scholarly journals Heavy Metal Accumulation Affects the Structure of Microorganisms and Increases Abundance of Resistance Genes in Rare Earth Mining Areas

2021 ◽  
Author(s):  
Minjie Chen ◽  
Xiaoru Jiang ◽  
Zhansheng Mi ◽  
Yafei Li ◽  
Zhe Wang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Rare Earth ◽  
Microbial Community ◽  
Resistance Genes ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
High Throughput Sequencing ◽  
Mining Area ◽  
Mining Areas

Abstract Background Environmental pollution from rare earth mining areas is of great concern, but the impact on microbial ecology and genomics has received little attention. In this study, the relationship between heavy metals and soil microbial community in the northern rare earth mining area was explored. Methods In order to study the detoxification mechanisms of heavy metals by microorganisms in this typical rare earth mining area, the study area was divided into three parts (mining area, residential area and control area). Analysis of microbial community diversity, structure and functional abundance using high-throughput sequencing techniques. Analysis of the effect of heavy metal pollution on the abundance of heavy metal resistance genes in soils of different regions using real-time fluorescence quantitative PCR. Results The results showed that the heavy metal pollution rules: mining area > residential area > control area. Under the condition of long-term heavy metal pollution, the original microbial community composition was changed, and the species richness and evenness of soil in mining areas were higher than that in residential areas. The high-throughput sequencing analysis showed that existed metal-resistant microbial communities such as Actinobacteria, Proteobacteria, Korarchaeota and so on under the stress of heavy metal. High concentrations of heavy metals can inhibit the activities of catalase and sucrase. According to Tax4Fun function prediction analysis, heavy metal accumulation increased the ABC transporter protein in microbial function. The results of fluorescence quantification experiments also demonstrated that the abundance of heavy metal resistance genes, czcA, czcB, czcC and czcD, encoding ABC transporter proteins, increased with increasing heavy metal concentrations. Conclusions In conclusion, the accumulation of heavy metals not only changed the soil physicochemical properties and the microbial community structure, but also decreased soil enzyme activities and increased the abundance of resistance genes, which activated the detoxification mechanism of heavy metals. which provided a reference for future ecological remediation.

scholarly journals Study on soil pollution caused by heavy metals in coal mining areas and vegetation restoration in surrounding areas

2021 ◽  
Author(s):  
Xun Wang
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Coal Mining ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Soil Layer ◽  
Mining Area ◽  
Vegetation Restoration ◽  
Mining Areas ◽  
Ligustrum Lucidum

Abstract In this study, taking a coal mining area as an example, three vegetation restoration modes were designed: Populus L., Ligustrum lucidum Ait., and Amygdalus persica L., and soil and plant samples were collected to determine and evaluate the heavy metals. It was found that all the three modes were effective in eliminating heavy metal pollution in the soil, especially Populus L. and Ligustrum lucidum Ait.; in the soil layer at a depth of 0–20 cm, the content of Cd was the lowest (2.68 mg/kg) in Populus L., and the content of Cr and Pb was the lowest (58.64 mg/kg and 95.36 mg/kg) in Ligustrum lucidum Ait., which was significantly lower than that in the bare land. The evaluation results demonstrated that the pollution under Populus L. and Ligustrum lucidum Ait. modes was moderate. In the aspect of the heavy metal content in plants, the content of Cd was the lowest, and the content of Cr and Pb was high. In the same plant, the content of heavy metals in the leaf was the lowest, followed by the stem and root. The experimental results show that the vegetation restoration mode can relieve the heavy metal pollution, which makes some contributions to solve the ecological restoration problem in coal mining areas.

scholarly journals Real-Time Detection Method for Heavy Metal Pollution in Soil of Mining Area

2020 ◽  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Real Time ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Detection Method ◽  
Pollution Index ◽  
Mining Area ◽  
Pollution Sources ◽  
Real Time Detection

<p>Solid wastes and acid wastewater lead to the enrichment of heavy metals in the soil of mining area. Heavy metal pollution causes the decline of soil quality, ecosystem degradation, crop yield reduction, and even threatens human health. For this reason, the real-time detection method for heavy metal pollution in mining area is studied. Taking a mining area as an example, the data of heavy metal content in mining area soil are collected by PLSR model. Based on the collected data, the real-time detection model of heavy metal pollution in mining area soil based on improved analytic hierarchy process and weighted average method is adopted to real-time detect the heavy metal pollution index in the soil of mining area. The results show that the pollution index of Cu, Zn and Pb in the soil of this mining area belongs to heavy pollution, and the pollution of Cd is relatively small. Among them, the pollution index of Pb is the largest among the four heavy metals, and the pollution is quite serious. The pollution sources of Pb, Zn and Cu in this mining area are the same, and the pollution sources of Cd are different from those of other three heavy metals.</p>

scholarly journals Ecological Effects of Heavy Metal Pollution on Soil Microbial Community Structure and Diversity on Both Sides of a River around a Mining Area

2020 ◽  
Vol 17 (16) ◽  
pp. 5680
Author(s):  
Xingqing Zhao ◽  
Jian Huang ◽  
Xuyan Zhu ◽  
Jinchun Chai ◽  
Xiaoli Ji
Keyword(s):  
Heavy Metal ◽  
Community Structure ◽  
Microbial Community ◽  
Environmental Factors ◽  
Microbial Communities ◽  
Microbial Community Structure ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Mining Area ◽  
Soil Microbial

The objectives of this study were to understand the characteristics of heavy metal pollution caused by mining activities on the two sides of the Shun’an river and the response of soil microorganisms to the habitats by different contamination levels and vegetation. This paper selected soil samples from the banks of the Shun’an River near the Shizishan mining area, which is at the left of the river, in Tongling, Anhui Province, China. Using Illumina MiSeq 2500 technology, we analyzed the relationship between environmental factors and microbial communities. As the distance from the mining area increased, the heavy metal comprehensive pollution and potential risk value decreased. Additionally, the pollution severity and risk value of the left bank, where the mining area lies, were generally higher than those of the right bank. Because the symmetric sampling points on both banks of the river had similar planting types, their environmental factors and microbial community structure were similar and clustered. However, under different vegetation, the paddy soils tended to have a higher nutrient content and community richness and diversity than the vegetable fields or the abandoned land. It was found that soil microbial communities in this area were mostly affected by pH and Nemerow pollution index (PN). The pH significantly affected the abundance and structure of most microorganisms. In addition, Proteobacteria, Acidobacteria, and Bacteroidetes had significant tolerance to Zn, Pb, and Cd. By exploring the potential use of these tolerant microorganisms, we seek to provide strains and the theoretical basis for the bioremediation of areas contaminated by heavy metal.

scholarly journals Study of Heavy Metals and Microbial Communities in Contaminated Sediments Along an Urban Estuary

2021 ◽  
Vol 8 ◽  
Author(s):  
Jun Yi ◽  
Linus Shing Him Lo ◽  
Hongbin Liu ◽  
Pei-Yuan Qian ◽  
Jinping Cheng
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Microbial Community ◽  
Microbial Communities ◽  
Ecological Risk ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Risk Index ◽  
Estuarine Sediments ◽  
Yangtze River Estuary

Estuarine sediments are increasingly contaminated by heavy metals as a result of urbanization and human activities. Continuous multi-heavy metal accumulation in the ecosystem can provoke new effects on top of the complex environmental interactions already present in estuarine ecosystems. It is important to study their integrated influence on imperative microbial communities to reflect on the environmental and ecological risks they may impose. Inductively coupled plasma optical emission spectroscopy analysis for five metals Cd, Cr, Cu, Pb, and Zn showed that Cr and Cu concentrations in intertidal sediments of the urbanized Yangtze River estuary in China have consistently exceeded respective threshold effect concentration (TEC) levels. The geo-accumulation and potential ecological risk index results of the five metals showed that all sampling sites were weakly to moderately polluted, and at considerable to high ecological risk, respectively. Redundancy and correlation analyses showed that Zn followed by Cr in the ecosystem were explanatory of the shifts in recorded microbial community structures. However, the spatial variation in metal concentrations did not correspond to the selection of metal resistance genes (MRGs). Unlike many other dominant bacterial taxa, most of the sulfate-reducing bacteria (SRB) and associated sulfate respiration as the dominant microbially contributed ecological function were found to negatively correlate with Zn and total heavy metal pollution. Zn concentration was proposed to be a potent indicator for heavy metal pollution-associated microbial community compositional shifts under urbanized estuarine conditions. The associations between heavy metals and estuarine microbial communities in this study demonstrate the influence of heavy metals on microbial community structure and adaptations that is often overshadowed by environmental factors (i.e., salinity and nutrients).

scholarly journals Evaluating ecological risks and tracking potential factors influencing heavy metals in sediments in an urban river

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Dongping Liu ◽  
Jian Wang ◽  
Huibin Yu ◽  
Hongjie Gao ◽  
Weining Xu
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Ecological Risk ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Risk Index ◽  
Urban River ◽  
Ecological Risks ◽  
Background Values ◽  
Potential Factors

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.

scholarly journals Assessment of Heavy Metal Pollution Levels in Sediments and of Ecological Risk by Quality Indices, Applying a Case Study: The Lower Danube River, Romania

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1801
Author(s):  
Valentina Andreea Calmuc ◽  
Madalina Calmuc ◽  
Maxim Arseni ◽  
Catalina Maria Topa ◽  
Mihaela Timofti ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Ecological Risk ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Surface Sediments ◽  
Risk Index ◽  
Potential Ecological Risk ◽  
Danube River ◽  
Pollution Indices

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.

Opportunities for Biotesting of the Water Environment for Heavy Metal Pollution Using a Plant Spirodela polyrhiza (L.) Schleid

2021 ◽  
Vol 25 (5) ◽  
pp. 52-57
Author(s):  
S.I. Alekseeva ◽  
Zh.M. Okhlopkova
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Growth And Development ◽  
Water Environment ◽  
Biological Testing ◽  
Spirodela Polyrhiza ◽  
Model Object ◽  
Chlorophyll A And B

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.

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