Main Sources Of Heavy Metals Research Articles

Concentration, sources and human health risk of heavy metals and polycyclic aromatic hydrocarbons bound PM2.5 ambient air, Tehran, Iran.

The exposure to heavy metals and polycyclic aromatic hydrocarbons (PAHs) bound to particulate matter 2.5 (PM2.5) ambient air can result in some adverse health effect. In the current study, PM2.5 ambient air of Tehran metropolitan, Iran, was characterized by the aid of scanning electron microscope and energy-dispersive X-ray techniques. Also, the human health risk of heavy metals and PAHs bound PM2.5 for adults and children was assessed using the Monte Carlo simulation method. According to our findings, a size range of 0.97-2.46μm with an average diameter of 1.56μm for PM2.5 was noted. The average concentration of PM2.5 in ambient air (8.29E+04 ± 2.94E+04ngm-3) significantly (p < 0.05) was suppressed the national (2.50E+04ngm-3), World Health Organization (2.50E+04ngm-3) and Environmental Protection Agency (3.50E+04ngm-3) standard limits. The rank order of heavy metals bound PM2.5 was determined as Al > Cu > Cd > Cr > Pb > Ni > Fe > Mn. The maximum concentration among 16 PAHs compounds investigated was correlated with Phenanthrene. Considering the principal component analysis, the main source of heavy metals (Ni, Pb and Cr) is vehicle combustion. Moreover, the rank order of exposure pathways based on their health risk was ingestion > inhalation > dermal contact. Moreover, the significant health risks for Tehran residents due to heavy metals bound PM2.5 [target hazard quotient > 1; carcinogenic risk > 1.00E-06)] were noted based on the health risk assessment. Excessive carcinogenic risk (ECR) of PAHs bound PM2.5 was 4.16E-07 that demonstrated that there is no considerable risk (ECR < 1.00E-06).

Removal of heavy metals using kaolinite and Bentonite filter media

Heavy metals are among the most lethal pollutants of surface water. The main sources of heavy metals are industrial wastes from processes such as mining operations and ore processing, smelter, textile, leather dyeing, coating, metal finishing, chemical manufacturing, refineries, power generation and nuclear fuel processing. The concentration of heavy metals should be reduced to the acceptable levels before discharged into the environment because these are non degradable into nontoxic metals end products and the well known damaging effects of heavy metals on human being and other habitants. Sets of experiments were carried out to examine the ability of (kaolinite and bentonite) to reduce the concentration of chromium and cadmium ions in raw synthetic wastewater using upflow filter respectively. The main parameters were solution pH 2-6, retention time 12-72 hrs, the initial concentration of pollutants 100–500 ppm and filter media height 10.5-42 cm. All data were analyzed by regression analysis model to correlate the different boundary conditions. The highest achieved % removal efficiency of Cr and Cd were 96% and 91% through kaolinite and bentonite clay filter media at pH 6.0 and 5.0 respectively, retention time 24 hr, initial concentration 100 ppm and filter media height 42 cm. The results of regression models indicate that the most influential independent variables in the % removal efficiency of Cr and Cd ions from aqueous solutions using kaolinite and bentonite clay upflow filter pH, retention time and height media filter, which affects positively. Results of the experimental data show that the best empirical correlation achieved the highest fitting of predicted % removal of Cr and Cd using kaolinite and bentonite clay separately that gives the highest value of (R2 = 0.995 and 0.988)respectively.

Heavy metal quantification of classroom dust in school environment and its impacts on children health from Rawang (Malaysia).

This study aimed to determine bioavailable heavy metal concentrations (As, Cd, Co, Cu, Cr, Ni, Pb, Zn) and their potential sources in classroom dust collected from children's hand palms in Rawang (Malaysia). This study also aimed to determine the association between bioavailable heavy metal concentration in classroom dust and children's respiratory symptoms. Health risk assessment (HRA) was applied to evaluate health risks (non-carcinogenic and carcinogenic) due to heavy metals in classroom dust. The mean of bioavailable heavy metal concentrations in classroom dust found on children's hand palms was shown in the following order: Zn (1.25E + 01μg/g) > Cu (9.59E-01μg/g) > Ni (5.34E-01μg/g) > Cr (4.72E-02μg/g) > Co (2.34E-02μg/g) > As (1.77E-02μg/g) > Cd (9.60E-03μg/g) > Pb (5.00E-03μg/g). Hierarchical cluster analysis has clustered 17 sampling locations into three clusters, whereby cluster 1 (S3, S4, S6, S15) located in residential areas and near to roads exposed to vehicle emissions, cluster 2 (S10, S12, S9, S7) located near Rawang town and cluster 3 (S13, S16, S1, S2, S8, S14, S11, S17, S5) located near industrial, residential and plantation areas. Emissions from vehicles, plantations and industrial activities were found as the main sources of heavy metals in classroom dust in Rawang. There is no association found between bioavailable heavy metal concentrations and respiratory symptoms, except for Cu (OR = 0.03). Health risks (non-carcinogenic and carcinogenic risks) indicated that there are no potential non-carcinogenic and carcinogenic risks of heavy metals in classroom dust toward children health.

Multivariate linear regression model for source apportionment and health risk assessment of heavy metals from different environmental media

The study evaluated source apportionment of heavy metals in vegetable samples from the potential sources of fertilizer, water and soil samples collected along the Changjiang River delta in China. The results showed that 25.72% of vegetable samples (Brassica chinensis L.) containing Pb, and Cd, Cu, Hg and Zn at relatively serious levels were from soil. Combined with principle component analysis (PCA) and cluster analysis (CA), the results of the spatial distribution of heavy metals in different environmental media indicated that fertilizer, water and soil were the main sources of heavy metals in vegetables. The results of multivariate linear regression (MLR) using partition indexes (P) showed that fertilizer contributed to 38.5%, 40.56%, 46.01%, 53.34% and 65.25% of As, Cd, Cu, Pb and Zn contents in vegetables, respectively. In contrast, 44.58% of As, 32.57% of Hg and 32.83% of Pb in vegetables came from soil and 42.78% of Cd and 66.97% of Hg contents in vegetables came from the irrigation water. The results of PCA and CA verified that MLR using P was suitable for determining source apportionment in a vegetable. A health risk assessment was performed; As, Cd and Pb contributed to more than 75% of the total hazard quotient (THQ) values and total carcinogenic risk values (Risktotal) for adults and children through oral ingestion. More than 70% of the estimated THQ and Risktotal is contributed by water and fertilizer. Therefore, it is necessary to increase efforts in screening limits/levels of heavy metals in fertilizer and irrigation water and prioritize appropriate pollution management strategies.

Spatial Distributions, Pollution Assessment, and Qualified Source Apportionment of Soil Heavy Metals in a Typical Mineral Mining City in China

Daye is a city in China known for its rich mineral resources, with a history of metal mining and smelting that dates back more than 3000 years. To analyze the spatial distribution patterns, ecological risk, and sources of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn) in soils, 213 topsoil samples were collected in the main urban area of Daye in September 2016. The mean concentrations of Cd, Cu, Pb, and Zn were higher than the corresponding background values, with the mean concentration of Cd being almost seven times its background value. Spatially, the high concentrations of Cd, Mn, Pb, and Zn were mainly concentrated in the southeastern part of the region due to nonferrous metal mining and smelting. However, the high concentrations of Co and Cu were concentrated in the central part of the study area, resulted from copper mining and smelting. The data of the geoaccumulation index showed that the contamination levels ranged from no pollution (Co, Cr, Mn, and Ni) to heavy contamination (Cd, Cu, and Pb). Ecological risk assessment showed that Cd posed a high, serious, and even severe ecological risk in 53.78% of the area of Daye. According to the results of the principal component analysis, mineral exploitation and smelting involving a variety of minerals (ES_M), mining exploitation, and smelting of copper ore (ES_C), and natural sources are the three main sources of heavy metals in these soils. Furthermore, the absolute principal component scores showed that 69.21% and 23.17% of the heavy metal concentrations were ascribed to ES_M and ES_C, respectively.

Analysis of Historical Sources of Heavy Metals in Lake Taihu Based on the Positive Matrix Factorization Model.

Analysis of sediment grain sizes and heavy metal correlations in the western part of Lake Taihu shows that the grain size of the sediment is stable as a whole. With increasing depth, the grain size tends to decrease. Heavy metals such as Cr, Cd, Pd and Sr are strongly correlated and influence each other. Based on the positive matrix factorization (PMF) model, this study classified the origin of heavy metals in the sediments of western Lake Taihu into three major categories: Agricultural, industrial and geogenic. The contributions of the three heavy metal sources in each sample were analyzed and calculated. Overall, prior to the Chinese economic reform, the study area mainly practiced agriculture. The sources of heavy metals in the sediments were mostly of agricultural and geogenic origin, and remained relatively stable with contribution rates of 44.07 ± 11.84% (n = 30) and 35.67 ± 11.70% (n = 30), respectively. After the reform and opening up of China, as the economy experienced rapid development, industry and agriculture became the main sources of heavy metals in sediments, accounting for 56.99 ± 15.73% (n = 15) and 31.22 ± 14.31% (n = 15), respectively. The PMF model is convenient and efficient, and a good method to determine the origin of heavy metals in sediments.

One-century sedimentary record of heavy metal pollution in western Taihu Lake, China

Long-term trends of sediment compositions are important for assessing the impact of human activities on the sediment and protecting the sediment environment. In this study, based on the contents of heavy metals and the Pb isotope ratios in lake sediments, atmospheric dustfall and soil in Yixing, China, the representative heavy metals (Zn, Pb, Cr and Cd) in lake sediments from western Taihu Lake were studied. The evolution history of heavy metals in the local environment was constructed for the past 100 years. From 1892 to the 1990s, the anthropogenic fluxes of the representative heavy metals were negligible, indicating minimal anthropogenic emissions of heavy metals. Since the 1990s, anthropogenic fluxes of the representative heavy metals began to increase, concurrent with the economic growth and development in the western Taihu Lake Basin after the Chinese economic reform. The maximum flux percentage of the heavy metals in the sediments, caused by human activities, is 23.0% for Zn, 31.6% for Pb, 39.5% for Cr and 85.3% for Cd, indicating that most of the Cd comes from human activities. The Cd content in the western Taihu Lake Basin was significantly higher than that in the other areas, and the rapid development of the industry in the western Taihu Lake Basin and ceramics in Yixing led to the enrichment of heavy metals in local sediments. Since the 21st century, measures have been taken to control the pollution of heavy metals, including the increase in local government attention and the deployment of environmental monitoring technology. However, heavy metal content remains high, and the Pb content is still increasing. The ratios of Pb isotopes show that the main sources of heavy metals in the western Taihu Lake sediments, the local soil of Yixing and the atmospheric dustfall are coal combustion, leaded gasoline combustion, industrial wastewater and domestic sewage.

Effect of site on sedimentological characteristics and metal pollution in two semi-enclosed embayments of great freshwater reservoir: Lake Nasser, Egypt

This study was carried out to assess the effect of site on the spatial variations of sedimentological characteristics and heavy metal pollution of two semi-enclosed embayments of Lake Nasser. Grain Size, texture and mode of transportation as well as some heavy metals and organic matter were assessed in sediment samples from those embayments. The results indicated that the grain size of the lake sediments was affected by site variation. Moreover, heavy metal distribution in the sediments was mainly directed by grain size distribution and organic matter, though, the organic matter was more critical than grain size in controlling heavy metals distribution in each embayment. The main source of heavy metals in studied embayments was concluded to be the metals brought with flood waters rather than being of anthropogenic origin. The results also indicated the association of studied metals with Fe and Mn oxides of suspended matters and dissolved solids which come with flood water and trapped and settled to the bottom sediment in the stagnation period. Measured indices indicated that southern embayment is more polluted than northern one, which could be explained on the basis that the southern embayment reserves larger amounts of suspended matter coming with the flood than northern embayment.

Heavy Metals on Technogenic Objects of Mining and Processing Enterprises of the Kryvyi Rig Basin

The goal of the paper is to determine and explain the patterns of distribution of heavy metals in the territories of ore mining and processing enterprises in Kryvyi Rig and to substantiate the legitimacy of applying the method of semiquantitative atomic emission spectral analysis in such studies. Methodology. In the course of the study, various methods of spectral analysis (semiquantitative atomic emission and atomic absorption using 0.5 M HCl and 2 M HNO3) were used in the analysis of soil contamination, and their comparison was made. Results. The content and distribution of heavy metals in soils at the sites of mining and processing enterprises depends primarily on the share of different sedimentary material in them. These are: material of the weathering crust of granites and rocks of greenstone belts of the Middle Dnieper, as well as rocks of the Kryvyi Rig series; products of iron ore beneficiation at mining and processing enterprises and sediments formed during discharge of highly mineralized mine and industrial waters of enterprises; material of slags and smokes of metallurgical enterprises, introduced by the wind; products of domestic waste treatment. The main sources of heavy metals in the soils of the Kryvyi Rig are slags and smokes of metallurgical enterprises. Such a source cannot be the sludge of processing enterprises because of the low content of impurity elements in iron banded formations, including heavy metals. When heavy metals fall onto the soil, their redistribution occurs under the influence of wind and atmospheric precipitation, with the transfer and accumulation of clay-scale particles, the main concentrators of heavy metals, into the lower places of the relief. In general, this leads to the dispersion of heavy metals in soils. Scientific novelty. The factors of geochemical migration of heavy metals within the local geochemical arenas of ore mining and processing enterprises are determined. Practical significance. The educed conformities to law of migration of heavy metals open possibility of more exact prognosis of their distribution in soils on the objects of mining and processing enterprises.

СОРБЦИОННЫЕ СВОЙСТВ ЦЕОЛИТА ХОТЫНЕЦКОГО МЕСТОРОЖДЕНИЯ И ПЕРСПЕКТИВЫ ЕГО ПРИМЕНЕНИЯ КАК ЭНТЕРОСОРБЕНТА

This work is aimed at investigating the sorption properties of Zeolite in the Khotynetsky deposits. A syste-matic study was conducted to examine the sorption properties of the natural Zeolite mined in the Khotynetsky deposits towards a number of toxic subtances: heavy metals (Hg, Pb, As, Cd, Zn, Ni), antibiotics (tetracycline, doxycycline, levomycetin and penicillin) and polycyclic aromatic hydrocarbons (benzo(a)pyrene). Water and food are the main sources of heavy metals in the body. Benzo(a)pyrene is known to be a highly toxic carcinogen belonging to the class of polycyclic aromatic hydrocarbons. This substance exhibits mutagenic, embryotoxic and hematotoxic effects, thus contributing to the development of malignant tumors. For all the studied toxicants, we have determined the effect of medium acidity and sorption time on the substance extraction, the sorption capacity of Zeolite and respective sorption isotherms. A relationship between the destruction of the Zeolite structure and its sorption properties is presented, taking into account the acidity of the medium. The data obtained are of practical interest and can be used for the development of recommendations concerning the application of Zeolite from the Khotynetsky deposits as an enterosorbent. Such recommendations can facilitate the development of diet optimization models in terms of the amount and combination of pharmaceutical biologically active substances.

Characteristics and Sources of Heavy Metals in PM2.5 during a Typical Haze Episode in Rural and Urban Areas in Taiyuan, China

PM2.5 samples were collected in the rural and urban areas of Taiyuan, China during a typical haze episode and the heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd and Pb) in PM2.5 were analyzed. The haze was characterized by start-up stage with a daily mean PM2.5 of 149.34 ± 52.33 and 146.73 ± 18.96 μg m−3 in the rural and urban sites, respectively, a peak stage (288.20 ± 12.43 and 323.44 ± 5.23 μg m−3), and a weakening stage (226.59 ± 12.43 and 195.60 ± 2.93 μg m−3). The concentrations of PM2.5 in the rural and urban sites in the peak stage were 5.9 and 5.5 times higher than those in the normal stage, respectively. The order of concentrations of heavy metals in PM2.5 at the rural and urban sites were the same and are listed as follows: Zn &gt; Pb &gt; Mn &gt; Cr &gt; Cu &gt; Ni &gt; Cd &gt; As. Pb at the rural site, As at the urban site, and Cd at the both sites failed to meet the air quality standard. The concentrations of Pb and Zn were higher at the rural site than those at the urban site. Principal component analysis indicated that the main sources of heavy metals for the rural area were raw coal combustion and soil/road dust, and for the urban area were coal combustion/industrial emissions, road/soil dust, and vehicle emissions/oil combustion.

Atmospheric heavy metal deposition in agro-ecosystems in China

Atmospheric deposition has become one of the main sources of heavy metals in crops in developed and industrial zones in China for the past several years. However, lack of data of the agro-ecosystems on the vast areas of China makes it difficult to assess the impacts of air pollution on the heavy metal accumulation in crops. In this study, with deposit samples from 67 sites located at different agro-ecosystems (typical, factory nearby, town nearby, roadside, and remote) of four natural regions [Huanghuai (HH), Southeast (SE), Southwest (SW) and upper-mid Yangzi River (Up-mid YR)], atmospheric heavy metal deposition in agro-ecosystems on a large scale in China was studied. The results showed that during the growing season, the deposition fluxes of Cr, Ni, As, Cd, and Pb in typical agro-ecosystems were 0.60-36.86, 0.65-25.37, 0.05-8.88, 0.12-5.81, and 0.43-35.63μgm-2day-1, respectively, which varied greatly between the four different regions. The average deposition fluxes of Cr, Ni, Cd, and Pb in the HH region, as well as the fluxes of As in the SW region, were significantly higher than those in the SE region. Heavy metal deposition rates among agro-ecosystems were very similar, except for the sites around cement factory in flat HH region. In mountainous SW region, however, deposition rates varied widely with sites nearby towns relatively higher and remote regions much lower. Higher correlation coefficients were observed between Cr, As, Pb, and Ni deposition rates, suggesting that they had similar sources. Samples from the SW and SE regions exhibited higher 207Pb/206Pb and 208Pb/206Pb ratios than those from the HH and Up-mid YR regions. Airborne Pb in SW agro-ecosystems were mainly derived from vehicle exhaust and local smelting, whereas that in the HH region from burning of northern Chinese coal.

Biogenic and contaminant heavy metal pollution in Estonian coniferous forests

Estonia is the only country in Europe that is actively mining oil shale. Oil-shale-burning power plants have been and still are the main sources of heavy metals in Estonia. In order to establish how coniferous ecosystems are affected by Zn, Cu, Cr, Ni, Cd and Pb, heavy metal content in current-year and older needles, in litterfall needles and litterfall miscellaneous fraction, in fine roots and in soil organic horizons was analysed at six coniferous stands of ICP Forests and ICP Integrated Monitoring networks. Root uptake, translocation and accumulation indexes were calculated for each heavy metal. The highest concentrations of most of the heavy metals were found in the soil organic horizons, with the exception of Zn and Cu, the highest concentrations of which were found in fine roots. The results showed that concentrations of the rest of the heavy metals (Cr, Ni, Cd and Pb) were also higher in fine roots compared to other plant material. Significant correlations between the concentrations in soil organic horizons and fine roots indicated that heavy metals had accumulated in the soil organic horizon over time and, in some cases, they may have been transported to above-ground living biomass of coniferous trees.

Magnetic Nano mineral and acid mine drainage interaction: An experimental study

In the environment, two main sources of heavy metals are natural backgrounds derived from parent rocks and anthropogenic contamination including mineral industrial wastes, tailing damps of sulfide mines, agrochemicals, and other outputs of industrial activities and factories. In this work, the physico-chemical aspects of the magnetic Nano- mineral surfaces are studied in contrast to acid mine drainage using the multi- -analytical techniques XRF, XRD, BET, SEM, TEM, FT-IR, and AFM before and after adsorption of toxic elements. According to the results obtained, the FT-IR analysis presents a suitable curve, showing that the adsorption site of the sorption is filled with Ni(II) and Cd(II) ions. The results obtained show that the adsorption reaction is due to the high removal of the toxic elements from acid mine drainages.

Assessment of Heavy Metal Pollution and Tracing Sources by Pb & Sr Isotope in the Soil Profile of Woodland in Quanzhou

The contents of 8 heavy metal elements (Sr, Ni, Fe, Cr, Cu, Mn, Pb, Zn) and the lead & strontium isotope composition of soil profile of woodland in Quanzhou city were analyzed by AAS and ICP-MS, respectively. A modified BCR four-step sequential extraction procedure was carried out to obtain the speciation fractionation of heavy metals in the soil profile from 4 stations. The results of the heavy metal elements and the speciation fractionation of heavy metals in the soil profile showed that the heavy metal pollution in the woodland in Quanzhou was relatively light, and the main pollution factor was Sr. The non-residue state of Pb was the highest, leading to the highest activity. The result of Nemero comprehensive pollution index showed that Sr in the depth of 0-60 cm was at heavy pollution level. The results of the RSP showed that the activity of Pb was the highest. The results of EF showed that Pb, Sr, Mn and Zn had exogenous sources. Factor analysis showed that the main sources of heavy metals were the compound pollution of agricultural activities, natural resources, and the vehicle exhaust. Composition of Pb isotopic ratios showed that, Pb in soil profile of woodland in Quanzhou was from vehicle exhaust and parent material. The contribution rates of the two sources in the soil profile were calculated by using the two-mixed model. The contribution rates of parent material and vehicle exhaust were 85.14%(62.53%-98.36%) and 14.86%(1.640%-37.47%) on average, respectively. Strontium isotope tracing results showed that the main sources of strontium were also vehicle exhaust and parent material. Coupling both Pb and Sr isotope ratios agreed with the above mentioned results.

Heavy metals contamination and assessment in gas station dust of Xi’an, a mega-city of China

The dust samples from 30 gas stations located in Xi’an are analyzed for Mn, Ni, Co, Cr, Cu, Cd, Pb and Zn by using atomic absorption spectrometry. The concentration, spatial distribution, source and the contamination levels provide scientific basis for urban planning and environmental renovation in Xi’an. The results indicate that the mean values of Ni, Cr, Co, Cu, Pb, Zn and Cd in the dust are 1.15, 1.19, 8.13, 3.94, 4.42, 5.09 and 15.62 times higher than the corresponding background values of Shaanxi soil, respectively. The high concentration of heavy metals is located in the inner and second ring road of Xi’an, China. Furthermore, the contents of metals in the south are higher than in the north. In addition, the concentrations of the gas station dust metals in the west are higher than in the east, particularly in the southwest. Three main sources of heavy metals of gas station dusts are identified in Xi’an. Mn and Ni mainly originate from a natural source; Cr, Cu, Pb, Cr and Zn mainly originate from traffic flow; and Co is mainly from industrial sources. The results of the potential ecological risk assessment indicate that the potential ecological risk index (RI) of Co is moderate; Cd is very high ecological risk, and the other analyzed metals belong to low ecological risk. The mean RI value of eight heavy metals in the gas station dusts from Xi’an is considerable ecological risk.

The Effect of Colorants on the Content of Heavy Metals in Recycled Corrugated Board Papers

Recycled paper is an important raw material to provide sustainability of natural resources and reduce the environmental impact of the use of paper from recycled pulp in the packaging industry. Hence, recycled paper production is higher in terms of volume and utilization. Recycled paper products are used in the packaging industry partially or fully. Such usage leads to the presence of heavy metals due to recycled and chemical additive sources. The present study aims at determining the amounts and also identifying the sources of heavy metals such as Pb, Cd, Zn, Ni, and Cu contained in recycled testliner (TL) and fluting (FLT), which are main products used in production of corrugated cardboard. The metals in the structure of the paper used in packages directly or indirectly in contact with foods are heavy metals. Mean values of 2.6 mg kg-1 Pb (lead), 2.8 mg kg-1 Zn (zinc), 0.094 mg kg-1 Cd (cadmium), 1.8 mg kg-1 Ni (nickel), and 25.4 mg kg-1 Cu (copper) were detected in test liner and fluting papers using inductively coupled plasma optical emission spectrometry (ICP-OES). The main sources of heavy metals are colorants, mainly consisting of conventional paint and pigments as well as spot and Pantone Matching System (PMS) colorants.

重金属污染土壤的生物修复技术研究进展

土壤重金属污染的生物修复作为治理环境污染的重要手段之一，是建立环境友好型社会不可或缺的一部分。本文首先介绍了土壤中重金属污染的主要来源以及重金属对土壤肥力、土壤微生物和酶活性及人类健康的影响；其次比较详细地综述了重金属污染土壤的生物修复技术，包括植物修复技术、微生物修复技术及二者联合修复等；最后提出了现阶段修复技术的不足，并对该领域今后的发展进行了展望。 Bioremediation of soil heavy metals contamination, as one of the important means to control environmental pollution, is an integral part to establish the environmentally friendly society. This article firstly introduces the main sources of heavy metals in soil and the influence of heavy metals on soil fertility, soil microorganism and enzyme activity and human health. What’s more, it also summarizes the bioremediation of heavy metals contaminated soil in detail, including phytoremediation, microbial remediation and their combined repair technology. Finally, this article proposes the lake of repairing technology at present stage and the future development in this field.

Закономірності розподілу важких металів в об'єктах навколишнього середовища м. Суми

Results of the ecological and geochemical investigation of soils, vegetation and water resources of Sumy city environment are considered in this paper. The aim of scientific investigation is definition of the main peculiarities of heavy metals distribution in some environmental objects (soils, vegetation and water resources) of Sumy city. Special attention was payed to investigation of regularities of heavy metals distribution in “Sumyteploenergo Ltd.” affected area. Concentration of chemical elements in samples was determined by classical geochemical and modern methods on mass spectrometer with inductively coupled plasma (ICP-MS) in the M.P. Semenenko Institute of geochemistry, mineralogy and ore formation of the National Academy of sciences of Ukraine. Based on an analysis of the total indicator of pollution were defined that the level of soil’s pollution in the central part of the city is lower then average values. They have following association - Pb (3,4) > Cr (2,9) > Cu (2,2) > Ni (2,1) > Co (1,8). Soils in the “Sumyteploenergo Ltd.” main building affected area are characterized by middle (moderately hazardous) level of pollution, but soils near slurry tanks have high (hazardous) level of pollution with heavy metals. Also the technogenic geochemical associations of heavy metals were defined, and the main sources of pollution, which determine toxic elements accumulation in the components of environment, were investigated. Activity of “Sumyteploenergo Ltd.” during many years led to changes in natural distribution of heavy metals in all investigated objects of environment. In technogenically polluted areas (territory of “Sumyteploenergo Ltd.”) the concentration of heavy metals in ash of Elytrigia repens (L.) Nevski increases significantly compared with the natural values. In surface water of Psel river in “Sumyteploenergo Ltd.” affected area the content of Cu, Zn, Mn, Ni, Cr, V is much higher then in outside water objects. This investigation proves that the processes of metamorphism of the surface waters horizons in the affected area of “Sumyteploenergo Ltd.” slurry tanks took place. Analysis of tailings showed that they are characterized by high concentration of many chemical elements, especially high values are typical for V, Cr, Cu, Pb and Zn. As the result of geochemical investigations were defined that high concentration of these elements are specific for soils and surface water in the affected area of “Sumyteploenergo Ltd”. Conclusions and their analysis of this investigation give the main representation of peculiarities of heavy metals pollution in different industrial areas of urban territory. In the study area some industrial zones were defined, which are characterized by special chemical elements pollution and peculiarities of their distribution. Investigation of environmental objects showed the strong relations between specializing of industrial production and defined geochemical associations of chemical elements and their distribution. This important not only for determination the main sources of heavy metals, but for environmental protection activities. Investigation of heavy metals distribution peculiarities in soils, vegetation and surface waters gives abilities for determination anomalous fields and making prognosis of ecological risks.

Heavy metal deposition through rainfall in Chinese natural terrestrial ecosystems: Evidences from national-scale network monitoring

Industrialization and urbanization have led to increasingly serious levels of atmospheric heavy metal pollution, which is one of the main sources of heavy metals to terrestrial ecosystems. Therefore, it is essential to quantify atmospheric fluxes and explore their potential effects on natural ecosystems and human welfare. We monitored water-soluble heavy metals (lead (Pb), cadmium (Cd), and chromium (Cr)) in rainfalls on a monthly basis in 2013 and 2014, at 31 field stations located in typical natural Chinese ecosystems. The average soluble Pb, Cd, and Cr deposition was 1.90 ± 1.54, 0.28 ± 0.25, and 0.96 ± 0.48 mg m−2 yr−1, respectively, with a large variation among the different sites. Generally, the atmospheric deposition of soluble Pb, Cd, and Cr was higher in the southwest, central, south, and north China than in the northwest and northeast China, Inner Mongolia, and Qinghai-Tibet. As expected, the atmospheric heavy soluble metal deposition fluxes were significantly correlated with the number of vehicles (Ps < 0.1). The wet deposition of soluble Pb and Cr was positively correlated with oil and coal consumption, unlike Cd deposition. Moreover, soluble Pb and Cd in atmospheric wet deposition were positively correlated with the contents of Pb and Cd in soil at different regions. In this study, atmospheric heavy metal deposition through rainfall in typical natural ecosystems in China is assessed at the national scale, alerting potential ecological hazards resulting from an increasing atmospheric heavy metal deposition and providing a basis for future studies.