Numerical Modeling of Heavy Metal Pollution in the Rivers

Author(s):  
maryam khalilzadeh poshtegal ◽  
Mojtaba Noury ◽  
seyed ahmad mirbagheri

<p><strong>Abstract: </strong>Based on the deep studies of existing mathematical models, a mathematical model that expresses the dynamic of transport and transformation of heavy metals in the rivers has been presented. In this model, the basic principles of chemistry in the environment, hydraulic and fluid transfer dynamics have been used as well as recent studies of researchers. The effects of sediment on the transfer and evolution of heavy metals pollution can be investigated by the proposed models. For example, the evolution and transport of heavy metal pollutants in a steady state flow containing sediment are studied using the present model. The results of theoretical analysis and calculations show that transport and transformation of heavy metal pollution in sediment laden flows, not only have common characteristics of general pollutant but also have features of transport and transformation induced by the movement of sediments.</p><p><strong>Keywords:</strong> Numerical Simulation; Heavy Metal; Pollution; Sediment; Finite Difference Method.</p>

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Muyun Sun ◽  
Kaiyuan He ◽  
Shi Shu

Despite the extensive attention paid to the transport of heavy metals in sludge landfills, the processes of transporting these pollutants from a landfill to the underground environment are quite complicated and subject to significant uncertainty. In this study, the transport of typical heavy metal pollutants in a sludge landfill through saturated and unsaturated soil zones during rainfall was investigated via numerical modeling. The objectives of the study are to evaluate the heavy metal pollution risk from a sludge landfill under rainfall infiltration conditions and to propose several management suggestions. The results indicate that, during rainfall, heavy metal concentrations at the top of the unsaturated sludge layer decrease rapidly, but they decrease more gradually at the bottom of the layer. The maximum concentration appears in vertical distribution and decreases gradually through the saturated zone. Nickel is the first heavy metal pollutant to break through the low-permeability natural silt barrier. The transport parameters not only influence the simulated time for heavy metal pollutants to break through the silt layer and cause underground environmental pollution but also affect the extent to which the heavy metal pollutants in pore water exceed the guidelines. On the basis of these results, for dredged sludge with heavy metal concentrations significantly exceeding the standard, the concentration of heavy metals in pore water should be reduced before the sludge is landfilled, and a covering layer should be established on the sludge surface to control rainfall infiltration.


2021 ◽  
Author(s):  
Guangmei Tang ◽  
Xiaole Zhang ◽  
Lanlan Qi ◽  
Chenjiao Wang ◽  
Lei Li ◽  
...  

Abstract Background: Soil heavy metal pollution is widespread around the world. Heavy metal pollutants are easily absorbed by plants and enriched in food chain, which may harm human health, cause the loss of plant, animal and microbial diversity. Plants can generally absorb soil heavy metal pollutants. Compared with hyperaccumulation plants, non-hyperaccumulator plant communities have many advantages in the remediation of heavy metals pollution in soil. However, the amount of heavy metals absorbed could be less, and the biomass would be reduced under heavy metal pollution. The application of nitrogen (N) and phosphorus (P) is inexpensive and convenient, which can increase the resistance of plants to adversity and promote the growth of plants of heavy metal polluted soils.Methods: We designed a comparative greenhouse experiment with heavy metal contaminated soils, and set up four treatments: CK treatment (soil without fertilizer), N treatment (soil with N addition), P treatment (soil with P addition), and N+P treatment (soil with N and P addition).Results: Our results showed that plant aboveground biomass were 231.17%, 14.84%, 269.86% greater than CK treatment, respectively. N and P fertilizer stimulated plants to allocate more biomass to the aboveground parts. In addition, N treatments significantly reduced the content of Cd in aboveground and belowground biomass of plants (P < 0.05); P fertilizer significantly decreased the content of Cu in aboveground biomass (P < 0.05). N+P treatments significantly reduced the content of Cd, Cu in aboveground and belowground biomass of plants (P < 0.05). Meanwhile, N and N+P significantly increased the accumulation (mg/m2) of Cd, Cu, and Pb in plant aboveground biomass (P < 0.05). N and N+P fertilizer increased aboveground-belowground heavy metals accumulation ratio (P < 0.05), promoting plants to uptake more heavy metal pollution out of soil.Conclusions: N and P fertilizer increased the accumulation of heavy metals in aboveground of the natural plant community and accelerated the absorption of heavy metals by plants, and N fertilizer had a better effect. Our results provide an inexpensive method for remediation of heavy metal pollution in low economic value soils, such as contaminated farmland, abandoned land and mine tailings, etc.


2014 ◽  
Vol 955-959 ◽  
pp. 1107-1111
Author(s):  
Shu Hong Si

This paper is mainly based on a city in surface soil heavy metal pollution on the measured GPS data,Application of the Nemeroww method to study the city all functional areas of the 8 kinds of heavy metals pollution degree.


2021 ◽  
Vol 25 (2) ◽  
pp. 207-214
Author(s):  
Jianghong Mo ◽  
Xinling Tian ◽  
Wei Shen

To effectively prevent heavy metal pollution in water sources in tourist attractions, clarify the degree of control of heavy metal pollution sources, and improve the accuracy of tracing results, a GIS-based remote sensing method of heavy metal pollution in tourist attractions is proposed. Using GIS spatial analysis method, the DEM elevation data monitored by remote sensing is obtained, the watershed geographic information is compiled, and the GPS obtains the longitude and latitude coordinates to locate the source of heavy metal pollution. The plug-in application framework is designed, and the watershed geographic information and plug-in application framework are integrated to build the pollution tracing platform. According to the mixing direction of pollutants after entering the water source, the migration and diffusion coordinate system of heavy metal pollution in the water source is established. The spatial-temporal distribution function model of heavy metal pollutants in water sources is constructed through the migration, transformation, and concentration of heavy metal pollutants in water sources. The tracing results of heavy metal pollution in water sources of scenic spots are obtained. The results showed that the order of variation coefficient of heavy metal pollution elements was Cr > Cd > Cu > Ni > Zn > Pb. The spatial distribution of heavy metal pollution elements was extremely uneven. There was a certain positive correlation between Ni and Cr, and the correlation coefficient of Cu and Zn was 0.78. The positive correlation was very significant, and the homology was very strong. Moreover, the identification result of the proposed method is very close to the real value, which can accurately trace the source of heavy metal pollution in the water source of tourist attractions, with small tracing error and high accuracy of tracing result evaluation.


2012 ◽  
Vol 518-523 ◽  
pp. 1536-1539
Author(s):  
Jian Guo Liu ◽  
Yi Cheng Huang ◽  
Jia Kuan Xu

In order to investigate the quality of agricultural environment in Wuxi, agricultural soils in 371 sampling points of seven areas in Wuxi were sampled and tested for heavy metal concentrations. Single and compositive pollution indexes were used for the evaluation of the soils. The results showed that the level of heavy metal pollution in agricultural soils of Wuxi is low, and the average compositive pollution index is 0.514, a safe grade. But the compositive pollution indexes in Binhu, Xishan and Suburb districts were higher than 0.7, a cautionary grade. The single pollution index of Cu in Xishan district was higher than 1.0, a grade of light pollution. The levels of heavy metal pollution were higher in the areas near city zones, because of dense population and concentrated industries. The major heavy metal pollutants are Cu, Hg and Cd.


2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Dongping Liu ◽  
Jian Wang ◽  
Huibin Yu ◽  
Hongjie Gao ◽  
Weining Xu

Abstract Background Heavy metal pollution of aquatic systems is a global issue that has received considerable attention. Canonical correlation analysis (CCA), principal component analysis (PCA), and potential ecological risk index (PERI) have been applied to heavy metal data to trace potential factors, identify regional differences, and evaluate ecological risks. Sediment cores of 200 cm in depth were taken using a drilling platform at 10 sampling sites along the Xihe River, an urban river located in western Shenyang City, China. Then they were divided into 10 layers (20 cm each layer). The concentrations of the As, Cd, Cr, Cu, Hg, Ni, Pb and Zn were measured for each layer. Eight heavy metals, namely Pb, Zn, As, Cd, Cr, Cu, Ni, and Hg, were measured for each layer in this study. Results The average concentrations of the As, Cd, Cu, Hg, and Zn were significantly higher than their background values in soils in the region, and mainly gathered at 0–120 cm in depth in the upstream, 0–60 cm in the midstream, and 0–20 cm downstream. This indicated that these heavy metals were derived from the upstream areas where a large quantity of effluents from the wastewater treatment plants enter the river. Ni, Pb, and Cr were close or slightly higher than their background values. The decreasing order of the average concentration of Cd was upstream > midstream > downstream, so were Cr, Cu, Ni and Zn. The highest concentration of As was midstream, followed by upstream and then downstream, which was different to Cd. The potential factors of heavy metal pollution were Cd, Cu, Hg, Zn, and As, especially Cd and Hg with the high ecological risks. The ecological risk levels of all heavy metals were much higher in the upstream than the midstream and downstream. Conclusions Industrial discharge was the dominant source for eight heavy metals in the surveyed area, and rural domestic sewage has a stronger influence on the Hg pollution than industrial pollutants. These findings indicate that effective management strategies for sewage discharge should be developed to protect the environmental quality of urban rivers.


Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1801
Author(s):  
Valentina Andreea Calmuc ◽  
Madalina Calmuc ◽  
Maxim Arseni ◽  
Catalina Maria Topa ◽  
Mihaela Timofti ◽  
...  

It is a well–known fact that heavy metal pollution in sediments causes serious problems not only in the Danube basin, but also in the large and small adjacent river streams. A suitable method for assessing the level of heavy metals and their toxicity in sediments is the calculation of pollution indices. The present research aims to assess heavy metal pollution in the Lower Danube surface sediments collected along the Danube course (between 180 and 60 km) up to the point where the Danube River flows into the Danube Delta Biosphere Reserve (a United Nations Educational, Scientific and Cultural Organization – UNESCO, protected area). In addition, this monitored area is one of the largest European hydrographic basins. Five heavy metals (Cd, Ni, Zn, Pb, Cu) were analyzed in two different seasons, i.e., the autumn of 2018 and the spring of 2019, using the Inductively Coupled Plasma Mass Spectrometry (ICP– MS) technique. Our assessment of heavy metal pollution revealed two correlated aspects: 1. a determination of the potential risks of heavy metals in sediments by calculating the Potential Ecological Risk Index (RI), and 2. an evaluation of the influence of anthropogenic activities on the level of heavy metal contamination in the surface sediments, using three specific pollution indices, namely, the Geo–Accumulation Index (Igeo), the Contamination Factor (CF), and the Pollution Load Index (PLI). The results of this pioneering research activity in the region highlighted the presence of moderate metal (Ni and Cd) pollution and a low potential ecological risk for the aquatic environment.


2021 ◽  
Vol 25 (5) ◽  
pp. 52-57
Author(s):  
S.I. Alekseeva ◽  
Zh.M. Okhlopkova

The methods of biotesting of the aquatic environment based on the representative of the duckweed family (lat. Lemnaceae) greater duckweed (Spirodela polyrhiza (L.) Schleid) were considered. A review is presented on the use of greater duckweed as a model object in biological testing, in partic-ular, when exposed to heavy metals salts. When cultivated Spirodela polyrhiza with the addition of heavy metals salts, a change in the growth and development of plants in the experienced line of plants was revealed, as well as a decrease in the content of chlorophyll a and b.


2021 ◽  
Author(s):  
Concepcion Pla ◽  
Javier Valdes-Abellan ◽  
Miguel Angel Pardo ◽  
Maria Jose Moya-Llamas ◽  
David Benavente

&lt;p&gt;The impervious nature of urban areas is mostly responsible for urban flooding, runoff water pollution and the interception of groundwater recharge. Green infrastructure and sustainable urban drainage systems combine natural and artificial measures to mitigate the abovementioned problems, improving stormwater management and simultaneously increasing the environmental values of urban areas. The actual rate of urban growth in many urban areas requires the enhancement and optimization of stormwater management infrastructures to integrate the territorial development with the natural processes. Regarding the quality of runoff stormwater, heavy metals are critical for their impact on human health and ecological systems, even more if we consider the cumulative effect that they produce on biota. Thus, innovative stormwater management approaches must consider new solutions to deal with heavy metal pollution problems caused by runoff. In this study, we propose the employment of Arlita&lt;sup&gt;&amp;#174;&lt;/sup&gt; and Filtralite&lt;sup&gt;&amp;#174;&lt;/sup&gt;, two kind of lightweight aggregates obtained from expanded clays, to remove heavy metal concentration from runoff stormwater. Laboratory experiments were developed to evaluate the removal rate of different heavy metals existent in runoff stormwater. The lightweight aggregates acted as filter materials in column experiments to quantify their removal capacity. In addition, batch tests were also developed to evaluate the exhaustive capacity of the materials. Results from the study confirmed the efficiency of the selected lightweight aggregates to reduce the heavy metals concentration by up to 90% in urban stormwater runoff.&lt;/p&gt;


RSC Advances ◽  
2017 ◽  
Vol 7 (30) ◽  
pp. 18421-18427 ◽  
Author(s):  
Haiming Wu ◽  
Li Lin ◽  
Guangzhu Shen ◽  
Ming Li

The risk of heavy metals to aquatic ecosystems was paid much attention in recent years, however, the knowledge on effects of heavy metals on dissolved organic matter (DOM) released byMicrocystiswas quite poor, especially in eutrophic lakes.


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