用微生物对单一碳源利用方法探讨重金属在城市土壤中积累的环境效应

Biolog研究表明，英国阿伯丁市城市土壤的微生物群落结构显著有别于农村土壤，并使微生物对碳源的消耗量增加，消耗速度加快。城市土壤中不仅重金属Cu,Pb,Zn,Ni的含量明显高于农村土壤，而且其化学形态的主成分分析表明，有效态Pb,Zn,Cu及有机态Ni和Cu是导致城市土壤区分于农村土壤的主要因子。相关性分析表明，Biolog的这种变化规律与重金属的上述化学形态密切相关；典型变量分析表明，重金属对城市土壤微生物群落结果的这种损伤具有长期性效应及不可恢复性。     

干旱区绿洲土壤共存重金属元素形态变化及生物有效性实验分析——以Cd、Zn、Ni元素为例

采用盆栽试验,初步研究了干旱区绿洲土壤—胡萝卜系统中镉、锌、镍3种重金属的形态变化特征及其生物有效性问题。结果表明:供试绿洲土壤原状土中,Cd、Zn、Ni均以稳定的残渣态形式存在,而处理土壤中重金属被钝化的量有限,Cd的存在形式主要以碳酸盐态为主,Zn、Ni则主要以铁锰氧化态为主;3种元素的活性大小依次为Cd>Ni>Zn。根据回归分析,元素Zn对胡萝卜块茎和茎叶吸收Zn量贡献最大的分别是Zn的碳酸盐结合态和铁锰氧化态;元素Ni对胡萝卜各部位吸收贡献最大的均为Ni的铁锰氧化态。     

干旱区绿洲土壤共存重金属元素形态变化及生物有效性实验分析

采用盆栽试验,初步研究了干旱区绿洲土壤—胡萝卜系统中镉、锌、镍3种重金属的形态变化特征及其生物有效性问题。结果表明：供试绿洲土壤原状土中,Cd、Zn、Ni均以稳定的残渣态形式存在,而处理土壤中重金属被钝化的量有限,Cd的存在形式主要以碳酸盐态为主,Zn、Ni则主要以铁锰氧化态为主;3种元素的活性大小依次为Cd＞Ni＞Zn。根据回归分析,元素Zn对胡萝卜块茎和茎叶吸收Zn量贡献最大的分别是Zn的碳酸盐结合态和铁锰氧化态;元素Ni对胡萝卜各部位吸收贡献最大的均为Ni的铁锰氧化态。     

福建龙海土壤重金属含量特征及影响因素研究

为有效预防土壤重金属生态风险,以福建龙海市表层土壤为研究对象,应用经典统计分析、随机森林等方法,研究重金属元素含量特征及其影响因素。结果表明：(1)第四纪冲洪(海)积成因水稻土中多数重金属元素含量较高;(2)燕山期中酸性岩风化形成的残坡积红壤中重金属元素活动态含量较高;(3)As、Cu、Ni形态含量与全量相关性较好,而Cd、Cr、Hg的多数形态含量与全量相关性较差;(4)除元素全量外,土壤有机质对弱有机结合态重金属(不包括Ni、Pb元素)以及离子交换态、碳酸盐结合态Cd、Zn有重要影响,阳离子交换量对各形态Ni,(Fe×Al)/Si对各形态Cu具有重要影响,而土壤成因、土壤类型对重金属形态组成的影响较小。研究表明土壤重金属形态组成及其富集区与其全量不尽一致,土壤重金属生态风险评价应考虑土壤重金属形态分布特征。     

固体聚合膜电解浓集法测量天然水中低含量氚的化学淬灭效应研究

固体聚合膜电解浓集法是浓缩氚含量较低(1 Bq/m~3)的天然水样的常用方法,但因水样自身含有杂质离子或电解装置聚合膜带入杂质进入浓集液,使浓集液偏酸性,在测量过程中易产生化学淬灭效应,导致氚的测量值偏低。本文研究了水样自身存在的杂质离子和聚合膜上残留的杂质离子、样品溶液的pH值及其电导率所产生的化学淬灭效应的影响,实验表明,为减少化学淬灭效应,提高测量低含量氚的准确性,需保证水样溶液呈中性,电导率≤1μS/cm,同时避免杂质沉积在聚合膜上。如果水样溶液的pH值偏酸性、电导率大于1μS/cm,可采用酸碱混合型离子交换树脂去除水样中自身的杂质;对于聚合膜引入的杂质,可在电解后的水样中加入微量氨水将其pH值调节至中性。     

包头市典型工业区表层土壤中重金属污染状况及其潜在生态风险研究

为了解包头市典型工业企业对其所在地土壤中重金属含量的影响及污染现状,利用相关性系数对其表层土壤中7种重金属(Cu、Zn、Pb、Cr、Cd、Mn、Ni)来源进行研究,并采用内梅罗综合污染指数法和潜在生态危害指数对其污染状况进行评价。结果表明,7种重金属含量平均值均高于内蒙古土壤背景值,其中Cd、Mn、Ni超标率已达100%,而Cu、Pb、Zn的超标率分别为97%、93%和93%,只有Cr超标率较低(53%),污染程度依次为CdPbCuNiZnMnCr,其中Pb和Cd为重度污染,Cu、Zn、Ni为中度污染,Cr、Mn为轻度污染;Cu、Zn、Cr、Mn、Ni可能同时来自工业生产和交通运输两个源,而Pb和Cd除上述来源外,燃煤烟气的排放有较大贡献。潜在生态危害依次为CdPbCuNiCrZnMn,其中Cd的潜在生态风险最大,应予以高度重视,其他金属的风险均为轻微。     

Effects of humic acid on heavy metal uptake by herbaceous plants in soils simultaneously contaminated by petroleum hydrocarbons

The effects of humic acid (HA) on heavy metal uptake by herbaceous plants in soil simultaneously contaminated with heavy metals and petroleum hydrocarbons were investigated. The results showed that HA reduced readily soluble and exchangeable forms of heavy metals in the contaminated soil but increased their plant-available forms. Potential bioavailability and leachability factors became larger than 1 after adding HA to the soil, except for those of Ni, suggesting that more heavy metals could be potentially phytoavailable for plant uptake. Furthermore, HA increased the accumulation of Pb, Cu, Cd, and Ni in the shoots and roots of selected plants. The greatest increase in the accumulation of heavy metals was 264.7 % in the shoot of Festuca arundinacea, with the bioconcentration factor (BCF) increasing from 0.30 to 1.10. Humic acid also increased the BCFs of the roots of Brassica campestris for Ni and Pb. These results suggest that HA amendment could enhance plant uptake of heavy metals, while concurrently reducing heavy metal leachability and preventing subsurface contamination, even in soils simultaneously contaminated with petroleum hydrocarbons.     

Heavy-metal loadings related to urban contamination in the Kooloonbung Creek catchment,Port Macquarie,New South Wales

Urbanisation and industrial development lead to contamination of estuaries and streams with dispersed loadings of heavy metals and metalloids. Contributions of these elements also occur from natural sources. This study provides baseline geochemical data on the respective natural and anthropogenic inputs of Cu, Pb, Zn, Cd, As, Sb, Cr, Ni, Mn and S to estuarine, fluvial and wetland sediments, and adjacent soils, in the Kooloonbung Creek catchment that drains the Port Macquarie urban area in north coastal New South Wales. There have been anthropogenic additions of Cu, Pb, Zn and As from dispersed urban sources at Port Macquarie, but they are restricted to the local catchment and do not impact on the adjacent Hastings River estuary. The most contaminated sediments display enrichment factors up to 20 × for Cu and Pb, 9 × for Zn and 5 × for As relative to local background values. However, only one value (for Pb) exceeds National Water Quality Management Strategy interim sediment quality guideline (high) values. On the other hand, sediments and local soils are commonly strongly enriched in Cr, Ni and Mn, reflecting adjacent ultramafic and mafic rock substrate and lateritic regolith. Concentrations of Cr and Ni are commonly well above interim sediment quality guideline (high) values for sediments, but are in mineralogical forms that are not readily bioavailable. Sediment and soil quality guideline values consequently need to recognise natural enrichments and the mineralogical siting of heavy metals. Although dissolved concentrations of heavy metals in stream waters are commonly low, there is evidence for mobility of Cu, Zn, Fe and Al. Parts of the Kooloonbung Creek wetland area lie on sulfidic estuarine sediments (potential acid sulfate soils). Experimental oxidation of uncontaminated and contaminated sulfidic sediments leads to substantial dissolution of heavy metals under acid conditions, with subsequent aquatic mobility. The results warn about disturbance and oxidation of potential acid sulfate soils that have been contaminated by urban and natural heavy-metal sources.     

Characteristics of distribution and chemical speciation of heavy metals in environmental mediums around Jinchang mining city,Northwest China

Heavy metal contamination was the main environmental problem around the Jinchang Ni–Cu mine area of Gansu, Northwest China. The concentration of heavy metals (Cr, Cu, Ni, Pb, and Zn) in various environmental mediums around the Jinchang Ni–Cu mine area were analyzed using atomic absorption spectrometry (AAS). The different chemical speciation of heavy metals was extracted using BCR (European Community Bureau of Reference) sequential extraction procedure, and the concentration of chemical speciation of each heavy metal was measured by inductively coupled plasma-atomic emission spectrometry. The results showed that Cu and Ni were the most important heavy metal pollutants in various mediums including cultivated soils, dust on slagheap surfaces, tailings, and sediments in waste water drains. In the tailings and sediments, the concentrations of Ni were obviously higher than those of Cu, whereas, in the soil and dust, the concentrations of Cu were higher than those of Ni. Analysis of chemical speciation indicated that Cr and Zn were mainly in residual fraction; Cu was mainly in oxidizable fraction; Ni was mainly in reducible fraction and acid soluble fraction; and Pb was mainly in reducible fraction and residual fraction. The extent of contamination of various environmental mediums was different because the heavy metals were derived from different sources. Furthermore, the mobility of various heavy metals was different because of the different distribution of chemical speciation.     

Heavy metal distribution and contamination in soils of Thane–Belapur industrial development area,Mumbai, Western India

There is a growing public concern over the potential accumulation of heavy metals in soil, owing to rapid urban and industrial development in the last decade in India. Therefore, an attempt was made to investigate the pollution caused due to excessive accumulation of heavy metals in soils near Thane–Belapur industrial belt of Mumbai. Soil samples were collected from surrounding industrial areas and were analyzed for toxic/heavy metals by X-ray fluorescence spectrometer. The analytical results indicate that the soils in the study area were enriched with Cu, Cr, Co, Ni and Zn. The concentration ranges were: Cu 3.10–271.2 mg/kg (average 104.6 mg/kg), Cr 177.9–1,039 mg/kg (average 521.3 mg/kg), Co 44.8–101.6 mg/kg (average 68.7 mg/kg), Ni 64.4–537.8 mg/kg (average 183.6 mg/kg) and Zn 96.6–763.2 mg/kg (average 191.3 mg/kg). The visualization of spatial data is made by preparing distribution maps of heavy metal concentration in soils and co-relation diagrams. These results highlight the need for instituting a systematic and continuous monitoring of the study area for heavy metals and other forms of pollution to ensure that pollution does not become a serious problem in future.     

An approach to studying heavy metal pollution caused by modern city development in Nanjing, China

 Nanjing is currently one of the fastest developing regions in terms of construction and economy in China. Heavy metal pollution is becoming more serious with the expansion of production and life scales. Four environmental units (highway, refinery, rubbish dumps associated with human daily life, and shoal of the Yangtse River) were selected from the region according to the geneses of the pollution to study and evaluate the distribution and mechanism of the contamination, the speciations of the polluting elements, and the geneses of the pollution in the soils and sediments. The purposes of the study are to understand generally the current situation and the cause of the pollution, and to provide a scientific basis to prevent and solve the pollution problem. At the same time, it would be helpful to probe the effective way of studying heavy metal pollution resulting from the development of modern cities and to accumulate data. It is indicated by the study that the heavy metals contained in the soil of the environmental unit of the highway are Pb, Co and Cr; in the soil of the refinery Cr, V, Pb, Ni, and Co; in the soil of the rubbish plot Co, Cu, and Sb; in the sediments of the shoal Pb, Co, Cu, and Ni. Fe-Mn oxide is given the first place to the speciations in polluting heavy metals transmitted by air. Carbonate is more in speciations of polluting heavy metals transmitted by water than in speciations of the metals transmitted by air. In the ten elements studied, Pb is most directly poisonous to the plants in the region; Co and Cu are the next, and Ni is the least. Heavy metal pollution has been occurring in the soils and sediments of the region and the situation will worsen if some effective measures are not taken. Received: 18 October 1997 · Accepted: 3 February 1998     

三峡库区澎溪河消落带土壤中重金属形态分布与迁移特征研究

消落带是水域与陆地的过渡地带,对水环境有着至关重要的影响。本文以三峡库区消落带面积最大的澎溪河流域作为研究区域,采集消落带土壤及其沿岸土壤样品,分析重金属形态分布特征,并使用地质累积指数法和风险评价准则(RAC)对重金属污染程度及生态风险进行评价。研究表明,消落带土壤中Pb、Cu、Cr、Cd、Zn和Ni平均含量分别为68.70、36.96、55.10、0.68、108.26、31.68 mg/kg,污染程度依次为CdPbZnCuNiCr,以Cd和Pb污染较为突出,普遍高于长江干流土壤,远高于重庆地区土壤。Cd的RAC值为20.62%,呈中等环境风险;其形态稳定性最差,以可还原态和酸提取态为主。Pb、Cu、Cr、Zn、Ni的RAC值为5.45%~10.0%,环境风险较低;且均以残渣态为主,占总量的54.69%~83.05%。以消落带沿岸土壤为对照,消落带形成后土壤中各重金属总量均有不同程度升高,且不同重金属在其增量部分的形态存在差异,Cr和Ni的增量部分以残渣态为主,Cd、Pb、Zn的增量以非残渣态为主。研究发现,由于受到水域与陆地污染源的双重影响,澎溪河流域重金属具有由沿岸向消落带沉积富集的趋势。     

An assessment study of heavy metal distribution within soil in upper course of Zarqa River basin/Jordan

Levels of heavy metals are found in soils and waters of the major tributary valleys of the Jordan Valley. Heavy metal content in soils irrigated by treated waste water were measured for a 40 km reach of Zarqa River. Soil samples from eight different sites along the upper course of this river were analyzed to determine the concentration of selected heavy metals (CO, Cr, Cu, Pb, Ni, Zn). Silt forms the major component of the soils with an average of 54%. Clay fractions show an increase with depth from 17 to 41%. Trends in particle size distribution and metal contents were compared across sample sites. Samples contained moderate to considerable levels of Pb and Ni. Concentrations of Cu and Cr ranged between 33–59 and 65–90 ppm, respectively. These values represent a slight to moderate class of pollution. The concentration of Cr shows a decrease with depth and distance from the waste water plant. Cu, Zn, and Ni show increasing concentrations with depth but Pb and CO do not. The concentrations of the measured heavy metals increases near the waste water treatment plant but decreases with distance from the plant due to precipitation in the stream bed and dilution with stream water. This decline in metal content with distance from the treatment plant suggests that most metals reaching floodplain soils may derive from the same source. Although current metal concentrations are low to moderate, floodplain surface soils in this area should be regarded as a potential source for future heavy metal pollution downstream.     

Experimental modeling of the immobilization of heavy metals at the carbonate adsorption–precipitation geochemical barrier

Experimental data obtained on the adsorption–precipitation immobilization of heavy metals (Cu, Zn, Pb, Cd, Co, and Ni) from acidic and neutral solutions by calcite and dolomite demonstrate that interaction of solutions of heavy metals with these minerals at pH > 7.8–8.1 leads to a significant decrease in the concentrations of the metals because of the crystallization of carbonates of these metals. Except Pb, which is equally removed from solutions by both minerals, the immobilization efficiency of the metals on dolomite is greater than on calculate at the same pH. Residual Zn, Cd, Co, and Ni concentrations are immobilized by chemosorption, which is the most efficient for Cd and less significant for Co, Ni, and Zn. It is proved that artificial geochemical barriers on the basis of carbonate rocks can be efficiently applied to protect environment from contamination with heavy metals.     

广西贵港岩溶地质高背景区富含铁锰结核土壤的矿物学与重金属地球化学特征

岩溶地质高背景区土壤中普遍存在的铁锰结核对重金属的赋存状态和有效性有重要影响。选择广西贵港覃塘岩溶地质高背景区富含铁锰结核的表层土壤(0~20 cm)为研究对象,筛分出不同粒径的铁锰结核(10~120目)和细粒径土壤(<120目)样品进行化学分析,针对以下三个方面开展研究:(1)重金属(As、Cd、Cr、Cu、Hg、Ni、Pb和Zn)在铁锰结核和细粒径土壤中的分布分配规律和铁氧化物矿物的组成;(2)铁氧化物矿物对富含铁锰结核的土壤中Cd等重金属富集的影响;(3)重金属在富含铁锰结核的土壤中的赋存机制。研究发现,铁锰结核中的Fe和Mn以及Cd等重金属含量随着粒径的增大而不断增加,说明Cd等重金属元素更倾向于在大粒径铁锰结核中富集;土壤中Cd等重金属总量的约90%赋存在结核中,表明研究区土壤中重金属主要以结核形式赋存;富含铁锰结核的土壤中赤铁矿和针铁矿的平均含量分别为0.61%和4.94%,且结核粒径越大,针铁矿和赤铁矿含量越高;除Hg外,Cd等重金属含量与针铁矿和赤铁矿的含量均呈现极显著正相关,与赤铁矿的相关性稍优于针铁矿,表明铁氧化物矿物与富含铁锰结核土壤中的Cd等重金属元素富集密切相关。铁锰结核的存在既能促进Cd等重金属在土壤中的富集,又能降低土壤中重金属的生物有效性,研究结果为解释岩溶地质高背景区土壤Cd等重金属元素高含量、低生物有效性提供了理论依据。     

Relationships between heavy metals and iron oxides,fulvic acids,particle size fractions in urban roadside soils

Urban roadside soils are the “recipients” of large amounts of heavy metals from a variety of sources including vehicle emissions, coal burning waste and other activities. The behavior of heavy metals in urban roadside soils depends on the occurrence as well as the total amount. Accordingly, knowledge of the interactions between heavy metals and other constituents in the soil is required to judge their environmental impact. In this study, correlations of heavy metal concentrations (Pb, Zn, Cu, Ag, Se, Ni, Cr and Ba) to iron extracted using dithionite–citrate–bicarbonate (DCB) buffer (Fe_DCB), fulvic acids and particle size fractions were examined from the Xuzhou urban roadside soils. Heavy metals except for Cr and fulvic acids had a positive significant correlation with Fe_DCB, indicating these metals and fulvic acids are principally associated with the surfaces of iron oxides of the soils. Significant positive correlations were also found between the contents of fulvic acids and heavy metals, showing these heavy metals (especially for Cu, Ni and Cr) form stable complexes with fulvic acids. Such finding is of importance with regard to the increased mobilization of heavy metals, e.g., into freshwater ecosystems. Ag, Se and Cr are independent of particle size fractions because of their low concentrations of Ag and Se in the studied soils. Pb, Zn, Cu, Ba and Ag are mainly enriched in the finer soil particles (especially <16 μm).     

Sources of very high heavy metal content in soils of volcanic island (La Réunion)

The objective of this study was to conduct an inventory of heavy metal concentrations (Cd, Cr, Cu, Hg, Ni, Pb and Zn) in the soils of La Réunion. 39 sampling sites were selected to cover the distribution of soils of the island. The results show that soils of La Réunion are rich in heavy metals: most of them exceed the French standard values beyond which sewage sludge spreading is not authorized. To identify the sources of heavy metals, we used: (i) the relationship between the heavy metal content in soils and the origin of the volcanic parent material; (ii) the comparison of heavy metal content between cultivated and uncultivated soils; and (iii) the heavy metal distribution in soil profiles. Cd and Pb evolution in soil profiles indicate an impact of human activities. High Hg concentrations in soils can be explained by the volcanic activity of the island. For Cr, Cu, Ni and Zn, we demonstrate that high concentrations in soils are mainly determined by the natural pedo-geochemical background.     

Distribution of heavy metals in Gaborone urban soils (Botswana) and its relationship to soil pollution and bedrock composition

The capital city of Botswana, Gaborone, has seen unprecedented population, economic, and industrial growth in recent years. In order to assess how this rapid urbanisation process impacts the environment, 106 silt and clay (particle size <0.053 mm) samples, separated from Gaborone surface soil samples representing urban, agricultural and rural sites, were investigated. The concentrations of nine heavy metals (Sc, Cr, Co, Ni, Cu, Zn, Nb, Cd, and Pb) were measured using ICP–MS and GFAAS, and the resulting patterns were correlated to the bedrock composition and anthropogenic activities. As expected, we found that samples from soils on top of dolerites show higher levels of Cr, Ni, and Cu than those on top of granites and rhyolites. However, our studies also show that Gaborone city centre soils are moderately polluted by Pb (up to 222 mg/kg, i.e. 5.7-fold the concentration in comparable rural soils), as a result of heavy traffic. Furthermore, Cr and Ni pollution originating from agrochemicals were shown to be accumulating in Gaborone crop soils. Our studies also showed moderate levels of Zn pollution and low level, dot-shaped pollution of Cr, Co, Ni, Cu detected in Gaborone residential and industrial soils that are correlated to waste disposal. Interestingly, the highest levels of Sc, Cr, Co, Ni and Zn pollution are found near two abandoned sewage works. The results of sequential extraction indicate that the polluting Co and Ni exist in all speciations; the polluting Cu mainly exists in the residue of the sequential extraction, whereas the polluting Pb is mostly bound to organic matters and Fe- and Mn-oxides. These results highlight the need for instituting a systematic and continuous monitoring of heavy metals and other forms of pollutants in Gaborone to ensure that pollution does not become a serious problem in the future.     

Comparison of extractability of Cd, Cu, Pb and Zn with sequential extraction in contaminated and non-contaminated soils

Various extraction procedures were employed for measuring extractable concentrations of potential toxic elements in soil. The extractability of Cd, Cu, Pb and Zn in four contaminated and four non-contaminated soils of Japan, was compared by single extraction (CaCl₂, DTPA, NH₄Cl, 0.1 M HCl and 1 M HCl ) and sequential extraction procedures [(six operationally defined chemical phases, viz. water soluble (Fl), exchangeable (F2), carbonate (F3), oxide (F4), organic (F5) and residual (F6) fractions)]. Extractability of metals from soils samples varied depending on metals and/or extradants used. Among the extradants, 1 M HCl extracted the largest proportion of Cd (79 to 96% of total), Cu (61 to 83%), Pb (51 to 99%) and Zn (23 to 52%) from soils followed by 0.1 M HCl, NH₄Cl, DTPA and CaCl₂. In all the extradants, the proportion of extractability of metals was higher in the contaminated soils than the non-contaminated soils. Regardless of soils and extradants, relative extractability was higher for Cd as compared to other three metals. The use of 1 M HCl may be recommended for first-level screening of soil contamination with heavy metals. The other four weak extradants are believed to provide a better assessment of bioavailable/mobile metals content in soils than 1 M HCl extradant. However, 0.1 M HCl mobilized all four metals irrespective of soil types, therefore, might be the best choice if only one extradant is to be used. The sequential extraction procedures showed 22 to 64% of total Cd was in the mobile fraction (sum of Fl to F3), while the corresponding values for Cu, Pb and Zn in this fractions were 2 to 23% suggesting higher mobility of Cd than other three metals. The single extraction procedures are simple and easy to perform and obtained results are comparable with sequential extraction procedure.     

Capability of vis-NIR spectroscopy and Landsat 8 spectral data to predict soil heavy metals in polluted agricultural land (Iran)

Heavy metals are toxic elements that have hazardous effect on the environment. They cause soil pollution as a result of their toxicity, potential reactivity, and mobility in soils. There are so many methods for the measurement of heavy metal concentrations in soils and aquatic systems. The traditional methods used for detecting heavy metal distribution in soil involve laboratory analysis and raster sampling. Both of them are expensive and time-consuming for large areas. Remote sensing techniques are used for obtaining the earth’s surface information, and these techniques have been used in the investigations of heavy metal distributions in preliminary analysis of soils as a rapid method. Today, near-infrared reflectance spectroscopy (NIRS) of soil characteristics has been of interest as a significant object. The present investigation is focused on the detection of heavy metals in contaminated soils by the application of reflectance spectroscopy in the spectral range of 350 to 2500 nm. This study also discusses the circumstances of the applied current methods for the detection and estimation of arsenic (As), cadmium (Cd), nickel (Ni), and lead (Pb) in contaminated agricultural soils. In the first part of laboratory spectroscopy, estimations were done using heavy metal reflectance spectroscopy and partial least square regression (PLSR) approaches, while in the second part, the heavy metal estimations were done using soil organic carbon reflectance spectroscopy through the PLSR approaches. Similar to the tasks above, estimations of As, Cd, Ni, and Pb by using Landsat 8 images were done in the forms of direct and indirect methods and the distribution of heavy metals in the study area was determined. Finally, the results obtained using direct and indirect methods were compared with the wet chemical measurements of heavy metals and organic carbon. It was found that although the direct detection of heavy metals using the images of Landsat 8 produced more accurate results than the indirect detections, the results obtained from laboratory spectroscopy corresponded more with the results from atomic adsorption spectroscopy. On the other hand, based on the fact that the soil has a complex content, the use of nonlinear methods, such as artificial neural networks in predicting soil heavy metal contents, could be regarded as a trusted method.