沿海滩涂区土壤重金属含量分布及其有效态影响因素

为揭示沿海地区土壤重金属含量的空间分布特征及其与自然、人为因素的关联,以近年来围垦开发强度较大的江苏沿海某滩涂区为研究对象,采用经典统计与地统计相结合的方法研究了表层土壤主要重金属Pb、Cr、Cd、As全量与有效态含量状况及其空间分布,分析了沿海滩涂区土地利用方式对重金属含量的影响,探讨了重金属有效态含量与土壤理化性质的相关性。结果表明:目前研究区土壤环境质量状况良好,土壤Pb、Cr、Cd、As均呈累积趋势但基本都低于土壤环境质量一级标准值;土地利用方式不同程度地影响了Pb、Cr、Cd全量与有效态含量,As全量与有效态含量受土地利用方式影响较小;研究区土壤Pb、Cr、Cd全量与Pb、Cr有效态含量具有明显的趋势效应,且研究区土壤重金属全量与有效态含量的空间分布受大尺度的潮汐作用与小尺度的人为因素的共同控制;土壤Pb、Cr、Cd有效态含量与黏粒含量、阳离子交换量和p H显著负相关,与有机质呈显著正相关,土壤As有效态含量仅与土壤p H显著正相关。本研究为沿海滩涂区土壤重金属源头减量、活性钝化、污染消减与风险防范提供科学依据。     

Changes of heavy metals in soil and wheat grain under long-term environmental impact and fertilization practices in North China

Abstract

We evaluated the effects of long-term fertilization on heavy metals in soil and wheat grain under no-fertilizer control (CK), nitrogen, phosphorus, and potassium fertilizers (NPK), NPK plus straw (NPKS), and NPK plus manure (NPKM) treatments. Total lead (Pb) significantly increased in the CK over the initial soil. All fertilization treatments increased soil total arsenic (As) than CK, and the NPKM increased total cadmium (Cd), copper (Cu), and zinc (Zn) than NPK. All fertilization treatments increased soil available As and Cd than CK, and the NPKM increased available As and chromium (Cr) than NPK. The NPKS decreased grain As, Cd, Cu, and bran Cr, Zn, and Pb; but the NPKM increased grain Cr, Pb, and bran As, and Cu than NPK. Under current manure fertilization systems, the maximum bearing year of soil for As, Cr, Cd, Cu, Zn, and nickel (Ni) was 1136, 2990, 694, 1530, 910, and 1555?years, respectively.     

Occurrence and infectivity of arbuscular mycorrhizal fungi in some norwegian soils influenced by heavy metals and soil properties

Mycorrhizae are ubiquitous symbiosis which can mediate uptake of some plant nutrients. In polluted soils they could be of great importance in heavy metal availability and toxicity to plants. Mycorrhizae have also been reported to protect plants against toxic metals. We investigated the occurrence and infectivity of arbuscular mycorrhizal (AM) spores as affected by heavy metal levels and other soil properties in Norwegian soils collected from heavy metal polluted, high natural background and non-polluted areas. Spore numbers, mycorrhizal infectivity and spore germination of indigenous mycorrhizal fungi and of a reference strain (Glomus mosseae) in soils showed lower values in two soils with high metal concentrations and in one soil with a low pH. Mycorrhizal infectivity was negatively correlated with extractable metals. Spore number and mycorrhizal infectivity in a soil with naturally high heavy metal content were not different to in non-polluted soils, and indigenous AM fungi appeared more tolerant to metals than those in non-polluted soils. Mycorrhizal infectivity, expressed as MSI₅₀ values, was significantly correlated (r′=0.89, P< 0.05) with the percentage of germinating G. mosseae spores in the soils. However, the number of spores per volume of soil was not significantly correlated with infectivity or spore germination of the reference strain. The spore germination method is discussed as a bioassay of heavy metal toxicity in soil.     

Differential accumulation of heavy metals in soil profile and corn and soybean grains after 15-year poultry litter application under no-tillage

Journal of Soils and Sediments - Heavy metal contamination in soil and crop grain due to long-term poultry litter (PL) application is largely unknown under no-till production and subtropical...     

Long-term effects of heavy metals from composted municipal waste on some enzyme activities in a cultivated soil

A 3-year field experiment on a calcareous Fluventic Xerochrept planted with corn (Zea mays L.) was carried out to evaluate the effects of amending the soil with high and low rates of composted municipal waste on soil enzyme activities (alkaline phosphomonoesterase, phosphodiesterase, arylsulphatase, dehydrogenase, and l-asparaginase). These enzyme activities all increased when compost was added at rates of up to 90 t ha^-1, and the phosphatases continued to show a linear increase with compost rates of up to 270 t ha^-1. The addition of mineral fertilizer increased enzyme activities in unamended soil, and masked the stimulating effect of compost on the amended soils. Heavy metals did not affect soil enzyme activities up to a compost addition of at least three times the amount specified by Italian law.     

扬州市土壤重金属含量的调查

对全市385个土样分析结果表明,扬州市耕地土壤总体是清洁的,全市89 35%的土壤属于清洁地范围(综合污染指数≤0 7),7 53%的土壤属尚清洁范围(综合污染指数0 7～1 0之间),3 12%的土壤属轻度污染(综合污染指数1 0～2 0之间)。全市土壤重金属污染的顺序是Hg>Cr>As>Cu>Pb>Cd,各地区中,以邗江区土壤重金属含量相对较高。     

不同复垦时间的粉煤灰充填复垦土壤重金属污染与评价

为了解粉煤灰充填复垦土壤重金属污染情况，通过实地试验与现场采样化验相结合的方法，对复垦时间不同的粉煤灰复垦土壤里砷(As)、镉(Cd)、铬(Cr)、汞(Hg)、铅(Pb)、铜(Cu)、硒(Se)、锌(Zn)、、镍(Ni)和氟(F)等重金属和微量元素含量的时空变异性进行了研究。结果发现：以土壤本底值作为评价标准时，粉煤灰充填复垦土壤整体处于受污染状态。其中，表层复垦土壤受到Cd、Se、Zn、F 4种元素污染较重；粉煤灰充填复垦土壤适合旱作，不适合用作水田；随着复垦时间的增加，表层复垦土壤的污染指数呈递增趋势。     

红壤中重金属的复合污染及污染指数

A field experiment was conducted to study the effects of Pb,Cd,Cu,Zn and As coexisting in red soil on growth of rice (Oryza sativa L.) mung bean(Vigna rabiata(Linn.) Wilczek),alfalfa(Medicago sativa L.),Slash pine(Pinus elliottii Engelm.)and aspen(Populus L.).Results showed that rice,mung bean and alfalfa were significantly influenced by combined poollution of the heavy metals,the contents of Pb,Cd and As in rice grains greatly exceeded the National Standards for Food Hygiene of China.Heavy metals at a high concentration seriously retarded growth of mung bean and alfalfa,but not so obviously with slash pine and aspen.The composite index is suggested for evaluating the relativity of combined pollution with heavy metals in soil.     

用固定剂减少污泥中重金属污染土壤的研究

该研究将加有重金属固定剂的污泥装入废弃塑料容器制成施肥器,利用人工淋水或自然降水,使污泥中的养分从施肥器中流入土壤,而重金属被固定在污泥中,减少重金属土壤污染,再收集处理残渣,防止二次污染。通过淋滤试验和种植油麦菜、蕹菜的盆栽试验得出以下结论：硫酸钾作为固定剂和污泥混合,不仅肥效好,作物产量高,而且污泥重金属被水淋出量少,植物体内重金属的含量低。该文为污泥合理农用提供了新方法,同时充分利用了废弃塑料容器等废弃物,成本低而收效显著。     

Combination effects of heavy metals and fluoranthene on soil bacteria

The effects of (1) Cd, Cu, Zn, and fluoranthene (FLA), separately applied, and (2) combinations of one of these heavy metals with FLA on the growth of bacteria were studied in agar plate experiments. The bacteria were extracted from A horizons of a Eutric Regosol and a Calcic Chernozem. Significant reductions of bacterial counts were observed for both soils at concentrations > 1.0 mg Cd l^–1, 0.5 mg Cu l^–1, and 0.5 mg Zn l^–1, respectively. Additions of FLA up to 100 mg l^–1 did not result in increasing reductions of bacterial growth in the Regosol. Only 0.5, 2, and 100 mg FLA l^–1 caused significant reductions of 22–27%. Bacterial counts were not affected by 0.2 mg FLA l^–1. Low concentrations of heavy metals which were not affective when added separately were found to reduce bacterial growth when applied in combination with 0.2 mg FLA l^–1. At higher levels of heavy metals up to 2.5 mg l^–1, addition of FLA also increased the toxicity of the metals. It is assumed that the enhancement of toxicity by FLA is due to an alteration of the permeability of bacterial cell membranes. Received: 19 July 1996     

Incidence of heavy metals in street surface sediments: Solubility and grain size studies

Samples of surface and gutter sediment from roads within N.W. London have been analyzed for levels of Cd, Cu, Fe, Mn, Pb, and Zn. Sediment and associated metal grading curves are presented and apart from Mn and Fe which reflect natural background levels, the remaining metals show distributions which relate to road type and traffic conditions. For highways carrying the highest traffic densities the concentrations of Cd and Pb are greatest for grain sizes between 100 and 500 µm and an aggregation process is postulated. Residential side street samples show a marked affinity of Cd, Fe, and Zn for the coarsest grain fractions. Laboratory sorption and desorption studies are described and solution concentrations are obtained for Cd, Cu, Mn, Pb, and Zn over 1 to 30 day time periods. Solubility curves are typically variable with time. The relationship of leachate patterns to particle size and sample site location is discussed and its relative importance to Stormwater loadings is considered. Extraction efficiencies for the five metals are found to be independent of road type and in the order Cd > Zn, Cu > Mn > Pb. The relevance of this hierarchy to Stormwater toxicity is discussed.     

Solubility and uptake of heavy metals from a Swedish soil

Samples of the surface layer (Ap) and of grass, collected from: (1) grass ley fertilized in the normal way; (2) permanent pasture fertilized in the normal way; and (3) permanent pasture treated with large amounts of sewage sludge five years earlier, were analysed for Mn, Zn, Cu, Cr, Co, Ni, Pb, and Cd.The soil samples were extracted with: (1) distilled water saturated with CO₂; (2) 1 M neutral ammonium acetate; (3) ammonium acetate + acetic acid, pH 4.75; and (4) 2 M nitric acid on a waterbath. The efficiency of these extractants differed greatly and, in relative values, was: 1 for H₂O + CO₂, 3.4 for NH₄OAc, 20.7 for NH₄OAc + HOAc, and 343 for 2 M HNO_3- The dissolving effects of the extractants differed markedly with the kind of element.Grass from the field treated with sewage sludge showed much higher contents of Mn and Zn and somewhat higher contents of Cu and Pb than grass from the untreated field. The levels of Cr, Co, Ni, and Cd were practically uninfluenced by the treatment. Grass from a field close to a highway accumulated large amounts of air-borne Pb and Cd during the summer.It is concluded that the total contents of heavy metals in soils have only limited importance for the uptake by plants. Weak extractants therefore give better information about the plant-available amounts in soils.     

吉林省人参土壤中重金属污染水平及生物有效性研究

为了解吉林省人参土壤中重金属污染水平及其生物有效性,人参对重金属的吸收、转化及富集程度,运用ICP-OES对农田栽参和林下参及其土壤重金属进行测定分析。结果表明,人参土壤中重金属Cd含量超过国家三级土壤标准,所测的其它八种重金属含量均处在国家一级土壤水平内,重金属Pb的生物有效性系数最高达27.37%,虽然含量较低但存在一定的风险性,人参土壤中Ti的含量最高,其全量在476-1038 mg/kg,生物有效性最低为0.09%;两种模式下人参根区土壤中重金属生物有效态含量差别不大,但林下参土壤重金属生物有效性系数低于农田栽参土壤,尤其是对生物毒性较大的Cd、Cr、Cu和Pb元素,Cd的生物有效态含量与其生物有效性系数达极显著负相关(P<0.01),相关系数为0.79;不同肥料的施用对农田栽参土壤重金属生物有效态有一定影响,同一种肥料对不同重金属生物有效态含量影响亦不同;人参对Cu、Zn和Pb的富集系数最大,潜在风险较大,其中Cu富集系数达到0.63;综合分析人参土壤中重金属全量、有效量及人参根中含量,发现人参土壤中Cd超标,污染严重,Cu和Zn受土壤类型影响较大,其它重金属均可通过培肥改土调节其有效态含量。     

吉林省人参土壤中重金属污染水平及生物有效性研究

人参(Panax Ginseng C.A.mey)属五加科多年生草本植物,是主要大宗道地中草药,人参产业作为吉林省东部山区及黑龙江、辽宁省山区的主要支柱产业,对地方经济发展具有极大的影响作用。自从1998年国家实行"天保工程"以来,传统的伐林栽参模式受到限制,农田栽参和林下参成为人参产业主要发展模式,农田栽参的发展避免了参林争地的矛盾,保护了生态环境,同时为市场提供了大量     

Distribution of some heavy metals in organisms in Hardangerfjord and Skjerstadfjord,Norway

Near Odda, in West Norway, metal-bearing waters enter the Sorfjord, a tributary of the Hardangerfjord. Unusually high concentrations of Cd, Pb, and Zn are present in marine life over a considerable length of the fjord. Marine life near Odda also contained concentrations of Hg higher than normal. At Fauske, in North Norway, marine organisms contain high concentrations of Cu, but this contamination is confined to a small area of the Skjerstadfjord system.     

Assessment of soil contamination by the content of heavy metals in the soil profile

A new soil-ecological definition of the maximal permissible concentration (MPC) of heavy metals in soils is suggested that regulates the sampling in contaminated territories. Instead of the shallow pits usually used for collecting surface samples for soil-hygienic and other investigations, it is proposed to fulfill a detailed analysis along the entire soil profile including not only the determination of the heavy element content in certain horizons but also the soil density in these horizons. For the polyelemental contamination Zc (according to the Saet equation) based on the background (clarke) excess, the established Zc values ranging from 1 to 128, may reach absurd values of 800–900 upon taking into consideration only one surface layer. At the same time, the use of the weighted average content of the metals in the soil profile adjusts the Zc values for the existing natural conditions. Upon aerial impact, the consideration of the heavy metal contents along the soil profile instead of their contents in the surface horizon only leads to a decrease in the indices of the soil contamination degree. Upon the hydrogenic impact, the transition from the heavy metal contents in the surface horizon to their contents in the soil profile gives higher values of the soil contamination.     

Single and competitive adsorption isotherms of some heavy metals onto a light textured calcareous soil amended with agricultural wastes-biochars

This study investigated the adsorption behavior of selected heavy metals (Pb, Cu, and Ni) under single and multi-metal conditions by a light textured calcareous soil amended with plant residue biochars (corn straw, wheat straw, rice husk and licorice root pulp each at 3% w/w). The Freundlich isotherm best described the heavy metal adsorption suggesting multilayer adsorption. For all treatments under both adsorption conditions, the heavy metal adsorption capacity followed the order of Pb > Cu > Ni, which was associated with the hydrolysis constant, ionic radius, and electronegativity of these metals. Simultaneous presence of multiple metals decreased the adsorption capacity for each metal and the sequence was in the order of Ni > Pb > Cu. The corn straw biochar (CSB) had the highest adsorption capacity (Freundlich K_f (mg g^?1) for Ni = 0.23, Cu = 1.41 and Pb = 2.73) and medium distribution coefficient (K_{d medium}(L kg^?1) for Ni = 59.30, Cu = 1961.00 and Pb = 2602.00), indicating the CSB is the best treatment for stabilization of heavy metals in the soil. This was associated with the chemical characteristics of the CSB (high amounts of CaCO₃ and P) and the greatest increase in soil pH value.     

不同高粱种质对污染土壤中重金属吸收的研究

利用重金属含量较高的污水污染土壤,以未污染土壤作对照,种植8个甜高粱品种、2个饲用高粱品种和1个粒用高粱品种,检测8种重金属在高粱植物体内不同器官的含量,以研究不同高粱种质对重金属的吸收特性。结果表明:甜高粱对汞(Hg)、镉(Cd)、锰(Mn)和锌(Zn)的吸收在两种土壤间差异显著,对钴(Co)、铬(Cr)、铅(Pb)和铜(Cu)的吸收差异不显著。Mn在甜高粱体内含量表现为未污染土壤高于污染土壤;而Zn含量在不同器官之间存在差异,未污染土壤叶中含量远高于穗,穗中含量远高于茎和根。不同重金属在甜高粱体内的储存部位不同,污染土壤上Hg、Cd、Co、Cr和Zn在根中积累量较高,Cu、Mn和Pb在穗中的积累量较高。甜高粱、饲用高粱和粒用高粱对重金属的吸收、运输及储存在品种之间差异较大,同一品种对不同重金属的吸收也存在差异。饲用高粱表现为叶部对Cr和Zn的储存量较高,而粒用高粱‘晋中0823’则显示了茎对多种重金属的储存能力。高粱根对土壤中重金属的富集系数较高,为0.02(Pb)~0.23(Cd),转移系数变幅为0.21(Co)~3.42(Pb)。对同一种重金属的吸收量品种间差异较大,甜高粱‘西蒙’根对Co、Cr、Cu、Mn、Pb和Zn具有高富集系数,粒用高粱‘晋中0823’茎对Hg、Cd、Mn、Pb和Zn富集系数较高。高粱对重金属的吸收能力与转移能力不同步,甜高粱‘绿能1号’具有对多种重金属的高转移能力,粒用高粱‘晋中0823’只对Zn有较高的转移能力。因此本文认为甜高粱对不同重金属的吸收和转移有选择性。对Zn吸收并转移到地上部后,首先储存在叶和穗中,当吸收量足够大时,茎和根也成为储存器官;对Mn的吸收与其他重金属的吸收存在竞争作用,Hg吸收后很少向地上部转移;而对Cu、Mn和Pb吸收后在穗部的储存量较大。饲用高粱与甜高粱相比对重金属的吸收未显示明显的不同,甜高粱‘西蒙’根对多种重金属具有强储存能力,而粒用高粱‘晋中0823’的茎秆显示了比甜高粱更强的储存能力,甜高粱‘绿能1号’对多种重金属的转移能力较强。所以,选择富集和转移能力均强的高粱品种能更有效地吸收土壤中的重金属,达到修复污染土壤的目的。     

Pig manure digestate-derived biochar for soil management and crop cultivation in heavy metals contaminated soil

Management of heavy metal-contaminated soil under drought and other harsh hydrological conditions is critical for protecting soil ecosystem services. In this study, we examined the effect of pig manure digestate-derived biochar as a soil amendment (15 t ha⁻¹) with N fertilizer (180 kg ha⁻¹) on soil and plant heavy metal levels and nutrient availability under various moisture regimes (optimal moisture ~15%, drought condition ≤5%, and flooded condition ≥35% wt.). It was observed that biochar applications significantly decreased heavy metals in the spring wheat plants, lowering Cr by 90%, Ni by 50%, Cd by 9% and Pb by 34% compared to non-biochar (control) treatments. However, the pig digestate-derived biochar increased heavy metals in soil under all moisture regimes, increasing soil Cr by 21%, Ni by 43%, Cu by 55%, Zn by 70%, and Pb by 12%. The availability of macroelements also increased with the biochar applications under the optimum moisture regimes in both soil and plants, increasing Mg²⁺ by 11%, P by 4%, K⁺ by 50%, and Ca²⁺ by 56% in the soil, and Mg²⁺ by 13%, P by 69%, K⁺ by 29, and Ca²⁺ by 39% in plants. Biochar addition also improved chlorophyll fluorescence (CF) levels in the crop for the entire season (12^th to 62^nd day) and the aboveground crop biomass and dry matter contents both increased. Consequently, the use of pig manure digestate-derived biochar with N fertilizer under normal moisture conditions was able to reduce heavy metal availability to plants and thus could be used in contaminated soils to maintain better crop growth and development.