Variation Of Heavy Metal Pollution Research Articles

SEASONAL VARIATION OF HEAVY METAL POLLUTION OF GROUNDWATER AND SOIL IN THE M’NASRA REGION (GHARB, MOROCCO)

M’nasra region is well known for increasing levels of heavy metal pollution in the environment, mainly due to waste discharge of Ouled Berjal, the irrational use of fertilizers, and the discharge of waste from several industries. The objective of this study was to access the seasonal variations in the groundwater and soil quality with respect to heavy metal pollution. Water samples from wells and samples from soil near them were taken during wet (January - March 2017) and dry (July 2017) seasons and concentrations of Cd, Cu, Cr, Mn, Ni, Pb, and Zn were determined using an Atomic Absorption Spectrophotometer (AAS). Contamination factor for each heavy metal and Nemerow pollution index was calculated. Results of the study revealed a decrease in pollution degree from wet to dry for soil and an increase in the case of groundwater. Cu had the lowest and Ni had the highest concentration in irrigation water whereas, for soil, Cd had the lowest and Zn had the highest concentration. During the wet season, all the concentrations of heavy metals decreased compared to the dry season, this can be explained by the dilution of these concentrations by precipitation water and therefore to lower absorption of these heavy metals in the water of irrigations and/or soil. Vertical transfer of pollutants from topsoil to groundwater was assessed using Hierarchical Cluster Analysis to identify associations between heavy metals and soil texture. In the case of Ni and Cr, the variables corresponding to the concentrations from soil and groundwater were part of the same cluster, in both seasons, the distribution maps of concentrations confirmed the pattern of transfer. This study can be considered as a baseline for the seasonal variation of heavy metal pollution of groundwater and soil. This study can be used not only for monitoring the study area but also as a tool for the implementation of environmental protection policies.

Inter-estuarine and seasonal to decadal variations of heavy metal pollution in the Gulf of Cambay, India

Toxic heavy metals adsorbed preferentially onto suspended sediments enter our food chain by bio-assimilation in coastal ocean organisms. To decipher metal pollution status in the Gulf of Cambay (food hub of India) under rising anthropogenic pressure, we present seasonal abundances of Ti, Cr, Co, Ni, Cu, Zn, Cd, and Pb in > 150 samples of suspended sediments (> 0.45µm) collected in four seasons (2016-2017) from two large estuaries (Narmada and Tapi). The suspended sediments of both the estuaries generally show low heavy metal pollution (Igeo < 1). The hotspots of moderate-to-high pollution of Pb (Igeo < 4), Cd (Igeo < 3), and Zn (Igeo < 2) are found at salinity < 2, and those of Co (Igeo < 2) at salinity ~ 20-30 in the Tapi estuary during the non-monsoon seasons indicating their decoupled sources in Surat. The PLI values show no or little seasonality in the overall metal pollution status of both the estuaries. A comparison with the literature data suggests that suspended sediments efficiently capture active metal pollution in Indian estuaries. Furthermore, a recent decline (2004-2017) in estuarine metal pollution in the Gulf of Cambay found in this study could be due to enhanced organic matter supplies by enhanced urban sewage discharge and/or more trapping of contaminated riverine sediments upstream of the newly built large dam reservoirs counteracting the growth of anthropogenic metal inputs in the Narmada and Tapi watersheds. The data scarcity of heavy metal concentrations in suspended sediments limits reporting unambiguously the current pollution status of other major Indian estuaries.

The spatial-temporal evolution of heavy metal accumulation in the offshore sediments along the Shandong Peninsula over the last 100 years: Anthropogenic and natural impacts

The anthropogenic and natural impacts on the temporal and spatial variations of heavy metals in sediments under the Shandong Peninsula coastal current are still unclear. Here, the concentrations\\burial fluxes of Cr, Cu, Zn, As, and Pb in three sediment cores retrieved from the Bohai Sea and the Yellow Sea along the Shandong Peninsula were analyzed to study the spatial-temporal variability of heavy metal accumulation over the last century. The results showed that the buried heavy metal fluxes were relatively low at the end of the Shandong Peninsula coastal current. The enrichment factor (EF) and geoaccumulation index (Igeo) indicated that those metals did not severely pollute the sediments except As that reached a moderate enrichment. Principal component analysis (PCA) revealed that Cr, Cu, Zn, and Pb were mainly derived from natural weathering and As was determined by anthropogenic contamination. The strength of the Shandong Peninsula coastal current, the Yellow River estuary location, and sediment discharge load significantly influenced the concentrations of natural-origin heavy metals by affecting sediment grain size and the source-sink process. The emission of pollutants from agricultural and industrial activities in the Shandong Peninsula region resulted in As enrichment since the 1950s. Moreover, the EF values of heavy metals in sediment cores from China's coastal seas showed apparent spatial variations of heavy metal pollution but had coherent temporal variability with China's economic development process. Heavy metals pollution has weakened in most coastal seas since the 2000s, likely due to the extensive industrial upgrading and the implementation of pollution control. These results have a reference significance for studying the evolution and source-sink process of the heavy metals in offshore sediments and tracing anthropogenic impacts in different periods.

Natural and Human Factors Affect the Distribution of Soil Heavy Metal Pollution: a Review

Summarized the heavy metal pollution caused by natural and human activities. The natural causes include the migration and redistribution of soil debris and the hydraulic migration of soil parent rock with high background value under the action of wind; human factors include mining, abandoned mining areas, fertilizer and pesticide application, and sewage irrigation. By examining the sources of heavy metals in soil, the temporal and spatial variation and source variation of heavy metal pollution can be summarized, and then find a reasonable way to intervene as early as possible from the origin to reduce the harm of this pollution to the soil. Finally, future research trends and key problems were indicated, which laid a theoretical foundation for further effective research.

Heavy metal pollution and comprehensive ecological risk assessment of surface soil in diffe-rent functional areas of Shenzhen, China

To explore the impact of urban functional zones on surface soil metal pollution, we analyzed the concentrations and pollution status of eight heavy metals (i.e., Mn, Ni, Cr, Pb, Cd, Zn, Cu, and As) in surface soils from various urban functional zones of Shenzhen City. Nemero index and potential ecological hazard indices were used to quantify the ecological risk levels of different heavy metals in different urban functional zones. Moreover, we spatially classified ecological risk zones for soil heavy metal pollution. Results showed that: 1) concentrations of Cd, Zn, Cu, and As in the surface soil were heavily impacted by human activities, while those of Mn, Ni, Cr, and Pb were not. High-intensity urbanization and industrialization with the constraints of physical environment were identified as the determining factors for regional and functional variation of heavy metal pollution. 2) Pb, Cd, Zn, and Cu had high pollution risks in the surface soils, with Pb having the highest risk, which necessitated further management and control of heavy metals. The overall level of heavy metal pollution risk in the surface soils of Shenzhen was higher than that of other cities in China. 3) Nemero index and potential ecological hazard indices had different emphases in terms of assessing the risk level of heavy metals. Those indices showed different performances in the risk assessment of single heavy metal, overall ecological risks in the different urban functional zones, and ecological risk classification of heavy metal pollution in the urban surface soils. We suggest that those indices should be combined to provide more holistic information about urban heavy metal pollution.

Historical evolutions of sediment quality in bays under serious anthropogenic influences in China, basing on fuzzy comprehensive assessment of heavy metals.

Fuzzy comprehensive assessment was applied, for the first time, to investigate the sediment environmental quality and compare the historical variations of heavy metal pollution in Daya Bay and Jiaozhou Bay, which are representative for sub-tropical and temperate zone of China, respectively. Results shown the Daya Bay had undergone three contrasting stages in the past 100years. Before 1980s, the sediment was not contaminated by metals and its quality generally conformed to class I of China National Standard for marine sediment quality. During from 1980s to 2000s, however, Daya Bay's environment had experienced significant deterioration. The metal concentrations were significantly higher than the background values, suggesting that there was a sharp increase of metal input. The category of sediment quality fell to class II and class III. Copper was the dominant pollutant during that time. The good thing is sediment quality of Daya Bay has improved to class I since 2000s, and chromium turned to be the major pollutant. As for the Jiaozhou Bay, enrichment of heavy metal was generally not detected and the sediment quality strictly conformed to class I during the recent 90years. Chromium and zinc were the major pollutants in this bay.

Spatio-Temporal Variation of Heavy Metal Pollution during Accidents: A Case Study of the Heshangshan Protected Water Area, China

Recently, water environmental accidents have occasionally occurred which have had wide-ranging influences, long durations and are difficult to deal with. The development of the social economy, the acceleration of industrialization, the huge discharge of industrial wastewater and the occasional occurrence of ship transportation accidents pose serious threats to the water quality of water inlets and protected water areas. This article applied the two-dimensional water quality model, used a GIS platform and FORTRAN language, and predicted spatio-temporal variations of the iron concentration during a water pollution accident. This research selected the water inlet of Heshangshan Water Plant and the Heshangshan protected water area as the research objective, and assumed a water pollution event had occurred. It was suggested that we should take corresponding emergency measures and relevant solutions to deal with the bad effects of water pollution accidents. The processes mainly included the selection of the study area, the determination of the equation to be used, parameters determination, as well as the identification of the accident scenario and source. The durations of the iron concentration exceeding the standard at the water inlet were 12–18 min and in the protected water area were 16–36 min in four water periods after the accident. In addition, the durations taken for the iron concentration to decrease to the background value in the protected water area were 18–38 min after the accident in four water periods in the accident scenario. Relevant departments should take some contingency measures to avoid fetching water from the intake after the accident within 40 min after the accident and the relevant staff can cancel the warning 40 min after the accident.

Spatial Variation of heavy metal Pollution on road surfaces from Traffic sources in University of Nigeria, Enugu campus

This study aims to analyze heavy metal concentrations on road deposited sediment (RDS) using the road network within Enugu Campus of University of Nigeria, (UNEC) as a study site. RDS samples were collected at two transverse positions from different sites within a week in order to describe the influence of traffic on heavy metal emissions. The heavy metal concentrations of the RDS were determined by strong tri-acid digestion and atomic absorption spectrometry. The mean concentrations for Co, Mn, Zn, Ni and Fe were found to be 11.53, 99.92, 221, 44.23 and 216 mg kg-1 from samples near the curb and 12.37, 92.25, 248.87, 43.62 and 197.5 mg kg-1 from samples 1 m from the curb respectively. The mean electrical conductivity (EC), pH and total organic matter (TOM) were found to be 304μS/cm, 7.13, and 6.9% from samples near the curbS/cm, 7.13, and 6.9% from samples near the curb and 408μS/cm, 7.13, and 6.9% from samples near the curbS/cm, 7.33 and 5.57% 1 m from the curb, respectively. The results of the geochemical models: contamination factor (degree of contamination and enrichment factor agree to a very high level of contamination and enrichment of Zn in all the sampled sites. These results suggest a high anthropogenic influence on the heavy metals levels.

Assessment of Microscale Variation of Heavy Metal Pollution of the Bystrzyca River Alluvia Downstream from Lublin

Fluvial sediments accumulated in the bottoms of river valleys downstream from large cities are characterised by higher levels of heavy metal content, which poses a threat to the environment and humans. This study presents a comprehensive assessment of the degree of pollution of four alluvial sediment profiles (80 samples), collected from the bottom of the Bystrzyca river valley downstream from Lublin, conducted with the use of five geochemical indices. Channel deposits and sediments (alluvial soils) sampled from the floodplain were analysed. The content levels of the six heavy metals under study were as follows: Cd: 10.6–291.2 mg/kg, Cr: 53.1–292.4 mg/kg, Cu: 20.4–223.1 mg/kg, Ni: 2.9–19.3, Pb: 39.3–280.3, Zn: 108.9–991.4 mg/kg. The horizontal and vertical variation of the pollution level was linked with the history of anthropogenic pressure on the one hand, and the geomorphological location of a given profile on the other. Heavy metal content in the samples did not show any correlation with grain size composition, organic matter content, and Fe and Mn content. Cadmium was the element whose concentration levels were comparable with those in alluvial sediments of rivers in industrialised areas while the indices for the other metals showed varied levels of pollution: from low to high. However, the ecological risk is high for all samples as indicated by the synthetic potential ecological risk index, which takes into account the toxicity of all the metals under study.

Seasonal Variations of Heavy Metal Pollution in the Sediment of Visakhapatnam Coast, India

Seasonal Variations of Heavy Metal Pollution in the Sediment of Visakhapatnam Coast, India

Heavy Metal Pollution in Urban Soil from 1994 to 2012 in Kaifeng City, China

Heavy metal pollution in urban soil has become a serious environmental issue in China since the last three decades. Attention has been given to the investigation of soil contamination; however, there is little information available on the variation of heavy metal pollution in soils. To resolve this problem and provide references on similar regions, 18 topsoil (0∼20 cm) samples were collected from identical sites of districts that with different functions in Kaifeng City in 1994 and 2012. Total contents of As, Cd, Hg, and Pb were determined by standard methods. The variation of heavy metal pollution was evaluated by using geoaccumulation index and pollution load index. Results show a descending trend in heavy metal pollution of soil in Kaifeng City that demonstrated over the last 20 years, though there are still some contaminations in 2012. The highest concentration of soil metal was observed in industrial district, followed by the cultural and educational district, administrative business district, and entertaining district in turn. Concentrations of Pb in all soils and As in most soils were higher in 2012 than that in 1994, which mainly due to the rapid increase of motor vehicles and domestic garbage. Meanwhile, the concentrations of Hg and Cd in most soils were lower in 2012 than that in 1994, as the relocation and shutdown of industry and the wide development of environmental facilities. Land use and land cover change in urban areas can effect on soil metal pollution. When farmland transforms into urban land, the concentrations of soil metals would be increased, and also, the soil pollution will increase severely.

Seasonal and Spatial Variations of Heavy Metal Pollution in Water and Sediments of China’s Tiaozi River

Seasonal and Spatial Variations of Heavy Metal Pollution in Water and Sediments of China’s Tiaozi River

A Flex and ArcGIS Server based system for farmland environmental quality assessment and prediction in an agricultural producing area

A farmland environmental quality assessment and prediction system was developed based on the database technology, WebGIS and model theory to provide intuitional information of farmland environmental pollution situation and the pollution trend for scientific decision making regarding monitoring soil quality. The designed system could be used for the query of agricultural environmental information, assessment of farmland environmental quality, and forecasting of farmland environmental pollution. An environmental quality assessment model was developed and integrated in the system by single factor index and weighted pollutant index method. The application of the assessment model showed that the single factor index of soil heavy metal Hg in the study area reached light pollution levels. The pollutant area occupied 21.3% of the entire study area. The other five soil heavy metals (Pb, Cu, Cd, Cr, and As) were in safe levels of soil environmental quality assessment classification standard. The average weighted pollutant index was 0.54, indicating good soil environmental quality. Most parts of the region was in safe level. An exponential smoothing forecasting model was established based on the time series characteristics of the heavy metal pollution in the agricultural producing area to predict heavy metal pollution. The analytical results showed that the prediction accuracy of the models was approximately 90%, indicating that the exponential smoothing model can fit the variation of heavy metal pollution.

Study on Distribution and Variation of Heavy Metal Pollution in Guangxi Coastal Seawater during Dry Season

To study the distribution of heavy metal pollution in Guangxi coastal water, we set up 10 monitoring stations in Guangxi coastal water, monitored and analyzed Hg, Cu, Pb, Cd, As, Zn and Cr in each monitoring stations during 2007 and 2009 dry season. The results show that the heavy metal pollutants distribution concentration of Guangxi coastal water during the dry season can meet Grade I sea water quality standard. From 2007 to 2009, heavy metal pollution of Guangxi coastal water is reduced. Heavy metal contents in seawater of all stations is decreased expected Cu, whose content is slightly elevated. And besides the reduction of As is small, other heavy metals declined obviously, theirs contents are all below or near the detection limit. Cu contamination of seafood proliferative zone and dredged sludge dumping areas need to be strengthened supervision.

Geophysical Contribution for the Mapping the Contaminant Plume of Leachate from Rubbish Dumpsite of Hevie, Benin

In majority of the countries in the process of development like the Benin, the presence of dumpsite of rubbish can cause pollution of the groundwater. Indeed, the leachate resulting from the seepage of rain water into rubbish can infiltrate and pollute the water table. The evaluation of the infiltration of the leachate was carried out by the geophysical methods of frequential electromagnetism in EM34 and Electrical Resistivity Tomography (ERT). The electromagnetic map circumscribed the lateral limits of the leachate diffusion and the electromagnetic surveys showed that it infiltrated with a depth of 20m. The two cross sections of electrical resistivity tomography of NS and SW-NE direction made it possible to map the plume of leachate. These results show that the contact water table leachate is rather discontinuous, the depths of the feather of leachate varying from few meters to 22m for an average static level of 18m. The leachate infiltration occurs with variable depths and is not everywhere in contact with the water table. This discontinuous pollution has been observed in the water quality of the wells. Indeed, the analyses of water samples of the wells showed a great variation of heavy metal pollution in rather close wells. Research Article British Journal of Applied Science & Technology, 4(1): 127-143, 2014 128

Spatial and Temporal Variation on Heavy Metals in the Sediments of Dapeng Bay and Neighboring Rivers

The Typhoon Morakot raged through Taiwan bringing torrential rain for two days, which led to debris-flow in mountains and severe flooding in the coastal areas of southern Taiwan. In order to realize the impact of the Typhoon Morakot on heavy metals in the sediments this research discriminate the pollution brought from three neighboring rivers to the Dapeng Bay lagoon by using the R. A. Fisher Method. The results generally indicate that the samples from Dapeng Bay and the three neighboring rivers are displaying individual crowd-distribution phenomena, which means that the heavy metal content in the sediments of Dapeng Bay and the three neighboring rivers are not totally similar. Today, due to a massive variation in eco-habitat and a more frequently changing climate, the understanding of spatial-temporal variation of heavy metal pollution of sediments in Dapeng Bay and pollution sources from three neighboring rivers will provide useful information regarding disaster management, habitat recovery, operative management, as well as ecotourism specification.

Evaluation on Characteristics of Heavy Metal Spatial Pollution in Farmland Soils along the Bijiang River

Based on the farmland soils along the Bijiang River, a main tributary of the international Lantsang-Mekong River flowing through the Jinding Lead-Zinc Deposit, this dissertation makes analyses on the pollution characteristics of spatial variation in farmland soils by adopting the soil sampling and testing analysis and applying single-factor pollution index (SPI) evaluation and Nemerow composite pollution index (NCPI) evaluation. The results indicate that: (1) In accordance with Environmental Quality Standard for Soils (II), the content of Cd contained in the farmland soils has severely exceeded the standard in a large scale, followed by Pb and Zn. However, the content of As is maintained within the specified standard; (2)The SPI values of soils are in the following sequence: Cd＞Zn＞Pb＞As. The pollution level caused by the heavy metal “Cd” to the farmland soils is extremely heavy in a wide range, and a majority of the farmlands are heavily polluted by Zn. The farmlands with moderate pollution by Pb are centered at Plot 2 in the deposit, and only a few farmland soils are moderately polluted by As at Plot 2 in the deposit;(3) Based on the NCPI, the results indicate that the NCPI of the farmland soils has reached to the degree of heavy pollution; (4) It is indicated based on the RPI evaluation that the RPI values of As, Cd, Pb and Zn contained in the farmland soils have exceeded the standard in the following sequence: Pb＞Zn＞Cd＞As, which illustrates that during the development of Jinding Lead-Zinc Deposit in Lanping County, the heavy metals imposing the most profound influence on the soil pollution are Pb and Zn. The heavy metal pollution in the farmland soils from the upper reaches to the lower reaches of the Bijiang River is not only caused by the development of Jinding Lead-Zinc Deposit in Lanping County, but is also associated with its high soil background value;(5) There is a remarkable spatial variation of heavy metal pollution in farmland soils from the upper reaches to the lower reaches of the Bijiang River. Both the SPI and the NCPI values of heavy metals in the soils within the deposit at the upper reaches of the Bijiang River are the lowest; the pollution index of the soils closest to the deposit are the highest, and the pollution index of the soils with a certain distance from the deposit drops swiftly; the pollution index of Plot 4 rises to a certain degree at the middle reaches, and gradually ascends near the Yunlong County seat at Plot 5, however, with a comparatively small growth rates.

Temporal variation of heavy metal pollution in urban stormwater runoff

Stormwater runoff from three types of urban surfaces, a parking lot, a street, and a building roof, was monitored during four rainfall events that occurred in the one-year period from June 2009 to June 2010. The event mean concentrations (EMC) of dissolved copper (Cu), lead (Pb), zinc (Zn), manganese (Mn), and iron (Fe) exceeded China’s National Water Quality Standards for Surface Water. The degree of heavy metal contamination was related to the type of underlying surfaces. Additionally, the concentration of dissolved heavy metals peaked shortly after the runoff began and then declined sharply as a result of adequate flushing. First flush effects of varying degrees were also observed during all of the monitored rainfall events based on the first flush ratio (FF25). Redundancy analysis revealed that four environmental variables (rainfall depth, intensity, antecedent dry weather period and type of underlying surface) had significant effects on the strengths of the first flush effects, accounting for 72.9% of the variation in the FF25. Dissolved metals presented varying first flush effects on different underlying surfaces that occurred in the following relative order: parking lot>roof>road for low intensity and high runoff volume rainfall events; parking lot>road>roof for high intensity and low runoff volume events. The relative strength of the first flush for dissolved heavy metals was Fe, Mn>Cu, Zn>Pb.

Distribution of heavy metals in the sediments of agricultural fields adjacent to urban areas in Central Taiwan

In 2002, the Environmental Protection Administration of Taiwan began a detailed survey of heavy metals in soils, to determine the scope of the contaminated lands in the Changhua County’s agricultural fields. It was found that agricultural lands have been seriously polluted with Cr, Hg, Cu, Ni, and Zn, due to industrial wastewaters. This study, characterized the processes associated with heavy metal pollution by analyzing heavy metal contents in sediments within two periods, 2002 and 2010. This study employed geostatistical and multivariate statistics to obtain spatio-temporal variations of heavy metal pollution in paddy fields. The results indicate that, changes in industrial types have been altered the characteristics of pollutions, such as reducing the number of plants in industries (i.e., electroplating, surface treatments, metal works, chemicals, papermaking, etc.). Their wastewaters contained a large number of Ni, making the pollution composition of driven factors have been changed that can be indicated in this study. Pollution distribution and irrigation systems are positively correlated and concentrations of Cr, Cu, Ni, and Zn were inversely proportional to the scale of irrigation channels.