ emissions and other variables, namely, terrorism, FDI inflow energy consumption and economic growth are detected.     

Environmentally safe sewage sludge disposal: the impact of liming on the behaviour of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn

Dewatered sewage sludge containing relatively high total concentrations of Cr (945 micrograms ml-1), Cu (523 micrograms ml-1), Ni (1186 micrograms ml-1) and Zn (2950 micrograms ml-1) was treated with quicklime and sawdust for sludge disinfection and post-stabilisation. The mobility of the heavy metals in the sludge samples was assessed by applying a modified five-step Tessier sequential extraction procedure. Water was added as a first step for estimation of the proportion of the easily soluble metal fractions. To check the precision of the analytical work the concentrations of heavy metals in steps 1-6 of the extraction procedure were summed and compared to the total metal concentrations. The mass balance agreed within +/- 3% for Cd, Cu, Cr, and Zn and within +/- 5% for Ni, Pb, Fe and Mn. Data from the partitioning study indicate that in the lime-treated sludge at a pH of 12 the mobility of Cu and Ni notably increased with the solubilisation of these metals from their organic and/or carbonate and Fe and Mn oxide and hydroxide fractions, respectively. Liming slightly decreased the proportion of other heavy metals in the easily soluble fractions while its impact on the partitioning between other sludge phases was almost insignificant. Due to the increased solubility of Ni and Cu as well as potential Cr oxidation at high pH, liming cannot be recommended for sludge disinfection. Addition of sawdust did not change the heavy metal partitioning.     

Groundwater resource assessment, categories, and typologies: case study, Andhra Pradesh, India

In India, groundwater assessment units are classified as overexploited areas, critical areas, semi-critical, or safe areas based on the stage of groundwater development and long-term water level trends. Intuitively, in the safe units, wells are expected to function and have good yields. Besides, in the safe units, new wells are expected to be successful. Conversely, the expectation of a successful well or wells with good yields is much lesser in the overexploited units. However, when these expectations are not met in the field, doubts are raised about the quality of assessment and its usefulness, and there is outright distrust on the agencies assessing groundwater resource by the common man as well as on the planners, administrators, and the politicians. Therefore, there is a need to present the results in a way that does not create confusion. One of the methods is to combine the assessment results with aquifer characters using geographic information system (GIS); when this is done, a whole set of newer classes emerge, which can be mapped. These classes are termed as groundwater typologies in this study. Each typology has some characteristics or traits in common, which include basic aquifer character as well as the stage of groundwater development. Thus, a class may be safe, but if the aquifer is poor, then it is separated from a class that is safe and where the aquifer is good and so on. In Andhra Pradesh, which is taken as the case study for this purpose, eight main typologies emerged, and two of these main typologies were further divided into four subtypologies each. This new way of understanding the pattern of groundwater abstraction (using GIS) has a better visual impact. Groundwater typologies are found to be much more rational and useful in developing management strategies, rather than simple listing as overexploited areas, critical areas, semi-critical areas, and safe areas as is commonly done. The typologies so delineated indicate on the map (or table) that balanced usable groundwater is in between 5 and 6 bcm/a as against the estimated balance of 20.5 bcm/a, and it is largely in poor hard rock type of aquifers, which occupy about a third of the area of the state.