Content Of Heavy Metals In Soil Research Articles

Heavy metal contamination risk assessment and correlation analysis of heavy metal contents in soil and crops.

Heavy metal pollution is a notable threat to agricultural production. Soil heavy metal pollution can cause potential ecological risk (ERI), and crop heavy metal pollution can cause human health risk (HRI). However, most previous studies partially focused on heavy metal pollution in soil or crop but often neglected the relationship between them. Actually, soil heavy metal can pollute crops to some extent, while not all heavy metal pollution in crops comes from soil. The inner relationship of pollution risk in soil-crop system is worth attention. In this study, we selected Ningbo as the study region and used sample data to assess both soil and crop heavy metal risks, in order to explore the differences between heavy metal contamination risks in soil and crops as well as the relationships between heavy metal contents in soil and crops. Our results showed that Hg was the most polluted heavy metal in soil, which led to the highest ecological risk in Jiangbei (Comprehensive ERI=567) with the maximum ERI of Hg (430). However, As in crops contributed the most to health risk and caused the highest health risk in Fenghua (HRI=10) with the largest contribution of 64.5%. Such differences of pollution risk assessment indicated that the contents of the same heavy metal were inconsistent in soil and crops. Our results further showed that the heavy metals in soil had the greatest influence on Zn in crops. Pb and Cr in soil had synergistic effects on the crop absorption of Zn, whereas As, Hg and Cu played antagonistic roles in the crop absorption of Zn. Our study confirms that heavy metals in soil would variously influence heavy metals in crops and the interaction of heavy metals is very important for pollution risk control, which have been largely ignored yet.

Heavy Metal Contents of Soil and Surface Dust and Its Ecological Risk Analysis in a Multifunctional Industrial Park

A multifunctional industrial park can perform both producing and living functions. The smelting and processing of non-ferrous metals may lead to soil pollution, posing risks to human beings. In this study, an industrial park located in central Anhui Province, China, with copper (Cu) processing and mechanical components as the main industries, was selected as the study object. By collecting and testing soil and dust samples, the horizontal and vertical distribution characteristics of heavy metals in soil and dust in the park were analyzed. The ecological risk index is used to identify areas with higher risks and correlation and principal component analysis are used to disclose the potential source of heavy metals. Results showed that the contents of Cu, Zn, As, Pb, and Cd in the soil were 2.65, 1.76, 1.56, 2.14, and 3.87 times that of the background value, respectively. The heavy metal content of dust was significantly higher than that of soil, with contents of Cr, Ni, Cu, Zn, Hg, As, Pb, and Cd of 1.93, 1.05, 7.57, 4.63, 6.08, 5.39, 2.58, and 5.50 times that of the background value, respectively. Horizontally, the areas with higher ecological risks concentrated in the western part of the park, while vertically there was no significant trend with increases in soil depth. For the dust samples, areas with high ecological risks were closer to the main traffic arteries. Principal component analysis indicated that the main source of heavy metal in western soils was probably irrigation with contaminated river water. Road traffic, on the other hand, is more likely to be the main contributor to high dust heavy metal levels. This result is important for the park to control the potential health risks caused by heavy metals through zoning management according to the functions of different areas.

Predictive model of heavy metals inputs to soil at Kryvyi Rih District and its use in the training for specialists in the field of Biology

The importance of our research is due to the need to introduce into modern biological education methods of predictive modeling which are based on relevant factual material. Such an actual material may be the entry of natural and anthropic heavy metals into the soil at industrial areas. The object of this work: (i) to work out a predictive model of the total heavy metals inputs to soil at the Kryvyi Rih ore-mining & metallurgical District and (ii) to identify ways to use this model in biological education. Our study areas are located in the Kryvyi Rih District (Dnipropetrovsk region, Central Ukraine). In this work, classical scientific methods (such as analysis and synthesis, induction and deduction, analogy and formalization, abstraction and concretization, classification and modelling) were used. By summary the own research results and available scientific publications, the heavy metals total inputs to soils at Kryvyi Rih District was predicted. It is suggested that the current heavy metals content in soils of this region due to 1) natural and 2) anthropogenic flows, which are segmented into global and local levels. Predictive calculations show that heavy metals inputs to the soil of this region have the following values (mg ⋅ m2/year): Fe – 800-80 000, Mn – 125-520, Zn – 75-360, Ni – 20-30, Cu – 15-50, Pb – 7.5-120, Cd – 0.30-0.70. It is established that anthropogenic flows predominate in Fe and Pb inputs (60-99 %), natural flows predominate in Ni and Cd inputs (55-95 %). While, for Mn, Zn, and Cu inputs the alternate dominance of natural and anthropogenic flows are characterized. It is shown that the predictive model development for heavy metals inputs to soils of the industrial region can be used for efficient biological education (for example in bachelors of biologists training, discipline “Computer modelling in biology”).

Hyperspectral inversion of soil heavy metals in Three-River Source Region based on random forest model

Hyperspectral remote sensing technology has considerable research value in monitoring and evaluating soil heavy metal pollution. In this study, the Three-River Source Region was taken as the study area. The occurrence relationship of six heavy metals in soil, such as Mn, Cu, Zn, Pb, Cr, Ni, with soil organic matter, clay minerals, and iron-manganese oxides, was studied through the determination and analysis of soil samples and the collection of soil reflectance spectrum. Spectral transformation was carried out by first derivative, second derivative, inverse-log, continuum removal and multiple scattering correction of the spectrum. The correlation between soil heavy metal content and soil spectrum was analyzed to select the characteristic band, and partial least squares (PLS) method, support vector machine (SVM) method and random forest (RF) model were used to build inversion model based on characteristic band. Then the best combination of spectral transformation and inversion model were explored. The results showed that Pb contents were the twice of the background in Qinghai province. The combination spectrum processing method can improve the correlation between spectrum and heavy metals. The location and quantity of characteristic bands of six heavy metals are different. The accuracy of RF was significantly better than that of SVM and PLS for all six heavy metal (i.e. pb: R2RF = 0.83, R2SVM = 0.62, R2PLS = 0.18), and the model effective of soil properties in non-polluted sites were reliable (i.e. clay: R2RF = 0.93, R2SVM = 0.87, R2PLS = 0.74). This study can provide technical support for the larger-scale monitoring of soil heavy metal content and heavy metal pollution assessment.

Successful Plant Growth-Promoting Microbes: Inoculation Methods and Abiotic Factors

Plant-microbe interactions have been the subject of several biotechnological studies, seeking sustainable development and environmental conservation. The inoculation of plant growth-promoting microbes (PGPM) in agricultural crops is considered an environmental-friendly alternative to chemical fertilization. Microbial inoculants are mainly inoculated onto seeds, roots and soil. PGPM improve plant growth by enhancing the availability of nutrients, the regulation of phytohormones, and by increasing plant tolerance against biotic and abiotic stresses. One of the main obstacles with PGPM research are the inconsistent results, which may be the result of inoculation methods and abiotic factors, such as soil (nutrient or heavy metal contents and pH), water availability, light intensity and temperature. This review addresses how the PGPM inoculants act on plant growth, what mechanisms they use to survive under stressful environmental conditions, and how inoculation methods and abiotic factors can interfere on the success of microbial inoculation in plants, serving as a basis for research on plants-microorganisms interaction.

Влияние антропогенного загрязнения среды г. Тюмени на показатели жизнедеятельности травянистых растений

The purpose of this study was the investigation of lipid peroxidation products and photosynthetic pigment content in cells of herbs of various species in conditions of anthropogenic pollution of Tyumen. The material for the research was collected near different plants of Tyumen: metallurgical, engine, oil refinery, battery manufacturing as well as highway pollution. The following species of plants were analysed: coltsfoot (Tussilago farfara), red clover (Trifolium rubens), chamomile (Matricaria chamomilla) and wild vetch (Vicia cracca). Heavy metal concentration in soils of urban areas turned out to be elevated compared to background sites. Especially high heavy metal content was registered near metallurgical and battery manufacturing plants. Changes in photosynthetic pigment concentration turned out to be species-specific. An increase in photosynthetic pigments was obtained in chamomile cells, while in other plants oppression of photosynthetic apparatus was revealed. Concentration of lipid peroxidation cells of chamomile, meadow grass and wild vetch was increased compared to background site, while in coltsfoot and red clover it decreased. Heavy metal content in soils positively correlated with lipid peroxidation in plants. Oxidation stress in chamomile cells created energetic starvation, which was reflected in a positive correlation between photosynthetic pigments and the concentration of conjugated dienes in cells.

Spatial heterogeneity of soil heavy metal content in Baiyinhua mining area, Inner Mongolia, China.

To evaluate the spatial distribution characteristics of soil heavy metal content in Xiwuzhumuqin Banner, Inner Mongolia, we analyzed the spatial heterogeneity of soil Cu, Cr, Pb, and Mn contents within 8 km distance of the mining area. Results showed that the contents of Cu, Cr, Pb and Mn in soil were 12.7, 32.6, 29.9 and 201.3 mg·kg-1, and their coefficients of variation were 26.8%, 33.9%, 27.1% and 45.7%, respectively. According to the model fitting by semi-variance function, the spatial distribution of Cu, Cr, Pb and Mn were consistent with the Gaussian model, Gaussian model, Gaussian model and linear model, respectively. Results of the spatial distribution pattern analysis showed that the spatial correlation levels of Mn, Cr and Cu were high, which were mainly affected by structural factors, but little affected by random factors. The spatial correlation level of Pb element was moderate, which was affected by both structural factors and random factors. Results of the fractal dimension analysis showed that the spatial distribution of four heavy metal contents was simple. Combined with 2D and 3D views, the four types of heavy metals all presented gradient distribution, which decreased with the increases of distance. The contents of Cu and Mn were mainly concentrated within 1.5 km from the mining area, while Cr and Pb were mainly concentrated within 2.0 km and 3.0 km from the mining area, respectively.

Characteristics of Soil Heavy Metal Contents and its Source Analysis in Affected Areas of Luning Coal Mine in Huaibei Coalfield

Characteristics of Soil Heavy Metal Contents and its Source Analysis in Affected Areas of Luning Coal Mine in Huaibei Coalfield

Effect of Mechanic Village Activities on Selected Soil Properties in Abakaliki Southeastern Nigeria

The study was conducted to evaluate the effect of mechanic village on selected soil physico-chemical properties and heavy metals content in Abakaliki Southeastern Nigeria. Five replicate soil samples were collected from arable land (Control), lorry automobile repair site (Lorry), motorcycle automobile repair site,(motorcycle) car and bus repair site(car and bus), automobile spare parts market (spare parts). These samples were taken to laboratory for the determination of selected soil physico-chemical properties and heavy metal content. The data obtained from this research was analysed using analysis of variance (ANOVA) based on CRD and difference between treatment means were dictated using F-LSD at P < 0.05. The result showed significantly (p < 0.05) adverse effect among the different automobile locations studied with respect to control in bulk density, total porosity, mean weight diameter and aggregate stability. The chemical properties of soils of mechanic village were also significantly adversely affected by mechanic village. The observed heavy metals in mechanic village were higher than the recommended ranges in soils. Therefore, it advisable that some agronomical practices that could increase the nutrients and lower the heavy metals level should be employed in order to get high crop yield and safe produce.

Soil Mesofauna Community Changes in Response to the Environmental Gradients of Urbanization in Guangzhou City

There has been a recent increase in interest on how urbanization affects soil fauna communities. However, previous studies primarily focused on some limited land use types or line transects of urban-rural gradients. At family and higher taxonomic levels, we investigated the changes of soil mesofauna communities (abundance, species richness, and community structure) with urbanization intensity along different disturbance features in 47 sites evenly located in downtown Guangzhou and adjacent regions. The 47 research sites were classified into four ecosystem types mainly according to the location (rural/urban), vegetation cover, and management intensity. In turn, the four types with increasing urbanization intensity were rural forest, urban forest, urban woodland, and urban park. Firstly, the role of urban soil property (soil physicochemical characteristic and soil heavy metal content) in regulating soil mesofauna community was investigated. The results showed that soil mesofauna abundance and diversity decreased with increasing soil pH, total nitrogen content (TN), and heavy metal comprehensive index (CPI). Soil Pb decreased soil mesofauna species richness (taxa number) and regulated soil mesofauna community structure. Secondly, we examined the effects of landscape changes on the soil mesofauna community. We found impervious surface (IS) ratio did not predict changes in soil mesofauna abundance, species richness, or community structure. Instead, IS ratio was positively correlated with soil pH, soil TN, and CPI. After excluding sites that belonged to rural forests and urban parks, site area was positively correlated with soil mesofauna abundance. Thirdly, our results revealed significant differences in soil property, landscape trait, and soil mesofauna community among the four ecosystem types. Interestingly, urban forest, the one lightly disturbed by urbanization, but not rural forest, had the highest soil mesofauna abundance. Soil mesofauna abundance in urban woodlands was similar to that in urban parks, which was about half of that in urban forests. Species richness in urban parks was 21% lower than that in rural forests. Our results also showed that urban woodland and urban parks had distinct mesofauna community structures compared to those in rural forests and urban forests. In conclusion, the present study suggested that (1) soil property changes due to urbanization, such as increased pH and heavy metal enrichment in urban soil, decreased soil mesofauna abundance and species richness, changed community structure, and mediated the effect of landscape change on soil mesofauna community; (2) however, soil and landscape changes could not explain the increase of abundance in urban forests, which supported the intermediate disturbance hypothesis.

Physico-chemical Characteristics and Heavymetal contents in Soil of South West EL-Fasher City,Western Sudan.

The objectives of this study were to assess levels of trace and heavy elements in South west EL-Fasher cityin North Darfur soils and to provide information regarding accumulation of these metalsin top and sub-soils and to determine the most important soil factors (chemical and physical) which influence trace and heavy elements concentrations in soil.Top and sub-soil samples were taken at various locations in South west EL-Fasher city. The soil characterization was carried out for parameters like pH, E.C, O.C, M.C, soil texture, and trace and heavy elements (Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb and Zn). The results obtained in this research work provides documentation of the relationship between physicochemical properties and heavy metals concentrations in soils of North Darfur. The pH was found to be slightly alkaline. The values of E.C indicated that all samples of the soils are non-saline. Fe, Mn, Cr, Zn and Cu were distributed in very high concentrations compared to other metals. This study will help the industrial section and can be benefit from it for commercial purposes.There were obvious differences in correlation coefficients among the selected criteria (65.6% from total number of correlated between pH and some other selected physicochemical characteristics, whereas 42.3% from the total number were positive correlated between soil texture and some other selected physicochemical characteristics. This study can serves as a database of trace and heavy elements build-up in soil, allowing preventive actions to be taken.

Analysis of Heavy Metal Contents of Marsilea crenata Presl. Leaves and Soils from East Java Province, Indonesia

Introduction: Marsilea crenata Presl. grows in East Java Province, Indonesia, and showed several pharmacological activities due to its phytoestrogen content. Research indicated its phytoremediation property, and therefore has an impact on heavy metal accumulation in the plants. Lead, cadmium, and mercury are amongst heavy metals that are toxic to the human body. This study aimed to determine and compare Pb, Cd, and Hg mineral contents of soils and leaves of the plants grew in Batu, Pasuruan, Surabaya, and Kediri cities in the province. Method: 10 g of dried powdered leaves and soils were put in separate crucible porcelains, and add 2ml of nitric acid. All were burnt in low heat until white smoke were not formed, and then stood to cool. Ashes obtained were examined using AA 6200 Atomic Absorption Spectrometer (AAS). Result: Showed that leaves samples from the areas showed no Pb and Hg mineral contents that exceeded the permissible limit. Batu City leaf sample had Cd heavy metal content of 2.79 ± 0.01 ppm, which exceeded the permissible limit. Conclusion: Analysis of heavy metal contents of soils from all of the areas showed no exceed limit of Pb and Hg mineral concentrations. Cd soil contents of Surabaya and Kediri cities, were 0.73 ± 0.00 and 2.61 ± 0.08 ppm respectively.

Heavy metal pollution characteristics and assessment of environmental quality and safety of facility agriculture soil in Shouguang

Taking Shouguang Facility agriculture in Weifang City as the research object, heavy metals and other pollutants in new and old facility agriculture soil were investigated and analyzed from 2017 to 2019. The content of heavy metals in soil was analyzed, and the environmental quality of heavy metals was evaluated by single-factor pollution index method and Nemerow index method. The correlation between heavy metal content in surface soil and cultivation years, vertical distribution of heavy metal content in soil, frequency distribution of heavy metal in surface soil, and correlation between heavy metals in surface soil and soil nutrients were analyzed. The results showed that the average contents of the eight heavy metals were Cd 0.23 mg•kg−1, Hg 0.05 mg•kg−1, As 8.09 mg•kg−1, Pb 23.31 mg•kg−1, Cr 70.81 mg•kg−1, Cu 38.54 mg•kg−1, Ni 25.87 mg•kg−1 and Zn 147.52 mg•kg−1. Aside from Pb and Ni, the average content of all other heavy metals in the surface soil of facility agriculture was higher than the average of the control and the geochemical background level of soil in Weifang. Compared with the Environmental Quality Evaluation Standard for Farmland of Greenhouse Vegetables Production (HJ333-2006) and the Soil Environmental Quality Risk Control Standard for Soil Contamination of Agricultural Land (trial) (GB15618-2018), the average content of heavy metals met the standards, with Cd, Hg and Zn content in some samples exceeding the standards. Most surface soil environmental quality is clean or relatively clean, but there is also part of the soil has reached the level of mild or moderate pollution. The content of heavy metals in the soil of the old facility agriculture (cultivation years > 10) was higher than that of the new facility agriculture (cultivation years ≤ 10), and the content of heavy metals in the surface soil (0∼20cm) was higher than that in the deep soil. The quality distribution of heavy metals in the surface soil is affected by exogenous heavy metals, among which Hg and Cd have the largest skewness coefficient and are most affected by exogenous. There was significant positive correlation between heavy metals in surface soil and available phosphorus, hydrolytic nitrogen, available potassium and organic matter. The results indicated that the accumulation of heavy metals in soil was related to the application of organic fertilizer, phosphate fertilizer and compound fertilizer.

Influence of diversified anthropogenic pressure on heavy metals contents in soils and plants of garden allotments

The presented research aimed at assessing the impact of anthropogenic pressure of varying intensity on the heavy metals content in the soils of garden allotments and in the biomass of plants grown there. In order to achieve the study purpose, the contents of Pb, Zn, Cu, Cd were determined in the soil samples of three allotments located in Silesia (strong industrial and urban pressure), Lublin (moderate industrial and urban pressure) and Biała Podlaska (weak urban pressure). The same elements were analysed in leaves and roots of red beets grown on the soils in urban areas mentioned above. It was found that the soils derived from Silesia were the most polluted, less polluted were the soils from Lublin, and the least polluted were the soils from Biała Podlaska. The content of Pb, Cu, and Cd in the leaves and roots of red beet harvested on the examined soils was dependent on the concentrations of these elements in soils. The obtained results indicated that the contamination of soils and plants with heavy metals should be included into the comprehensive assessment of the human impact on the environment, especially in industrial and urbanised areas, and suggested the need for further, widely spread studies of soils in such areas.

Use of high-energy ionizing radiation for microbiological decontamination of coastal soil in the Kolubara river basin, Serbia

The Kolubara river pollutes the coastal land in the river basin and makes it unsuitable for agricultural activities in that area. Also, contaminated land poses a risk to the environment. Different methods can be used for soil decontamination. These methods include biological treatment/bioremediation, chemical oxidation, soil stabilization, physical methods, such as soil leaching, or treatment with high-energy ionizing radiation. Gamma irradiation of soil is a well-known method of inhibiting microbial activity. This paper investigated the influence of different doses and dose rates of gamma irradiation on microorganisms' decontamination of coastal soil, in the Kolubara river basin. The irradiation effects on reducing the total number of microorganisms and removing mold and pathogenic bacteria from soil samples were examined. Gamma radiation affects the soil's organic matter, causing the formation of free reactive radicals, which act as reducing and oxidizing agents, cleaving C-C bonds, and depolymerizing carbohydrates. It was found that a dose of 3 kGy of gamma radiation, neutralizes all pathogenic bacteria, a dose of 5 kGy deactivates mold in soil samples, and a dose of 10 kGy is optimal to kill all microorganisms in the samples and sterilize exposed soil. The research showed that the dose rate does not significantly affect microbiological decontamination of soil using gamma irradiation. The content of heavy metals in soil was determined, and the obtained values were compared with the remediation limit values prescribed by the regulations. It was concluded that the content of heavy metals in the analyzed soil samples is below the limit of remediation values. The only exception is the slightly increased copper content in one sample. The result of this research is the conclusion that the coastal land from the Kolubara basin can be decontaminated by gamma radiation treatment. This advanced soil treatment technology is available in Serbia because there is an industrial plant for gamma radiation treatment within the Vinca Institute.

公路源重金属对青藏高原高寒草甸土壤线虫群落的影响

为了解重金属对青藏高原高寒草甸土壤线虫群落的影响，在邦杰塘草原利用公路源重金属含量差异，采用高通量测序技术，分析重金属对高寒草甸土壤线虫群落多样性及群落组成的影响。结果表明：在重金属含量较低样本中，土壤线虫群落Shannon指数、Ace指数、Chao指数比重金属含量较高样本均要小，且整体上Shannon指数、Ace指数、Chao指数与重金属含量较高样本差异显著（P<0.05）。重金属含量升高改变了高寒草甸土壤线虫纲水平和目水平的群落结构，使近自然状况下的色矛纲（Chromadorea）、小杆目（Rhabdtida）优势土壤线虫群落转变为一类未分类线虫纲（unclassified_p_Nematoda）、一类未分类线虫目（unclassified_p_Nematoda）的优势土壤线虫群落。重金属Cu、Pb、Zn、Cd与线虫门（Nematoda）和刺嘴纲（Enoplea）正相关，但与色矛纲（Chromadorea）负相关，且对土壤线虫Chao指数的变异解释比例依次减小。研究表明土壤重金属含量对青藏高原高寒草甸土壤线虫群落多样性及组成产生很大影响，但仍需对高寒草甸区域进行系统的土壤线虫调查，并丰富土壤线虫生物信息数据库。;Soil nematode is a sensitive soil organism. In order to understand the effects of heavy metals on the alpine meadow soil nematode community in the Tibet Plateau, this study based on the differences in heavy metals content from highway sources in the Bangjietang grassland used the high-throughput sequencing technology to analyze the influence of heavy metals on the diversity and community structure of the alpine meadow soil nematode community. In August 2019, we collected soil samples at 0, 5, 15, 30, 50 and 75 m away from the highway in Bangjietang grassland. Cu, Pb, Zn, Cd were determined by flame atomic absorption spectrophotometry, and the community composition and structure of soil nematode were determined by high-throughput sequencing technology. The influence of heavy metals on soil nematode community was discussed by redundancy analysis. The results showed that the Shannon index, Ace index and Chao index of the soil nematode community in the samples with lower heavy metal content were smaller than the samples with higher heavy metal content (P<0.05). The increase of heavy metal content changed the community structure of soil nematode in alpine meadow, and the dominant soil nematode communities of Chromadorea and Rhabdtida under the natural conditions were transformed into the dominant soil nematoda communities of unclassified_p_Nematoda and unclassified_p_Nematoda. Cu, Pb, Zn and Cd were positively correlated with Nematoda and Enoplea, but negatively correlated with Chromadorea. The proportion of Cu, Pb, Zn, Cd to the variation explanation of Chao index decreased successively. The study shows that soil heavy metal content has a great influence on the diversity and structure of soil nematode community in alpine meadow of the Tibet Plateau, but it is still necessary to conduct a systematic investigation of soil nematode in alpine meadow and enrich the database of biological information of soil nematode.

Estimation and Spatial Analysis of Heavy Metals in Metal Tailing Pond Based on Improved PLS With Multiple Factors

With the exploitation of mineral resources, pollution of the ecological environment in mines has garnered public attention. Particularly,erosion of the surrounding ecological environment re-sulting from heavy metals in tailings pond could be highly concerning. Instead of traditional field sampling and laboratory analysis method, remote sensing can be used to high-precisi es-timation soil heavy metal with less time and effort. soil heavy metal content is generally low, the spectral sensitivities of various heavy metals are insignificant, and the surface landscape is complex, there exist difficulties associated with heavy metal content estimation. Therefore, herein, we propose optimization of the commonly used partial least-square regression (PLS) method. In the optimized method, a variety of remote sensing indices and the modeled heavy metals were added as modeling factors to indirect estimation soil heavy metal. The method was validated via inversion experiments of heavy metals (Ni, Cu, and Zn) in the tailing pond and its surrounding environment,it improve the goodness-of-fit of Ni, Cu, and Zn by 0.0852,0.2291, and 0.2919 compared with traditional PLS. Spatia l analysis was then conducted on the entire studied area using the estimation model of the three heavy metals. It was shown that the results were essentially consistent with the actual heavy metal distribution in the area. Therefore, the indirect PLS model with multiple factors proves effective for the estimation of soil heavy metals. It also provides technical support for treatment and evaluation of ecological environments in mining areas.

围垦对辽东湾北部滨海湿地土壤重金属含量的影响及生态风险评价

PDF HTML阅读 XML下载 导出引用 引用提醒 围垦对辽东湾北部滨海湿地土壤重金属含量的影响及生态风险评价 DOI: 10.5846/stxb201908061654 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 辽宁省自然科学基金项目（2020-BS-183）；辽宁省教育厅人文社科研究项目（WQ2019020）；辽宁省社会科学规划基金项（L19CJY005）；辽宁省省社科联 2021年度辽宁省经济社会发展研究课题（2021lslybkt-055） Effect of reclamation on soil heavy metal content of coastal wetland and ecological risk assessment in Northern Liaodong Bay, China Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:围垦历史与围垦方式被认为是人类对滨海湿地生态系统干扰的主要因素。选取辽东湾北部区作为研究区，采集129个表层土壤样品（0-20 cm），测定土壤理化性质（盐分、pH、土壤颗粒组成、土壤有机碳、硝态氮、速效磷）和重金属元素（Fe、Mn、Cu、Cr、Cd、Ni、Zn、Pb）含量；运用多元统计和反距离权重插值方法揭示研究区土壤重金属元素的来源与空间分布特征，最后利用Hakanson潜在生态风险指数法对重金属的潜在生态风险进行评价。结果表明：①6种重金属表现为彼此的显著正相关（P<0.01）。除Pb外，Cd、Cr、Cu、Ni和Zn的浓度与土壤有机碳、黏粒、粉粒含量呈极显著正相关（P<0.01），而与砂含量呈极显著负相关（P<0.01）。②化工、造纸、石油开采及加工等工业活动可能引起Cr、Cu、Ni和Zn的富集，持续的农业施肥和农药使用可能会增加土壤中Cd、Pb的含量。③围垦初期（1990s），土壤侵蚀和淋洗脱盐对土壤重金属分布具有显著影响。随着开垦年限的延长（1960s），持续的农业施肥、工业活动（如造纸、石油开采）和城市扩建，都大大增加了土壤重金属含量的累积。④不同的围垦方式影响下，除Fe标准化的Cd和Pb在水产养殖区有较高的浓度外，Fe标准化的Cr、Ni、Cu和Zn的浓度均在自然区域（滩地和芦苇）高于人类活动区域（水产养殖、耕地、建设用地）。⑤综合潜在生态风险指数平均值为325.69，表现为极强的生态风险程度，其中Cd表现为极高生态风险的采样点比例为46.51%，是造成区域重金属污染的主要贡献元素，特别是在水产养殖和农业地区。 Abstract:The history and methods of reclamation are considered as the main factors that drive human to disturb the coastal wetland ecosystems. In this study, a total of 129 samples were collected from the topsoil (0-20 cm) in Northern Liaodong Bay, and were determined for their physical and chemical properties (including salinity, pH, soil particle composition, SOC, NO3-N, and AP) and heavy metal levels (including Fe, Mn, Cu, Cr, Cd, Ni, Zn, and Pb). The heavy metals in soils were studied for sources and spatial distribution by using multivariate analysis and Inverse Distance Weight (IDW) interpolation method, and were evaluated for the potential ecological risk by using Hakanson's method. The results showed that: ①The levels of six heavy metals were significantly positively correlated (P<0.01) with each another. The Cd, Cr, Cu, Ni and Zn (excluding Pb) concentrations were significantly positively correlated (P<0.01) with the SOC, clay, and silt content, but were significantly negatively correlated (P<0.01) with the sand content. ②The levels of Cr, Cu, Ni and Zn in soils might be influenced by industrial activities (chemical industry, paper, oil exploitation and processing). Continuous use of fertilizers and pesticides might increase the levels of Cd and Pb in soils. ③In the early stage of reclamation (1990s), soil erosion, leaching and desalination had significant effects on the distribution of heavy metals in soils. Until the 1960s, continuous agricultural fertilization, industrial activities (such as paper making, and petroleum exploitation), and urban expansion had greatly increased the levels of heavy metals in soils. ④Under the influence of different reclamation methods, except that the levels of Fe standardized Cd and Pb were higher in the aquaculture areas, while the levels of Cr, Ni, Cu and Zn were higher in natural areas (marsh and reeds) than in human areas (aquaculture areas, cultivated land and construction land). ⑤The average value of the comprehensive potential ecological risk index was 325.69, showing a high level of risk. The Cd accounted for 46.51% as the highest ecological risk element in samples, which was the major contributor to heavy metal pollution, especially in aquaculture and agricultural areas. 参考文献 相似文献 引证文献

IDP: An Intelligent Data Prediction Scheme Based on Big Data and Smart Service for Soil Heavy Metal Content Prediction

In the application of regression prediction through big data technology, the error between the predicted value and the true value is often large. In order to reduce the error of data prediction, this paper proposes an Intelligent Data Prediction (IDP) scheme for Smart Service. It uses Least Squares Support Vector Machine (LSSVM) as the basic prediction model. Since there is no standard procedure for determining the main parameters of LSSVM, an improved Particle Swarm Optimization (MBPSO) algorithm is used to simultaneously optimize the parameters of LSSVM. The main disadvantage of PSO is precocity due to the disappearance of population diversity. Based on this, Improvement strategy of MBPSO aims to continuously generate “More” and “Better” particles. First, in order to avoid the early disappearance of particle diversity, MBPSO re-adjusted the inertia weight and learning factor. Secondly, a renewable access strategy is proposed to allow a part of the disappeared population to regenerate. Finally, the method of global optimal adjustment is introduced to help particles find the optimal flight direction. In order to verify the effectiveness of MBPSO, 9 test functions are used to test the algorithm performance. The results show that MBPSO’s optimization speed, best and mean all perform best. Taking the farmland soil heavy metal data sets of Dongxihu District and Hannan District of Wuhan City as examples of application, the content of heavy metals Cr and Pb in the soil was predicted. The results show that the predicted value of IDP is closer to the actual value, and the three error index values are significantly lower than other models. Especially in the prediction of Pb content, compared with the LSSVM model, the prediction errors of the two regions are reduced by 25.67% and 20.70% respectively. We can conclude that the proposed IDP scheme has practical significance in data prediction.

Irrigation water of different sources affects fruit quality attributes and heavy metals contents of un-grafted and commercial mango cultivars

In peri-urban areas, waste water is used to irrigate orchards due to scarcity of fresh water which increases heavy metals contents in soils, leaves and fruits. Due to excessive waste water irrigations, heavy metals enter into the food chain, which eventually causes metabolic disorders in humans. The present study was envisaged to investigate the effects of canal, tubewell and sewage water on the quality of mango fruits and heavy metals accumulation in soils, leaves and fruits. Leaf and fruit samples from an un-grafted (Desi mango) and six commercial cultivars of mango (Anwar Rataul, Aman Dusehri, Sufaid Chaunsa, Samar Bahisht Chaunsa, Kala Chaunsa and Anwar Rataul Late) grafted on Desi mango were collected from different mango orchards located in peri-urban areas of Multan (Pakistan) and analyzed for some physico-chemical attributes and heavy metals contents. Soil samples were also taken from these orchards irrigated with different water sources to assess the soils' heavy metals status. A significant variation was observed among the mango cultivars for their physico-chemical attributes. Sewage water irrigation improved total soluble solids (TSS), titratable acidity, ascorbic acid content, total phenolics, total carotenoids, total flavonoids and antioxidant activity of mango fruits. However, it did not affect fruit weight and shelf life. Among the heavy metals, copper and nickel contents were found in greater amounts in soils, leaves and fruits of sewage water irrigated orchards than canal and tubewell water irrigated ones. However, zinc and cadmium were not detected in any soil, water, leaf or fruit sample. The interaction among the sources of irrigation and the mango cultivars was significant for copper accumulation in different soil layers, copper and nickel accumulation in leaves of different mango cultivars, and fruit weight, titratable acidity, ascorbic acid content, total flavonoids and shelf life of mango fruits.