玉米根尖细胞遗传学效应监测孔雀石绿污染的研究

以玉米(Zea mays L.)根尖为材料,研究孔雀石绿对玉米根尖的致畸效应.以不同浓度的孔雀石绿为诱变剂,测定玉米根尖细胞的微核率、有丝分裂指数和染色体畸变率.结果表明:孔雀石绿能诱发较高频率的微核率,即在一定的浓度范围内(0mg/L～0.50mg/L)其微核率随孔雀石绿处理浓度的升高而增加,但高于一定浓度(0.50mg/L～2.00mg/L)反而呈下降趋势;在一定浓度时能引起玉米分生组织细胞的分裂指数变化,在1.00mg/L时,有丝分裂指数最大;孔雀石绿还能诱导玉米根尖细胞产生较高频率的染色体畸变,在0.50mg/L时,畸变率最高且产生多种类型的染色体畸变.孔雀石绿对玉米根尖细胞具有明显的致畸效应,在一定范围内可以指示环境中孔雀石绿的污染程度.     

陶瓷包装材料中铅和镉向白酒中迁移规律的研究

目的 研究温度、酒精度和时间对陶瓷包装材料中重金属铅和镉向白酒迁移的影响规律,并对其进行迁移动力学分析。方法 在避光、20 ℃和40 ℃温度条件下,用酒精体积分数为38%和53%的2种白酒溶液浸泡陶瓷制品表面一定时间,萃取陶瓷制品表面溶出的铅和镉,微波消解后用电感耦合等离子体发射光谱仪进行测定。结果 当温度升高时,重金属铅、镉向白酒的迁移量也增加,迁移速率与温度成正比;当酒精度升高时,铅的迁移量则减少,而镉的迁移量增加;根据迁移动力学分析,重金属铅、镉的迁移量与时间的平方根呈线性相关关系。结论 陶瓷包装材料中重金属向白酒的迁移是一个以离子交换为主的扩散控速过程。     

重金属污染土壤植物修复效果试验研究

为了研究络合剂NTA（氨三乙酸）和覆膜条件对绿叶苋菜、土豆和紫花苜蓿三种植物修复土壤铅、铜、镉、铬复合重金属污染的影响,采用L16（4^3）正交表进行盆栽试验。植物培养30天后,植物富集铅和镉的含量主要受到络合剂含量的影响,随着NTA的含量的增加,植物富集能力先促进,后抑制;铜和铬主要受植物种类的影响。正交试验结果极差分析和方差分析表明,当络合剂添加量为2mmol时,土豆在不覆膜的条件下对四种金属的吸收量最大。另外,在研究植物修复单一重金属时发现,绿叶苋菜对铅有一定的富集潜力,土豆对铜的富集效果最好,紫花苜蓿对镉和铬都具有较好的富集能力。     

工业烟气重金属离子脱除方法研究进展

大气重金属污染严重影响人体健康和环境安全,而工业烟气是大气重金属污染的重要贡献源,因此工业烟气中的重金属离子脱除技术已成为国内外众多学者研究的热点问题。总结了关于大气中重金属污染控制的研究现状,综述了3种常见重金属污染离子汞、铅、镉(Hg、Pb、Cd)的来源、迁移分布、生物毒性及其脱除方法,同时提出了大气重金属污染未来研究可能关注的新趋势。     

火焰原子吸收光谱法测定肥料中重金属含量的不确定度评估

根据GB/T 23349—2009 《肥料中砷、镉、铅、铬、汞生态指标》中所规定的方法,采用火焰原子吸收光谱法测定肥料中重金属镉、铬和铅的含量,并建立了火焰原子吸收光谱法测定肥料中重金属含量的不确定度测量模型。测定肥料中重金属镉的含量为0. 003 6%(1±4. 2%),k=2;铬的含量为0. 006 3%(1±3. 8%),k=2;铅的含量为0. 005 0%(1±2. 1%),k=2。结果表明,对镉、铬和铅元素的测试而言,不确定度主要影响因素均来源于样品浓度测定中标准曲线的拟合及测量重复性引入的不确定度分量。     

ICP-OES法测定固体废弃物中重金属含量的不确定度评估

根据GB 5085.6—2007《危险废物鉴别标准毒性物质含量鉴别》中所规定的方法,采用微波消解-电感耦合等离子体发射光谱法测定固体废弃物中重金属铬、镉、汞和铅的含量,并建立电感耦合等离子体发射光谱法测定重金属含量的不确定度测量模型。结果表明,对铬、镉和铅元素的测试而言,不确定度主要影响因素来源于样品浓度测定中标准曲线的拟合;而对于汞元素的测试而言,不确定度除了来源于标准曲线拟合外,测试重复性带来的影响也不可忽略。     

失水程度对板栗贮藏中部分生理指标的影响

为了解不同失水程度对板栗保鲜贮藏的影响机制,以镇安红栗为试验材料,研究了不同失水程度的板栗在贮藏过程中腐烂率、水分含量、电导率、呼吸强度、过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)等生理指标的变化.结果表明,失水5%的板栗在贮藏期间的腐烂率、呼吸强度和电导率显著低于对照;CAT、POD和SOD活性维持较高水平.失水10%和15%的板栗在贮藏期间的腐烂率、相对电导率和呼吸强度显著高于对照,POD和SOD显著低于对照、处于低水平.试验表明,板栗采后少量失水对保鲜贮藏有一定的促进作用.     

纺织品中重金属残留生态环保问题的研讨

一、纺织品中重金属的来源纺织品中重金属的来源比较复杂,可分为前原生期和后加工期两个污染阶段。前原生期是对天然植物纤维和动物纤维类织物而言。对所有的织物来说,重金属主要来源于后加工期,是织物加工过程中使用的某些染料和助剂,如各种金属络合染料、媒介染料、酞菁结构染料、固色剂、催化剂、阻燃剂、后整理剂等以及用于软化硬水、退浆精练、漂白、印花等工序的各种金属络合剂等。对天然纤维织物而言,重金属还可能从环境的污染中来,如植物纤维生长过程中重金属铅、镉、汞、砷等通过环境迁移和生物富集而污染纤维。(1)纺织品中重金属…     

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儿童用品颜色越鲜艳越危险儿童用品重金属超标,问题不容小觑。一般来说,对人体毒害最大的重金属元素包括铅、汞、铬、砷等。儿童积木、童车等表面都涂有各种油漆或涂料,不可避免的会含有一些对人体有害的重金属元素。一旦超标,对儿童身体会影响较大。我国对8种重金属有限量规定,包括铅、镉、汞等,这个标准是和欧盟现在仍在实施的标准相似。质检总局对儿童玩具的检测中,曾发现含有重金属铅和铬。儿童玩具和家具是重金属污染的主要监控对象。PVC玩具和带有表层油漆     

石墨烯对树莓组培苗生长发育影响

以树莓继代组培苗为试材,研究了不同质量浓度的石墨烯对树莓组培苗的长势及其不定根发育的影响。采用激光粒度仪、扫描透射电子显微镜、透射电子显微镜、X射线光电子能谱仪及拉曼光谱仪对石墨烯进行表征。利用LA-S根系分析系统和扫描电子显微镜对组培苗的苗高、根长、根比表面积、分叉数、根尖数及根部微观形态进行系统表征,并确定树莓组培苗生长的最适石墨烯浓度。结果表明,随着石墨烯浓度的增加,树莓的苗高、根长、根尖数、根的比表面积均表现为先增加后减小的趋势。石墨烯最佳浓度为2 mg·L~(-1),组培苗的苗高是对照组的1.46倍,其根长、比表面积、根尖数及分叉数约为对照组的2倍。     

杭州下沙河道底泥重金属检测及污染分析

检测了杭州下沙河网区18条河道表层底泥重金属Cu、Zn、Pb、Cd、Ni的含量,分析了研究区域内的重金属污染情况,并用潜在生态危害指数法对河道底泥重金属污染情况进行评价,通过聚类分析法分析重金属的空间分布特征.结果表明,Cd污染最严重,超标率为94.44%,平均超标倍数为16.50,Cd的平均潜在生态风险为很高风险,Cu、Zn、Pb、Ni的平均潜在生态风险为低风险,重金属平均综合潜在生态风险属于高风险.重金属聚类分析结果显示Cd、Ni、Pb三种元素相关性显著,应受同一污染源因素影响;采样点聚类分析结果显示下沙河网河道底泥重金属污染分布较为均匀.     

Assessment of the metal pollution, potential toxicity and speciation of sediment from Algeciras Bay (South of Spain) using chemometric tools

A study to determine total and mobile heavy metals concentrations in sediments from Algeciras Bay was performed and pollution hotspots were identified. The effects on aquatic organisms were established using sediment quality guidelines (SQGs). Ni and Cr exceeded the effect range medium and low levels, respectively, around industrial area. Potential toxicity of metals was determined by diethylenetriaminepenta-acetic acid (DTPA) extractions and low alert levels of Co, Cu, Zn, Cd, Ni and Pb were exceeded at most sampling sites. Three pollution indicators were used showing significant values for As, Ni, Cr, Pb and Cd. Sediment speciation using the sequential extraction BCR procedure was carried out, being Cd, Zn, Pb and As the most available metals. Principal component, cluster and ANOVA analyses were performed in order to assess the sources of metals and the influence of seasonality and anthropogenic activities on the sediment quality. Two principal component analysis (PCA) factors were obtained identifying the sampling sites affected by anthropogenic activities; Ni-Cr and Zn-Cu-V clusters were also obtained associated with stainless steel and petrochemical industrial activities. ANOVA showed the outstanding sites because of total metal concentration and significant differences among sampling sites by the acid extractable and reducible fractions for all metals except for Ba and V.     

Contamination assessment of copper, lead, zinc, manganese and nickel in street dust of Baoji, NW China

Street dusts collected from Baoji, NW China were analyzed for Cu, Pb, Zn, Mn and Ni by using PANalytical PW-2403 wavelength dispersive X-ray fluorescence spectrometry and assessed the contamination level of heavy metals on the basis of geoaccumulation index (I(geo)), enrichment factor (EF), pollution index (PI) and integrated pollution index (IPI). The results indicate that, in comparison with Chinese soil, street dusts in Baoji have elevated metal concentrations as a whole. The concentrations of heavy metals investigated in this paper are compared with the reported data of other cities. The calculated results of I(geo) and EF of heavy metals reveal the order of I(geo) and EF are Pb>Zn>Cu>Ni>Mn. The high I(geo) and EF for Pb, Zn and Cu in street dusts indicate that there is a considerable Pb, Zn and Cu pollution, which mainly originate from traffic and industry activities. The I(geo) and EF of Mn and Ni are low and the assessment results indicate an absence of distinct Mn and Ni pollution in street dusts. The assessment results of PI also support Pb, Zn and Cu in street dusts presented serious pollution, and IPI indicates heavy metals of street dust polluted seriously.     

Removal and recovery of lead(II) from single and multimetal (Cd, Cu, Ni, Zn) solutions by crop milling waste (black gram husk)

The study reports removal of heavy metals when present singly or in binary and ternary systems by the milling agrowaste of Cicer arientinum (chickpea var. black gram) as the biosorbent. The biosorbent removed heavy metal ions efficiently from aqueous solutions with the selectivity order of Pb>Cd>Zn>Cu>Ni. The biosorption of metal ions by black gram husk (BGH) increased as the initial metal concentration increased. Biosorption equilibrium was established within 30 min, which was well described by the Langmuir and Freundlich adsorption isotherms. The maximum amount of heavy metals (qmax) adsorbed at equilibrium was 49.97, 39.99, 33.81, 25.73 and 19.56 mg/g BGH biomass for Pb, Cd, Zn, Cu and Ni, respectively. The biosorption capacities were found to be pH dependent and the maximum adsorption occurred at the solution pH 5. Efficiency of the biosorbent to remove Pb from binary and ternary solutions with Cd, Cu, Ni and Zn was the same level as it was when present singly. The presence of Pb in the binary and ternary solutions also did not significantly affect the sorption of other metals. Breakthrough curves for continuous removal of Pb from single, binary and ternary metal solutions are reported for inlet-effluent equilibrium. Complete desorption of Pb and other metals in single and multimetal solutions was achieved with 0.1 M HCl in both shake flask and fixed bed column studies. This is the first report of removal of the highly toxic Pb, Cd, and other heavy metals in binary and ternary systems based on the biosorption by an agrowaste. The potential of application for the treatment of solutions containing these heavy metals in multimetal solutions is indicated.     

Bioavailability of heavy metals monitoring water, sediments and fish species from a polluted estuary

Concentrations of heavy metals (Cu, Zn, Cd, Pb and As) were measured in water, sediment and two fish species, Sparus aurata and Solea senegalensis, from the estuary of Tinto and Odiel rivers in Huelva (Spain), one of the most metallic polluted estuaries in Europe. As a forward step to understand metal bioavailability and assess the potential impact on aquatic biota, a study of heavy metal speciation of sediments and water were achieved. High levels of total and dissolved Zn and Cu were found in water and high pollution of Zn, Pb, As and Cu were found in sediments. Availability of metals was established as following ranking: Cd>Zn>Cu>Pb in both water and sediment. In addition, the effect of this pollution was studied by evaluation of metal bioaccumulations and correlations obtained between metal levels in fractions of water and sediment and metal levels in fish tissues. High Cu and Zn levels were observed in liver tissue of both species, in according with higher total content and more available metals in water and sediment. Correlations among metal content in tissues and different fractions of metal in water for S. aurata and sediment for S. senegalensis were found.     

Assessment of metals contamination of soils in Ulaanbaatar, Mongolia

The purpose of this survey is to investigate the current status of metal pollution of the soil in Ulaanbaatar, the capital city of Mongolia. During the last decade, the city has been rapidly urbanized. Twenty-two soil samples were collected from different parts of the city and analyzed by aqua regia extraction. Generally, metal pollution was not a serious problem in the city and there was no significant evidence of infiltration of metal solutions into subsoil (at a depth of 30 cm). However, it was recently found that the arsenic(As) concentration in the soil was higher than the guideline value and the lead(Pb) content in some samples was higher than normal. The source of As pollution appears to be the coal combustion in three power plants in the city. The sources of the increase in Pb pollution might be the remarkable increase in the number of used vehicles and the increase in the use of leaded fuel in the last few years. To evaluate the leaching potential of heavy metals, sequential extraction was conducted. The quantity of the easily extractable fraction of metals was lower than that of the hardly extractable (residual) fraction. As a result, the leaching potential of heavy metals in Ulaanbaatar was found to be quite low.     

Assessing soil heavy metal pollution in the water-level-fluctuation zone of the Three Gorges Reservoir, China

The water-level-fluctuation zone (WLFZ) between the elevations of 145-175 m in China's Three Gorges Reservoir has experienced a novel hydrological regime with half a year (May-September) exposed in summer and another half (October-April) submerged in winter. In September 2008 (before submergence) and June 2009 (after submergence), soil samples were collected in 12 sites in the WLFZ and heavy metals (Hg, As, Cr, Cd, Pb, Cu, Zn, Fe, and Mn) were determined. Enrichment factor (EF), factor analysis (FA), and factor analysis-multiple linear regression (FA-MLR) were employed for heavy metal pollution assessment, source identification, and source apportionment, respectively. Results demonstrate spatial variability in heavy metals before and after submergence and elements of As, Cd, Pb, Cu, and Zn are higher in the upper and low reaches. FA and FA-MLR reveal that As and Cd are the primary pollutants before submergence, and over 45% of As originates from domestic sewage and 59% of Cd from industrial wastes. After submergence, the major contaminants are Hg, Cd, and Pb, and traffic exhaust contributes approximately 81% to Hg and industrial effluent accounts about 36% and 73% for Cd and Pb, respectively. Our results suggest that increased shipping and industrial wastes have deposited large amounts of heavy metals which have been accumulated in the WLFZ during submergence period.     

Stabilization of heavy metals in ceramsite made with sewage sludge

In order to investigate stabilization of heavy metals in ceramsite made with sewage sludge as an additive, the configuration of heavy metals in ceramsite was analysed by XRD and while leaching tests were conducted to find out the effect of sintering temperature (850 degrees C, 900 degrees C, 950 degrees C, 1000 degrees C, 1100 degrees C, and 1200 degrees C), pH (1, 3, 5, 7, 9, and 12), and H2O2 concentration (0.5molL(-1), 1molL(-1), 1.5molL(-1), 3molL(-1), and 5molL(-1)) on stabilization of heavy metals (Cd, Cr, Cu, and Pb) in ceramsite. The results indicate that leaching contents of heavy metals do not change above 1000 degrees C and sintering temperature has a significant effect on stabilization of heavy metals in ceramsite; leaching contents of heavy metals decrease as pH increases and increase as H2O2 concentration increases. XRD analysis reveals that the heavy metals exist in steady forms, mainly Pb2O(CrO(4)), CdSiO3, and CuO at 1100 degrees C. It is therefore concluded that heavy metals are properly stabilized in ceramsite and cannot be easily released into the environment again to cause secondary pollution.     

Growth responses of three ornamental plants to Cd and Cd-Pb stress and their metal accumulation characteristics

Up to now, there was no document on ornamental plants that had been applied to phytoremediation, which can remedy contaminated environment and beautify it at the same time. Thus, the growth responses and possible phytoremediation ability of three ornamental plants selected from the previous preliminary experiments were further examined under single Cd or combined Cd-Pb stress. The results showed that these tested plants had higher tolerance to Cd and Pb contamination and could effectively accumulate the metals, especially for Calendula officinalis and Althaea rosea. For C. officinalis, it grew normally in soils containing 100 mg kg(-1) Cd without suffering phytotoxicity, and the Cd concentration in the roots was up to 1084 mg kg(-1) while the Cd concentration in the shoots was 284 mg kg(-1). For A. rosea, the Cd accumulation in the shoots was higher than that in the roots when the Cd concentration in soils was <100 mg kg(-1), and reached 100 mg kg(-1) as the criteria of a Cd hyperaccumulator when the Cd concentration in soils was 100 mg kg(-1). Their accumulation and tolerance to Cd and Pb were further demonstrated through the hydroponic-culture method. And A. rosea had a great potential as a possible Cd hyperaccumulator under favorable or induced conditions. Furthermore, the interactive effects of Cd and Pb in the three ornamentals were complicated, not only additive, antagonistic or synergistic, but also related to many factors including concentration combinations of heavy metals, plant species and various parts of plants. Thus, it can be forecasted that this work will provide a new way for phytoremediation of contaminated soils.     

Identification of a new potential Cd-hyperaccumulator Solanum photeinocarpum by soil seed bank-metal concentration gradient method

A new method, soil seed bank-metal concentration gradient method was used to screen for heavy metal hyperaccumulators, and Solanum photeinocarpum was found to be a potential Cd-hyperaccumulator. The chlorophyll content and photosynthetic rate of S. photeinocarpum were not affected by Cd pollution, while leaf stomas and transpiration rate were significantly decreased by more than 60 mg kg(-1) Cd, and leaf water use efficiency and shoot water content were significantly increased by more than 60 or 100 mg kg(-1) Cd, respectively. In the seed bank-Cd concentration gradient experiment, the shoot biomass of S. photeinocarpum showed no significant reduction with soil Cd treatment as high as 100 mg kg(-1), but the root biomass was significantly reduced by more than 60 mg kg(-1) Cd contamination. Plant tissues accumulated 544, 132 and 158 mg kg(-1) Cd in roots, stems and leaves, respectively, and extracted 157 and 195 μg Cd plant(-1) in roots and shoots at 100 mg kg(-1) Cd in soil, respectively. In the transplanting-Cd concentration gradient experiment, plant shoot biomass and root biomass were unaffected by soil Cd as high as 60 mg kg(-1). Plant tissues accumulated 473, 215 and 251 mg kg(-1) Cd in roots, stems and leaves, respectively, and extracted 176 and 787 μg Cd plant(-1) in roots and shoots at 60 mg kg(-1) soil Cd, respectively. Soil seed bank-metal concentration gradient method could be an effective method for the screening of hyperaccumulators.