Study Of Heavy Metal Pollution Research Articles

Evaluation and Study of Pollution in The Elements in The Baiji Refinery After the Recent Terrorist Operations

The research is about the evaluation and study of heavy metal pollution in Baiji refinery after the recent terrorist operations. The samples were examined with an atomic absorption spectrometer (Atomic Absorption Spectrometer) model Shimadzu (AA6200) working with acetylene gas - in the laboratory of mechanical analysis - chemical engineering - Tikrit University, where the concentrations of heavy elements ranged (cadmium ≥ 4 mg/kg), nickel (16.8) - (4 mg/kg), copper (1.4-268.1) (mg/kg), zinc (21.6-554.8 mg/kg) and lead. (165.2 -2 mg/kg) (cobalt is less than (2 mg/kg), where the values ​​of the pollution coefficient showed the presence of a low pollution coefficient in most areas and most of the elements, while there was (a very high pollution coefficient of zinc in the area of ​​​​the loading arms, pumping and storage of fats Hydrogenation of fats, and less pollution of zinc (i.e., a significant pollution coefficient of zinc in the dewaxing division area), while the lead element was there (a very high pollution coefficient in the desalination of gases and northern refining), while for the copper element, there was significant pollution in the hydrogenation of fats. The results of laboratory tests have indicated that the values ​​of some of the heavy elements taken within this study were outside the permissible limits when compared with the approved determinants for zinc, copper, cobalt, and lead.

A Comparative Study of Heavy Metal Pollution in Ambient Air and the Health Risks Assessment in Industrial, Urban and Semi-Urban Areas of West Bengal, India: An Evaluation of Carcinogenic, Non-Carcinogenic, and Additional Lifetime Cancer Cases

Air pollution is an immense problem due to its detrimental health effects on human populations. This study investigates the distribution of particle-bound heavy metals and associated health risks in three diverse areas (Durgapur as an industrial complex, Kolkata as an urban area, and Bolpur as a semi-urban region) in West Bengal, India. Twenty-one (84 samples) sampling sites were chosen, covering industrial, traffic, residential, and sensitive zones. The respirable suspended particulate matter (RSPM) samples were collected using a portable Mini-Vol Tactical Air Sampler, and heavy metal concentrations (Cd, Cr, Mn, Ni, Pb, and As) were analyzed using ICP-OES. The non-carcinogenic and carcinogenic health risks were assessed using exposure concentration (EC), hazard quotient (HQ), hazard index (HI), and additional lifetime cancer cases. The results highlight variations in heavy metal concentrations across the regions, with industrial areas exhibiting higher levels. Principal component analysis (PCA) unveiled distinct metal co-variation patterns, reflecting sources such as industrial emissions, traffic, and natural contributors. The sum of non-carcinogenic risks (HI) of all heavy metals exceeded the US EPA’s risk limit (HI<1) in both Kolkata and Durgapur, except for Bolpur. Similarly, the sum of cancer risk in three distinct areas exceeded the USEPA limits (1.00E-06). The Monte Carlo simulation revealed the 5th and 95th percentile range of cancer risk was 9.12E-06 to 1.12E-05 in Bolpur, 3.72E-05 to 4.49E-05 in Durgapur and 2.13E-05 to 2.57E-05 in Kolkata. Kolkata had the highest additional lifetime cancer cases compared to Bolpur and Durgapur. This study provides information on the complex connections between heavy metal pollution and possible health risks in industrial, urban, and semi-urban regions.

Analysis of the content of heavy metal ions in the coastal zones of the northern part of the Apsheron peninsula

The article is devoted to studies of heavy metal pollution of the soil cover of the coastal zones of the northern part of the Apsheron Peninsula. Pollution of the coastal zones of the Caspian Sea, serving to a greater extent as a recreational area for the population, by toxic substances is of great concern and to solve this problem, periodic studies of these zones for the presence of heavy metals are necessary. For the first time, a comparative analysis of the content of heavy metals in different areas (Buzovna, Sumgait, Novkhany) of the northern part of the Apsheron peninsula was carried out and the presumable causes of their accumulation were outlined. The researched soils in the northwestern and northeastern part of the peninsula were grouped according to the degree of concentration of heavy metals depending on the depth of the researched soils. Zinc (77.0 mg/kg, at 0–16 cm depth, transect № 03), copper, and cadmium (88 mg/kg and 0.36 mg/kg at 0–20 cm depth, transect № 05) had the highest concentrations relative to other trace elements. Concentrations of zinc and copper in the northwestern direction of the peninsula increase by 1.5 and 3–3.5 times, respectively, as compared with the generally accepted norms. Average content of heavy metals, especially Ni, Cd, Pb in flooded soils at the depth of 0–100 cm increased 2.7 times on average as a result of coastal flooding by waters of Caspian Sea. The value of total heavy metals reaches a maximum in the northwestern direction.

Distribution and ecological risk assessment of heavy metals in sediments of Dajiuhu Lake Wetland in Shennongjia, China.

The rapid development of modern society has resulted in discharge of large, heavy metal quantities into wetlands that have been continuously accumulating, causing severe pollution. Dajiuhu, located in the Shennongjia Forest District of Hubei Province in China, is a wetland of significant value internationally, serving as a model wetland ecosystem with heightened scientific research value. In this study, 27 surface sediment samples from nine sub-lakes in Dajiuhu were collected in August 2020. The concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in the sediments were determined. The heavy metal occurrence and speciation characteristics were analyzed by an improved BCR (European Community Bureau of Reference) extraction method. Four methods were used to evaluate heavy metals' pollution degree and ecological risk. The possible source of heavy metals was inferred using correlation analysis and principal component analysis. The heavy metal content in the lake sediments of Dajiuhu wetland was from the highest to the lowest concentration as follows: Zn [Formula: see text] Cr [Formula: see text] Ni [Formula: see text] Pb [Formula: see text] Cu [Formula: see text] Cd. The average Cd content exceeded the national nature reserve threshold values, while the other heavy metals measured were below their respective threshold values. However, due to the occurrence of Pb and Cd in different forms, they still pose certain pollution and ecological risk to the lake wetlands. On the other hand, Zn, Cr, Ni, and Cu do not pose an ecological risk in the lakes of the Dajiuhu wetland. The spatial distribution of heavy metal content in the nine sub-lakes did vary significantly. Regarding the heavy metal sources in the lake sediments, Ni, Cr, and Cu originate from natural factors, and Cd and Pb have mainly anthropogenic origins. In contrast, Zn has both natural and anthropogenic origins. This study provides further insights into the study of heavy metal pollution in lake wetlands. It provides a framework and a direction for managing heavy metal pollution in the Dajiuhu wetland.

Development of Monitoring System for Heavy Metal Pollution in Sea Water of Mangrove Wetland in Leizhou Peninsula

Mangrove is a wetland ecosystem with high productivity in tropical and subtropical regions, which is of great significance for maintaining ecological diversity and protecting wetlands. With the rapid development of urbanization and industrialization, human activities such as the use of agricultural fertilizers and pollutant discharge have brought a series of problems. A large number of heavy metal pollutants enter rivers, lakes, seas and soils in different ways, bringing heavy pressure to the restoration of the ecological environment. Leizhou Peninsula Mangrove Nature Reserve, as one of the largest nature reserves in Chinese Mainland, is highly valued. Aiming at the study of heavy metal pollution in Leizhou Peninsula mangrove wetland, this paper proposes a monitoring system for heavy metal pollution in seawater of mangrove wetland. Wireless packet switching technology based on Global System for Mobile Communications (GSM) system, which provides end-to-end and wide area wireless IP connection. The main function modules of the system include: data input, real-time display of monitoring data, data query, data statistics and analysis, decision-making and early warning, early warning information release, etc. Through this technology, real-time monitoring of heavy metal pollution in sea water of mangroves in Leizhou Peninsula can be realized, which can effectively solve the problem of mangrove protection and maintain the ecological environment.

Spatial distribution and sources of heavy metals in the sediment and soils of the Yancheng coastal ecosystem and associated ecological risks.

Studies of heavy metal pollution are essential for the protection of coastal environments. In this study, positive matrix factorization (PMF) and a GeoDetector model were used to evaluate the sources of heavy metal contamination and associated ecological risks along the Yancheng Coastal Wetland. The distribution of heavy metals was shown to be greatly affected by clay content, except for Cr in shoal. Components from 6.5 to 9φ have the strongest ability to absorb heavy metals, where the effects of Cd and Zn sequestration in the wetlands were most apparent. The abilities of various wetland environments to sequester heavy metals were shown to be Spartina alterniflora wetland > woodland > Phragmites australis wetland > aquaculture pond > shoal > paddy > meadow > dry land. The sources of the heavy metals included parent soil material (59%), agriculture (15%), and industrial pollutants (26%). According to the single-factor pollution index, there was no evidence of pollution except Cr and Pb. In general, the heavy metal pollution was insignificant. The order of pollution loading index was shoal > paddy field > dry land > Spartina Alterniflora wetland > aquaculture ponds > woodland > meadow > Phragmites australis wetland. The ecological harm of heavy metal exposure was slight except for Cd and Hg, where vehicle emissions appeared to be the main cause of heavy metal pollution.

Comprehensive study of heavy metal pollution in surface water of Guntur region of Andra Pradesh

The Water pollution is known of as the apperence of undesirable elements that are introduced into a natural water supply by human activity, changing its physical, chemical, or biological properties. The present study was conducted in the Guntur region of Andra Pradesh. The surface water samples were assembled from ten sample stations and analyzed for their heavy metal content by atomic absorption spectrometer (AAS). The acquired values were also compared to permissible limits. Magnesium and lead were detected in the surface water collected from all 10 sample stations. However, June 2019 surface water collection showed significantly (p<0.001) amount of magnesium as compared to other seasons collections. Sample stations 2, 6, 7 and 8 showed maximum concentration (>0.2ppm) of lead during December 17, June 18, June 19 and June 18, respectively. Selenium was detected in the surface water collected during four intervals from all sample stations except sample station 7. Arsenic was detected in the surface water collected from sample stations 1, 2, 3, 5, 6, 8 and 9. However, maximum concentration of both the elements was detected in the surface water collected from sample station 3 as compared to remaining sample stations. The Bandarupalle sample station showed presence of copper, nickel, chromium, iron, manganese, cadmium, mercury and molybdenum. The Tadikonda sample station showed copper, nickel, chromium, zinc, iron, and mercury. Mangalagiri and Mutluru sample station showed copper, cobalt, nickel, chromium, zinc, iron, manganese, cadmium, mercury and molybdenum in surface water which were found to be maximum polluted stations. The Chebrolu showed presence of all above elements except manganese. The Rompicherla and Guntur sample station surface water showed presence of all the above mentioned elements except copper and cadmium. Pedda Vadlapudi surface water detected nickel, chromium, zinc, iron, manganese, cadmium, and mercury. The Macherla showed presence of nickel, chromium, iron, cadmium, mercury and molybdenum. Acharya Nagarjuna University showed cobalt, nickel, chromium, iron, manganese, cadmium, and molybdenum in the surface water. Lead, arsenic, selenium, chromium and mercury were found to be above permissible limits in the surface water.

Evaluation and Source Analysis of Heavy Metal Pollution in Sediments of the Yellow River Basin Based on Monte Carlo Simulation and PMF Model

As sediment is an essential component of rivers, the enrichment of heavy metals in sediment presents a serious threat to the aquatic environment. Many industrial cities are located along the Yellow River, and heavy metal pollution is a prominent problem in these areas. Thus, the study of heavy metal pollution in sediments of the Yellow River basin is of vital significance to the safety of the Yellow River basin ecosystem. In this study, we collected data on the concentrations of heavy metals (Pb, Cd, Cr, As, Zn, Cu, Ni, and Hg) in the sediments of the Yellow River basin from 2000 to 2020. We first analyzed the spatial distribution characteristics of heavy metals based on descriptive statistics and geostatistics and then used the Monte Carlo method to evaluate the probability of the ground accumulation index(Igeo), potential ecological risk, and toxicity units. Finally, the number of pollution sources and their contribution rates were determined by combining the positive definite matrix factor (PMF) decomposition model and Pearson correlation analysis. It was found that the mean values of ω(Pb), ω(As), ω(Zn), ω(Ni), ω(Cu), ω(Hg), ω(Cr), and ω(Cd) in the Yellow River basin sediments were 26.92, 11.78, 87.17, 31.13, 24.96, 0.07, 73.36, and 0.58 mg·kg-1, which exceeded the mean soil background values in the Yellow River basin provinces by 1.27, 1.08, 1.26, 1.05, 1.09, 2.32, 1.14, and 5.95 times, respectively, among which Cd exceeded the standard by the largest factor and should be taken seriously. The Igeo was ranked as Cd>Hg>Cr>Cu>Pb>Zn>As>Ni, and Cd and Hg showed medium-severe pollution. The proportions of heavy ecological risk in sediments in the upper, middle, and lower reaches of the Yellow River basin were 18.6%, 15.7%, and 7.1%, respectively, with a decreasing trend. Heavy metals in the sediments of the Yellow River basin were in a low-toxicity state. The PMF-Pearson correlation analysis showed that the four sources of heavy metals in the Yellow River basin sediments were mining sources (42.2%), natural activities (38.3%), agricultural activities (11.6%), and electroplating wastewater (7.9%). The results of this study can provide a basis for developing relevant pollution prevention and control measures in the Yellow River basin.

Heavy Metal Pollution and Health Risk Assessment of Mine Soil in Yangtze River Economic Belt

The study of heavy metal pollution in mine soil of the Yangtze River Economic Belt is important for promoting the ecological restoration of mines and the construction of green mines in the Yangtze River Economic Belt. For this study, we collected the relevant research on the pollution of heavy metals in the mine soil of the Yangtze River Economic Belt from 2006 to 2020 and studied the pollution status, distribution law, and health risk of heavy metals by using the land accumulation index method, Kriging interpolation method, and health risk assessment method. The results showed that the average contents of Pb, Cd, Cr, Hg, As, Zn, Ni, and Cu in mine soil far exceeded the background value in China, and the accumulation degree of Cd and Hg was significant. The pollution evaluation results showed that the pollution degree of the eight heavy metals was Cd>Hg>Pb>Zn>Cu>As>Ni>Cr, the pollution degree of Cd and Hg was the highest, and more than 60% of the sample points were at medium pollution. The pollution evaluation showed that the soil pollution of tin and lead-zinc mines was more prominent than that of other minerals. The health risk assessment indicated that oral intake was the main intake route for non-carcinogenic and carcinogenic risks, the total non-carcinogenic and carcinogenic risk index was within the unacceptable range, and the non-carcinogenic and carcinogenic risk of mine soil in the middle and upper reaches of the Yangtze River Economic Belt was significantly higher than that in the lower reaches.

Environmental Hazards of Heavy Metal Pollution and Toxicity: A Review

Metals and especially heavy metals are one of the major constituents of environmental pollution. The sources of heavy metal pollution can be geogenic or anthropogenic. The man-made sources include fumes, metal laden dust or food components. Although, many metals are essential for animal metabolism but a dose exceeding the required concentration is often deleterious. The hazardous nature of these heavy metals has been extensively studied in human, animal and plants showing various toxicological impacts of toxic metals. The acute or chronic exposure of heavy metals to animals and human can result in severe injury to the structure and function of vital organs as liver, kidney, brain along with systemic disease conditions. The growth of plants is also severely affected by the intake of metallic compounds through the mineral and water absorption route. The deleterious effects on plants range from symptoms of injury to metabolic, enzymatic, and growth inhibition. The study of heavy metal pollution and the subsequent impact to flora and fauna can contribute in spreading public awareness and sensitizing policy makers to develop strategic planning in order to reduce the pollution and implement biological protection strategies.

A new three-band spectral and metal element index for estimating soil arsenic content around the mining area

Owing to the advantages of fast and non-destructive measurement, visible and near-infrared reflectance (VNIR) spectra have been widely used in the study of heavy metal pollution. However, few studies have focused on the estimation of soil heavy metal concentration by the enhanced joint architecture of spectral indices and metal elements enriched in clay minerals. In this work, a new composite index, namely Three-band Spectral and Metal Element Index (TSMEI), is proposed to retrieve arsenic (As) in soil by utilizing the multi-view spectral information. Based on obtained data, including spectra and the concentration of iron (Fe), potassium (K), aluminum (Al), magnesium (Mg) and arsenic (As) of the soil around the open-pit coal mine area, the three-band spectral index (TBSI) for As, K, Fe, Mg and Al were calculated from four types of spectral data, that is, raw reflectance (R), the first-order derivative of the spectrum (FD), spectral continuum removal (CR) and spectral reciprocal logarithmic (RL). Then, the metal element index (MEI) for As concentration were constructed via estimated content of K, Fe, Mg and Al based on their TBSIs. Finally, the optimized TBSIs and MEIs were used to construct TSMEI, and it was combined with random forest to invert the As concentration. The following conclusions are drawn: TBSIs is significantly better than that dual-band spectral index and single-band spectrum for estimating As content, and the correlations between the TBSIs based on the FD and the As concentration perform best (r ≥ 0.7684). In addition, two/three element MEIs show higher correlation coefficients with As concentration compared to individual metal element. Furthermore, the proposed TSMEI allow high-precision estimation of As content, which acquired highest correlation coefficient and lowest RMSE (r = 0.9732, RMSE = 0.0703). The results confirm that the TSMEI is significantly effective in estimating soil As content.

Environmental study of heavy metal pollution of two species of plants Juncus acutus and Hammad salicornica of Shadegan wetland

Environmental study of heavy metal pollution of two species of plants Juncus acutus and Hammad salicornica of Shadegan wetland

Long-term study of heavy metal pollution in the northern Hangzhou Bay of China: temporal and spatial distribution, contamination evaluation, and potential ecological risk.

Coastal ecosystem is vulnerable to heavy metal contamination. The northern Hangzhou Bay is under intensifying impact of anthropogenic activities. To reveal the heavy metal pollution status in the coastal environment of the Hangzhou Bay, a long-term investigation into the heavy metal contamination during 2011 to 2016 was initiated. Seawater and sediment samples of 25 locations depending on the sewage outlet locations in the northern Hangzhou Bay were collected to analyze the concentrations and temporal and spatial distribution of Cu, Pb, Zn, Cd, Hg, and As. Pollution condition, ecological risk, and potential sources were additionally analyzed. Results show that the annual mean concentrations of Cu, Pb, Zn, Cd, Hg, and As were 2.13-4.59, 0.212-1.480, 7.81-20.34, 0.054-0.279, 0.026-0.090, and 1.08-2.57 μg/L in the seawater, and were 16.34-28.35, 16.25-26.33, 67.32-97.61, 0.084-0.185, 0.029-0.061, and 6.09-14.08 μg/L in the sediments. A decreasing trend in Cu, Pb, Zn, Cd, and Hg concentrations and an increasing trend in As of the seawater were observed. However, in the sediment, the heavy metals demonstrated a rising trend, except for Hg. The single-factor pollution index showed an increasing trend in Cd and As in the seawater, depicting an enhanced pollution of Cd and As, while in the sediments, Cu, Pb, and As were in pollution-free level (average Geo-accumulation index (Igeo) values below 0) in general, and only occasional slight pollution occurred in individual years, e.g., As with 0.403 in 2016. The mean Igeo values of Cd ranged from - 0.865 to 0.274 during 2011 to 2016, indicating that the pollution level of Cd was slight, but is likely to increase in the forthcoming years. The level of heavy metal contamination in sediments was low in 2011 (5.853) and 2012 (5.172), and moderate during 2013 to 2016 (in the range of 6.107 to 7.598), while the degree of potential ecological risk was low in the study period, except moderate in 2013 (125.107). The highest contamination degree and potential ecological risk appeared in 2013 (Cd = 7.598; RI = 125.107), while Cd and Hg contributed over 75% of the ecological risk. Overall, the results show low pollution level and low potential ecological risk in the northern Hangzhou Bay; however, more attention should be paid to the potential ecological risk due to Hg and Cd. Graphical abstract Spatial distribution of the heavy metal levels in the sediment of the coastal environment of the northern Hangzhou Bay on a long-term basis.

Spatial Distribution and Pollution Characteristics of Heavy Metals in Plant Leaves in Baoji City

As an important carrier of heavy metal pollutants in urban dust, green plants play an important role in the study of heavy metal pollution in the environment. To quantitatively assess the pollution degree, spatial distribution, and characteristics of dust accumulation of heavy metals in the leaves of 10 dominant green plants in Baoji City, the contents of Pb, Zn, Cu, Cr, Ni, Co, Cd, and As were determined in 156 leaf samples with a ground height of 0, 1, and 3 m in Baoji City, and the biological enrichment coefficient (BCF), pollution load index (PLI), and potential ecological risk index (RI) were calculated. The enrichment amounts of Cr, As, Ni, Pb, and Cd were the highest in the leaves of the green plants in Baoji City. The contents of Cr, Ni, and As in Ophiopogon Japonicus were the highest; the highest content of Cd was found in privet leaves, and the contents of Pb, Ni, and As in the leaves of tarasone were the highest. Clover, privet, and photinia revealed significant enrichment of Cd. The contents of Cr, As, Ni, Pb, Cd, and Zn decreased with an increase in the height of spatial distribution. Moreover, the rate of decrease in Cr was up to 24%, and the peak areas were around the Qianhe industrial zone, Renjiawan railway station, and the municipal government. According to PLI and RI values, the Renjiavan railway station and Qianhe industrial zone were moderately polluted areas with moderate ecological risk level, whereas the high-tech avenue area represented a strong ecological risk level. In addition, the PLI values of both Cr and As in the leaves of the green plants were greater than 3, indicating a level of severe pollution. Based on the average Eri values, Cd and As were the most ecologically harmful elements. The study area was at a medium risk level.

Impact of intensive land use on heavy metal concentrations and ecological risks in an urbanized river network of Shanghai

• Concentrations and spatial distribution of HMs in the river network were influenced by intensive land use. • AVS and TOC in river sediments influenced the migration and transformation of Cd, Hg and Zn. • Hg and Cd were the main contributors of RI, HMs in the central city area showed the highest potential ecological risk. • HMs in the river network primarily originated from industrial activities, traffic emissions and coal-burning emissions. Heavy metal pollution characteristics in the urbanized river network are closely related to urban land use. The existing studies mainly focused on the pollution characteristics of heavy metals in single rivers, but fewer studies reported the impact of land use on the concentrations and ecological risks of heavy metals in surface water and sediments of the urban river network. This study combined land use types with heavy metal pollution in rivers, and explored the specific impact of intensive land use on the characteristics of heavy metal pollution in rivers, which provided scientific basis for the study of heavy metal pollution in plain river networks. The concentrations, spatial variations and potential ecological risk levels of cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb) and zinc (Zn) in surface water and sediments from five different intensive land use areas of Shanghai river network (industrial areas, agricultural areas, central city, suburban towns and Chongming Island) were analyzed. Results showed the concentrations of Cd, Cr, Cu, Pb and Zn in surface water of the Shanghai river network were relatively low, but Hg pollution existed in some rivers. Influenced by intensive land use, heavy metal concentrations in the central city were generally higher than those in other areas. Heavy metals in sediments had considerable ecological risk, in which Hg and Cd were the main contributors, and showed the highest potential ecological risk in central city. Acid volatile sulfides (AVS) and total organic carbon (TOC) in river sediments affected the migration and transformation of Cd, Hg and Zn. Industrial activities, traffic emissions and coal-burning emissions were the main sources of heavy metals. Intensive land use caused by anthropogenic activities led to the weakening of hydrodynamic conditions and the discharge of a large number of pollutants into the river network. In the central city with intensive anthropogenic activities, heavy metals in the river network showed higher levels than those in other areas. This study found that intensive land use and high-intensity anthropogenic activities led to the high pollution level of heavy metals in the plain urbanized river networks. Quantitative analyses of the effects of intensive land use on heavy metal pollution in urbanized river networks were suggested to conduct further to protect the urban river water quality.

Baseline Study of Heavy Metal Pollution in a Tropical River in a Developing Country

Massive load of toxic heavy metals is discharged by human activities, as well as by natural actions, give rise to metal contamination in water body. Sg. Sembilang is one of the rivers that is receiving effluent from various sources such as landfill, industrial, residential, and agricultural runoff. In this study, the concentration of heavy metals in nine stations along the Sg. Sembilang was collected for one year period to evaluate their levels of pollution. Ten heavy metals were analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES). The mean concentrations of Fe, Mn, Zn, Al, and Cu were 3.01, 0.68, 0.29, 0.007, and 0.027 mg/L respectively, were below the National Water Quality Standards of Malaysia (NWQS), with the exception of Cd, Cr, Pb, Mg, and Ni. Calculated HPI based on the mean concentration of heavy metals, was found to be 6.05, that is below the critical pollution index value of 100. With respect to sampling locations, station J03 registered the highest value of 7.989. This is probably due to the location of J03 which is very near to the effluent discharge point. The analysis indicates the present scenario of water quality of Sg. Sembilang due to the effect of effluent from the landfill material, and waste water from industry, agricultural runoff and residential area. Required steps should be taken to conserve this river from pollution, and also to lessen the environmental risk.

Concentration, Spatial Distribution, Contamination Degree and Human Health Risk Assessment of Heavy Metals in Urban Soils across China between 2003 and 2019-A Systematic Review.

This study provides an overview of the studies of heavy metal pollution regarding As, Cd, Cr, Hg, Pb, Cu, Zn and Ni in the urban soils throughout 71 cities of China, based on data from online literature, during the period 2003–2019. The concentrations, spatial distributions, contamination degrees and health risks of heavy metals in the urban soils were evaluated. The results demonstrated that the mean values of eight heavy metals all exceeded the soil background values in China, and the kriging interpolation method showed that the hot-spot cities with heavy metal contamination in urban soils were mainly concentrated in the southwest, southcentral, southeast coast, northcentral and northwest regions of China. The geoaccumulation index (Igeo) indicated that Hg and Cd were at moderate contamination levels and that the levels of the other six metals did not appear contamination. The pollution index (PI) showed that Cd and Hg reached high contamination levels, and the other metals reached moderate contamination levels. The integrated pollution index (IPI) and potential ecological risk index (PRI) indicated that the integral urban soils in the study areas ranked high contamination levels and moderate ecological risk degree, respectively, and Cd and Hg should be labeled as priority metals for control in the urban soils around China. The human health risk assessments for the heavy metals indicated that ingestion was the dominant exposure pathway for having adverse effects on human health. The mean Hazard index (HI) values of eight heavy metals all showed that adverse effects on human health were unlikely, and the mean carcinogenic (CR) values of As, Cr and Ni for children and adults all suggested an acceptable carcinogenic risk to human beings. In addition, children exposed to these heavy metals faced more serious non-carcinogenic and carcinogenic health threats compared to adults. The results could provide valuable information for demanding the better control of heavy metal pollution and mitigation of the adverse effects on residents by environmental regulators in national urban regions.

By using low-cost Adsorbents process elimination of heavy metals from wastewater

The beginning of industrialization human being has observed a variety of environmental concerns on the earth. The industrialization has not simply carried growth and affluence but finally troubled the environment. One of the crashes is noticeable, in form of water pollution. Now the present study of heavy metal pollution of water body has been talk over. Effluents from an unlimited amount of industries viz., textile, tannery, dyes, pigment, paint, wood processing, electroplating, leather, petroleum refining etc., have a key amount of heavy metal in their wastewater. The conventional technique of treatment heavy metal contamination contains chemical precipitation, membrane separation, chemical oxidation, ion exchange, electro dialysis, reverse osmosis, etc. These procedures are costly, energy intensive and often linked with creation of toxic by-product. Hence, the adsorption has been experimental as a cost-efficient method for treatment of heavy metals removal from wastewater. In the existing study numerous inexpensive adsorbent has been an analysis as a reduction of heavy metal effluence from wastewater. These adsorbent include resources of natural origin similar to zeolites, peat moss, peat moss, chitin, clay are find to be a real agent for elimination of lethal heavy metal like Cu, Ni, Hg, Zn, Cr , Pb, Cd, etc. Distinctly from these, a range of farming wastes like waste tea, rice husk, black gram neem bark, walnut shell, etc. Also known to be an influential adsorbent for the eliminating heavy metal from wastewater. at the side of that inexpensive or low-cost manufacturing byproduct like lignin, fly ash, iron (III) red mud, hydroxide and coffee husks, tea factory waste, Areca waste, sugar beet battery industry waste, pulp, waste slurry, blast furnace sludge, grape stalk wastes, sea nodule residues have been found for their methodological option for removal toxic metal from waste water.

Risks related to heavy metal pollution in urban construction dust fall of fast-developing Chinese cities.

Urban construction is a major contributor to air pollution, but few studies have examined heavy metal pollution in urban areas caused by construction dust fall. We measured the concentrations of Cr, Ni, Cu, Zn, Pb, Cd, and Hg and particle size distribution in dust fall from various construction activities in seven fast-developing cities in China and conducted a health risk assessment. Mean metal concentrations in construction dust fall were on the order of Zn (246.3mg/kg)>Cr (94.2mg/kg)>Pb (56.5mg/kg)>Cu (53.6mg/kg)>Ni (22.8mg/kg)>Cd (0.68mg/kg)>Hg (0.08mg/kg). Cu and Zn were positively correlated in areas of subway and building construction, and Pb and Cd were positively correlated in areas of road construction, likely because of the materials specific to these activities. Enrichment factors for heavy metals at all sampling sites were on the order of Cd (10.4)>Zn (6.37)>Cu (4.25)>Pb (3.84)>Hg (2.41)>Cr (2.02)>Ni (1.32). The enrichment factors for all metals except Zn indicated that heavy metal pollution was highest in road construction, followed by building and subway construction. Non-carcinogenic risks to children (hazard index >1) were 1.01-1.08 in four of the seven sampling sites, indicating possible risk from deposition of construction dust fall. In contrast, the hazard index for adults was <1at the seven cities and total carcinogenic risks (<1×10-6) were at acceptable levels. An integrated ecological risk assessment demonstrated that heavy metal particles in construction dust fall in two of the cities (Shijiazhuang and Qingdao) were likely to be suspended in the atmosphere. Our study of heavy metal pollution in construction dust fall provides data on ecological and human health impacts and suggests that extensive measures are required to control construction dust fall in China.

Targeting Remediation Dredging by Ecological Risk Assessment of Heavy Metals in Lake Sediment: A Case Study of Shitang Lake, China

Understanding the spatial distribution and pollution characteristics of heavy metals in lake sediment is crucial for studying deposition and migration processes, assessing lake conditions, and determining the extent of remediation dredging. The present work is a case study of heavy metal pollution in Shitang Lake in Anhui province, China. Heavy metal concentrations were determined in sediment at locations across the lake to a depth of 100 cm, and pollution levels were assessed on the basis of the Geoaccumulation Index (Igeo) and Potential Ecological Risk Index (RI). Hg and Cd were the predominant heavy metals in the sediment, and the Igeo and RI indicated high pollution levels in the northern and southern zones of the lake. These findings can be used to guide the prioritization of dredging operations.