scholarly journals Heavy Metal Contents and Assessment of Soil Contamination in Different Land-Use Types in the Qaidam Basin

2021 ◽  
Vol 13 (21) ◽  
pp. 12020
Author(s):  
Bayan Nuralykyzy ◽  
Pan Wang ◽  
Xiaoqian Deng ◽  
Shaoshan An ◽  
Yimei Huang
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Land Use ◽  
Soil Contamination ◽  
Qaidam Basin ◽  
Rapid Development ◽  
Quality Standard ◽  
Soil Heavy Metal ◽  
Land Use Types ◽  
Metal Contents

Due to the unique geographical location and rapid development in the agricultural industry, heavy metals’ risk of soil contamination in the Qaidam Basin is gradually increasing. The following study was conducted to determine the soil heavy metal contents under different types of land use, contamination levels, and the physicochemical properties of soil. Soil samples were collected from facility lands, orchards, farmlands, and grasslands at 0–10 and 10–20 cm soil layers. Heavy metals including copper (Cu), chromium (Cr), nickel (Ni), zinc (Zn), lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg) were analyzed using inductively coupled plasma mass spectrometry and the soil was evaluated with different methods. Overall, the average Cu (25.07 mg/kg), Cr (45.67 mg/kg), Ni (25.56 mg/kg), Zn (71.24 mg/kg), Pb (14.19 mg/kg), Cd (0.17 mg/kg), As (12.54 mg/kg), and Hg (0.05 mg/kg) were lower than the environmental quality standard. However, the Cu, Cr, Ni, and As were highest in farmland, and Zn and Hg were highest in the facility land. The Pb content was highest in orchards, and the Cd content was the same in facility land, orchards, and farmland. Among the different land-use types, the soil heavy metal concentrations decreased in the order of facility land > farmland > grassland > orchards. The pH was alkaline, the content of SOC (soil organic carbon) 15.76 g/kg in grassland, TN (total nitrogen) 1.43 g/kg, and TP (total phosphorus) 0.97 g/kg in facility land showed the highest result. The soil BD (bulk density) had a significant positive correlation with Cu, Cr, Ni, Zn, Pb, Cd, and the TP positively correlated with Cu, Zn, Cd, and Hg. The soil evaluation results of the comprehensive pollution index indicated that the soil was in a clean condition. The index of potential environmental risk indicates that heavy metals are slightly harmful to the soil.

scholarly journals Integrating a Hybrid Back Propagation Neural Network and Particle Swarm Optimization for Estimating Soil Heavy Metal Contents Using Hyperspectral Data

2019 ◽  
Vol 11 (2) ◽  
pp. 419 ◽  
Author(s):  
Piao Liu ◽  
Zhenhua Liu ◽  
Yueming Hu ◽  
Zhou Shi ◽  
Yuchun Pan ◽  
...  
Keyword(s):  
Neural Network ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Back Propagation ◽  
Back Propagation Neural Network ◽  
Hyperspectral Data ◽  
Estimation Accuracy ◽  
Soil Heavy Metals ◽  
Soil Heavy Metal ◽  
Metal Contents

Soil heavy metals affect human life and the environment, and thus, it is very necessary to monitor their contents. Substantial research has been conducted to estimate and map soil heavy metals in large areas using hyperspectral data and machine learning methods (such as neural network), however, lower estimation accuracy is often obtained. In order to improve the estimation accuracy, in this study, a back propagation neural network (BPNN) was combined with the particle swarm optimization (PSO), which led to an integrated PSO-BPNN method used to estimate the contents of soil heavy metals: Cd, Hg, and As. This study was conducted in Guangdong, China, based on the soil heavy metal contents and hyperspectral data collected from 90 soil samples. The prediction accuracies from BPNN and PSO-BPNN were compared using field observations. The results showed that, 1) the sample averages of Cd, Hg, and As were 0.174 mg/kg, 0.132 mg/kg, and 9.761 mg/kg, respectively, with the corresponding maximum values of 0.570 mg/kg, 0.310 mg/kg, and 68.600 mg/kg being higher than the environment baseline values; 2) the transformed and combined spectral variables had higher correlations with the contents of the soil heavy metals than the original spectral data; 3) PSO-BPNN significantly improved the estimation accuracy of the soil heavy metal contents, with the decrease in the mean relative error (MRE) and relative root mean square error (RRMSE) by 68% to 71%, and 64% to 67%, respectively. This indicated that the PSO-BPNN provided great potential to estimate the soil heavy metal contents; and 4) with the PSO-BPNN, the Cd content could also be mapped using HuanJing-1A Hyperspectral Imager (HSI) data with a RRMSE value of 36%, implying that the PSO-BPNN method could be utilized to map the heavy metal content in soil, using both field spectral data and hyperspectral imagery for the large area.

scholarly journals Inoculation of paddy soils with Rhodopseudomonas palustris enhanced heavy metal immobilisation

2021 ◽  
Vol 67 (No. 1) ◽  
pp. 55-60
Author(s):  
Xian Xiao ◽  
Yan Zhu ◽  
Yuexiang Gao ◽  
Jing Fu ◽  
Yuan Zhao ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Bacillus Subtilis ◽  
Rhodopseudomonas Palustris ◽  
Paddy Soils ◽  
Optimal Dosage ◽  
Soil Heavy Metal ◽  
Rice Grains ◽  
Pot Experiments ◽  
Metal Contents

To investigate the effect of microbial inoculum on soil heavy metal immobilisation, pot experiments were conducted with paddy soils contaminated by cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg), respectively. The results showed that the inoculation of Rhodopseudomonas palustris was more effective in the immobilisation of Pb and Cd in soils than the composite of R. palustris and Bacillus subtilis. Interestingly, a lower dosage of inoculum immobilised significantly more heavy metals than the higher dosage, potentially due to the competition of bacteria with limited nutrients. The heavy metal contents in rice grains also supported this finding, as less Pb and Cd were accumulated under the lower dosage. However, there were limited effects of microbial inoculations on the immobilisation of Hg and As. In general, our study indicated the effectiveness of R. palustris in immobilising Pb and Cd in soils and highlighted the importance of determining the optimal dosage of inoculum in bioremediation.  

scholarly journals Effect of Land Use Conversion on Surface Soil Heavy Metal Contamination in a Typical Karst Plateau Lakeshore Wetland of Southwest China

2019 ◽  
Vol 17 (1) ◽  
pp. 84
Author(s):  
Caili Sun ◽  
Sixi Zhu ◽  
Bin Zhao ◽  
Wujiang Li ◽  
Xiaoye Gao ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Land Use ◽  
Metal Contamination ◽  
Southwest China ◽  
Heavy Metal Contamination ◽  
Waste Treatment ◽  
Surface Soil ◽  
Land Use Conversion ◽  
Soil Heavy Metal ◽  
Land Use Types

Land use conversion could directly or indirectly influence heavy metal geochemistry by changing soil properties. The aim of this study was to explore the effect of land use conversion on surface soil heavy metal contamination in the karst plateau lakeshore wetlands of Southwest China. Based on this, a total of 120 soil samples were collected from 30 sites from different types of land uses (farmlands, grasslands and woodlands) around a lake in Suohuangcang National Wetland Park in August 2017. Contents of As, Cd, Cu, Cr, Hg, Pb and Zn were analyzed, and soil heavy metal contamination was assessed in all three land use types. Results showed that land use transformation from farmland to grassland or woodland was not conducive to the release of soil heavy metal. Surface soil of all three land use types have been moderately polluted by As, Cr, Pb, and Zn, and grassland and woodland also had moderate Cd contamination. The pollution load index (PLI) results revealed low heavy metal contamination in grassland and woodland but no contamination in farmland. Although the integrated contamination in the studied region did not pose a serious potential ecological risk (RI < 150), it might affect human health through the water supply and food chain. Therefore, it is necessary to monitor and control As, Cd, Cr, Pb, and Zn concentrations of surface soil through controlling pollutants, improving waste treatment, as well as strengthening supervision and management in the vicinity of the Suohuangcang National Wetland Park.

Analysis of the Change of Heavy Metal Contents in Farmland in Mengcheng

2012 ◽  
Vol 178-181 ◽  
pp. 773-776
Author(s):  
Guo Wei Xu ◽  
Xue Wu ◽  
Su Ling Huang ◽  
Xin Tian Yuan ◽  
Yang Gao ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Content ◽  
Heavy Metal Content ◽  
National Standard ◽  
Soil Heavy Metal ◽  
Metal Contents ◽  
Survey Results ◽  
Changing Rate

In order to find out the variations of soil heavy metal contents in Mengcheng, the heavy metal of the soil was tested in the same way in 2010, based on the survey results of 2001. The results showed that the contents of the 8 kinds of heavy metal in Mengcheng County were lower than those of the national standard, but the heavy metal content of Mengcheng County in 2010 were significantly higher than those in 2001, especially Pb, and the content of Hg, Ni, As also increased greatly; The increased of changing rate of various heavy metals contents are in the following descending order: Pb> Hg> Ni> As> Cu> Cd> Cr> Zn. The uneven dispersion of various heavy metals element in different sections of Mengcheng County also increased.

scholarly journals Study on the Immobilization Technology of Hydroxyapatite in Heavy Metal Contaminated Sediment

2021 ◽  
Author(s):  
Yunfei Li
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Rapid Development ◽  
Quality Standard ◽  
Curing Agent ◽  
Contaminated Sediment ◽  
Overlying Water ◽  
Metal Pollutants ◽  
Immobilization Technology ◽  
Heavy Metal Pollutants

With the rapid development of industry, large amounts of untreated industrial waste water and domestic sewage carried heavy metal pollutants below into the water body with enrichment in sediments. When environmental conditions change, enrichment of heavy metals in sludge may be released into the overlying water causing the overlying water quality standard. The agent on immobilization of heavy metals in sludge is to be an extremely promising remediation technology in order to reduce impact on the environment. This test selects Hydroxyapatite and Nano Hydroxyapatite as curing agent and puts it into heavy metal pollution by different proportion. The paper conducts the research of curing agent and optimizes the better one. The paper selected HAP as matrix and CaO and MgO as different additives and studied complex condition of heavy metals in sediment of curing effect. Also the paper conduct the static releases test for pollutants in cured sediment in order to provide technical support for contaminated sediment remediation of heavy metal.

scholarly journals Assessment of Heavy Metal Contamination in Saguling Reservoir Water West Java Province Indonesia

2018 ◽  
Vol 73 ◽  
pp. 06009
Author(s):  
Wardhani Eka ◽  
Notodarmojo Suprihanto ◽  
Roosmini Dwina
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Water Samples ◽  
Heavy Metal Contamination ◽  
Quality Standard ◽  
Sampling Location ◽  
West Java ◽  
Reservoir Water ◽  
Metal Contents ◽  
Mean Concentration

Saguling reservoir in West Java Province is becoming increasingly polluted by heavy metals. The purpose of this study was to determine the level of four heavy metals such as Cd, Cr, Cu, and Pb concentration at Saguling Reservoir at ’2 sampling location. Water samples were collected during rainy and summer 2008-2017 to determine the spatial distribution seasonal and temporal variation of different heavy metal contents. Mean metals concentrations in summer seasons were Cd, Cr, Cu, and Pb higher than rainy season. Mean concentration of Cd, Cu, Cr, and Pb in water samples were accordance water quality standard in both season. Heavy metal pollution that occurs in the Saguling reservoir must be monitored because this reservoir is planned to be a source of raw water for Bandung City.

scholarly journals The spatial distribution pattern of heavy metal concentrations in urban soils — a study of anthropogenic effects in Berehove, Ukraine

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Tímea Vince ◽  
György Szabó ◽  
Zoltán Csoma ◽  
Gábor Sándor ◽  
Szilárd Szabó
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Land Use ◽  
Spatial Distribution ◽  
Statistical Analysis ◽  
Urban Soils ◽  
Heavy Traffic ◽  
Anthropogenic Activity ◽  
Limit Values ◽  
Metal Contents

AbstractIn the present study we examined the Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn contamination levels of the soils of Berehove, a small city in West-Ukraine. As a first step we determined the spatial distribution of the heavy metal contents of the urban soils; then, by studying the land use structure of the city and by statistical analysis we identified the major sources of contamination; we established a matrix of correlations between the heavy metal contents of the soils and the different types of land use; and finally, we drew a conclusion regarding the possible origin(s) of these heavy metals. By means of multivariate statistical analysis we established that of the investigated metals, Ba, Cd, Cu, Pb and Zn accumulated in the city’s soils primarily as a result of anthropogenic activity. In the most polluted urban areas (i.e. in the industrial zones and along the roads and highways with heavy traffic), in the case of several metals (Ba, Cd, Cu, Pb, Zn) we measured concentration levels even two or three times higher than the threshold limit values. Furthermore, Cr, Fe and Ni are primarily of lithogenic origin; therefore, the soil concentrations of these heavy metals depend mainly on the chemical composition of the soil-forming rocks.

scholarly journals Vermi-remediation of Heavy Metal-Contaminated Soil

2013 ◽  
Vol 3 (4) ◽  
pp. 4-10 ◽  
Author(s):  
Suneet V. Dabke
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Soil Contamination ◽  
Heavy Metal Contamination ◽  
Low Cost ◽  
Rapid Development ◽  
Nutrient Balance ◽  
Industrial Facilities ◽  
Earthworm Population ◽  
Cadmium And Lead

Background. Rapid development in India has lead to pollution around industrial facilities. Earthworms are tolerant of many contaminants, and some are reported to remove heavy metals and pesticides from soil via tissue accumulation. Earthworm activity also increases levels of beneficial microbes. Objectives. Test vermi-remediation as a low-cost, on-site method of remediating heavy metal soil contamination. Methods. Soil was assessed for heavy metal contamination. Existing worm population was estimated via sampling, then the soil supplemented with beneficial bacteria, compost and a proprietary earthworm growth accelerator. Site was seeded with grass and maize, and Eisenia fetida worms introduced. Earthworm population was studied and soil contamination and accumulation in maize roots analyzed at the end of the project. Discussion. Worms were expected to remove heavy metals via bio-accumulation and also stimulate microbial remediation by increasing soil micro-organisms. Conclusions. The study showed positive results, with a reduction in chromium and survival of introduced earthworms, which reproduced after soil treatment, indicating improved conditions. Chromium concentrations were reduced to as low as 4.54mg/kg from a high of 194.17 mg/kg. There was variation in iron content and a controlled reduction in cadmium and lead. Due to limited funding, further study of the soil's final nutrient balance and earthworm analysis was not possible. Further study is necessary.

Divergent response of heavy metal bioavailability in soil rhizosphere to agricultural land use change from paddy field to various drylands

2021 ◽  
Author(s):  
Yujuan Gao ◽  
Jianli Jia ◽  
Beidou Xi ◽  
Dongyu Cui ◽  
Wenbing Tan
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Land Use ◽  
Land Use Change ◽  
Agricultural Land ◽  
Rhizosphere Soil ◽  
Agricultural Land Use ◽  
Metal Bioavailability ◽  
Soil Rhizosphere ◽  
Divergent Response

The heavy metal pollution induced by agricultural land use change has attracted great attention. In this study, the divergent response of bioavailability of heavy metals in rhizosphere soil to different...

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