Harmful evaluation of heavy metals from soil layer to the groundwater: Take the Jilin Hunchun Basin as an example

The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the theory of groundwater circulation and solid-liquid equilibrium,a simple and easy-touse flux model of soil heavy metals migrating to groundwater is constructed.Based on groundwater environmental capacity,an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed,which has been applied in Hunchun Basin,Jilin Province,China.The results show that the fluxes of soil heavy metals into groundwater in the study area are Zn,Cu,As,Pb,Cd,Ni,and Hg in descending order.The content of heavy metals in groundwater(As,Hg,Cu,Pb,Zn,Ni,and Cd)in most areas has not risen to the threshold of environmental capacity within 10 years.The harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or below.This evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly,determine the residual capacity of groundwater to heavy metals,evaluate the harm level of soil heavy metals to groundwater,provide support for relevant departments to carry out environmental protection of soil and groundwater,and provide a reference to carry out similar studies for related scholars.

Evaluation of the potential risks of heavy metal contamination in rice paddy soils around an abandoned Hg mine area in Southwest China

To assess the potential ecological and health risks of trace elements(Hg,Cd,As,Mn,Sb,Pb,Cu,Ni,Cr,and Zn),a total of 138 soil samples from rice paddies were collected during the rice harvest season in the Wanshan mining area,Guizhou Province,Southwest China.Factors of the pollution load index(PLI),geo-accumulation index(I-Geo),enrichment factor(EF),and risk index(RI)were determined.High concentrations of Hg,Sb,As,Zn,Cd,Cu,and Mn were observed in the soils.The PLI,I-Geo,and EF results all showed high levels of contamination by Hg and Sb and moderate levels of contamination by As,Pb,Zn,Cu,Cd,and Mn.There was no significant contamination from Ni and Cr.The RI was very high,with Hg as the dominant pollutant,as expected,indicating that the historical large-scale Hg mining,as well as artisanal mining,has had a significant impact on the Wanshan area.Moreover,coal combustion,manganese factories,and the use of agrochemicals by the local population could also have an impact on the soil through the introduction of heavy metal loads.To address the current state of contamination,pollutant remediation and the regulation control of the anthropogenic activities in Wanshan are urgently needed.

Investigation and Analysis of Soil Pollution of Heavy Metals(Hg,As) in Duanzhou District,Zhaoqing City

The soil heavy metals(Hg and As)in Duanzhou District of Zhaoqing City were determined by AFS200 T atomic fluorescence spectropho-tometer,and the soil environment in Duanzhou District was evaluated by several evaluation methods of soil heavy metal pollution,such as single factor index method,pollution load index method and Nemerow comprehensive pollution index method.Finally,according to the data and conclu-sions,the soil pollution situation in Duanzhou District of Zhaoqing was analyzed.The results will let more people pay attention to the changes of the environment and realize the harm of the environment,and the government can formulate a new plan conducive to the coordinated development of the environment and economy.

Cumulative Risk Assessment of Exposure to Heavy Metals through Aquatic Products in China

Objective This study aimed to assess the risk of cumulative exposure to Pb,Cd,Hg,and iAs through aquatic products consumed by Chinese people.Methods Heavy metal concentration data were obtained from the national food contamination monitoring program during 2013–2017.Consumption data were derived from the China National Food Consumption Survey in 2014 and the relative potency factor(RPF)method was used to estimate cumulative exposure for neurotoxicity and nephrotoxicity.Results The results demonstrated that the cumulative exposure based on neurotoxicity was below the lower confidence limit on benchmark doses of lead(BMDL01)for nephrotoxicity and the cumulative exposures were all lower than the provisional tolerable monthly intake(PTMI)of Cd.However,the margin of exposure values(MOEs)of the cumulative exposures for neurotoxicity in the 2–6 year-old group was close to 1 and the cumulative exposure level for nephrotoxicity accounted for 90.21%of the PTMI.Conclusion The cumulative exposures of the 2–6 year-old group to the four heavy metals did not reach(but came close to)the corresponding safety threshold for both neurotoxicity and nephrotoxicity.Given that there are still other food sources of these four heavy metals,it is necessary to more closely study their cumulative health effects.

Heavy Metal Pollution in Soil and Water in Some Selected Towns in Dunkwa-on-Offin District in the Central Region of Ghana as a Result of Small Scale Gold Mining

Illegal small scale gold mining popularly called “Galamsey” in our local communities is on the increase. This has led to concerns about the level of environmental pollution resulting from these mining activities. This work was conducted to determine the level of heavy metal contamination in the environment due to the activities of the small scale miners. This paper discusses the concentrations of some selected heavy metals—Hg, Pb, and Cu which were measured in 14 sampling sites in Dunkwa-on-Offin in the Central Region of Ghana, known for these activities. The heavy metal concentrations have been investigated for soil and water samples in the selected towns and compared with the relevant guidelines of the Environmental Protection Agency. The concentration of heavy metals was measured by using AAS. In most locations, the concentration for the investigated heavy metals far exceeded the concentration admitted by the guidelines. The mean concentration of Lead was 95.13 mg/Kg for soil and 190.27 mg/L in water;Copper was 63.26 mg/Kg in soil and 75.92 mg/L in water while Mercury was 140.87 ug/Kg in soil and 211.31 mg/L in water. The mean recorded concentrations in the sensitive areas exceeded greatly. Hence the levels of heavy metal contamination have spread beyond control.

Mechanochemical synthesis of oxygenated alkynyl carbon materials with excellent Hg(Ⅱ) adsorption performance from CaC2 and carbonates

Adsorptive removal of heavy metal ions from wastewater is very important,and the key is the development of efficient sorbents.In this work,oxygenated alkynyl carbon materials(OACMs)were synthesized via mechanochemical reaction of CaC_(2) and a carbonate(CaCO_(3),Na2CO_(3),or NaHCO_(3))at ambient temperature.The resultant OACMs are micro mesoporous carbon nanomaterials with high specific area(>648 m2 g^(-1)),highly crosslinked texture,and rich alkynyl and oxygenated groups.The OACMs exhibit excellent Hg(Ⅱ)adsorption due to the soft acid-soft base interaction between alkynyl and Hg(Ⅱ),and OACM-3 derived from CaC_(2) and NaHCO_(3) has the saturated Hg(Ⅱ)adsorbance of 483.9 mg g^(-1)along with good selectivity and recyclability.The adsorption is mainly chemisorption following the Langmuir mode.OACM-3 also shows high adsorbance for other heavy metal ions,e.g.256.6 mg g^(-1)for Pb(II),232.4 mg g^(-1)for Zn(II),and 198.7 mg g^(-1)for Cu(II).This work expands the mechnochemical reaction of CaC_(2)with carbonates and possibly other oxyanionic salts,provides a new synthesis approach for functional alkynyl carbon materials with excellent adsorption performance for heavy metal ions,as well as a feasible approach for CO2 resource utilization.

Modifying action of heavy metal salts on an-ti-inflammatory aspirin action

Nowadays pollution of the environment is one of the major problems of mankind. Moreover, studying of the effect of different kinds of med- icine on selected, specially bred, non-exposed to external pollutants animals is becoming distant from reality. Thus in this work we have investigated the modifying action of heavy metals on anti-inflammatory effect of aspirin. The investigation were carried out on rats which were injected during 7 days intraperitoneally by PbCl3, HgCl2, CdCl2 in concentration of 100, 20, 1 mg/kg accordingly, modulating accumulation of the metals in the organism tissues. On the 8 days inflammation was invoked by formalin. As anti-inflammatory medicine was use aspirin. Judging by obtained results the conclusion can be drawn that cadmium in concentration 1 mg/kg significantly increases anti-inflammatory aspirin activity. The observed outcome can be explained in the following way. It is generally known that zinc in a certain concentration demonstrates anti-inflammatory properties. Be- ing an element of the same group cadmium has similar properties and also can have anti-inflammatory action. Lead and mercury suppre- ssed anti-inflammatory aspirin activity. Obvious inhibitory action of mercury and lead salts on aspirin action related to the fact that these elements by themselves were inflammation factors. From the obtained results the following conclusion can be drawn: a definite dose of anti-inflammatory medicine (aspirin) which is sufficient in normal conditions became less effective against the background of accumulation of ions of some heavy metals in an organism.

Geochemistry and Heavy Metal Levels in the Sediments of the Port of Santa Bárbara de Samana, Dominican Republic

In the Port of Santa Bárbara de Samana, chemical residues, organic matter and heavy metals from domestic activities are deposited together in the waters and sediments. The analysis of the sediments by X-ray fluorescence of four extracted and sectioned cores showed that concentrations of trace metals such as Nickel, Chromium, Lead and Mercury were present at various depths, exceeding Limits of Toxicity (PEL) for marine sediments according to National Oceanic and Atmospheric Administration (NOAA) and Canadian Council of Ministers of the Environment (CCME). Cadmium presented values above the toxicity threshold (TEL) in its minimum values and in its maximum values they exceeded the PEL value. While the Zinc and Copper values were low in all sections and lower than TEL. The analysis of the loss by ignition and the dating with lead 210 due to excess of the C4 core, showed a sudden change in the organic matter content and sedimentation rate. The superficial sediments show that unlike the deeper ones, the heavy metal content is lower, as well as that they do not represent a risk to the ecosystem by not exceeding toxicity levels.

天然锰钾矿吸附水溶液中Hg^(2+)的实验研究

利用粉碎分级的天然锰钾矿去除水溶液中Hg2 + 的实验研究表明 :反应平衡时间约为 2 0小时 ;pH值对其吸附率影响很大 ,在中性 (氯化物在偏碱性 )条件下吸附率较高 ;溶液中阳离子的存在会产生竞争吸附而降低对Hg2 + 的吸附量 ,2价金属离子较 1价金属离子对Hg2 + 竞争干扰明显 ;溶液中Cl- 的存在能明显降低对Hg2 + 的吸附量。对等温吸附曲线的回归分析得出在浓度为5～ 35 0mg/L段能很好地符合Langmuir单吸附位吸附曲线 ,并计算出在该实验条件下其最大理论吸附量为 2 7.6mg/g。解吸实验结果表明 ,在无其他电解质参与的条件下解吸量较少 ,受多种电解质干扰时其解吸率不超过 2 0 %。

基于BCR和HG-ICP-AES的矿区土壤重金属污染特征分析

建立了基于BCR法(连续提取法)和HG-ICP-AES技术的土壤重金属形态含量的检测方法。在选定的实验条件下,HG-ICP-AES对Hg,Pb和As的检测限分别达到0.6,1.5和0.8 ng.mL-1。对国家标准沉积物样品中Hg,Pb和As的含量进行对照测定,检测结果与推荐值一致,标准物质中Hg,Pb和As多次重复测定的RSD均<8%。应用本法实测了湘西某有色金属矿区土壤中Hg,Pb和As各形态的含量,发现矿区土壤中Hg,Pb和As均以残渣态为主,有机态和Fe-Mn氧化态次之,酸交换态含量较少;与对照区相比,矿区土壤中酸交换态、Fe-Mn氧化态、有机态、残渣态Hg,Pb和As的含量分别增加1.2,3.0,47,272倍(Hg);1.2,4.6,8.1,4.5倍(Pb);1.5,2.9,3.3,2.2倍(As);表明湘西矿区土壤同时存在Hg,Pb和As的复合污染。

天然磁铁矿处理含Hg(Ⅱ)废水实验研究

利用重金属离子可在水合金属氧化物和氢氧化物矿物表面产生吸附作用的原理 ,进行了天然磁铁矿处理含Hg(Ⅱ )废水的实验研究 ,结果表明 :当温度为 2 5℃、吸附平衡时间为 6 0分钟、试样用量为 2 0g/L、试样粒径为 2 0 0目以下、pH值为 6 .4 0、离子强度为零时 ,Hg(Ⅱ )初始浓度为1.12mg/L的溶液的吸附率可达 98%,使废水中Hg(Ⅱ )的浓度达到国家排放标准。pH值、离子强度、粒径、试样用量、废水浓度、温度、时间均对Hg(Ⅱ )的吸附率有一定的影响 ,其中 pH值的影响最大。Hg(Ⅱ )在天然磁铁矿上的吸附等温曲线不同于Langmuir和Freundlich等温曲线 ,而是表现为台阶型 ,符合分级离子 /配位子交换等温曲线。

应用ICP-MS技术快速直接检测石脑油中的Pb、Hg、As

本研究发展了应用ICP—MS及其专用的有机进样系统对高挥发性的石脑油进行直接进样分析的方法。该方法采用乙醇对石脑油样晶进行最简单的1：1稀释后直接进样，采用标准加入法工作曲线转外标法工作曲线方法，克服了水性标准溶液无法溶于憎水性有机溶剂的问题。摸索出最适当的仪器工作条件，包括进样量（50—100μL／min）、氧气加入量（20％比例）、灵敏度（Y〉80000cps／ng／g）、氧化物干扰（〈1．5％）等重要参数，从而克服了高挥发性有机试剂对ICP—MS分析形成的秘碳、灭火问题。方法快速同时检测了石脑油样品中超痕量Hg、Pb、As，检出限达到Hg0.05ng／g，Pb0．01ng／g和As0．1ng／g，1h连续测定RSD为地1．0％，Pb4．0％和As8．0％，加标回收率在86％～95％之间。本研究不必使用碰撞／反应池技术，但对其在石化行业关键元素分析的潜在优势进行了探讨。

关于As和Hg在环境中的形态及其监测分析

叙述了水中重金属形态分析的含义及形态分析工作进展情况 ,并以 Hg、As在环境中的存在形态、动态变化及其监测分析为例 ,说明随着新仪器的开发研制及前处理技术的发展 ,现代化的分离技术和检测手段相结合已成为重金属形态分析的主要方法。

电场调控激光诱导石墨烯基重金属电化学检测装置的研制

为了快速、精准分析农田重金属,该文设计了一款基于施加电场与激光诱导石墨烯(laser-inducedgraphene,LIG)电极阵列的功能核酸比率电化学检测装置,用于农田中典型重金属离子Hg^(2+)、Pb^(2+)的分析。该装置主要包括电场施加模块与LIG电极阵列传感器两个部分,前者以AT89S52单片机作为主控芯片、DAC0832作为电压输出端口,设计单片机控制电压输出的电场施加装置,实现了可编程电压的稳定输出;后者则通过结合CO_(2)激光直写和环氧树脂转印技术,提出了LIG电极阵列的快速制备方法,并进一步构建了LIG基功能核酸比率电化学传感器。在检测过程中,通过调控施加电场的性质,该装置实现了Hg^(2+)、Pb^(2+)在传感器表面的快速特异性富集以及响应信号的稳定获取,其对Hg^(2+)、Pb^(2+)检测限分别低至8.5×10^(-12)mol/L(4.25×10^(-11)mg/L)和4.6×10^(-13)mol/L(2.22×10^(-12)mg/L),实现了农田灌溉用水中Hg^(2+)、Pb^(2+)的现场精准检测。该装置利用施加电场与LIG阵列传感器,实现了重金属离子的快速、精准、现场分析需求,对于农田环境重金属污染的监测及治理具有重要意义。

高分子重金属絮凝剂对Hg^(2+)的捕集及性能

以含Hg2+废水作为处理对象,研究了几个影响高分子重金属絮凝剂去除水中Hg2+的因素,实验表明(1)pH值对Hg2+的去除率影响不大;(2)水中某些二价离子的存在不仅不会消耗高分子重金属絮凝剂的用量,而且会促进螯合体MHMHg2+絮凝沉淀,Hg2+的去除率在99%以上,而一价金属离子对处理效果影响不大;(3)Hg2+和致浊物质会互相促进彼此的去除,浊度的去除率在98%以上,Hg2+的去除率在99%以上;(4)高分子重金属絮凝剂对重金属离子具有选择性,可将部分重金属离子从其它离子中分离开、回收再利用.

Cu、Pb、Cd、Hg亚致死浓度对三疣梭子蟹幼体的影响

为了解海洋重金属污染对三疣梭子蟹的危害,进行了Cu、Pb、Cd、Hg对三疣梭子蟹幼体影响的试验.结果发现,当Cu浓度为0.005mg·L-1(Cu渔业水质标准的1/2倍,简称1/2倍组,下同)以下时,蟹幼体能正常发育至2期幼蟹;Cu浓度为0.01mg·L-1(1倍组)时蟹幼体也能发育至2期幼蟹,但在试验第19d全部死亡;Cu浓度为0.02mg·L-1时(2倍组)蟹幼体仅发育至1期后就全部死亡;Cu浓度为0.04mg·L-1(4倍组)和0.08mg·L-1(8倍组)时蟹幼体只能发育至大眼幼体就全部死亡.Pb浓度为0.025mg·L-1(1/2倍组)、0.0125mg·L-1(1/4倍组)时,蟹幼体能正常发育至2期幼蟹;Pb浓度为0.05mg·L-1(1倍组)时蟹幼体能发育至2期幼蟹,但在试验的第20d全部死亡;Pb浓度为0.1mg·L-1(2倍组)和0.2mg·L-1(4倍组)时,幼体仅发育至1期幼蟹就全部死亡;Pb浓度为0.4mg·L-1(8倍组)时,幼蟹仅只能发育至Z4就全部死亡.Cd浓度为0.00125mg·L-1(1/4倍组)时,蟹幼体能正常发育至2期幼蟹;Cd浓度为0.0025mg·L-1(1/2倍组)仅有1期幼蟹出现,至试验结束时虽未死亡,但未能变态为2期幼蟹;Cd浓度为0.005mg·L-1(1倍组),仅只有1期幼蟹出现就全部死亡;Cd浓度为0.01mg·L-1(2倍组)、0.02mg·L-1(4倍组)时,仅只能发育至大眼幼体就全部死亡;Cd浓度为0.04mg·L-1(8倍组),幼体仅只能发育至Z4就全部死亡.Hg浓度为0.0005mg·L-1(1倍组)时,三疣梭子蟹幼体均能正常发育至2期幼蟹;Hg浓度为0.001mg·L-1(2倍组)只能发育至1期幼蟹就全部死亡;Hg浓度为0.002mg·L-1(4倍组)、0.004mg·L-1(8倍组)仅只能发育至Z4就全部死亡.以上结果说明,Cu浓度为0.005mg·L-1(1/4倍组),Pb浓度为0.025mg·L-1(1/2倍组)、Cd浓度为0.00125mg·L-1(1/4倍组)和Hg浓度为0.000125mg·L-1(1/4倍组)以下进行三疣梭子蟹幼体培育比较安全.

Pb、Cd、Hg复合污染对蕹菜生长和重金属累积规律的影响

通过大棚盆栽试验研究在不同pH条件下,土壤中铅、镉、汞3种重金属的4个水平下蕹菜中重金属的累积特征。结果表明,在适宜的土壤酸度水平下,中低浓度的铅、镉、汞混合污染有利于蕹菜的生长;相反,在高浓度铅、镉、汞混合污染的碱性土壤中,蕹菜的生物量小,根茎短且易受病虫害危害;蕹菜是耐镉性植物,蕹菜中的镉含量易受到土壤中重金属含量和土壤pH值的影响。

海洋巨藻(Durvilaea potatorum)生物吸附剂对Hg^(2+)的吸附动力学研究

对经特殊的稳定化预处理所得的海洋巨藻 (Durvillaeapotatorum)生物吸附剂对Hg2 + 的吸附动力学进行了研究 ,报导了不同Hg2 + 初始浓度、温度以及生物吸附剂平均粒径下动态吸附量与时间的关系 .结果显示 ,各吸附动力学曲线呈优惠型 ;当生物吸附剂平均粒径为 0 .45mm时 ,Hg2 + 的半饱和时间tS均不超过 6 0min ;Hg2 + 初始浓度和生物吸附剂粒径越小 ,吸附温度越大 ,达到吸附平衡所需的时间越短 .在测试范围内 ,生物吸附剂的平衡吸附容量与粒径和温度无关 .同时考察了吸附过程中的传质效应并对液膜传质系数kL进行了关联 ,结果表明 :当吸附时间t≤tS时 ,Hg2 + 的吸附速率为液膜传质控制 ;在测试范围内 ,kL为 0 .0 40 7～ 0 .112cm/s.本研究结果为利用海洋巨藻 (Durvillaeapotatorum)生物吸附剂处理含汞废水的规模化应用提供了一定的依据 .图 5表 2参

螺旋藻FACHB-439对重金属Hg吸附性能的研究

藻类作为生物吸附剂对于监测和防治水体重金属污染得到极大的关注。本实验以螺旋藻FACHB-439作为生物吸附剂,从干粉复水处理、藻粉的起始含量、重金属离子的起始浓度及pH等四个方面对螺旋藻FACHB-439对重金属Hg的吸附性能研究做了初步研究。结果表明,吸附前藻粉的复水处理,有助于吸附过程的进行,能在较短时间达到最高的吸附效率。随着藻粉浓度的增大,吸附效率加大,单位藻粉的吸附效率减少。汞离子浓度的升高,藻的吸附效率下降。当pH为6时,吸附效率最大。

海洋巨藻生物吸附剂对Hg^(2+)吸附性能的研究

就丰产廉价的海洋巨藻(Durvillaea Potatorum)所制的生物吸附剂对Hg2+的吸附性能进行了研究,该生物吸附剂经特殊的稳定化预处理而得。研究表明,该生物吸附剂的Hg2+吸附容量对溶液的pH值十分敏感,在pH=3时,最大吸附容量达到3.1mmol/g(干重),在溶液pH=0.4～5.0的范围内,Hg2+的吸附容量为0.49—3.1mmol/g(干重);溶液中的C1-能显著地降低生物吸附剂对Hg2+的吸附容量;其对Hg2+的去除率可达到99％以上。该生物吸附剂可以有效地去除工业废水中的Hg2+。