广西凭祥市土地重金属元素地球化学特征及物质来源分析

选择广西凭祥市的土地为研究对象,展开土地重金属元素地球化学调查评价的研究工作。本研究旨在通过对该区土地重金属元素的物质来源分析,对土地重金属元素进行评价,并为该区土地的合理利用提供科学依据。因此,本课题的研究具有一定的现实意义。

国土整治中关于土地重金属污染生态修复的问题与对策

土地整治一般包括土地回收、土壤修复、植被保护等方面。在进行土地整治时,相关人员需要考虑场地条件、污染情况和生态修复要求,并结合当地的实际情况选择最合适的措施。对于已经受到重金属污染的土壤,通常需要采用一些处理和修复方法,包括物理清理、化学清理和生物清理等。物理清理主要是使用机械或者物理方法清除污染物质;化学清理则是使用化学试剂或肥料降低土壤中的重金属含量;生物清理是利用生物物质或微生物分解土壤中的污染物。总之,土地重金属污染是一个复杂的问题,需要相关人员根据实际情况选择最合适的方法和措施。同时,在国土整治中,工作人员也需要综合考虑多方面的因素,以确保土地的可持续利用和环境保护。

基于多传感器的土地重金属污染范围测量研究

为准确测量土地重金属污染情况,给后续治理提供帮助,研究设计了一种基于多传感器的土地重金属污染范围测量方法。先制备电沉积金纳米生物传感器,采用溶出法进行扫描测量,然后分析对于不确定的溶质影响,建立浓度与峰值的线性回归法,推导溶液浓度与峰值之间的关系式,最后建立重金属污染迁移传播模型,采用多传感器融合方法将检测结果融合,实现土地重金属污染范围测量。实验结果表明,所提方法能够较为准确地测量出重金属污染范围,并在Cu^(2+)、Zn^(2+)、Cr^(6+)与Cd^(2+)四个重金属含量测量上具有较高的准确性,进一步验证了该方法的测量效果。

广西防城港市防城区土地重金属元素地球化学特征及形态研究

以广西防城港市防城区为研究对象,对土壤重金属元素进行了地球化学调查与评价。通过分析土壤中重金属元素的地球化学特征,对该区土壤重金属元素进行评价,为该区土地利用提供科学依据。因此,本研究具有一定的理论意义。

国土整治中关于土地重金属污染生态修复的问题与对策

在土地整治项目中,处理土地的重金属污染成为一项紧迫的任务。这种污染通常由诸如砷、汞、镉、铅等重金属元素引起,当这些元素渗入土壤和地下水后,可能对植物、动物乃至人类健康构成威胁。可见,重金属污染程度的加剧会直接影响土地的品质与其使用价值,因此,此类土地亟须进行生态恢复以恢复其原有价值。本文将详细分析国土整治中土地重金属污染生态修复的相关问题,并提出相应的解决对策,以供参考。

植物修复技术在重金属污染土壤修复中的应用

如何将被污染的土地再生利用,对污染的土地和植物等进行修复,成为当今世界需要面对和解决的一项重要难题,而利用绿色植物修复重金属污染土壤就是一项新兴的技术。文章主要阐述了重金属污染土壤中植物修复技术的相关问题,并提出提高植物修复技术的相关措施。

Source and hazard identification of heavy metals in soils of Changsha based on TIN model and direct exposure method

A total of 153 soil samples were collected from Changsha City, China, to analyze the contents of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn. A combination of sampling data, multivariate statistical method, geostatistical analysis, direct exposure method and triangulated irregular network （TIN） model was successfully employed to discriminate sources, simulate spatial distributions and evaluate children＇s health risks of heavy metals in soils. The results show that not all sites in Changsha city may be suitable for living without remediation. About 9.0% of the study area provided a hazard index （HI）1.0, and 1.9% had an HI2.0. Most high HIs were located in the southern and western areas. The element of arsenic and the pathway of soil ingestion were the largest contribution to potential health risks for children. This study indicates that we should attach great importance to the direct soil heavy metals exposure for children＇s health.

Effect of colonial breeding of Chinese Egret(Egretta eulophotes) on the heavy metal accumulation in heronry soil

We measured the concentrations of heavy metal elements,i.e.,V,Cr,Mn,Ni,Cu,Zn,Cd,Se and Pb and the semi-metal element As in feces of Chinese Egret(Egretta eulophotes)on Caiyu Island in Zhangpu County,Fujian Province,China using inductively coupled plasma-mass spectrometry(ICP-MS) and compared the differences between the topsoil of their nesting and non-nesting areas before and after breeding.The results show that no Se and Cd was detected in any of the samples,including feces and soil,while heavy metal concentrations in the non-nesting soil were not significantly different before and after breeding(p > 0.05),but the differences in concentrations of Zn and Pb in the nesting soil were highly significant before and after breeding(p < 0.01).A comparison of the concentrations of the elements in the nesting and non-nesting soils also reveals that before breeding,the concentration of Zn in these two soils were significantly different(p < 0.01).After breeding,concentrations of Cu,Zn,As and Pb in the nesting and non-nesting soil were significantly different(p < 0.01) while V and Ni concentrations showed merely significant differences(p < 0.05).These findings indicate that the colonial breeding activities of E.eulophotes play an important role in the transfer of heavy metals between wetland and island eco-systems and that such activities may,over time,result in heavy metal contamination of the heronry soil on the island.

Application of Biotechnology in Environmental Remediation of Mining Area

Based on the characteristics of the ecological environmental remediation of mining area, the application of biotechnology was proposed to do the remediation of the polluted environment in the mining area, mainly including the treatment of gangue dump and tailing heap, improvement of reclamation soil as well as the re- mediation of contaminated soil. Finally, the application and deveiopment trend of biotechnology in environmental remediation and soil remediation of mining area were pointed out.

Investigation and Evaluation on Soil Heavy Metal Contents in Fruit Producing Area in Baise City,Guangxi Zhuang Autonomous Region

[Objective] This study was conducted to investigate heavy metal conditions in fruit producing area in Baise City, Guangxi Province. [Method] Heavy metal contents in 106 soil samples collected from fruit producing area in Youjiang District, Baise City, Guangxi Province were analyzed, and soil heavy metal pollution condition in this area was estimated applying single factor index method and Hakanson＇ potential ecological risk index method with reference to the second grade of National Soil Environmental Quality Standard and soil background values of this area. [Result] According to the second grade of National Soil Environmental Quality Standard, soil heavy metals in this fruit producing area is at the level of no pollution; and the total potential ecological risk pollution risk （RI） of soil heavy metals was 97.7, indicating no risk. [Conclusion] The fruit producing area in Baise City, Guangxi Province is free of heavy metal pollution.

Soil heavy metal(loid)s and risk assessment in vicinity of a coal mining area from southwest Guizhou, China

Total concentrations of arsenic, lead, cadmium, mercury, nickel, chromium, and copper in the soils from near a coal mine area in southwest Guizhou, China, were measured to evaluate the level of contamination, and the potential ecological risks posed by the heavy metals were quantitatively estimated. Results reveal that all heavy metals/metalloid exceeded the background values for soil environmental quality of heavy metals in Guizhou area. Geo-accumulation index(I_(geo)) showed that arsenic had the highest contamination level(I_(geo)=4) among the seven heavy metals/metalloid, and the contamination levels of mercury and lead were also relatively high(I_(geo)=3). Pearson correlation and cluster analysis identified that mercury, copper and arsenic had a relationship, and their presence might be mainly related to mining activity, coal and oil combustion, and vehicle emissions. Improved Nemerow index indicated that the overall level of heavy metal contamination in the studied area ranged from moderately–heavily contaminated to heavily contaminated level. Potential ecological risk index(R_I) analysis manifested that the whole ecological risk level ranged from high degree to very high degree(325.30≤R_I≤801.02) in the studied soil samples, and the potential ecological risk factors (E_r^i) of heavy metals/metalloid were as follows: Hg > As > Cd > Pb > Cu > Ni > Cr, and the E_r^i of Hg and As reached very high risk grade.

Spatial Distribution and Changes of Heavy Metals of Agricultural Lands in Typical Pregrading Coast in Dongtai City,Jiangsu Province,China

According to the historical changes of coastal lines, seven soil sampling districts, from land to sea, were arranged in Dongtai City, Jiangsu Province to sample soils from surface and profile. Concentrations of seven major heavy metals (HMs), granularity, pH, organic matters and C/N of the soil samples were analyzed. Results show that concentrations of heavy metals in agricultural land present a certain spatial variance, decreasing from land to sea. Pollution assessment indicates that the agricultural soils were not polluted by HMs, but the potential pollution of Cu and Hg needs to be alerted. Different HMs accumulate in the surface and sub-surface of the soil profiles, and concentrations of Hg and Pb decrease significantly with the increment of soil depth. Concentrations of HMs exhibit a significantly negative correlation to pH, but have no significant relation with organic matters in soil. Principle component analysis show that the concentrations of HMs relate to the land use history. Concentrations of Hg, Ni and Cr in soil are closely related with land use history, and concentrations of Pb, Cu and Cr are affected by land use history as well as other factors. However, there is no significant relation between concentration of As and land use history.

Analysis of Soil Heavy Metal Pollution in Hechuan Wetland

Soil samples were collected from Hechuan wetland and digested by the national standard method. The contents of Pb, Cd, Cr, Cu, Zn and Mn in the wetland soil were determined, and the degree of soil heavy metal pollution was estimated by single-factor pollution index, root-mean-square comprehensive pollution index and geo-accumulation pollution index methods. The results showed that the wetland in the sampling range was seriously polluted by heavy metals, mainly by heavy metal Cd, while the effects from other heavy metals were relatively less.

Heavy Metal Distribution Map in Soil by Using GIS Techniques

A detailed investigation was conducted to understand the contamination characteristics and distributions of heavy metal pollution in terms of contributions of the heavy metal concentrations as mg/kg ofCd, Cr, Cu, Ni, Zn, Pb, Fe and Mn in the urban soil in Eskisehir city center. The amount of these heavy metals were determined from 15 soil sample points collected within urban area and every sample point included 6 separated samples for chemical analyses. The results indicated that concentration values of all metals except Ni and Cr in soils were below the risky limit pollution values which are recommended by Turkey Ministry of Environment and Forestry in some sample points. Spatial distribution maps were created and recoded, in terms of these heavy metals concentrations as contribution to heavy metal pollution in soil, through Geographical Information Systems techniques. As a result, risky areas were modeled in terms of contamination of heavy metal and it is shown that, every different risky area can be interpreted based on buildings in city center quickly and easily.

Effects of organic mineral fertiliser on heavy metal migration and potential carbon sink in soils in a karst region

Heavy metal pollution in karst mountainous area of Guizhou has spread due to the long-term exploitation of mineral resources and the improper disposal of environmentally hazardous waste. Heavy metals are characterised by non-degradation, strong toxicity, and constant accumulation, posing a grave threat to karst mountain fragile soil ecosystem. To reduce the harm caused by heavy metal pollution and damage to agricultural products, research was undertaken on the basis of previous work by simulating pot experiments on pak choi cabbage(Brassica rapa chinensis)planted in Cd-contaminated soil: different amounts of organic mineral fertilisers(OMF) compared with chemical fertiliser(CF) were used and by detecting the amount of heavy metal in the mature vegetable, a better fertilisation strategy was developed. The results showed that the Cd content in vegetables grown with CF was 23.70 mg/kg,while that of vegetables grown with OMF and bacterial inoculant was the lowest at 15.13 mg/kg. This suggests that the use of OMF and microbes in karst areas not only promotes plant growth but also hinders plant absorption of heavy metal ions in the soil. In addition, through the collection of pot leachate, the detection of water chemistrycharacteristics, and the calculation of the calcite saturation index, it was found that the OMF method also induces certain carbon sink effects. The results provide a new way in which rationalise the use of OMFs in karst areas to alleviate soil heavy metal pollution and increase soil carbon sequestration.

Land Use Effects on the Distribution and Speciation of Heavy Metals and Arsenic in Coastal Soils on Chongming Island in the Yangtze River Estuary, China

The reclamation of tidal fiats has been one of the important approaches to replenish the arable lands in the coastal areas; pollution status of reclaimed soils has received wide attention recently, especially for the study of heavy metals due to the relative high pollutant concentrations in wetlands. To understand the impact of land use change on heavy metal and arsenic （As） geochemistry by the reclamation of wetlands for agriculture, surface soils and soil profiles were collected from the agricultural land reclaimed in the 1990s and the intertidal flat wetland at Dongtan on Chongming Island in the Yangtze River Estuary, China. The soil samples were analyzed for total concentrations and chemical speciation of chromium （Cr）, zinc （Zn）, copper （Cu）, lead （Pb）, nickel （Ni）, cadmium （Cd） and As using inductively coupled plasma mass spectrometry （ICP-MS）. Results showed that soil properties （salinity, total organic carbon and grain-size distribution） and the concentrations of heavy metals and As in the soils differed under the different land use types. The conversion of wetland to forest had caused obvious losses of all the measured heavy metals. In paddy field and dryland with frequent cultivation, the concentrations of Cr, Zn, Cu, Ni and As were higher when compared to forest land which was disturbed rarely by human activities. Speciation analysis showed that Cr, Zn, Cu, Ni and As were predominated by the immobile residual fraction, while Pb and Cd showed relatively higher mobility. In general, metal （except Ni） and As mobility decreased in the following order： wetland 〉 dryland 〉 paddy field 〉 forest land, which suggested that the reclaimed soils had lower metal and As mobility than the intertidal fiat wetland. The results of this study contribute to a better understanding of the effects of land use on heavy metals and As in the reclaimed soils of the study area and other similar coastal areas.

Spatial and Seasonal Variations of Heavy Metals in Wetland Soils of the Tidal Flats in the Yangtze Estuary, China: Environmental Implications

The environment of estuarine wetlands has been attracting worldwide attention. To study the spatial distribution of pollutants in the tidal flats of the Yangtze Estuary, Southeast China, the Eastern Tidal Flat of Chongming Island (EC) and the Jiuduansha Shoal (JS) of the estuary were selected as the study sites. At each of the two sites, a cross-transect from land to sea was established and topsoil and soil core samples in the cross-transect were collected spatially and seasonally to determine their contents of heavy metals (Cu, Zn, Pb, Cd, Cr, Ni, Mn, and Fe) and grain-size characteristics. The results showed that the heavy metal loads were commonly higher in the soils of nearshore high tidal flats and had a tendency of decreasing from land to sea at both of the study sites. The contents of heavy metals in the soils of the high and medial tidal flats were mostly higher in April and November but lower in July. Corresponding spatial and seasonal variations in grain size of the intertidal soils were also observed at the two study sites. The soils in the nearshore high tidal flats were finer and gradually got coarser seawards; they were relatively finer in April and November but coarser in July. Furthermore, the contents of heavy metals in the intertidal soils of both the sites EC and JS were significantly positively correlated with the clay (<2 μm) and 2-20 μm fractions, but negatively with the sand (>63 μm) and 20-63 μm fractions, which suggested that the heavy metals in the intertidal soils were primarily combined with the fine particulate fraction (<20 μm), especially clay, and hence the spatial and seasonal variations in heavy metals were actually caused by the change of the grain-size characteristics of the intertidal soils due to the different sedimentary environments in the estuary. The results of this study may also contribute to a better understanding of the soil formation and classification in the tidal flats of the Yangtze Estuary.

Source Apportionment of Heavy Metals in Soils Using Multivariate Statistics and Geostatistics

The main objectives of this study were to introduce an integrated method for effectively identifying soil heavy metal pollution sources and apportioning their contributions, and apply it to a case study. The method combines the principal component analysis/absolute principal component scores (PCA/APCS) receptor model and geostatistics. The case study was conducted in an area of 31 km2 in the urban-rural transition zone of Wuhan, a metropolis of central China. 124 topsoil samples were collected for measuring the concentrations of eight heavy metal elements (Mn, Cu, Zn, Pb, Cd, Cr, Ni and Co). PCA results revealed that three major factors were responsible for soil heavy metal pollution, which were initially identified as "steel production", "agronomic input" and "coal consumption". The APCS technique, combined with multiple linear regression analysis, was then applied for source apportionment. Steel production appeared to be the main source for Ni, Co, Cd, Zn and Mn, agronomic input for Cu, and coal consumption for Pb and Cr. Geostatistical interpolation using ordinary kriging was finally used to map the spatial distributions of the contributions of pollution sources and further confirm the result interpretations. The introduced method appears to be an effective tool in soil pollution source apportionment and identification, and might provide valuable reference information for pollution control and environmental management.

Kinetics of Specific and Non-Specific Copper Sorption on Aggregates of an Acidic Paddy Soil from the Taihu Lake Region in East China

The Taihu Lake region in East China has become prone to soil acidification, which changes heavy metals such as copper(Cu) in soil into water-soluble species and increases the mobility and contamination risks of heavy metals in the biological environment. In this study, the kinetics of Cu2+sorption by the bulk soil and the aggregate size fractions of an acidic paddy soil collected from the Taihu Lake region, the effects of temperature on Cu2+sorption, and the p H changes of the solution were investigated by static sorption and magnetic stirring. The aggregate size fractions were prepared by low-energy ultrasonic dispersing and freeze-drying. The total sorption amounts of the bulk soil and the aggregate size fractions for Cu2+followed a descending order of clay > coarse sand > bulk soil > silt> sand, corresponding to those of organic matter content, free iron oxide content, free aluminum oxide content, and cation exchange capacity. The kinetic sorption curves of Cu2+by the bulk soil and the aggregates, which were divided into two stages(rapid and slow sequentially), were well fitted by the first-order equation, the diffusion equation, and the Elovich equation, showing significant correlations(P < 0.05). Specific and non-specific sorption dominated in the fast and slow stages, respectively, and the former was predominant throughout the sorption process. The specific sorption accelerated and the non-specific sorption decelerated with rising temperature. The p H of the solution decreased significantly during the specific sorption and remained unchanged or increased slightly during the non-specific sorption. When the specific sorption terminated, the p H of the solution was minimized nearly simultaneously.The sorption progress of Cu2+by the bulk soil significantly preceded that by the aggregates. Therefore, heavy metal contamination may be another factor reducing soil p H and metal sorption forms should be taken into consideration in studies of mitigating soil heavy metal pollution or determining environmental capacity of heavy metal in soil.