生长于铬污染土壤上石榴产品铬污染评价

研究了攀西地区铬污染土壤和正常土壤铬含量分布及其石榴样品铬污染情况。结果表明攀枝花大田石榴基地土壤铬含量在23．1—504mg／kg,平均值高达184mg／kg,超标率为26％,而对该基地的石榴果实进行两年连续监测结果表明,铬含量在0．0012—0．067mg／kg之间,平均为0．016mg／kg,大大低于相应产品标准（0．5mg／kg）,超标率为0％;会理石榴基地土壤铬含量在34．5—99．1mg／kg,平均值为69．0mg／kg,超标率为0％,该基地的石榴果实铬含量在0．0075—0．104mg／kg之间,平均为0．024mg／kg,大大低于相应产品标准（0．5mg／kg）,超标率为0％。形态分析表明土壤中铬99％以上都是以不被植物利用的残渣态存在,因此土壤总铬再高,其被植物可吸收部分却很少,这就导致了受铬污染的土壤却不一定能生产出污染石榴的原因。     

全自动石墨消解电感耦合等离子体质谱法测定土壤中的重金属

建立了采用全自动石墨消解仪,硝酸-氢氟酸-高氯酸消解土壤样品,用电感耦合等离子体质谱仪分析测定土壤中的铜、锌、铅、镉、镍和总铬6种重金属的分析方法.土壤中铜、锌、铅、镉、镍和总铬的检出限可达0.04～0.70 mg/kg,线性相关系数为0.9995～0.9999,准确度相对误差为-1.5％～2.3％,精密度相对标准偏差...     

微波消解-电感耦合等离子体发射光谱法测定土壤中微量重金属

建立了微波消解-电感耦合等离子体发射光谱法测定土壤中微量重金属的样品前处理过程与方法,并通过仪器工作条件和酸消解体系的选择,以及光谱干扰和基体干扰的消除对方法进行了优化。结果表明,使用6m LHNO_3+2 m L HCl+1m LHF+1m LH_2O_2对土壤进行微波消解,在建立的试验条件下,土壤中重金属(铜、铅、锌、镉、锰、镍、铬和钒)的检出限为0.002~0.014 mg/kg,精密度为1.3%~3.6%,回收率为97.4%~106%。本方法简便、安全、准确、快速。     

火焰原子吸收法测定土壤镍结果的不确定度评定

根据《土壤和沉积物铜、锌、铅、镍、铬的测定火焰原子吸收分光光度法HJ 491-2019》测定某土壤样品镍的含量,分析测试过程中不确定度的来源,并对样品测定结果进行不确定度的评定。测得样品中镍的含量为38.7 mg/kg,扩展不确定度为4.30mg/kg(k=2)。采用新标准首次建立了火焰原子吸收法测定土壤镍含量的不确定度评定方法,得到标准曲线的配制和拟合过程、测量重复性是土壤镍含量不确定度的主要影响因素;为采取措施降低不确定度提供参考,为定量评价测量的质量提供帮助,为影响规范限度的符合性提供依据。     

石墨炉消解-电感耦合等离子体质谱法测定土壤中重金属

建立了石墨炉消解-电感耦合等离子体质谱法测定土壤中8种金属元素的分析方法,并通过仪器工作条件和消解条件的选择,以及质谱干扰和基体干扰的消除对方法进行了优化。结果表明,在建立的试验条件下对土壤进行石墨炉消解,土壤中重金属(锌、镍、铜、钒、铬、铅、镉、锰)的检出限为0.002~0.59μg/g,精密度为1.1%~8.7%,回收率为95.0%~105%。本方法消除干扰强,检出限低,精密度好,准确度高,试剂用量小,适用于大批量土壤样品的分析。     

攀西地区主要蔬菜基地土壤重金属含量及评价

对攀西地区米易县蔬菜基地的土壤进行采样,用原子吸收和石墨炉光谱法分析土壤中Cr、Cu、Ni、Zn、Pb、Cd、As和Hg8种元素的含量。蔬菜基地土壤重金属平均含量分别为Cr 68．8mg／kg、Cu 22．3mg／kg、Ni27．6mg／kg、Zn 146．2mg／kg、Pb31．7mg／kg、Cd0．258mg／kg、As10．3mg／kg、Hg0．0618mg／kg。根据土壤环境质量标准（GB15618—1995）对检测结果进行了单因子和多因子综合污染指数评价。分析表明调查区内少部分蔬菜基地土壤受到轻度重金属污染,主要污染物为Cd元素,其余重金属元素的含量均在安全警戒线内。     

ICP-AES法测定硅铁中铝磷钙钛铬锰镍铜钡钒钴镁钼含量

本文用ICP—AES内标法进行硅铁中的铝、磷、钙、钛、铬、锰、镍、铜、钡、钒、钴、镁、钼含量测定。研究了溶样方法、测定时溶液的酸度、仪器工作条件、各元素测定波长，测试结果与标准样品推荐值比较，结果令人满意。     

浅谈串联四极杆质谱（GC—QqQ-MS／MS）在土壤样品有机污染物分析中的应用

建立了ASE-GPC—GC-QqQ—MS／MS测定土壤中17种有机氯农药和19种多氯联苯以及MAE-SPE—GC-QqQ—MS／MS测定土壤中16种多环芳烃和18种邻苯二甲酸酯的方法。多环芳烃和邻苯二甲酸酯定量限在0．02～2．81μg／kg之间,有机氯农药和多氯联苯定量限在0．01～0．51μg/kg之间。样品加标浓度在5μg/kg时多环芳烃和邻苯二甲酸酯的平均回收率在66．6％～122．1％之间,相对标准偏差均小于20％;有机氯农药和多氯联苯平均回收率在79．6％～93．2％之间,相对标准偏差均小于15％。     

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。     

不同酸消解方法在土壤重金属测定中的比较研究

分别用三种不同的酸消解方法进行土壤标准样品的前处理,用原子吸收分光光度法测定其中铜、铅、锌、镉、镍、锰、总铬元素的含量。结果表明,电热板/硝酸-过氧化氢-氢氟酸消解方法耗酸量少,消解时间短,适用于土壤中铜、铅、锌、镉、镍、锰元素的前处理,相对标准偏差为1.0%～5.0%;而使用电热板/硝酸-硫酸-氢氟酸方法针对土壤中总铬元素进行消解前处理,准确度更高,相对标准偏差为2.7%～5.1%。     

Environmental concentrations of agricultural herbicides in Saskatchewan, Canada: bromoxynil, dicamba, diclofop, MCPA, and trifluralin

Herbicides are the most commonly used group of agricultural pesticides on the Canadian Prairies and, in 1990, more than 20000 Mg of herbicides were applied in the provinces of Alberta, Saskatchewan, and Manitoba. The present paper reports on environmental concentrations of five herbicides currently used in the prairie region. The herbicides bromoxynil [3,5-dibromo-4-hydroxy-benzonitrile], dicamba [3,6-dichloro-o-anisic acid], diclofop [(RS)-2-[4-(2,4-dichlorophenoxy)-phenoxy]propanoic acid], MCPA [(4-chloro-2-methylphenoxy)acetic acid], and trifluralin [alpha,alpha,alpha-trifluoro-2,6-dinitro-N,N-isopropyl-p-toluidine] were measured in the atmosphere, bulk atmospheric deposits, surface film, and dugout (pond) water at two sites near Regina, Saskatchewan, during 1989 and 1990. All five herbicides were detected in air and surface film and all but trifluralin were detected in the bulk atmospheric deposits and dugout water. Trifluralin was most frequently detected in air (79% of samples) whereas bromoxynil was present in maximum concentration (4.2 ng m(-3)). MCPA was present in maximum levels in bulk atmospheric (wet plus dry) deposits (2350 ng m(-2) d(-1)), surface film (390 ng m(-2)), and dugout water (330 ng L(-1)), whereas dicamba was most frequently detected in surface film (47%) and dugout water (97%). The highest quantities of the herbicides tended to be present during or immediately after the time of regional application.     

Accumulation, release, and solubility of arsenic, molybdenum, and vanadium in wetland sediments

This study was undertaken to determine the fate of As, Mo, and V (trace elements, TEs) in the sediments of a constructed wetland in use for the remediation of potentially toxic trace element-contaminated agricultural drainwater. After three years of wetland operation, sediment cores were collected to determine changes in TE concentrations as a function of depth and the effects of varying water column depth. All TE concentrations were highest in the top 2 to 4 cm and decreased with depth. Molybdenum accumulated in the wetland sediments, up to levels of 32.5 +/- 4.6, 30.2 +/- 8.9, and 59.3 +/- 26.1 mg kg(-1) in the top 1 cm of sediment at water depths of 15, 30, and 60 cm, respectively. In the top 2 cm of sediment, As accumulated (28.2 +/- 3.0 mg kg(-1)) only at the 60-cm water depth. Below 2 cm, as much as 10 mg kg(-1) of As was lost from the sediment at all water depths. In most cases, V concentrations decreased in the sediment. In this wetland system, the lowest redox potentials were found near the sediment surface and increased with depth. Thus, in general As, Mo, and V concentrations in the sediment were highest under more reducing conditions and lowest under more oxidizing conditions. Most of the accumulated Mo (73%) became water soluble on drying of samples. This has important implications for systems undergoing changes in redox status; for instance, if these wetland sediments are dried, potentially large amounts of Mo may be solubilized.     

Optimizing angles of rooftop photovoltaics,ratios of solar to vegetated roof systems,and economic benefits,in Portland,Oregon, USA

This study analyzed insolation data to account for multiple scattering in calculating optimal tilt angles for stationary and seasonally moving photovoltaics on three different roof types in the US Pacific Northwest: vegetated roofs, white roofs, and dark roofs. Using these results, we modeled the energy savings for vegetated roofs and roofs covered in varying numbers of photovoltaic panels. We then calculated the net present value, internal rate of return, and other economic measures for all possible combinations of covering rooftops in mixes of photovoltaic arrays and vegetation, accounting for installation costs, proposed carbon taxes, stormwater management discounts, and other relevant factors. Our results quantify how, in the US Pacific Northwest and similar locations, photovoltaics produce higher returns on investment than do vegetated roofs for new buildings, while vegetated roofs produce better returns on investment than do photovoltaics for older buildings. This is important because in many areas, some buildings have photovoltaics when a vegetated roof would have been more cost and energy efficient, while other buildings have vegetated roofs when photovoltaics would have been more cost and energy efficient. Potential applications include modifying incentive programs and other policies to account properly for building age, use, and other relevant factors to ensure building owners make the most energy-efficient decisions between photovoltaic versus vegetated roof installation. Our research also demonstrates how positive returns on investment can be realized in the US Pacific Northwest and similar regions through vegetated roofs and photovoltaics provided they are each installed optimally.     

Adsorption of pesticides onto quartz, calcite, kaolinite, and alpha-alumina

The fate of pesticides in aquifers is influenced by the small but not insignificant adsorption of pesticides to mineral surfaces. Batch experiments with five pesticides and four minerals were conducted to quantify the contributions to adsorption from different mineral surfaces and compare adsorption characteristics of selected pesticides. Investigated mineral phases included quartz, calcite, kaolinite, and alpha-alumina. Selected pesticides comprised atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine), isoproturon [3-(4-isopropylphenyl)-1,1-dimethylurea)], mecoprop [(RS)-2-(4-chloro-2-methylphenoxy)propionic acid], 2,4-D (2,4-dichlorophenoxyacetic acid), and bentazone [3-isopropyl-1H-2,1,3-benzothiadiazin-4-(3H)-one 2,2-dioxide]. Specific surface area and mineral surface charge proved to be important for the adsorption of these pesticides. Detectable adsorption of the anionic pesticides (mecoprop, 2,4-D, and bentazone) was only measured when positive sites were present on the mineral surface. However, when CaCl2 was added as an electrolyte, a detectable adsorption of mecoprop and 2,4-D was also measured on kaolinite (which exhibits a negative surface charge), probably due to formation of Ca-pesticide--surface complexes. Adsorption of the uncharged pesticides (atrazine and isoproturon) was detected only on kaolinite. The lack of adsorption on alpha-alumina indicates that the uncharged pesticides have a greater affinity for the silanol surface sites (=SiOH) than for the aluminol surface sites (=AlOH) in kaolinite. No measurable effect of ionic strength was found for the uncharged pesticides. The results indicate that quartz and calcite play a smaller role than clay minerals.     

Determination and Evaluation of Cadmium, Copper, Nickel, and Zinc in Agricultural Soils of Western Macedonia, Greece

The objective of this study was to determine the levels of major phytotoxic metals―including cadmium (Cd), copper (Cu), nickel (Ni), and zinc (Zn)―in agricultural soils of Western Macedonia, Greece. We also wanted to determine the possible relationships among elements and between soil properties and elemental concentrations. Surface soil samples, n = 570, were collected and analyzed. The results of the elemental analysis showed that the mean metal concentrations were consistent with reported typical concentrations found in Greek agricultural soils in the cases of Zn and Cu. Cd exhibited lower and Ni higher mean concentrations than the typical levels reported in the literature. Metal concentrations in the majority of the examined samples (>69%) were found to be higher than the respective critical plant-deficiency levels. However, only 0.4% and 0.2% of the analyzed soil samples, respectively, exhibited Cd and Ni concentrations higher than the levels that cause plant toxicity, as referenced by other investigators. These results suggest that the soils studied can be considered as unpolluted with respect to the examined food-chain metal contaminants. However, the levels of the metal concentrations in some of the soil samples, and the low correlation of the metals with soil properties, suggest an anthropogenic rather that lithogenic origin.     

Concentrations and pattern of Fe,Cu, Cr,and Zn contamination in the soils of Akure,Nigeria

An assessment was made on twenty-eight topsoils collected from seven sites with intense artisan activities in the city of Akure, Nigeria, using geochemical approach in order to establish anthropogenic influence on metal contamination and to assess the severity of the contamination in the urban environment. Concentrations of Fe, Cu, Zn, and Cr were determined in the samples by atomic absorption spectrophotometry. The results revealed between 137- and 165-fold elevation of Fe, between 17- and 94-fold elevation of Cu, between 50- and 137-fold elevation of Zn, and between 1- and 3-fold elevation of Cr in topsoil relative to background levels. This indicates that except for Cr, soil contaminations by the metals were due to anthropic sources such as mechanic and vulcanizers workshops. The current average levels of copper exceeded the target value in Nigeria and in many developed countries, while Zn and Cr are generally lower than the respective soil quality guidelines. The contamination/pollution index maps figured out mechanic workshop as the main source of diffuse contamination and also show the influence of the point sources of contamination to urban topsoils. Cu contamination found around the soils of the mechanic/battery charger workshop is potentially serious (severe pollution), and this may pose health risk to people dwelling around these sites or within the metropolis. Children could be at greater risk than adults, because of their hand-to-mouth behaviors that increase their exposure potential.