广西八一锰矿区土壤和主要农作物重金属含量的研究

对广西八一锰矿废弃地土壤基本理化性质及重金属全量(浓HC l 浓HNO3 HF HC lO4消解)、有效态含量(0.1MHC l浸提)和主要农作物重金属含量(浓HNO3 HC lO4消解)进行了测定(AA S)。结果表明:土壤营养缺乏和重金属污染是本矿区生态恢复面临的主要问题。土壤中全磷和全氮含量低于正常指标,且部分C/N比值偏高,同时土壤存在严重的Cd污染,并可能受到M n污染。在锰矿恢复区种植的主要农作物中,部分样品中Pb、M n含量与全部样品的C r、Cd含量超出了植物正常含量范围。农作物的食用部分中Cd、C r、Pb含量普遍超过国家食品限量卫生标准,不宜食用。     

Environmental distribution and health impacts of As and Pb in crops and soils near Vinto smelter,Oruro, Bolivia

The Vinto Sb–Sn smelter (Oruro, Bolivia) has been linked to arsenic and heavy metal pollution in air, soils, residual waters of the smelter, and hair and urine of workers, but crop concentrations had not been assessed previously. In this article, alfalfa, onions, and carrots, separated into roots and shoots, were analyzed for As and Pb, together with corresponding soil samples. The aim was to assess the environmental distribution and potential health impacts of these toxic elements and to compare them to levels observed at other sites around the world. As and Pb concentrations in all analyzed crop samples exceed the FAO/WHO, UK or Chilean limits by 1.5–2 orders of magnitude and As health risk indices were 286 (carrot) and 651 (onion), showing that the potential health risk due to consumption of these products is extremely high. As and Pb soil–plant transfer factors are similar to other contaminated sites around the world, but daily intake and health risk index for As are much higher in Vinto area due to very high concentrations in soils. Arsenic and lead soil and crop concentrations suggest increasing trends toward VMC. Correlations are significant for Pb in some crop fractions, but not for As, possibly due to considerable geogenic contributions to soil As in the area. In future surveys, larger numbers of soil and crop samples should be analyzed, and additional analyses should be carried out to distinguish anthropogenic and geogenic sources of As and Pb in soils and crops in the area.     

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.     

Natural background and pollution levels of some heavy metals in soils from the area of Dayton,Ohio

In a reconnaissance study, trace amounts of Cd, Cu, Pb, and Zn were determined in “A-zone” soil from 22 locations in the Dayton, Ohio, area. Soil samples were collected at high-volume air monitoring sites in urban, suburban, and rural areas. Measurable amounts of the elements were found in all of the samples. Positive correlations occur between each metal and particulate matter, with correlation coefficients of aboutr=0.70, at the 99% confidence level. Natural background values for the elements were measured in soil from rural areas. Theoretical background values, which are very close to those measured, were calculated from the individual regression equations. Natural background levels do not exceed 1.00 ppm Cd, 15 ppm Cu, 25 ppm Pb, and 55 ppm Zn. The heavy metal contents of most soils in the area exceed background by factors of up to 3.0 for Cd, up to 4.5 for Cu, up to 11 for Pb, and up to 4.5 for Zn. Significant positive correlations among the metals suggest a common source (or sources) for at least some, if not most, of the heavy metals. For the most part, the highest metal values are found in soils near coal-burning plants. Fly ash from a local plant contains substantial amounts of the elements. The high lead values are largely due to vehicular exhaust. However, there is evidence that the metals can also come from the normal deterioration of vehicles. It appears that airborne pollution is an important source of heavy metals in Dayton area soils.     

Selection of better extractants to indicate Pb bioavailability in lead-contaminated agricultural soils of Zhejiang Province

The accumulation of Pb in the food chain is one of the great concerns as it can cause chronic health problems and the available Pb is easily absorbed by crops. To shed light on Pb bioavailability in lead-contaminated agricultural soils of Zhejiang Province, a series of plant growth experiments were performed in a greenhouse to select more suitable extractants from five commonly used extractants (0.1 M HCl, 1 M NH4OAc, 0.1 M CaCl2, DTPA-TEA and Mehlich 3). The results showed that 1 M NH4OAc can extract Pb best, indicating the Pb bioavailability, then, DTPA-TEA and 0.1 M HCl in the tested soils. In case 1 M NH4OAc was used as an extractant, the critical Pb concentrations in soils were 50.19 mg/kg, 21.16 mg/kg and 114.00 mg/kg (1 M NH4OAc extracted Pb) in silty loam, yellowish-red soil and purplish soil, respectively. When the values exceed the above ones, the contents of Pb in Chinese cabbage leaves will exceed the Chinese Tolerance Limit of Lead in Foods (GB14935-94), as a result, potential ecological risk and hazard to human health via the food chain will appear.     

Effects of heavy metal pollution on farmland soils and crops: A case study of the Xiaoqinling Gold Belt,China

This paper focuses on the heavy metal enrichment and heavy metal pollution degree associated with mining activities in some crops and the soils of different parent materials in the Xiaoqinling Gold Belt. According to the geochemical analysis results of the soils observed in the gold belt, the soils are most highly enriched in Pb, followed by Cr, Cu, and Zn. Furthermore, they are relatively poor in Hg, Cd, and As. It is also shown that the heavy metals in all kinds of soils have the same geochemical characteristics in the gold belt. As for the crops (such as corn and wheat) in the gold belt, Zn and Cu are the most abundant elements, followed by Pb and Cr. Meanwhile, Hg, Cd, and As were found to have relatively low concentrations in the crops. The heavy metals in wheat and corn have the same geochemical characteristics in the gold belt in general. Compared to the aeolian loess soils and the crops therein, heavy metals are more enriched in diluvial and alluvial soils and the crops therein. As shown by relevant studies, the Hg, Pb, Cd, Cu, and Zn pollution are mainly caused by mining activities. Corn and wheat in the gold belt have a high tendency of risk exposure to heavy metal pollution since they are mostly affected by mining activities and feature high background values of heavy metal concentrations. Furthermore, wheat is more liable to be enriched in heavy metals than corn is grown in all types of soils. The Hg pollution in soils leads to Hg accumulation, increasing the risk of Hg uptake in crops, and further affecting human health. This study will provide a scientific basis for the control and management of heavy metals in farmland soils of mining areas.     

Enrichment of metals in soils subjected to different land uses in a typical Mediterranean environment (Murcia City, southeast Spain)

Industrialization, urbanization, and agricultural practices are 3 of the most important sources of metal accumulations in soils. Concentrations of Cr, Mn, Ni, Cu, Pb, Zn and Cd were determined in surface soils collected under different land uses, including urban (UR), industrial (IN-1 and IN-2), agricultural (AG), abandoned unused (AB), and natural (NA) sites to examine the influence of anthropogenic activities on metals in soils formed in a typical Mediterranean environment. The highest concentrations of Cr, Cd, and Pb observed in the NW industrial area (IN-2) were 63.7, 3.34 and 2330 mg metal kg⁻¹ soil, for each metal, respectively. The SW industrial area (IN-1) contained the highest Zn content at 135 mg kg⁻¹. However, soils with the highest concentrations of Ni and Cu were located in AG sites at 30.9 and 64.9 mg kg⁻¹ soil, respectively. Sampling locations with the highest concentrations of Mn were identified in AB sites. Using the concentrations of metals at the NA sites as the baseline levels, soils collected from all other land uses in the study area exhibited significantly higher total contents of Zn, Mn, Cr and Ni. Metal enrichment was attributed to fertilizer and pesticide applications, industrial activities, and metal deposition from a high volume of vehicular traffic (for Pb and Cd). High concentrations of Mn in some samples were attributed to parent materials. The study demonstrated that anthropogenic activities associated with various land uses contribute to metal accumulation in soils and indicated a need to closely monitor land management practices to reduce human and ecological risks from environmental pollution.     

Assessment of heavy metals in soil and terrestrial isopod <Emphasis Type="Italic">Porcellio laevis</Emphasis> in Tunisian industrialized areas

In this study, data on several metals (Cd, Pb, Zn and Cu) in soil and isopod Porcellio laevis taken at 21 sites from the most important industrial areas in Tunisia (Bizerte, Nabeul, Zaghouan, Sfax and Gabes) were presented. Heavy metal concentrations in both soil samples and isopods were determined using atomic absorption spectrometry. Soil contamination was estimated using the contamination factor (CF). On the other hand, the bioaccumulation factor (BAF) was determined to estimate metal accumulation in isopods. The CF values show that the level of contamination varies between sampled soils, which may be due to the source of pollution at each site. The BAF values allow defining the order of accumulation in P. laevis which was classified for the majority of the sampled sites as a macro-concentrator of Cu and Zn and a deconcentrator of Cd with some exceptions. A principal component analysis (PCA) was conducted between soil properties (pH, OM and CaCO₃) and metal concentrations in soils. Through PCA, we obtained four groups in which soils were distinguished by their physicochemical properties and their metal concentrations. Moreover, linear multiple regressions with a downward stepwise procedure were conducted to test the relationships between the physicochemical parameters and metal concentrations in both soils and isopods. Thus, positive correlations (0.78 < R ² < 0.99) were obtained for Pb considering dataset from the groups 1, 2 and for Zn with data of groups 2 and 3. Finally, results showed that P. laevis could be used as a bio-indicator for monitoring and reducing the impact of pollution in terrestrial ecosystems.     

Reclamation of mine-degraded agricultural soils from metal mining: lessons from 4 years of monitoring activity in Korea

The environmental issues associated with mining have damaged the industry’s substantial global economic value. In particular, the mining industry has a negative legacy of contaminated land. The effective reclamation of contaminated soil is therefore required before former mining land can be further developed for residential and commercial purposes. The objective of this study was to technically evaluate the feasibility of reclamation techniques for agricultural soils contaminated with toxic elements (As, Cd, Cu, Pb, and Zn) associated with metal mining. The reclamation methods investigated were covering without stabilization, covering with stabilization, and exchange with stabilization. The thickness of the soil layer used in covering and exchange was in the range of 30–50 cm. Limestone, furnace slag, and a mixture of limestone and furnace slag were applied as soil amendments. After reclamation, the contamination level in surface tillage soils and crops was monitored regularly. Four years of monitoring data revealed that surface soil contamination levels could be maintained at acceptable levels, although at some sites, the metal levels in crops exceeded legislative limits. Soil reclamation at former mining sites in Korea has not yet been perfected, but the results of this study show that there is potential for safe agricultural operations on large sites in a cost-effective manner, as long as the appropriate control of surface soil contamination and adequate agronomic management is undertaken.     

不同耕作方式下川芎对土壤中铅、镉含量的富集特征

以彭州川芎种植区的菜园土、稻田翻耕土、稻田免耕土和旱地(未种过川芎和蔬菜)四种土壤为研究对象,探讨了不同耕作方式下川芎对土壤中Cd、Pb的富集特征。结果表明:在四种耕作方式下,菜园土中Cd、Pb含量显著高于其他三种土壤,分别为1.10mg·kg-1和29.78mg·kg-1;土壤Cd综合污染指数和Hacanson系数分别为3.76和133.07,处于重污染和强生态危害状态。稻田翻耕土、稻田免耕土和旱地三种类型土壤在Cd含量上差异显著,依次为稻田免耕土(0.86mg·kg-1)稻田翻耕土(0.59mg·kg-1)旱地(0.37mg·kg--1),在Pb含量上三者差异不显著。川芎植株对Cd的富集在菜园土中显著高于其他土壤,表现为菜园土稻田免耕土旱地稻田翻耕土;川芎植株对Pb的富集以在稻田免耕土中最大,依次为稻田免耕土旱地稻田翻耕土菜园土。在四种土壤中,川芎叶片对Cd、Pb的富集能力均大于根茎,其中川芎叶片对Cd的富集能力是根茎的1.37倍,对Pb的富集能力是根茎的1.42倍,二者对Cd的富集能力在菜园土中差异最大(叶/根为1.56),对Pb的富集能力在稻田免耕土中差异最大(叶/根为1.98)。川芎对Cd、Pb的富集主要受轮作作物种类和耕作措施的影响。     

Accumulation and ecological effects of soil heavy metals in conventional and organic greenhouse vegetable production systems in Nanjing,China

The spatial variability of soil heavy metals in conventional and organic greenhouse vegetable production (CGVP and OGVP) systems can reveal the influence of different farming activities on their accumulation and plant uptake. This provides important basic data for soil utilization and pollution risk assessment. Based on horizontal and vertical spatial analysis, this paper presents the spatial variability and accumulation of soil heavy metals. The effects on plant uptake and factors influencing heavy metal accumulation are presented using the two typical greenhouse vegetable sites in Nanjing City, China as examples. Results showed that different greenhouse vegetable production systems had their own dominant heavy metal accumulation, specifically, Hg and Pb in CGVP system and Cd in OGVP system. The spatial analysis showed that horizontally, distribution of soil properties and heavy metal concentrations in the two sites showed decreases from specific regions to the periphery for organic matter (OM), Cd, Cu, Hg, Pb, and Zn in CGVP and OM, As, Cd, Cu, Hg, Pb, and Zn in OGVP. Vertically, soil properties and heavy metals mainly vary in the topsoil. The key factor for the accumulation was excess fertilizer input. Variation of soil properties and the accumulation of soil heavy metals significantly influenced heavy metal uptake by plants. However, accumulation risk varied according to different heavy metals and different plant species. Environmental management of these two kinds of production systems should pay more attention to fertilizer application, plant selection, and soil properties.     

Heavy metal concentrations in soils and plants in the vicinity of Arufu lead-zinc mine,Middle Benue Trough,Nigeria

This study focused on the influence of base metal mining on heavy metal levels in soils and plants in the vicinity of Arufu lead-zinc mine, Nigeria. Soil samples (0-15 cm depth) and plant samples were collected from cul-tivated farmlands in and around the mine, the unmineralized site and a nearby forest (the control site). The samples were analyzed for heavy metals (Fe, Zn, Mn, Cu, Pb, Cr and Cd) by Atomic Absorption Spectrophotometry (AAS). The physical properties of soils (pH and LOI) were also measured. Results showed that soils from cultivated farm-lands have neutral pH values (6.5-7.5), and low organic matter contents (10%). Levels of Zn, Pb and Cd in culti-vated soils were higher than the concentrations obtained from the control site. These heavy metals are most probably sourced from mining and agricultural activities in the study area. Heavy metal concentrations measured in plant parts decreased in the order of rice leavescassava tuberspeelings. In the same plant species, metal levels decreased in the order of ZnFeMnCuPbCrCd. Most heavy metals were found in plant parts at average concentrations normally observed in plants grown in uncontaminated soil, however, elevated concentrations of Pb and Cd were found in a few cassava samples close to the mine dump. A stepwise linear regression analysis identified soil metal contents, pH and LOI as some of the factors influencing soil-plant metal uptake.     

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。     

Biogeochemistry of Pb–Zn gossans,northwest Queensland,Australia: Implications for mineral exploration and mine site rehabilitation

The concentration and distribution of metals were studied in metallophytes, growing on and in the vicinity of Pb–Zn gossans, NW Queensland. The study investigated the accumulation of metals in plant species and assessed their potential use as indicators in geobotanical and biogeochemical prospecting and as metal excluders in mine site rehabilitation. Plant species colonising the gossans tolerate high concentrations of metals. Total mean metal concentrations of soils ranged from minima of 14 ppm Cu, 28 ppm Pb and 34 ppm Zn in background areas to maxima of 660 ppm Cu, 12000 ppm Pb and 2100 ppm Zn over mineralised soils. Over the gossans, the grass species Eriachne mucronata forma, Enneapogon lindleyanus and Paraneurachne muelleri replace the characteristic grass Triodia molesta where the soils have high Pb and Zn concentrations. Of the 16 plant species identified, 3 of them, Hybanthus aurantiacus, Clerodendrum tomentosum and Bulbostylis barbata, were confined to the gossan sites. B. barbata appears to be of particular use in geobotanical prospecting as it indicates base metal mineralisation in the region.     

氨基泡塑的合成及其应用于富集地质样品中的痕量金

采用泡塑(PUF)富集,AAS或ICP-OES测定地质样品中痕量金是常用的分析方法。与活性炭相比,PUF的选择性好,但吸附容量偏低,可将泡塑负载不同的萃取剂或修饰不同的官能团提高吸附容量。本文将聚醚型泡塑经盐酸水解制备成氨基泡塑(PUF-NH_2)。红外光谱和扫描电镜表征显示,PUF-NH_2峰形发生了明显红移(3376.5 cm-1),其中的氨基数量显著增加,另外PUF-NH_2的高分子出现明显断裂,发生水解后裸露出的氨基具有还原性,在吸附金的过程中易与金离子在PUF-NH_2表面发生氧化还原反应,形成金纳米颗粒。改性后的PUF-NH_2吸附容量达到96 mg/g,与PUF相比提高了8倍。将PUF-NH_2应用于富集地质样品中的金,经炭化灼烧、50%王水提取后用ICP-OES测定,金的加标回收率在95.0%~105.0%之间,检出限为0.15μg/g。实验证明用PUF-NH_2处理样品提高了富集倍数和分析灵敏度,有利于低品位矿石的分析。     

Comparative analysis of heavy metal concentration in secondary treated wastewater irrigated soils cultivated by different crops

The use of treated urban wastewater for irrigation is a relatively recent innovation in Botswana and knowledge is still limited on its impact on soil heavy metal levels. The aim of this study is to analyze and compare heavy metal concentration in secondary wastewater irrigated soils being cultivated to different crops: olive, maize, spinach and tomato in the Glen Valley near Gaborone City, Botswana. The studied crop plots have been cultivated continuously under treated wastewater irrigation for at least 3 years. Most crop farms have sandy loam, loamy sand soils. Based on food and agriculture organization, heavy metal threshold values for crop production have been studied. Results showed that the wastewater irrigated soils in the Glen Valley have higher cadmium, nickel and copper than desirable levels, while the levels of mercury, lead and zinc are lower than the maximum threshold values recommended for crop production. The control sites show that the soils are naturally high in some of these heavy metals (e.g copper, zinc, nickel) and that crop cultivation under wastewater irrigation has actually lowered the heavy metal content. Comparing between the crops, mercury and cadmium levels are highest in soils under maize and decline linearly from maize to spinach to olive to tomato and control site. By contrast, concentrations of the other metals are at their lowest in maize and then increase from maize to spinach to olive to tomato and to control site.     

Lead contamination of soil along road and its remediation

With a rapid development of road systems and an associated drastic increase in number of automobiles, the traffic has induced more and more obvious environmental pollution such as noise, dust, emission and heavy metal contamination. Lead, as one of the most harmful heavy metal contaminants, can execute a significant impact on soil quality and plant growth, depending on its form, as well as its transport and accumulation in soil. This paper describes the source and characteristics of Pb contaminant in soil along a road, and reviews the results of research on remediation of Pb-contaminated soils, aiming at identifying promising approaches to soil remediation along roads.     

Potential hyperaccumulation of Pb, Zn, Cu and Cd in endurant plants distributed in an old smeltery, northeast China

The absorption and accumulation of Pb, Zn, Cu and Cd in some endurant weed plant species that survived in an old smeltery in Liaoning, China, were systematically investigated. Potential hyperaccumulative characteristics of these species were also discussed. The results showed that metal accumulation in plants differed with species, tissues and metals. Endurant weed plants growing in this contaminated site exhibited high metal adaptability. Both the metal exclusion and detoxification tolerance strategies were involved in the species studied. Seven species for Pb and four species for Cd were satisfied for the concentration time level standard for hyperaccumulator. Considering translocation factor (TF) values, one species for Pb, seven species for Zn, two species for Cu and five species for Cd possessed the characteristic of hyperaccumulator. Particularly, Abutilon theophrasti Medic, exhibited strong accumulative ability to four heavy metals. Although enrichment coefficients of all samples were lesser than 1 and the absolute concentrations didn’t reach the standard, species mentioned above were primarily believed to be potential hyperaccumulators.     

Heavy-metal contaminated soils associated with drained fenland in Lancashire,England, UK,revealed by BGS Soil Geochemical Survey.

Areas showing anomalously high levels of heavy metals (eg. Cu, Pb, Sn, Zn) in both peri-urban and rural soils in parts of western Lancashire (UK) were indentified during a regional geochemical survey. The sites were identified as areas of former peat fenland that had been filled in with a variety of domestic and industrial wastes including furnace slag, as well as inert rubble. The very high levels of heavy metals present in the soil raises concerns about possible translocation into food crops, as this is an important market gardening area. There is no direct evidence of a health risk, and the high-pH soils will limit metal mobility and bioavailability, but these soils are worthy of further multidisciplinary scientific investigation.     

Historical record of heavy metal pollution deduced by lead isotope ratios in core sediments from the Osaka Bay,Japan

Three marine sediment cores from Osaka Bay were analyzed for ²¹⁰Pb geochronology, heavy metal concentrations (Zn, Cu, and Pb) and stable lead isotope ratios (²⁰⁶Pb/²⁰⁷Pb) in order to reconstruct high-resolution heavy metal pollution history from 1900–2006. Anthropogenic metal accumulation in sediments peaked in 1970 in agreement with the high economic growth period in Japan. The comparison of temporal patterns of ²⁰⁶Pb/²⁰⁷Pb ratio with other areas of Japan suggested that the heavy metals, imported from several different countries during the periods of economic growth (1955 to 1973), are the main pollution source for the country. For the period 1970–2006, the sediment data reflect the result of stricter environmental regulations applied after the late 1960s. However, heavy metal concentrations in the surface sediments are still elevated to levels several times higher than the levels at the bottoms of the cores. Additionally, the lead isotope ratio does not show significant change after the 1980s. Secondary heavy metal pollution through the mixing of deeper polluted sediment appears to be the likely reason for the deterioration of present time submarine sediment environments. In conclusion, this study has demonstrated that it is difficult to recover over a period of several years the benthic quality of a bay, once it is heavily polluted.