田块尺度上土壤重金属污染地统计分析及评价(简报)

该文以北京市某生态农场的大田为例,应用地统计学分析方法进行了变异函数的计算和模型拟合,建立了计算土壤重金属含量的最适空间插值理论模型,随后运用克立金估值方法绘制了田块尺度上土壤重金属的空间分布图,并与土壤重金属污染标准进行比较,土壤重金属污染评价结果表明：研究范围内的土壤重金属含量较低,未发现污染。该研究结果表明地统计学分析方法可为田块尺度上的农业优化管理提供决策支持。     

田块尺度上土壤重金属污染地统计分析及评价

该文以北京市某生态农场的大田为例,应用地统计学分析方法进行了变异函数的计算和模型拟合,建立了计算土壤重金属含量的最适空间插值理论模型,随后运用克立金估值方法绘制了田块尺度上土壤重金属的空间分布图,并与土壤重金属污染标准进行比较,土壤重金属污染评价结果表明:研究范围内的土壤重金属含量较低,未发现污染。该研究结果表明地统计学分析方法可为田块尺度上的农业优化管理提供决策支持。     

基于局部离群指数的土壤重金属污染评价方法

为评价土壤重金属污染,该文提出了一种局部离群指数方法。局部离群指数方法计算监测样点的局部离群指数,监测样点的局部离群指数越大,则该样点是污染样点的趋势越大。为确保算法的准确性,定义了深度离群点以及广度离群点;为减少算法处理海量数据的计算复杂性,开发了基于密度取样的数据过滤方法,以过滤数据分布致密的数据点而保留稀疏区域的数据点。以京郊农田重金属监测数据为实例,比较局部离群指数方法与内梅罗污染指数方法的评价结果的准确性,结果显示局部离群指数方法的评价结果与内梅罗污染指数方法的结果吻合,表明局部离群指数方法可作为一种有效的重金属污染评价方法。     

矿区复垦土壤种植小麦的重金属安全性

为分析矿区充填复垦土壤种植农作物的生态安全性,以中国徐州市柳新矿区复垦场地为例,对照当地农田土壤,对充填场地种植小麦不同部位As、Cd、Cr、Cu、Hg、Pb、Zn 7种重金属元素含量进行检测,分析了Cd、Cr在成熟小麦不同器官中的分布、富集情况,并利用单项污染指数法和综合指数法对小麦籽粒进行了风险评价。结果表明,三场地中Cd 和Hg在未成熟苗中的含量小于成熟茎中的含量,Cr、Cu和Zn则与之相反,Pb和As的含量规律性不太明显;复垦场地小麦未成熟根的重金属含量都小于成熟根中的含量;比照地中除Cr 和Zn之外,其余元素在未成熟根中的含量均大于成熟根的含量;参照粮食污染限量标准,小麦籽粒中Cd和Cr含量均超标。风险评价显示三场地小麦籽粒中Cd、Cr单项污染指数达到轻度至重度水平,综合污染指数处于轻度污染至中度污染水平之间。该研究对矿区粮食安全的监控具有重要的实际应用价值。     

徐州市北郊农业土壤重金属污染评价

研究评价徐州市北郊农业土壤重金属污染状况结果表明,该区农业土壤中Cu、Cd、Pb、Zn和Cr 5种重金属平均含量均高于土壤背景值,其农业土壤Cd、Cr为重污染,土壤Zn为污染警戒级(尚清洁水平),其他2种元素为安全级(清洁水平),其综合污染指数为Cr>Cd>Zn>Cu>Pb。     

Application of an algal bioassay to heavy‐metal contaminated soil samples

The aim of this study was to test the effect of heavy‐metal contamination (Cu, Zn) on the growth of Chlorella kessleri. Two soils (Chernozem and Podzoluvisol) were contaminated with several amounts of copper and zinc (100–3000 ppm), and the effects of the soil eluates on the growth of the alga were examined over several days. The soil eluates inhibited algal growth in dependence on metal concentration and soil properties. It was shown that this algal assay, which was first developed for aquatic samples, in principle seems to be suitable also in monitoring soil contamination.     

Suitability of soil microbial parameters as indicators of heavy metal pollution

Several microbial parameters (microbial biomass, respiration, dehydrogenase, phosphatase, sulphatase, glucosidase, protease and urease activities) were measured in soils from five sites located in urban green areas close to roads differing in traffic density. Our aims were to evaluate the suitability of such parameters as field biomarkers of stress induced by heavy metal pollution, and to compare results obtained by single microbial parameters with results given by an index expressing the average microbial (AME) response of the microbial community. Data showed that all parameters were significantly reduced in the sites characterized by the highest load of metals in soil. Dehydrogenase, sulphatase, glucosidase activities and respiration, declined exponentially with increasing metal concentration, whereas phosphatase activity and AME decreased following a sigmoidal type relationship. In contrast, protease, urease and microbial biomass were not significantly correlated with soil metal concentration. Microbial parameters differed both in sensitivity to critical metal concentrations and in the rate of decline at increasing metal loads in soil. Due to the complex interplay of chemical, physical and biological factors which influence microbial activities and biomass, the proposed index (AME) appeared more suitable than single microbial parameters for a biomonitoring study of this type.     

Improved three-dimensional mapping of soil chromium pollution with sparse borehole data: Incorporating multisource auxiliary data into IDW-based interpolation

Deriving an accurate three-dimensional (3D) spatial distribution of heterogeneous soil pollutants at contaminated sites using traditional spatial interpolation methods, such as inverse distance weighting (IDW), is challenging; especially when only limited borehole data are available. This study presents a novel IDW-COV method, where weighting is determined by optimizing relative importance between feature distances of covariates and spatial distances to soil sample locations. The method was tested by mapping the 3D distributions of Cr (VI) and total Cr at a Cr salt production workshop (Site A) and a legacy Cr slag stacking site (Site B). The results were compared with those of IDW, the soil land inference model (SoLIM), and the SoLIM combined with IDW method (SoLIM-IDW). The proposed IDW-COV method returned the highest accuracy, with R² values of 0.83 for Cr (VI) in Site A and 0.75 for total Cr in Site B, compared with 0.65 and 0.57 for IDW, 0.16 and 0.58 for SoLIM, and 0.73 and 0.61 for SoLIM-IDW. This study highlights the importance of considering differences in explanatory power between multidimensional covariate and geographical spatial distance when incorporating multisource auxiliary data into weighted average estimators and provides guidance for mapping 3D distributions of heterogeneous pollutants from sparse soil borehole data .     

改良剂对重金属污染红壤的修复效果及评价

采用盆栽试验,研究了施用改良剂—石灰、有机肥、海泡石对红壤上小油菜生物产量、镉锌吸收量、pH、吸收系数的影响。结果表明,施用改良剂,连续种植3季小油菜 (Brassia campestris L.) 的生物产量都显著提高,石灰、有机肥和海泡石配施的产量是对照的15倍。改良剂能不同程度提高红壤的pH,以石灰的效果最好,土壤pH平均升高了2个单位;而且小油菜对镉锌的吸收也较低。小油菜对镉的吸收系数大于对锌的吸收系数,说明镉容易在土壤-植物体系中迁移,施用改良剂后吸收系数降低。施石灰的小油菜中锌含量达到食品卫生标准。改良剂对提高土壤pH的后效逐渐减弱,对抑制小油菜吸收锌的后效不如抑制镉的后效好。     

南宁河洲生态农业规划区土壤重金属污染评价

对南宁河洲生态农业规划区土壤中Cd、As、Pb、Hg、Cu、Zn等重金属含量进行了调查和分析测定．应用模糊评判法进行评价。结果表明．其土壤主要受Cd和As的污染；12个试点中4个点为尚清洁，8个点为轻污染。     

Heavy metal pollution of agricultural soils and sediments in Liaoning Province,China

Heavy metal pollution of soils and sediments in Liaoning Province, Northeast China, was investigated. Fifty seven samples of agricultural soils and 8 samples of sediments were collected in 1996 from paddy or upland fields and irrigation channels, respectively, in Shenyang, Fushun, Liaoyang, Anshan, and Tieling regions, and concentrations of total and 0.1 mol L^-1 HCI-extractable Cd, Cu, Pb, and Zn were analyzed using ICP spectrometry. Seventeen samples of unpolished rice were also collected from selected paddy fields and total concentrations of the four elements were determined.–

Both paddy and upland soils were polluted with Cd: average total concentration was 0.70, 0.57, and 0.53 mg kg^-1 in the western and southern parts of Shenyang, and Anshan, respectively, and significantly higher than the background level of 0.32 mg kg^-1. Cd concentrations of four samples exceeded even 1 mg kg^-1, which corresponds to the critical level of Cd contamination in China. About 65% of the total Cd was extracted with 0.1 mol L^-1 HCI, suggesting that Cd was relatively mobile compared with other metals. The level of Cd pollution was, however, lower than that previously reported and serious polIution was not observed for Cu, Pb, and Zn. Accordingly, Cd concentration in upland rice was within the range of the unpolluted level in this study. Nevertheless, Cd concentration in a sediment of irrigation channels in the western part of Shenyang exceeded 16 mg kg^-1, indicating the possibility of further contamination of agricultural soils. In conclusion, soils and sediments were still polluted with Cd in the southern part of Shenyang, Anshan, and especially in the western part of Shenyang, and further countermeasures are urgently required to ensure safe food production in these regions.     

Does changing the taxonomical resolution alter the value of soil macroinvertebrates as bioindicators of metal pollution?

Ecological indicators are taxa that are affected by, and indicate effects of, anthropogenic environmental stress or disturbance on ecosystems. There is evidence that some species of soil macrofauna (i.e. diameter >2 mm) constitute valuable biological indicators of certain types of soil perturbations. This study aims to determine which level of taxonomic resolution, (species, family or ecological group) is the best to identify indicator of soil disturbance. Macrofauna were sampled in a set of sites encompassing different land-use systems (e.g. forests, pastures, crops) and different levels of pollution. Indicator taxa were sought using the IndVal index proposed by Dufrêne and Legendre [Dufrêne, M., Legendre, P., 1997. Species assemblages and indicator species: the need for a flexible asymetrical approach. Ecological Monographs 67, 345-366]. This approach is based on a hierarchical typology of sites. The index value changes along the typology and decreases (increases) for generalist (specialist) faunal units (species, families or ecological groups). Of the 327 morphospecies recorded, 19 were significantly associated with a site type or a group of sites (5.8%). Similarly, species were aggregated to form 59 families among which 17 (28.8%) displayed a significant indicator value. Gathering species into 28 broad ecological assemblages led to 14 indicator groups (50%). Beyond the simple proportion of units having significant association with a given level of the site typology, the proportion of specialist and generalist groups changed dramatically when the level of taxonomic resolution was altered. At the species level 84% of the indicator units were specialist, whereas this proportion decreased to 70 and 43% when families and ecological groups were considered. Because specialist groups are the most interesting type of indicators either in terms of conservation or for management purposes we come to the conclusion that the species level is the most accurate taxonomic level in bioindication studies although it requires a high amount of labour and operator knowledge and is time-consuming.     

Advances in long‐term soil‐pollution monitoring of Switzerland

The Swiss soil‐monitoring network (NABO) was launched in 1984 and comprises currently 105 observation sites covering all characteristic land‐use types across Switzerland. So far, the sampling periodicity was 5 y, and the fifth sampling campaign will be accomplished by end of 2009. The concentrations of Cd, Zn, Pb, Cu, Hg, Ni, Cr, Co, and F were measured. The major results and conclusions are: (1) Even topsoils in remote areas are to some extent polluted, mainly by Pb, Cu, and Cd. However, elevated concentrations can also be of natural origin, e.g., for F, Ni, Cr, and Cd. (2) Land use alone is often a rather unreliable indicator to discriminate soil pollution. (3) After the 2nd campaign positive, negative, or no temporal concentration changes were measured. From the 3rd campaign onwards, nonmonotonous (zigzag) evolutions were frequently observed. Therefore, no certified trends can be stated after three measurement campaigns during a period of 10 y. (4) Soil monitoring is an environmental time‐series problem. The only way to detect reliable signals and trends earlier is to improve the overall measurement quality (precision and bias) and to shorten the measurement periodicity. (5) The causes of temporal soil concentration changes are complex and result from natural processes, anthropogenic processes, and methodological artifacts. Hence, not all soil concentration changes are due to anthropogenic inputs. Based on the state‐of‐art of our experience, some basic methodological requirements and recommendations can be supported for a “good soil‐monitoring practice”: (1) Assurance of long‐term continuity and consistency under changing boundary conditions as site conditions, methodologies, etc. (2) Implementation of a scientifically and politically appropriate spatial and temporal measurement resolution. (3) Long‐term assessment of reliability (quality assurance) by adequate quantification of precision, bias, and confidence intervals along the whole measurement chain. (4) Documentation of all potentially relevant boundary conditions by suitable metadata. Only soil‐monitoring results meeting these requirements are fit to support political decisions.     

水土保持措施防治非点源污染的作用机制

 进入土壤或水体中的非点源污染物一般可分为化肥、农药和重金属3大类。这3大类污染物在土壤或水体中通过植物吸收、土壤胶体吸附、微生物降解、径流淋失与挥发等途径进行迁移转化。系统阐述水土保持生物措施、工程措施和农业技术措施3大措施对化肥、农药和重金属3大污染物的各种迁移转化途径所具有的促进与抑制作用,可为合理配置水土保持措施,有效防治非点源污染提供重要的理论依据。     

Construction and analysis of knowledge graphs for multi-source heterogeneous data of soil pollution

The decommissioning and overall relocation of urban industrial enterprises have generated a large number of decommissioned contaminated sites, and the leftover soil pollution is gradually becoming a major problem that restricts urban green development and damages human health. Deep mining and efficient management of site soil pollution information through digitization and informatization are needed to solve these problems more accurately and efficiently. Knowledge mapping for visual analysis of relevant pathways is a forward-looking approach in soil contamination management that does not require complex testing instruments, thus saving research manpower, time and cost. Data associated with contaminated sites come from a wide range of sources and have different structures. Through the natural language processing technology of computer, suitable methods such as entity recognition, relationship recognition and knowledge fusion are selected to extract various types of information from contaminated sites and establish semantic networks for fast targeting of soil contamination sources, thus providing a more convenient solution. In this paper, we propose a knowledge graph construction method for multi-source heterogeneous data of contaminated sites, find sulphide contamination sources through visual analysis of knowledge graph and explore the application prospects of natural language processing techniques such as knowledge graph in contaminated site management.     

The use of microbial parameters in monitoring soil pollution by heavy metals

Microbial parameters appear very useful in monitoring soil pollution by heavy metals, but no single microbial parameter can be used universally. Microbial activities such as respiration, C and N mineralization, biological N₂ fixation, and some soil enzymes can be measured, as can the total soil microbial biomass. Combining microbial activity and population measurements (e.g., biomass specific respiration) appears to provide more sensitive indications of soil pollution by heavy metals than either activity or population measurements alone. Parameters that have some form of internal control, e.g., biomass as a percentage of soil organic matter, are also advantageous. By using such approaches it might be possible to determine whether the natural ecosystem is being altered by pollutants without recource to expensive and long-running field experiments. However, more data are needed before this will be possible. Finally, new applications of molecular biology to soil pollution studies (e.g., genetic fingerprinting) which may also have value in the future are considered.     

铅锌矿区周边农田土壤跳虫群落特征与重金属污染的关联

以云南兰坪铅锌矿区周边的农田为对象,按距矿区距离设四条样带,每个样带按距河流由近至远等距选3个样点进行定量采样,测定和分析土壤跳虫物种多样性和群落结构、土壤重金属含量和理化性质、及跳虫体内的铅含量.共获跳虫26种,平均密度12042 ind·m2.样点与矿区或河流距离增加,土壤中镉、铅和锌含量下降,跳虫体内重金属含量下...     

陕西渭北苹果园土壤中汞、镉污染与分布特征研究

该文研究了陕西优势苹果产区果园土壤中汞和镉含量、污染情况、分布特征及对苹果绿色食品生产的影响.2003～2006年在陕西全部27个苹果基地县481个代表苹果园,每一果园采用"S"形法选取20个样点,采集0～40 cm层土样,分析了土壤中汞、镉含量.结果表明,果园土壤受到汞、镉的轻度污染;土壤中汞、镉频数分布为对数正态分布,其含量适宜的表示方法为几何平均值,汞,0.051 mg/kg,镉,0.055 mg/kg;土壤中汞、镉浓度与pH值相关性极显著,在pH值7.6～9.7范围内,土壤pH值越高越有利汞、镉的累积.果园土壤受到汞、镉的轻度污染,对绿色食品苹果生产不存在威胁.     

土壤重金属有效态含量检测与监测现状、问题及展望

随着经济和社会的发展,土壤重金属污染对粮食安全及人类的身体健康构成了巨大的威胁,而目前广泛采用的全量检测法并不能准确地反映土壤重金属的生物毒性。为了更好地了解土壤重金属的污染情况及其生物毒性,需快速有效检测土壤重金属的赋存形态及有效态含量。本文介绍了土壤有效态重金属的定义及其在土壤-有机体系统中的转移;并结合国内外相关研究领域的文献资料,按检测对象将土壤重金属有效态的检测方法分为直接检测方法(化学检测方法和物理检测方法)和间接检测方法(生物指示法),系统阐述了化学检测方法中的浸提法,物理检测方法中的梯度扩散薄膜技术和光谱分析法,及生物指示法中的指示植物检测法、微生物检测法和动物检测法的研究进展、适用范围及优缺点,概括了目前检测方法存在的主要问题是不能同时满足大面积监测和精确检测两个方面。并指出快速、大面积、原位测定污染物种类和含量,采取相应措施保障粮食安全及人类身体健康是目前迫切需要解决的问题。本文将土壤-植物-人作为一个整体,了解重金属有效态在该系统中的迁移富集机理,认为在此基础上选择合适的数据处理方法及建模参数,结合遥感、地理信息系统和全球定位系统对土壤重金属污染进行原位立体监测,是未来土壤重金属有效态含量检测与监测研究的主要发展方向。     

基于模糊逻辑的北京城市边缘区土壤重金属污染空间预测

Fuzzy classification combined with spatial prediction was used to assess the state of soil pollution in the peri-urban Beijing area. Total concentrations of As, Cr, Cd, Hg, and Pb were determined in 220 topsoil samples （0-20 cm） collected using a grid design in a study area of 2 600 kin2. Heavy metal concentrations were grouped into three classes according to the optimum number of classes and fuzziness exponent using the fuzzy comean （FCM） algorithm. Membership values were interpolated using ordinary kriging. The polluted soils of the study area induced by the measured heavy metals were concentrated in the northwest corner and eastern part, especially the southeastern part close to the urban zone, whereas the soils free of pollution were mainly distributed in the southwestern part. The soils with potential risk of heavy metal pollution were located in isolated spots mainly in the northern part and southeastern corner of the study region. The FCM algorithm combined with geostatistical techniques, as compared to conventional single geostatistical kriging methods, could produce a prediction with a quantitative uncertainty evaluation and higher reliability. Successful prediction of soil pollution achieved with FCM algorithm in this study indicated that fuzzy set theory had great potential for use in other areas of soil science.