Progress in the Treatment of Heavy Metal Pollution of Water Sediment

In recent years,as China's industrialization process and urban-rural integration strategy have continued to deepen,some industrial and domestic wastewater has been discharged directly into rivers without effective treatment.This has resulted in the continuous accumulation and enrichment of pollutants in water bodies.This phenomenon results in a significant accumulation of heavy metals in the sediment of water bodies,which not only represents a significant threat to the ecological environment but also ultimately poses a risk to human health.The objective of this study is to provide a comprehensive review of the current status of heavy metal pollution in water sediment in China.In addition,this paper analyzes the advantages and limitations of existing techniques for the harmless treatment of heavy metal pollution and forecasts the development direction of this field.

Heavy metal pollution assessment in marine sediments in the Northwest coast of Sabah,Malaysia

Heavy metal contents along the Northwest coast of Sabah were determined to interpret the pollution level in the marine sediment. The metal abundance is regulated by the physico-chemical properties such as the average sediment pH(7.82, 9.00 and 8.99), organic matter(0.62%, 1.60%, and 2.27%), moisture content(25.00%, 29.70%, and 15.00%) and sandy texture in Kota Belud, Kudat and Mantanani Island,respectively. The major elements show Ca>Fe>Mg>Al>Mn for all study sites, while the heavy metals show Ni>Cr>Zn>Cu>Co>Pb, Cr>Ni>Zn>Cu>Pb>Co and Zn>Pb>Cr>Ni, for Kota Belud, Kudat and Mantanani Island, respectively. The pollution degree of heavy metals was evaluated by using the Sediment Quality Assessment(SQA). The SQA parameters indicated none to moderate pollution in Kota Belud that shows Class 0, Class 1 and Class 2 pollution. The parameters also indicated none to low pollution in Kudat and Mantanani Island that show only Class 0 pollution. The enrichment factor(EF) suggested minor to moderately severe metal enrichment by anthropogenic sources in Kota Belud, whereas only minor enrichment in Kudat and Mantanani Island. The modified pollution degree(MCD<1.5) and pollution load index(0 PLI<1) indicating only low pollution level in the marine sediments for all study sites. The objectives of this study are:(1) to determine the physico-chemical parameters of sediments,(2) interpret the heavy metal contents and(3) evaluate the sediment quality.

Current Situation of Heavy Metal Pollution in Soil and Dustfall in Some Cities of China

Because of human activities, urban dustfall and soil in China have been polluted by heavy metals in different degrees. However, the type and pollution degree of heavy metal hazard are different among cities. Based on data about the heavy metal pollution of urban soil and dustfall as well as related information inves- tigated, the present situation of heavy metal pollution in soil and dustfall in 23 regions of China were summarized, and some suggestions were put forward accord- ing to the existing problems of research on heavy metal pollution, aiming to provide reference for government decision-making and related research in future.

Advances in Microbial Remediation on the Application of Heavy Metal Pollution in Agricultural Water Resources

Heavy metal pollution in agricultural water resources is very serious in re- cent years, resulting in large losses of the agricultural economy and endangering human life and health. Due to the advantages of low cost, high efficiency and less secondary pollution, microbial ramediation technology is widely used in the treatment of heavy metal pollution in agricultural water resources. At present, with the progress of modern biotechnology, microbial remediation of heavy metals in agricul- tural water resources has grown rapidly. The sources and status quo of heavy met- al pollution in agricultural water resources at home and aboard, and the principles of microbial remediation of heavy metals pollution in agricultural water resources were reviewed in this paper, as well as the several common microbial remediation technology of heavy metals in agricultural water resources. Additionally, the further research work of heavy metal contaminated agricultural water resources by microbial ramediation were prospected.

Assessment of Heavy Metal Pollution in Estuarine Surface Sediments of Tangxi River in Chaohu Lake Basin

A total of 30 surface sediments samples from the estuary wetland of the Tangxi River, Chaohu Lake Basin were obtained and tested. Enrichment factor （EF） and geoaccumulation index （Igeo） as well as multivariate statistical analysis methods including Factor Analysis （FA） and Hierarchical Cluster Analysis （HCA） were applied for the assessment of heavy metal pollution in surface sediments. The results of EF values show that the pollution of copper （Cu） and cadmium （Cd） occurs in the estuarine sediments, and that zinc （Zn）, lead （Pb） and chrome （Cr） may originate from crustal materials or natural weathering process. The mean EF values of the five heavy metals are in the decreasing order： Cu〉Cd）Zn〉Pb〉Cr. Based on the lgeo of target heavy metals, the surface sediments collected from the study area can be approximately categorized as unpolluted with Zn, Pb and Cr, and moderately polluted with Cu and Cd. The degree of heavy metal pollution decreases in the order of Cu〉Cd〉Zn〉Pb〉Cr. Three groups of pollution factors are presented from FA： Zn-TOC, Cu-Cd and Cr-Pb, which respectively accounte for 27.22%, 25.20% and 21.05% of variance. By means of HCA, a total number of seven groups are distinguished from 30 sampling sites. Results indicate that Cu and Cd are the prior controlled pollutants in the estuarine sediments of the Tangxi River.

Effect of Combined Heavy Metal Pollution on Nitrogen Mineralization Potential,Urease and Phosphatase Activities in a Typic Udic Ferrisol

Individual and combined effects of Cu, Pb, Zn and Cd on N mineralization, urease and phosphatase were examined in a Typic Udic Ferrisol in laboratory by employing an uniform design and a single factor design.Soil pollution caused by heavy metals inhibited N mineralization (No value) and urease and phosphatase activities. The combined pollution of metals alleviated their toxicity to N mineralization to some extent,whereas aggravated the toxicity to urease and phosphatase. Phosphorous application could mitigate the toxic effect of heavy metals on phosphatase activities, while alleviating effect of N application on the toxicity of heavy metals to urease was inconsistent. However, the mitigating effect of the fertilizers was limited in heavily polluted soils.

Heavy metal pollution and potential ecological risk in reclaimed soils in Huainan mining area

In order to determine the environmental quality condition of reclaimed soils inHuainan mining area, soil samples were collected from three representative mines, suchas Panyi Mine, Xinzhuangzi Mine and Datong Mine.The total concentration of Cd, Hg, Cu,Pb and As in the samples were analyzed.The potential ecological risk was used to evaluatethe heavy metals pollution.The investigation reveals that the reclaimed soils are contaminatedto a certain degree and the trace elements in coal gangue transferred to thesurface soil.The order of potential ecological risk is Cd>Hg>Cu>Pb>As; the pollution degreeof each sampling site is arranged in the following order: Xinzhuangzi Mine>DatongMine>Panyi Mine, and the multiform of heavy metals of potential ecological risk index is at357.35～484.62.

Effects of heavy metal pollution on farmland soils and crops:A case study of the Xiaoqinling Gold Belt,China

This paper focuses on the heavy metal enrichment and heavy metal pollution degree associated with mining activities in some crops and the soils of different parent materials in the Xiaoqinling Gold Belt.According to the geochemical analysis results of the soils observed in the gold belt,the soils are most highly enriched in Pb,followed by Cr,Cu,and Zn.Furthermore,they are relatively poor in Hg,Cd,and As.It is also shown that the heavy metals in all kinds of soils have the same geochemical characteristics in the gold belt.As for the crops(such as corn and wheat)in the gold belt,Zn and Cu are the most abundant elements,followed by Pb and Cr.Meanwhile,Hg,Cd,and As were found to have relatively low concentrations in the crops.The heavy metals in wheat and corn have the same geochemical characteristics in the gold belt in general.Compared to the aeolian loess soils and the crops therein,heavy metals are more enriched in diluvial and alluvial soils and the crops therein.As shown by relevant studies,the Hg,Pb,Cd,Cu,and Zn pollution are mainly caused by mining activities.Corn and wheat in the gold belt have a high tendency of risk exposure to heavy metal pollution since they are mostly affected by mining activities and feature high background values of heavy metal concentrations.Furthermore,wheat is more liable to be enriched in heavy metals than corn is grown in all types of soils.The Hg pollution in soils leads to Hg accumulation,increasing the risk of Hg uptake in crops,and further affecting human health.This study will provide a scientific basis for the control and management of heavy metals in farmland soils of mining areas.

Studies on Heavy Metal Pollution in Soil-Plant System:A Review

Heavy metal pollution in soil-plant system is of major environmental concern on a world scale and in China in particular with the rapid development of industry. The heavy metal pollution status in soil-plant system in China, the research progress on the bioavailability of heavy metals (affecting factors, extraction methods, free-ion activity model, adsorption model, multivariate regression model, Q-I relationship, and compound pollution), and soil remediation are reviewed in the paper. Future research and monitoring is also discussed.

Acid Mine Drainage and Heavy Metal Pollution from Solid Waste in the Tongling Mines, China

Based on investigation of the characteristics of solid waste of two different mines, the Fenghuangshan copper mine and the Xinqiao pyrite mine in Tongling, Anhui province in central-east China, the possibility and the differences of acid mine drainage （AMD） of the railings and the waste rocks are discussed, and the modes of occurrence of heavy metal elements in the mine solid waste are also studied. The Fenghuangshan copper mine hardly produces AMD, whereas the Xinqiao pyrite mine does and there are also differences in the modes of occurrence of heavy metal elements in the railings. For the former, toxic heavy metals such as Cu, Pb, Zn, Cd, As and Hg exist mostly in the slag mode, as compared to the latter, where the deoxidization mode has a much higher content, indicating that large amounts minerals in the waste rocks have begun to oxidize at the earth surface. AMD is proved to promote the migration and spread of the heavy metals in mining waste rocks and lead to environmental pollution of the surroundings of the mine area.

Heavy metal pollution model of tailings and the pollution simulation by visualization

Based on the analysis of whole mining process in metal mines, it was pointed out that the investigation of the heavy metal pollution of tailings should be taken as an important project for a metal mine. Combined with the anlysis of the characteristics of tailings, it is found that the transformation of the heavy metal dissolution process, the heavy metal ions migration with groundwater and the heavy metal transport in porous media are three key aspects. Accordingly, the models of heavy metal pollution were established with providing boundary conditions. Depending upon a case of Ibnglushan Copper Mine railings and its relevant area from Google maps＇, a three-dimensional grid view of the tailings was set up. By application of Fluent software, the contaminated process of the heavy metal pollutants in the tailings was shown through digital visualization pattern.

Health Risks Assessment of Heavy Metal Pollution in the Soil-Crop System from an E-Waste Dismantling Area

Soil is an essential resource for agricultural production.In order to investigate the pollution situation of heavy metals in the soil-crop system in the e-waste dismantling area,the crop and soil samples(226 pairs,including leaf vegetables,solanaceous vegetables,root vegetables,and fruits)around the e-waste dismantling area in southeastern Zhejiang Province were collected.The concentrations of Cd,Cu,Pb,and Cr were determined.The average concentrations of Cd,Cu,Pb,and Cr in soils were 0.94,107.79,80.28,and 78.14 mg kg-1,respectively,and their corresponding concentrations in crops were 0.024,0.7,0.041,and 0.06 mg kg-1,respectively.The transfer capacity of leaf vegetables was significantly higher than that of non-leaf vegetables,and the accumulation of four heavy metals in crops tended to be Cd>Cu>Cr/Pb.The pollution index’s results revealed that the soil pollution degree under different land uses ranked as root vegetables soil>leaf vegetables soil>solanaceous vegetables soil>fruit soil.The carcinogenic and non-carcinogenic risks of heavy metal exposure were ranked as food intake>accidental ingestion>dermal contact>inhalation.The comprehensive non-carcinogenic risk was ranked as Cr>Cd>Pb/Cu.Our results could be used to provide useful information for further crop cultivation layout in the study area,which can guarantee the local residents’health and food safety.

Farmland Soil Heavy Metal Pollution and Control Measures

Soil pollution has been considered as one of the main environmental problems in the world nowadays. The source of soil heavy metal pollution in farmland, the effect of heavy metal pollution on soil quality in farmland, growth of crops, quality of agricultural products and the effects of heavy metal pollution on human health were discussed in this paper. The heavy metal pollution control measures were introduced, including physical and chemical regulations, phytoremediation and agroecological restoration measures. The future research perspective was also discussed in this paper.

Application of synthetic principal component analysis model to mine area farmland heavy metal pollution assessment

Referring to GB5618-1995 about heavy metal pollution,and using statistical analysis SPSS,the major pollutants of mine area farmland heavy metal pollution were identified by variable clustering analysis.Assessment and classification were done to the mine area farmland heavy metal pollution situation by synthetic principal components analysis (PCA).The results show that variable clustering analysis is efficient to identify the principal components of mine area farmland heavy metal pollution.Sort and clustering were done to the synthetic principal components scores of soil sample,which is given by synthetic principal components analysis.Data structure of soil heavy metal contaminations relationships and pollution level of different soil samples are discovered.The results of mine area farmland heavy metal pollution quality assessed and classified with synthetic component scores reflect the influence of both the major and compound heavy metal pol- lutants.Identification and assessment results of mine area farmland heavy metal pollution can provide reference and guide to propose control measures of mine area farmland heavy metal pollution and focus on the key treatment region.

The Prediction Model of Heavy Metal Pollution in the Xiangjiang River Based on Matlab

[Objective] The study aimed to establish a model to predict heavy metal pollution in the Xiangjiang River （from Zhuzhou to Changsha） on the basis of Matlab. [ Methodl According to the data of heavy metal content in the Xiangjiang River （from Zhuzhou to Changsha）, we estab- lished a non-linear regression model based on Matlab to forecast the content of C,d, Pb, Cu, Zn, As and Cr in the Xiangjiang River. E Result] Verifi- cation showed that the prediction models had a high precision, and the spatial variation of the predicted heavy metal content was basically consistent with the actual conditions, which indicated that these models could forecast the spatial variation of heavy metal content in the Xiangjiang River （ from Zhuzhou to Changsha） well. [ Conclusion] The research could provide theoretical bases for controlling the heavy metal pollution in the Xiangjiang River.

Metal pollution in relation to mass outbreaks of Dendrolimus punctatus Walker on Pinus massoniana Lamb.in China

Insects with their ecological superpower have enormous capacity to transform small pollution damage in forests to full scale calamities. Acid rain resulting from extensive coal burning is the chief pollutant in China. Acid rain activates from soil deposits toxic metals, which are transferred to trees and further to insects eating them. We studied the levels of the toxic Cd, its antagonists Zn and Cu, and acid rain indicators Fe and Mn in the forest pest moth Dendrolimus punctatus Walker (Lepidoptera:Lasiocampidae) in variously polluted Pinus massoniana Lamb forests in China.\; The highest density of D. punctatus , as well as the highest Cd levels developed in the moderately polluted forests. Possibly Cd had there broken down the pest resistance of the pines. The paradoxical coexistence of high Cd level and elevated population density of the pest seems to result from the high accumulation of Cd in its ichneumonid parasitoid. In the most heavily polluted forests the Cd level in needles was low, possibly because the strong acid rain had washed away most of the Cd deposit in the soil. It existed there no D.punctatus population. Absence of pest insects from the most heavily polluted areas is a common phenomenon.

Applied research of correspondence analysis method in waste tailings reservoir heavy metal pollution monitoring points optimization

In order to optimize monitoring points and monitoring factor, the relationshipbetween pollutants and soil sample were established by correspondence analysis.Thestudy results show that the reflecting monitoring points and monitoring factors in thegraphic on the same factor axis can clearly express the intrinsic link between pollutantsand monitoring points and distribution characteristics.To determine the main monitoringpoint and the main monitoring indicators can reduce and optimize the number of monitoringpoints under the premise of ensuring the typical and representative of monitoring data.Using the correlation of pollutants can reduce the number of monitoring indicators and improvethe effectiveness of data collection.

The assessment of heavy metal pollution in river sands of Jalingo,Nigeria using magnetic proxy parameters,pollution,and ecotoxicological indices

The measurement of environmental magnetic properties and metal contents of sands from Nukkai(NKR),Mayo-Gwoi(RMYG)and Lamurde(LR)rivers located in Jalingo,Nigeria are reported.We seek to determine the extent of anthropogenic impact on the river sands using magnetic-proxy-parameters,pollution and ecotoxicological indices and multivariate statistics.Measurements of magnetic susceptibilityχ,frequency-dependentsusceptibilityχfd%,anhystericremanent magnetization,isothernal remanent magnetization and X-ray fluorescence were undertaken.The average values of theχ(in×10^(-8)m^(3)kg^(-1))were 24.53,12.76 and 39.27 for NKR,RMYG and LR sites respectively,implying that the magnetic minerals in the sands were mostly ferrimagnetic.The meanχfd%value of 2.64%,4.85%and 3.53%for NKR,RMYG and LR respectively suggest that the study area was dominated by multi-domain magnetic grain sizes.The value of the S-ratio is~1 in all river samples,suggesting that low coercivity magnetic minerals(e.g.,magnetite)dominated the samples.The mean concentrations of Ti,Zr,Sn,Ba and Pb were higher than the background values in the studied samples.All the estimated pollution indices puts the level of pollution of the river sands between low and moderate pollution with Sn,Ba and Pb as the elements of concern.Multiple sources of metal contents such as fertilizers,pesticides,waste dumps and vehicular sources etc.were found.Significant positive correlations between magnetic parameters(particularly,SIRM)and some heavy metals and pollution/ecotoxicological indices were obtained,showing that magnetic methods could be used as a geochemical proxy for pollution assessment.

Systematic and long-term technical validity of toxicity determination and early warning of heavy metal pollution based on an automatic water-toxicity-determination-system

Water toxicity determination with electrochemically active bacteria(EAB)shows promise for providing early warnings for heavy metal pollution in water.However,thus far,only idealized tests with a few types of heavy metals have been conducted.In this study,an automatic water-toxicitydetermination system with high technical maturity was established,and the toxicological properties of common heavy metals were systematically assessed.The results demonstrated that the common heavy metals linearly inhibited EAB currents in the range of 0.1 mg/L to 0.5 mg/L.The toxicity ranking of the tested heavy metals was Pb^(2+)>Tl^(3+)>Cu^(2+)>Cd^(2+)>Zn^(2+)>Ni^(2+)>Hg^(2+)>As^(3+).The toxicity interaction mainly exhibited an antagonistic effect in binary heavy metal mixtures.The system can accurately determine surface water toxicity and rapidly monitor heavy metal pollution,with good repeatability and a long lifetime.Overall,this study demonstrates that EAB are capable of long-term(>60 d)surface water quality monitoring and on-site early warning of heavy metal pollution.

A practical method for identifying key factors in the distribution and formation of heavy metal pollution at a smelting site

Smelting activities are the main pathway for the anthropogenic release of heavy metals(HMs)into the soil-groundwater environment.It is vital to identify the factors affecting HMs pollution to better prevent and manage soil pollution.The present study conducted a comprehensive investigation of HMs in soil from a large abandoned Zn smelting site.An integrated approach was proposed to classify and quantify the factors affecting HMs pollution in the site.Besides,the quantitative relationship between hydrogeological characteristics,pollution transmission pathways,smelting activities and HMs pollutionwas established.Results showed that the soils were highly contaminated by HMs with a pollution index trend of As>Zn>Cd>Pb>Hg.In identifying the pollution hotspots,we conclude that the pollution hotspots of Pb,As,Cd,and Hg present a concentrated distribution pattern.Geo-detector method results showed that the dominant driving factors for HMs distribution and accumulation were the potential pollution source and soil permeability.Additionally,the main drivers are variable for different HMs,and the interaction among factors also enhanced soil HMs contamination.Our analysis illustrates how the confounding influences from complex environmental factors can be distilled to identify key factors in pollution formation to guide future remediation strategies.