THE STUDY ON NOVEL MICROELECTRODE ARRAY CHIPS FOR THE DETECTION OF HEAVY METALS IN WATER POLLUTION

Qualitative and quantitative analysis of trace heavy metals in aqueous environment are rapidly assuming significance along with the rapid development of industry.In this paper,gold microelectrode array(MEA)plated with mercury film was used for simultaneous voltammetric detection of zinc,cadmium,lead and copper ions in water.The electrochemical behavior and the actual surface area of the MEA were investigated by cyclic voltammetry in K_(3)[Fe(CN)_(6)].Electrochemical impedance spectrum(EIS)was utilized to examine the deposition of mercury on the electrode surface.Based on anodic stripping voltammetry,mercury film
Au MEA was applied to the detection of heavy metals in artificial analyte,where good calibrate linearity was obtained for cadmium,lead and copper ions,but with zinc exhibiting poor linearity.

High efficiency of heavy metal removal in mine water by limestone

The removal of Cd, Cu, Ni and Zn from dilute mine water by using several geological materials including pure limestone, sand, carbonaceous limestone and brecciated limestone was performed on a laboratory scale. The results showed that to add geological materials in combination with sodium carbonate injection would notably enhance the efficiency of heavy metal removal to varying degrees. Pure limestone was found the best one among the four materials mentioned above for removing heavy metals from mine water. The removal efficiencies of pure limestone when it is ground as fine as 30–60 meshes are 58.6% for Cd, 100% for Cu, 47.8% for Ni, and 36.8% for Zn at 20℃. The optimum pH is about 8.9 to 9.1. The mechanism of higher effective removal, perhaps, is primarily due to co-precipitation under the control of calcite-related pH value. According to this research, Na2CO3 injection manners, including slug dosing and drip-wise, seemed to have little impact on the efficiency of heavy metal removal.

Assessment of Rainwater Quality in Warri and Environ, Southern Nigeria for Domestic Purposes

The study aimed at assessing the physiochemical characteristics of rainwater in Warri and it environ was investigated. Pb, Zn, Cd, Cu and Cr concentrations in rainwater from roof and non-roof sources were determined using Atomic Absorption Spectrophotometry. Three geospatial locations comprising Jakpa, Udu, and Ubeji were selected based on prevailing anthropogenic activities. The rainwater samples were systematically collected from (aluminum) roof and non-roof sources for the months of April, June, and August and October 2022, treated and analyzed in the laboratory for sixteen physicochemical parameters. Results were statistically analyzed using ANOVA, and T-test for the determination of the level of relationships and variations across geospatial locations. Significant correlations (r = 0.72) exist between Cr in rainwater from roof and non-roof sources. Implying point-source contaminations and may be emanating from the influence of roof materials. Furthermore, high concentrations of Cd and Pb in roof source above WHO standards were mostly in Jakpa and Ubeji. Calculated Health Risk Index (HRI) for children and adult is greater than 1. The results showed that most samples from the locations are considered not safe (HRI > 1) especially for Cd, which means that there are potential health risks consuming rainwater from Jakpa, Udu and Ubeji. Therefore, there is need for prompt sensitization program to dissuade people from directly drinking rainwater from these locations.

Determination of complexation capacity of trace metal-organic in natural water

The complexation capacity for heavy metals (Cu, Cd, Pb) were determined by anodic stripping voltammetry in South China Sea, Hulun Lake and Wuliang Suhai. The conditional stability constants and complexation capacity index were calculated. The data showed that the complexation capacity of the Hulun Lake was greater than that of seawater and Wuliang Suhai. The sequence of complexation capacity is C (CuL)> C (CdL)> C (PbL), the values are in concord with results of analysis on dissolved organic carbon. The conditional stability constants were in an opposite sequence: K (CuL)< K (CdL)< K (PbL). When log K are similar, the greater the complexation capacity, the greater the complexation capacity index.

Source analysis and risk evaluation of heavy metal in the river sediment of polymetallic mining area:Taking the Tonglüshan skarn type Cu-Fe-Au deposit as an example,Hubei section of the Yangtze River Basin,China

In this paper,25 sampling points of overlying deposits in Tonglushan mining area,Daye City,Hubei Province,China were tested for heavy metal content to explore pollution characteristics,pollution sources and ecological risks of heavy metals in sediments.A geo-accumulation index method was used to evaluate the degree of heavy metal pollution in the sediment.The mean sediment quality guideline quotient was used for evaluating the ecological risk level of heavy metal in the sediment.And a method of correlation analysis,clustering analysis,and principal component analysis was used for preliminary analysis on the source of heavy metal in the sediment.It was indicated that there was extremely heavy metal pollution in the sediment,among which Cd was extremely polluted,Cu strongly contaminated,Zn,As,and Hg moderately contaminated,and Pb,Cr,and Ni were slightly contaminated.It was also indicated by the mean sediment quality guideline-quotient result that there was a high ecological risk of heavy metals in the sediment,and 64%of the sample sites had extremely high hidden biotoxic effects.For distribution,the contamination of branches was worse than that of the main channel of Daye Dagang,and the deposition of each heavy metal was mainly influenced by the distance from this sample site to the sewage draining exit of a tailings pond.The source analysis showed that the heavy metals in the sediment come from pollution discharging of mining and beneficiation companies,tailings ponds,smelting companies,and transport vehicles.In the study area,due to the influence of heavy metal discharging from these sources,the ecotoxicity of heavy metals in the sediment was extremely high,and Cd was the most toxic pollutant.The research figured out the key restoration area and elements for ecological restoration in the sediment of the Tonglüshan mining area,which could be referenced by monitoring and governance of heavy metal pollution in the sediment of the polymetallic mining area.

Sources, distribution, behavior, and detection techniques of microplastics in soil: A review

In recent years, the problem of environmental pollution caused by microplastics has attracted widespread attention. This paper reviews the latest research progress in terms of the source, content and distribution characteristics, harm, and detection technology of soil microplastics by referring to the relevant literature on soil microplastics worldwide. It concludes that:(1) Existing studies worldwide have detected the presence of microplastics in soil, water, and atmosphere, and the use of agricultural films, sewage sludge,and other man-made activities are the main sources of microplastics in soil;(2) microplastics can adsorb heavy metals, persistent organic pollutants and antibiotics in soil, change the physical and chemical properties of soil. This will result in composite pollution and harm to the ecosystem;(3) microplastics in soil not only can destroy the activity of key soil microorganisms, but also enter the body of crops and soil animals, affecting normal growth of crops and soil animals, and further threaten human health;(4) at present, there is no unified operating standard for the sampling, processing, and detection process of microplastics. Analysis methods such as visual inspection, spectroscopy, and thermal analysis have both advantages and disadvantages, and emerging detection technologies require urgent development.Microplastics have become a new pollutant in soil and their distribution characteristics are closely related to human activities. They pollute the environment and threaten human health through the food chain.Although related research on soil microplastics has just begun, it will become the focus of research in the future.

Detection and quantification of Pb and Cr in oysters using laser-induced breakdown spectroscopy

The quantitative determination of heavy metals in aquatic products is of great importance for food security issues.Laser-induced breakdown spectroscopy(LIBS)has been used in a variety of foodstuff analysis,but is still limited by its low sensitivity when targeting trace heavy metals.In this work,we compare three sample enrichment methods,namely drying,carbonization,and ashing,for increasing detection sensitivity by LIBS analysis for Pb and Cr in oyster samples.The results demonstrate that carbonization can remove a significant amount of the contributions of organic elements C,H,N and O;meanwhile,the signals of the metallic elements such as Cu,Pb,Sr,Ca,Cr and Mg are enhanced by3–6 times after carbonization,and further enhanced by 5–9 times after ashing.Such enhancement is not only due to the more concentrated metallic elements in the sample compared to the dried ones,but also the unifying of the matter in carbonized and ashed samples from which higher plasma temperature and electron density are observed.This condition favors the detection of trace elements.According to the calibration curves with univariate and multivariate analysis,the ashing method is considered to be the best choice.The limits of detection of the ashing method are 0.52 mg kg-1 for Pb and0.08 mg kg-1 for Cr,which can detect the presence of heavy metals in the oysters exceeding the maximum limits of Pb and Cr required by the Chinese national standard.This method provides a promising application for the heavy metal contamination monitoring in the aquatic product industry.

煤矿生产区周边水体环境重金属污染分析与治理技术

水体环境受污染会严重影响生态平衡,利用物理化学技术与生物治理技术相结合的方式,治理煤矿生产区水体环境重金属污染。在分析重金属污染情况后,考虑到重金属污染物进入水体后会出现降解、沉淀、氧化以及吸附反应,根据水体环境实时变化特征,利用物理与化学治理技术实施过滤、物理吸附、土壤淋漓以及化学固化操作。同时,利用水中微生物种群,通过生物治理的方式,消纳、转移重金属污染物。实验结果表明,该技术对水中的锰、铁以及铬等重金属元素均能高效地治理、去除。

电动土工塑料排水板修复重金属污染高岭土试验研究

针对重金属锌和镉污染的低渗透性高岭土,采用电动土工塑料排水板(EKG)作为电极材料,通过自制模型试验装置研究了电动修复中电势梯度、通电时间、含水率对重金属去除率的影响,确定电动修复的最优试验条件。在最优试验条件下,开展了电极材料、电势梯度对不同种类重金属去除效果影响的试验研究。结果表明:随着修复时间的增长,阳极处重金属污染物逐渐减少,阴极处重金属污染物富集逐渐增加;试验条件相同情况下,重金属污染物Cd的除去率明显高于Zn;电势梯度越大,重金属Zn离子的去除率越高;电动土工塑料排水板作为电极的电动修复重金属污染土的效果要优于石墨电极。研究有助于揭示电动修复重金属污染土的效果和机理,为电动生态环境修复技术的应用提供技术支持。

磷石膏堆场区域水环境中主要污染物分布特征及其风险评价

分析了摆纪磷石膏堆场区域水环境中污染物的分布特征,对地表水、地下水水质进行了风险评价。研究结果表明:堆场渗滤液中TP、F^(-)、SO_(4)^(2-)、Mn、As、Cr、Zn、Cd、Pb、Cu构成渗滤液的主要污染物,含量分别是《地表水环境质量标准》Ⅲ类或规定水质标准限值的29814.9倍、2775.3倍、18.2倍、493.2倍、351.8倍、131.6倍、12.8倍、8.0倍、3.4倍和1.32倍。地表水、地下水采样点中TP较高的采样点分布在马场坪镇段及堆场附近;水体中F^(-)、SO_(4)^(2-)及重金属含量超标的采样点主要分布在马场坪镇街道段、发财洞区域及堆场附近;堆场水体中重金属元素超标的仅有Mn元素。单因子污染评价结果表明,仅Mn元素在马场坪镇街道段及堆场附近超出低污染水平,其他重金属造成污染的风险较低,处于低污染水平。Pn风险评价结果显示,23个采样点均处于无污染水平,水质状况良好。

应用GA-RBFNN全光谱水体COD与NO_(3)-N检测方法研究

应用全光谱测量水体化学需氧量(chemical oxygen demand,COD)、硝酸盐氮(NO_(3)-N)浓度等水环境质量指标容易受水质环境影响,检测模型与特征波长一直是全光谱检测推广关注重点。该文提出一种基于遗传算法-径向基神经网络(genetic algorithm-radial basis function neural network,GA-RBFNN)全光谱水体COD与NO_(3)-N浓度检测方法,鉴于GA搜索能力强、随机性高的特点,对预处理后全光谱吸收数据应用GA进行特征波长选取,以RBFNN神经网络留K法训练过程中平均决定系数作为适应度函数,输出最优特征波长与RBFNN神经网络参数进行部署,从而实现水体COD、NO_(3)-N浓度准确测量。最后,开展GA-RBFNN、偏最小二乘(partial least squares,PLS)、GA-PLS、RBFNN四种模型对160组水样的COD、NO_(3)-N浓度检测实验,结果表明GA-RBFNN模型对COD、NO_(3)-N检测平均决定系数、最大误差分别为0.9964、0.9950和3.9%、4.9%,均优于其他模型,方法具有重要推广价值。

沉淀分离ICP-OES法测定水质中的重金属

以沉淀分离法降低水样中固溶物含量,达到ICP-OES同心型雾化器盐含量(TDS<1%)要求,降低同心型雾化器在使用过程积盐,提高检测灵敏度。处理后的水样进行ICP-OES测定,研究表明,重金属砷、铅、镉、铬重金属元素线性相关系数>0.999,相对标准偏差(RSD)小于5%,检出限在0.8~9.5μg/L之间,加标回收率≥95%,满足地表水环境质量标准和地下水质量标准的分析要求。

粮食重金属检测方法研究进展

粮食是人们日常饮食的重要组成部分,但粮食容易被重金属污染。重金属通过被污染的粮食进入人体内,会影响人类健康。目前检测粮食中重金属的方法多种多样,本文对国内外的几种重金属检测方法在粮食中的应用进行了综述。

食品中重金属检测质量控制与分析

在工业化发展的时代背景下,环境污染越来越严重,重金属污染已经成为食品加工领域的一大隐患。食品中的铅、汞、镉等重金属元素长期累积会严重影响人体健康。基于此,本文综述了当前食品重金属检测新标准以及食品中重金属元素的提取及检测的方法,重点从石墨炉原子吸收光谱法、紫外可见光分光光度法、蒸气发生原子荧光光谱法和原子吸收光谱法4个维度详细阐述食品中重金属检测技术的原理和应用,旨在为食品安全领域提供准确、快速的重金属检测方法,确保食品质量与消费者健康。

水环境中锑分析检测方法的研究进展

锑(Sb)是广泛存在于水环境中的一种重金属,不断被证实对人和动植物等有慢性毒性和致癌风险。在监测和治理水环境中的Sb污染方面,建立快速、高灵敏度的Sb检测分析方法至关重要。重点阐述了分光光度法、原子荧光光谱法(AFS)、电感耦合等离子体质谱法(ICP-MS)、电感耦合等离子体原子发射光谱法(ICP-OES)、原子吸收光谱法(AAS)和电化学分析法在Sb分析检测中的相关研究及应用进展,探讨了水环境中Sb检测存在的问题和面临的挑战,如检测方法灵敏度低、间接测定Sb耗时且不准确、还原剂昂贵且有毒等。此外,对Sb检测未来的发展方向进行展望。未来Sb检测趋势是发展电化学分析方法。通过电极修饰和纳米材料设计提高传感器性能,如碳基材料、金属纳米颗粒和硅基材料。有机配体、纳米复合材料和裸电极的功能化可增强灵敏度和选择性,促进传感器小型化。未来Sb检测将迈向小型化、芯片化和快速化。

水质型缺水地区地下水重金属污染风险评价——以嘉兴市为例

以典型水质型缺水城市嘉兴市作为研究区,采集29个地下水点位的水样,检测Fe、Mn、Cu、As、Pb、Hg、Cd、Cr的浓度以及pH,采用内梅罗指数法和潜在生态风险指数法评价重金属污染程度,基于地统计分析和数理统计方法分析重金属空间分布特征和来源,并引用风险评估模型量化该污染给居民带来的健康风险。结果表明:①研究区地下水的Fe、Mn、As、Pb含量均值超出Ⅲ类标准的限值,超标率为Fe(86.2%)>Mn(75.9%)>As(62.1%)>Pb(20.7%),其余4种元素未超出Ⅲ类标准。②Fe、Mn、Cd的来源相似或迁移转化路径相近,As含量高的地下水呈弱碱性。③研究区的综合潜在生态风险指数为69.27,综合生态危害程度介于轻微—中等之间。④研究区内93.1%的地下水健康风险总值高于成人最大可接受值,海宁市和海盐县的南部地区健康风险总值最高。研究成果可为水质型缺水地区开发利用地下水,以及重金属污染与风险管控提供数据支撑和理论依据。

Comprehensive evaluation of heavy metal contamination of sediment in Lake Dianchi by using modified AHP method and ^(137)Cs dating

Through the use of general sampling and measurement by ^(137)Cs dating,problems regarding the absence of monitoring data can easily be resolved.Further,weighted values need to be determined while Environment Quality Comprehensive Index(EQCI)is commonly used as applied in environmental quality comprehensive evaluation.In order to overcome the subjectivity in determining weights,the modified Analytical Hierarchy Process(AHP)method was designed.The modified AHP method involved the following key procedures:First,the parameters y_(i1) and y_(i2) were calculated based on the monitoring data;second,the factors were put in order according to the symbol and value of y_(i1) and y_(i2);third,the continuous odd integers,which represented the importance of factors,were given to factors according to their seating order;and,fourth,the factor weights were determined from the pair-wise comparison matrix calculated by the ratio of the given odd integers.Therefore,the weights were completely based on the monitoring data.In the present study,the comprehensive quality of sediments in five sections of Lake Dianchi were evaluated and the results indicated that the current contamination of sediments in each lake section is much more serious than at any other time in history.

关于生活饮用水中金属元素检测方法分析及质量控制探讨

在生活饮用水中,不同金属元素的含量会因为自然环境和生产活动等因素变化而发生改变。因此,在检测和质量控制时需要综合考虑各种因素,选择合适的检测方法,确保测试结果的准确性和可靠性。同时,为了更好地保障人民的生命健康,需要制定更加严格的水质标准和检测方法,加强对生活饮用水中金属元素的监管,以确保人民饮用水的水质安全。基于此,本文阐述了生活饮用水中金属元素的危害及检测意义,对生活饮用水中金属元素的检测方法进行了分析,探讨了生活饮用水中金属元素检测质量的控制措施。