土壤-温郁金体系中重金属的吸收富集研究

通过盆栽实验研究了铅（Pb）、镉（Cd）、铜（Cu）、汞（Hg）和砷（As）污染条件下,温郁金和种植土壤中重金属含量,分析了植物对重金属的吸收富集能力。结果表明,随着土壤中污染物的投加量增强,Cu、Pb、Cd、As元素主要集中在根部,而Hg元素由于其极易挥发的特性,其块根中含量反而随着Hg投加量的增加而减小。温郁金对不同元素的吸收富集能力不同,对Cd的富集能力最强,对Hg的富集能力最弱。     

污泥堆肥农用中重金属在海桐中的积累效应

采用小区试验的方法,研究了金华污水厂污泥堆肥土地利用过程中海桐根部对重金属的吸收及富集作用。结果表明,海桐对Cu均表现出比Zn更强的富集能力,而对Cd、Pb的富集能力很弱,其须根对重金属的吸收能力显著高于主根;就不同重金属的绝对吸收量而言,对Zn的吸收总量是最高的;须根中的Zn含量总体呈现随土壤中Zn含量增加而上升的趋势。     

耐高盐碱蓬对湿地土壤中金属元素的富集特征研究

基于秦皇岛滨海湿地人工种植耐高盐碱蓬修复工程试验,通过分析湿地土壤沉积物及耐高盐碱蓬中不同金属元素的含量与变化,研究了耐高盐碱蓬对金属元素的富集特征。结果显示:湿地沉积物中Fe、Mn、Cr、Pb和Zn的浓度较高,分别为8 210. 94、110. 04、8. 78、8. 25、10. 95 mg/kg,Cd的浓度最低,平均值为0. 022 mg/kg,湿地试验区土壤中同一金属元素变异程度较小,分布较均匀。碱蓬体内重金属含量根据采集地点的不同有差异,但与各站位中土壤的重金属分布特征存在正相关性;其中碱蓬内Fe、Mn、Zn、Cu的平均含量相对较高,且Fe、Mn、Ni、Cu、As、Cd、Pb元素在碱蓬根中的平均含量高于茎叶,而Cr在茎中的平均含量最高,Zn和Mo在叶中的含量最高。碱蓬的根、茎、叶对Cd的富集效果最好,其次为Mo、Cu,对Fe、Mn、Zn、As和Pb的富集效果相对较差,说明碱蓬对沉积物中不同金属元素的富集移出率存在差异。金属元素在碱蓬中的转移系数研究表明,Mo、Zn、Cd和Mn等元素可由根部转移到叶中,而Fe、Ni、Pb、As和Cu等金属元素固定在根部,该研究可为利用碱蓬修复湿地重金属污染提供理论基础。     

川中丘陵区铁路旁土壤重金属含量及化学形态研究

对川中丘陵区成昆铁路的三圣段、吴场段和成渝铁路的五凤段3个典型路段铁路沿线土壤重金属Cd、Zn、Cu、Pb含量及其化学形态进行了研究,并运用次生相富集系数法对重金属的潜在生态风险进行评估。结果表明:铁路沿线土壤重金属Cd、Zn、Cu、Pb含量与对照点相比都有不同程度的升高。Cd不仅具有高的含量,且化学形态主要为酸可交换态和可还原态,残渣态含量很低,其有效态比例>75%,具有很强的生物活性和可迁移性。Cu、Pb、Zn的化学形态则主要为残渣态,酸可交换态比例很小,但是Pb和Zn的可还原态和可氧化态比例较高,所以有效态比例也较高,分别为51.1%~54.9%和36.2%~50%。土壤重金属Cu在各典型路段的次生相富集系数为1.4~4.2;Zn在三圣段、吴场段2个典型路段的次生相富集系数超过3.0,均具有较大的潜在生态风险。     

施用污泥对黑麦草生长及重金属含量的影响

采用单因素随机区组试验的方法,研究了金华市污水厂污泥堆肥对黑麦草生长和对重金属的吸收及富集的影响。结果表明,施用量以1kg／m^2和2kg／m^2的两个处理为宜,当年的产草量比对照分别增加了22．6％和27．8％;施用污泥黑麦草植株地上部组织重金属元素Pb、Cd和Cu的含量与对照相比无显著差异,Zn的积累量增多,重金属含量均未超过植物中的平均含量,施用污泥未对黑麦草造成重金属污染。     

贵阳污灌区菜地土壤团聚体中有机碳和重金属的含量特征及相关性分析

以贵阳某污灌区菜地土壤为研究对象,分别采用微波消解-电感耦合等离子体质谱(ICP-MS)法和水合热重铬酸钾氧化分光光度法分析不同粒径土壤团聚体中重金属和有机碳的含量特征,并对有机碳和重金属的相关性进行分析。结果表明,以2mm粒径团聚体的含量为最高,约占75%。Cu、Zn、Cd和Pb在0.25～0.5mm粒径团聚体中含量最高,Cr在5～8mm粒径团聚体中含量最高,As在不同粒径团聚体中的含量变化不大,重金属含量随土层深度增大而减小。土壤重金属富集因子表现为CuPbCdZnCrAs,Cu、Zn、Cd和Pb在0.25～0.5mm粒径团聚体中分布因子最高,而在5～8mm粒径团聚体中重金属的质量负载因子最大。土壤有机碳含量随团聚体粒径的增大表现为先增大后减小,不同粒径团聚体中Cu、Cd、Pb和As含量与有机碳含量均呈显著正相关(p0.05)。污灌区菜地土壤Cr、As在5～8mm粒径团聚体中富集现象显著,Cu、Zn、Cd、Pb在0.25～0.5mm粒径团聚体中均表现出显著的富集特征。6种重金属在5～8mm粒径团聚体中的质量负载因子均为最高,表明6种重金属在5～8mm粒径团聚体中的贡献最大。     

甜瓜各器官6种重金属富集及转运能力 差异的比较分析

为比较6种重金属元素在甜瓜植株各器官中富集及转运能力的差异,于果实成熟期采集土壤、根、茎、叶、果实并测定其中的Cr、Cu、As、Ni、Pb和Cd 6种重金属元素,在此基础上,通过富集系数、转运系数,评估了植株不同器官中重金属元素富集能力的差异,比较了各迁移阶段6种重金属元素转运能力的差异。结果显示,各器官中,根富集重金属元素的能力最强,较其他受试重金属元素,Cd和Cu更易在甜瓜植株中富集;迁移各阶段中,Cr、Ni、As、Pb 4种重金属元素由茎转运至果实和叶片的能力相对较强,Cd由根转运至茎的转运能力更强;重金属元素Cu由茎转运至叶片的能力相对较弱。不同重金属元素在甜瓜植株各器官中的富集、转运能力有所差异,宜根据目标调控重金属元素种类,开展对应主要转运阶段阻滞技术的研究与探讨。     

黄原脂棉富集-电感耦合等离子质谱法测定海水中的重金属元素

采用黄原脂棉富集技术,建立了电感耦合等离子质谱法测定海水中重金属Cu,Pb,Zn,Co,Cd含量的方法。完善前处理条件,优化仪器工作参数,选取Rh,Ir作为内标元素,有效克服基体效应及仪器波动影响。Cu,Pb,Zn,Co,Cd的检出限分别为1.26,0.21,0.24,0.0027,0.0051μg/L,RSD为0.77%~3.3%,回收率为87.2%~96.0%。方法适用于海水中重金属元素的含量测定。     

定南县废弃稀土矿区优势植物中5种重金属元素含量的测定

目的通过对赣南定南县某废弃稀土矿区生长的植物样品中5种重金属元素Cu、Mn、Cd、Pb和Cr的含量进行测定。方法采用火焰原子吸收分光光度法测定样品中Cu、Mn、Cd含量,采用石墨炉原子吸收分光光度法测定了样品中Pb和Cr的含量。结果在植物样品中,Mn含量最高的是芒萁(1 081.305 mg/kg);含Cd最高的是山鸡椒(0.716 mg/kg),Pb、Cu、Cr的含量未超过植物正常值。结论山鸡椒和芒萁可分别作为废弃稀土矿区Mn和Cd元素理想的植物修复备选植物。     

锦州市大气颗粒物中重金属形态分析及生物有效性评价

研究了锦州市秋冬季大气颗粒物中重金属元素Al、Cd、Cr、Cu、Zn、Pb的化学形态和生物有效性。结果表明锦州市主要商业街和交通主干道的PM10和PM2.5污染比较严重,冬季取暖期间PM2.5平均超标3.4倍,最高超标达8.1倍。PM10和PM2.5中重金属Zn、Pb和Cu的含量较高,在PM10中最大值分别为0.903、0.392、0.272μg·m-3。Cd、Cu、Pb、Zn在大气颗粒物中主要以酸可提取态(F1)和氧化物结合态(F2)存在,这两种形态在环境中易迁移和转化,特别是Cd的F1和F2形态含量之和占总量的95%,其毒性较大。Cd的含量较低(0.006~0.018μg·m-3),但富集因子高(1880~2819),表明Cd人为污染严重;Cu、Zn和Pb的富集因子较高(100),表明其受人类活动影响较大。Cd和Zn在PM2.5中生物有效性系数分别为0.56和0.58,对大气环境和人体健康危害较大。     

Trace Metals in Microcrustaceans and Brazilian Waterweed from a Contaminated Chilean Wetland Using Total Reflection X-Ray Fluorescence Spectrometry

The trace element content of individual copepod specimens and of the Brazilian water weed (Egeria densa) from a metal-contaminated wetland in Southern Chile were determined using total reflection X-ray fluorescence spectrometry. Sampling of the water and the organisms was carried out at three sampling sites during 2004. Enhanced concentrations of dissolved Fe and Mn were found in the column water and in the pore water. The Fe content in the benthic copepods was significantly elevated compared to other aquatic organisms from different Chilean lakes. Regarding E. densa, healthy (green coloured) plants showed mass fractions of Fe, Mn, Ni, Cu and Zn which were typical for uncontaminated systems. In contrast, damaged (brownish coloured) plants exhibited very high Fe and Mn concentrations indicative of contamination or processes which changed the element load from the environment to the plant.     

Determination of lead in waters and sediments from the wetland Tablas de Daimiel National Park (Spain)

Electrothermal atomic absorption spectrometry (ETAAS) has been used for lead control in waters and sediments of the wetland Tablas de Daimiel National Park. The lead determination in the wetland water is hindered by an enhanced salt content, so matrix interference was evaluated. The use of stabilized temperature platform atomization technique, Zeeman background correction and palladium nitrate as matrix modifier were found advisable. For the sediments a closed-vessel microwave dissolution method has been proposed using a mixture of HCl-HNO₃-HF and a heating time of 90 s. With subsequent ETAAS using platform atomization and Zeeman background correction, no chemical modification was necessary. Using these conditions, the interferences were completely removed for both waters and sediments and the calibration curve in ultrapure water (1% nitric acid) was linear up to 30 μg/L. The detection limits for waters and sediments were 0.95 μg/L and 0.78 μg/g, respectively. The accuracy of the proposed method for sediments was validated by analyzing certified reference materials (obtained values were within the certified ones) and spiked wetland sediments (mean recovery of 99.0%). Received: 11 October 1998 / Revised: 3 December 1998 / Accepted: 11 March 1999     

Determination of lead in waters and sediments from the wetland Tablas de Daimiel National Park (Spain)

Electrothermal atomic absorption spectrometry (ETAAS) has been used for lead control in waters and sediments of the wetland Tablas de Daimiel National Park. The lead determination in the wetland water is hindered by an enhanced salt content, so matrix interference was evaluated. The use of stabilized temperature platform atomization technique, Zeeman background correction and palladium nitrate as matrix modifier were found advisable. For the sediments a closed-vessel microwave dissolution method has been proposed using a mixture of HCl-HNO₃-HF and a heating time of 90 s. With subsequent ETAAS using platform atomization and Zeeman background correction, no chemical modification was necessary. Using these conditions, the interferences were completely removed for both waters and sediments and the calibration curve in ultrapure water (1% nitric acid) was linear up to 30 μg/L. The detection limits for waters and sediments were 0.95 μg/L and 0.78 μg/g, respectively. The accuracy of the proposed method for sediments was validated by analyzing certified reference materials (obtained values were within the certified ones) and spiked wetland sediments (mean recovery of 99.0%). Received: 11 October 1998 / Revised: 3 December 1998 / Accepted: 11 March 1999     

Uptake of sulfolane and diisopropanolamine (DIPA) by cattails (Typha latifolia)

Sulfolane (tetrahydrothiophene 1,1-dioxide, C₄H₈O₂S) and diisopropanolamine (DIPA) are highly water-soluble organic compounds used in the Sulfinol™ process to remove hydrogen sulfide from natural gas and have been found in samples of wetland vegetation collected near a sour gas processing facility in Alberta, Canada. Concentrations within individual plants and between plants at different locations within the wetland varied greatly but were generally higher than expected, based on exposure concentrations and plant uptake predictions using octanol/water partition coefficients. To better understand the uptake of these highly water-soluble compounds by wetland plants and to substantiate the field findings, the uptake of sulfolane and DIPA by cattails (Typha latifolia) was investigated in a greenhouse microcosm study. Cattails were grown hydroponically in aqueous solutions containing sulfolane and DIPA for a period of 50 days. Non-planted and non-planted poisoned hydroponic systems were run simultaneously as controls. Sulfolane and DIPA concentrations in the hydroponic solution and plant tissues were monitored throughout the study. Uptake and translocation of sulfolane and DIPA by cattails were found to be a function of exposure concentration and water transpired. However, the neutral sulfolane was translocated into the foliar portion of the cattails to a significantly greater extent than the protonated DIPA. Sulfolane concentrations were consistently greatest in the leaf tips with concentrations as high as 33,000 mg/kg dry weight for the 200 mg/L exposure. DIPA leaf concentrations were more uniform but much lower than sulfolane. The highest DIPA concentration observed was 1014 mg/kg dry weight for the 100 mg/L exposure. The average leaf to root tissue concentration ratio for sulfolane was 53 (152 for leaf tips), while for DIPA the ratio was 0.6. Normalizing the leaf concentration in each system to the amount of water transpired during exposure and dividing it by the average exposure concentration yielded approximate transpiration stream concentration factors (TSCF) that ranged from 0.1 (entire leaf) to 0.9 (leaf tip) for sulfolane and < 0.01 to 0.02 for DIPA. Overall, the laboratory uptake trends matched those observed in the limited field sampling and suggest that the uptake of non-ionizable, highly water-soluble organics such as sulfolane may not be well predicted using existing relationships between TSCF and log K_ow. In addition, the relatively high concentrations observed in the foliar tissue suggest that wetland plants could play an important role in the natural attenuation of sulfolane, provided the sulfolane is not released by the plants during winter dormancy.     

Gas chromatographic-mass spectrometric determination of sulfolane in wetland vegetation exposed to sour gas-contaminated groundwater

Described is a GC-MS method for the determination of the levels of sulfolane (tetrahydrothiophene 1,1-dioxide, C4H8O2S; a water miscible chemical used in the sweetening of sour gas) in wetland vegetation (roots, shoots, berries, seeds, grasses, and leaves). The technique was developed to provide positive detection of sulfolane in a variety of wetland vegetation and to determine the extent to which sulfolane may translocate within the plants. Vegetation samples collected at a sour gas processing facility were extracted using a two-stage process which utilized a back extraction of a water extract with toluene. The main advantages of this procedure were: good extraction efficiency (recovery of 80+/-12%), exclusion of most of the highly polar co-extractives during the toluene back extraction step, and a final extract well suited to routine GC-MS selected ion monitoring of sulfolane with a detection limit of 90 ng g(-1) (wet mass). In general, the method was rugged, based on a study period of 18 months in which over 175 runs were conducted.     

Microbial growth on pall rings

Biogas is upgraded using an absorption with water-wash technique by 11 of a total of 14 upgrading plants in Sweden. However, problems with microbial growth on the pall rings in the absorption column, and in one case in the desorption column, have a negative impact on the upgrading of raw gas to vehicle gas. Five of the nine biogas plants studied here have experienced problems with microbial growth. The objectives of this study were to identify such microbial growth and to determine possible factors for its control, in order to provide recommendations for process management. A questionnaire was sent out and visits were made to the upgrading plants to collect information about the upgrading process. Phospholipid fatty acid (PLFA) analysis was performed to determine microbial biomass and community structure in samples from four upgrading plants. In samples from two of the plants, methane-oxidizing bacteria (type I methanotrophs) were indicated, while samples from one of the other plants showed biomarkers indicating actinomycetes. Factors affecting development of microbial growth were found to be water quality and the pH and temperature of the process water. Plants that used wastewater in the upgrading process experienced far more problems than those using clean water of drinking quality.     

Water and potassium ion absorption by deuterium oxide resistant winter rye seedlings

The concentrations of deuterium oxide (D2O) in the root tissue water of winter rye seedlings equilibrated with the external D2O concentration within 30 min and in the shoot tissue water after 5-6 h. The equilibrated value in the root water was 87% and in the shoot water, 55% of the external concentration. The K+ absorption rate of the seedlings decreased from a value of 39 to 18 mumol g-1 h-1 when the D2O concentration was changed through a range from 0% to 97%. D2O suppressed the absorption of water and K+ by the seedlings. The higher the D2O concentration the greater the suppression, but it was less than with similarly treated rice plants. However, the process of D2O absorption by the seedlings was similar to that of rice seedlings (Envir. exp. Bot., 24, 369).     

微量元素在尘肺患病率不同电厂的比较研究

为了调查微量元素对电厂尘肺患病率（甲厂〉乙厂）的影响,分别用中子活化法和原子吸收法测定两电厂粉尘、排放水和职工头发中化学元素含量,用邻苯三酚自氧化法测定接尘人员血中ＳＯＤ,结果发现甲厂粉尘中Ｖ、Ｃｒ、Ｃｏ、Ｍｎ和稀土元素含量比乙厂高,有显著性意义;乙厂比甲厂高的元素有Ｚｎ、Ｓｅ、Ａｓ、Ｂａ,而Ｎｉ、Ｃｄ未见显著性差异。甲厂工业排放水中Ｃｒ电明显高于乙厂。提示Ｖ、Ｃｒ、Ｃｏ、Ｍｎ和稀土元素对尘肺的形     

壳聚糖棒材表面仿生拒水改性的研究

分析壳聚糖棒材在湿态环境下力学性能衰减速率过快的原因,通过对植物叶拒水机理的仿生,将壳聚糖表面进行复合式仿生疏水改性.先对壳聚糖棒材表面进行酰化改性,降低了棒材表面极性,使棒材表面形成一种微观凹凸的粗糙结构.然后在此粗糙结构上进行生物酯涂覆,以达到仿植物叶的拒水效果.结果表明,壳聚糖棒材表面经过乙酰化处理,表面变得粗糙.经接触角实验和吸水速率测试表明,壳聚糖棒材表面经酰化改性后,降低了材料表面的极性及亲水性.通过控制酰化反应时间,能有效地增大棒材的接触角,使得最外层的生物酯涂层紧密结合,经模拟体液浸泡实验,该材料3个月内完全拒水,达到了预期的目的.     

Influence of boric acid on the determination of iron in reactor coolant water by graphite furnace atomic absorption spectrometry

Summary The matric effect of boric acid was investigated in the determination of iron in the primary circuit coolant water of nuclear power plants by furnace atomic absorption spectrometry. The effect of boric acid was of particular interest. The method was applied during refuelling and maintenance periods and the results were used to interpret the chemical changes in the water.

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Einfluß von Borsäure auf die Bestimmung von Eisen in Reaktorkühlwasser durch GF-AAS