土壤弹尾目昆虫对铜污染的急性毒理初步研究

随着土壤环境重金属污染的加剧,有关重金属污染土壤的风险评估受到关注。对土壤质量评价的方法长期以来集中在检测重金属污染物质在土壤中的浓度及化学形态等方面,而对于重金属、土壤和生物之间的相互作用很少考虑,因而难以全面评估重金属对土壤环境的生态毒性效应。重金属污染土壤的     

土壤弹尾目昆虫Folsomia candida对铜污染的急性毒理初步研究

随着土壤环境重金属污染的加剧,有关重金属污染土壤的风险评估受到关注.对土壤质量评价的方法长期以来集中在检测重金属污染物质在土壤中的浓度及化学形态等方面,而对于重金属、土壤和生物之间的相互作用很少考虑,因而难以全面评估重金属对土壤环境的生态毒性效应[1].重金属污染土壤的生物评价是对化学评价的有效补充和相互验证.土壤弹尾目昆虫(跳虫)作为土壤动物群落中的优势物种之一,是土壤环境的重要指示生物,在对污染环境的生态评估研究中得到越来越多的重视[2-5].     

EDTA对Cu污染农田土壤的淋洗实验研究

为了解鄂西南地区土壤铜的赋存形态及其污染修复,采用Tessier连续提取法测定土壤铜的赋存形态,采用振荡淋洗法研究了乙二胺四乙酸二钠(EDTA)在提取时间、淋洗浓度、固液比、p H等四个因素作用下对重金属铜(Cu)去除效果的影响。结果表明:农田土壤中铜的赋存形态依次表现为残渣态(4.26 mg kg-1)铁锰氧化物结合态(3.29 mg kg-1)硫化物及有机结合态(2.29 mg kg-1)可交换态(2.10 mg kg-1)碳酸盐结合态(1.63 mg kg-1);在EDTA修复Cu高污染土壤时,单因素实验分析表明当提取时间、淋洗浓度、固液比、p H分别为18 h、0.01 mol L-1、1∶10和7时为最佳实验条件,最佳单因素组合后对Cu的去除率为20.14%,将之应用于农田土壤,重金属Cu的去除率略有降低,可达18.29%。EDTA对土壤Cu处理前后对其赋存形态分析表明,土壤中重金属Cu交换态、碳酸盐结合态和铁锰氧化物结合态去除效果明显,但不能有效去除土壤中有机及硫化物态和残渣态。     

DBP和Cd复合污染对油菜的毒性作用研究

通过盆栽试验,研究了不同浓度的DBP(0,5,10,20,30,50,100mg/kg)和Cd(5mg/kg)复合污染对油菜抗氧化酶系统(SOD、CAT、POD)活性、MDA含量、游离脯氨酸含量和可溶性蛋白含量的影响。结果表明,随着DBP浓度的升高,油菜抗氧化酶系统活性、游离脯氨酸及可溶性蛋白含量均呈先升高后降低的趋势;当DBP浓度为5,10mg/kg时,SOD和CAT活性比对照组显著提高,在一定程度上减轻了油菜受到的毒害作用;当DBP浓度为50,100mg/kg时,SOD和POD活性、游离脯氨酸及可溶性蛋白含量与对照组比均显著降低,说明高浓度的DBP可能进一步加剧了油菜受到的毒害作用;随着DBP浓度的升高,油菜MDA含量也逐渐升高,并与对照组比差异显著,说明其细胞膜脂质过氧化作用逐渐加重。     

产漆酶真菌筛选及其对PAHs污染土壤修复的初步研究

真菌漆酶可以高效转化多环芳烃(PAHs),因此,产漆酶真菌在PAHs污染土壤修复中极具应用前景。根据漆酶可将愈创木酚氧化为红色物质的特性,成功从土壤中筛选出一株能够分泌漆酶的真菌菌株F-1,初步鉴定该菌为疣孢漆斑菌(Myrothecium verrucaria)。通过Plackett-Burman试验对菌株F-1的产酶能力进行了分析,发现特定培养条件组合可将其酶活提高近300倍,达5628 U L-1,表明F-1的漆酶活性受到环境条件的显著影响。应用菌株F-1对PAHs污染土壤进行了初步修复研究,结果表明,接种F-1对菲、荧蒽、芘、苯并(a)蒽、屈、苯并(b)荧蒽、苯并(k)荧蒽、苯并(a)芘、二苯并(a,h)蒽、苯并(g,h,i)苝、茚苯(1,2,3-cd)芘等11种PAHs均有不同程度的降解,提示产漆酶真菌在PAHs污染土壤修复中的应用潜力。     

高温处理对结果期草莓叶片衰老特征的影响

以‘日本丰香’(Fragaria ananassa Duch.cv Toyonaka)草莓品种为试材,于2010-12-2011-02在人工气候箱进行环境控制试验,以25℃为对照,设30、32、34、36、38℃共5个高温处理,分别在处理1、3、5d后,测定与叶片衰老特征密切相关的生理指标,包括叶片中超氧化岐化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性以及丙二醛(MDA)含量、可溶性蛋白质和叶绿素含量.结果表明,在30 ～ 38℃范围内,随着温度升高及处理时间的延长,草莓叶片中MDA含量呈持续增加趋势;经30 ～ 34℃高温处理后,可溶性蛋白质含量、SOD、POD、CAT酶活性值均高于对照,其中SOD、POD酶活性在34℃处理3d后达到最高,可溶性蛋白质含量、CAT酶活性在34℃处理5d后达到最高.36℃及38℃高温处理后,可溶性蛋白质含量、SOD、POD、CAT酶活性明显低于对照(P＜0.05);高温处理中叶片的叶绿素a、b和类胡萝卜素含量均低于对照,而且随着高温时间的延长,草莓叶片叶绿素a、b及类胡萝卜素含量都呈持续下降趋势.表明高温胁迫降低了草莓叶片保护酶活性,导致体内活性氧大量积累,抗氧化能力降低,加速了草莓叶片的衰老,研究结果为设施草莓高温气象灾害的防御提供了依据.     

菜心对邻苯二甲酸酯(PAEs)吸收途径的初步研究

采用玻璃室处理和污染土壤覆盖原土壤来控制PAEs来源进行盆栽试验，应用GC/MS联机检测技术初步研究了菜心对PAEs的吸收途径。结果表明：污染土壤处理与污染土壤上覆盖原土壤处理相比，前者菜心茎叶中DBP和DEHP的含量均高于后者，但相差不大，表明菜心茎叶可以吸收污染土壤中挥发出来的DBP和DEHP，而根系吸收运移是菜心茎叶中DBP和DEHP的主要来源途径。玻璃室处理增加了菜心茎叶和根系中DBP的含量，而对DEHP的影响趋势不明显。DBP与DEHP相比，前者更易被菜心根系吸收并向地上部(茎叶)运移，后者主要滞留在根部。     

纳米碳对黄绵土Cu(Ⅱ)迁移影响的研究

重金属污染治理对改善环境污染具有重要意义,基于室内扰动土柱试验,以黄绵土为研究对象,初步研究了在黄绵土中均匀混合及在表层混合不同含量纳米碳材料对土壤中重金属Cu(Ⅱ)迁移过程的影响。结果表明:(1)相同平衡浓度,随着纳米碳含量的增加,Cu(Ⅱ)吸附量加大,采用Langmuir方程拟合Cu(Ⅱ)等温吸附曲线,最大吸附量(Sm)随着纳米碳含量增加而增大。(2)对于均匀混合纳米碳的黄绵土和仅表层混有纳米碳的黄绵土,Philip方程均能较好地描述Cu(NO3)2溶液累积入渗量变化过程,湿润锋推进过程遵循幂函数变化。(3)随着纳米碳含量增加,Cu(NO3)2溶液累积入渗量降低,纳米碳含量较低时(0.1%,0.5%,1%),两种纳米碳添加方式对土壤累积入渗量的影响差异不大,纳米碳含量较高时(5%),均匀添加纳米碳土壤的累积入渗量曲线则显著低于表层添加纳米碳的土壤。(4)相对于空白对照土壤,两种施碳方式均提高了土壤表层Cu(Ⅱ)含量,且表层Cu(Ⅱ)含量明显高于深层土壤。纳米碳含量为0.1%,0.5%,1%时,两种添加纳米碳方式之间表层土壤Cu(Ⅱ)含量无明显差异,当纳米碳含量上升到5%时,均匀添加纳米碳土柱的表层土壤Cu(Ⅱ)含量显著高于表层添加纳米碳土柱,随着土壤剖面加深,不同处理土壤剖面处Cu(Ⅱ)含量无明显差异。因此,纳米碳对重金属Cu(Ⅱ)有很好的吸附作用,且在土壤表层添加纳米碳是一种经济有效的施碳方式。     

pH对Cu(Ⅱ)和Pb(Ⅱ)在可变电荷土壤表面竞争吸附的影响

在实际的重金属污染体系中往往有多种重金属元素同时存在，当这一污染体系与土壤作用时不同重金属离子对土壤表面存在竞争吸附。Cu（Ⅱ）和Pb（Ⅱ）是土壤中常见的2种重金属离子，土壤和矿物表面对2种离子的竞争吸附或2种离子吸附亲和力的比较已有一些研究报道。一般认为土壤对Pb（Ⅱ）的吸附亲和力大于对Cu（Ⅱ）的吸附亲和力，但在可变电荷土壤和矿物中情况有所不同。McKenzie的结果表明合成赤铁矿在pH3．0～6．0范围内对Pb（Ⅱ）的吸附亲和力大于Cu（Ⅱ），而针铁矿的结果相反。     

腐殖酸对土壤中Cd形态的影响及利用研究

目前就腐殖酸对土壤重金属形态影响的研究较少 ,为此本文讨论了腐殖酸及其数量在棕壤上对Cd的赋存形态的影响作用。研究表明 :随腐殖酸投入比的加大 ,可溶态Cd含量明显下降 ,有机态Cd恰反之 ,铁铝 (锰 )氧化态Cd与有机态Cd雷同 ;腐殖酸对可溶态Cd分配比率最高 ,达 19～ 73 % ,分别是有机态Cd和铁铝 (锰 )氧化态Cd的 4.2～ 5 .5倍和1.6～ 3 .8倍。结果说明腐殖酸在棕壤上有明显降低有害的活性Cd之净化功能 ,其作用机制在于腐殖酸具备的络合 (螯合 )能力和胶体特性。研究确认腐殖酸不失为一重金属污染土壤修复的优选材料     

铜、锌污染梯度对自然林地和农田土壤线虫群落的影响

为从污染程度的角度探索土壤线虫多样性与群落稳定性的关系,以重金属铜和锌为扰动因子,设置不同程度的胁迫水平,通过恒温培养试验对比高生物多样性的自然林地和低生物多样性的农田土壤线虫群落对重金属胁迫的响应。结果表明:自然林地土壤线虫数量随Cu和Zn的添加浓度升高而降低;农田土壤线虫总数呈现低浓度扰动条件下降低,中、高浓度又反弹的现象。占绝对优势的食细菌线虫数量变化规律与线虫总数相近;自然林地中捕食杂食性线虫仅在添加高浓度Zn处理有所减少,而在农田土壤中,中、高浓度Cu,以及低浓度Zn处理均呈现出显著的抑制效应。重金属梯度对自然林地线虫多样性无显著影响,但是降低了农田线虫的香农指数,提高了优势度。总体上,Cu和Zn扰动对自然林地线虫的影响主要表现在数量上,对农田线虫的影响更多体现在群落结构、多样性和生态指数上。就污染程度以及生物群落结构的角度而言,高多样性的自然林地线虫群落对Cu和Zn污染的抵抗力更强。     

铜矿区土壤重金属污染与耐性植物累积特征

在铜陵矿区研究了4种植物:商陆(Phytolacca acinosa),鸭跖草(Commelina communis),菌陈蒿(Artemisia capillaries),农田紫云英(Astragalus sinicus)对重金属的富集特征及土壤重金属污染情况。采用ICP-MS分析了土壤中As、Cd、Cr、Cu、Zn、Pb的重金属全量及植物对As、Cd、Cr、Cu、Zn、Pb的积累情况。并计算了四种植物对重金属的生物转移系数BTC(Biological Transfer Coefficient)。结果表明:铜陵狮子山铜矿废弃地鸭跖草(Commelina communis)、菌陈蒿(Artemisia capillaries)群落的土壤养分状况相对较好,农田紫云英的养分状况次之,杨冲山尾矿库分布商陆(Phytolacca acinosa)的土壤养分状况最差。商陆耐瘠薄土壤、尾矿区与附近农田土壤重金属全量分析表明,杨山冲尾矿库附近农田土壤(种植紫云英)铜、镉、铅、锌总量均超过国家农业用地土壤二级标准,尾矿废弃地分布鸭跖草、茵陈蒿的土壤全铜含量超过国家工业用地土壤二级标准,土壤受Cu污染最严重。菌陈蒿、鸭趾草对高含量的土壤铜表现出很好的耐性。鸭跖草对砷和铅的转移系数大于1,茵陈蒿对镉与锌的转移系数大于1。鸭跖草、茵陈蒿、商陆都可以作为矿区生态恢复的先锋植物。     

铬铜复合污染下铬形态分布及与土壤酶活性的关系

采用土培盆栽实验和室内分析相结合的方法,研究了Cr单一和Cu-Cr复合污染条件下,外源施加的Cr在土壤中的形态变化及其对土壤酶活性的影响。结果表明：随外源Cr浓度的增加,土壤交换态Cr含量增多,残渣态占总量的百分比减少,铁锰氧化物结合态与有机结合态变化不大（碳酸盐结合态未检出）。Cu-Cr复合污染条件下,≤400mg·kg-1Cu能促进Cr从有机结合态向交换态及铁锰氧化物结合态转化（P〈0.05）,而高浓度Cu（800mg·kg-1）却抑制了这种转化的发生。与对照（CK）相比,重金属Cu、Cr单一及复合污染均对土壤脲酶、碱性磷酸酶和过氧化氢酶活性产生一定的抑制作用,且酶活性抑制率随外源金属浓度的增加而增大;3种供试酶相比较,Cr、Cu对土壤脲酶和碱性磷酸酶活性影响较大,对除C（r5mg·kg-1）处理的过氧化氢酶活性影响较小;低浓度C（r5mg·kg-1）对土壤过氧化氢酶活性有一定激活作用。土壤脲酶活性受土壤交换态Cr含量的影响较大;碱性磷酸酶活性与铁锰氧化物结合态Cr含量有关;铁锰氧化物结合态和有机物结合态Cr对土壤过氧化氢酶活性产生一定的影响。残渣态Cr含量与3种供试的土壤酶活性间无显著相关。     

Inorganic Soil Contamination from Cemetery Leachate

The increasing number of cemeteries has caused concern about the possibility of releasing hazardous chemicals and metals into the surroundings. Moreover, many studies use cemeteries for 'background' sampling. This study attempts to identify whether cemeteries are indeed good 'background' areas, or whether they themselves are sources of contamination. Possible contaminants include poisonous chemicals, such as arsenic and mercury, which were used in past embalming and burial practices, which used: formaldehyde from current embalming practices; varnishes, sealers, and preservatives used on wood coffins; and lead, zinc, copper, and steel from metal coffins. This study reports on adsorbed metals in a fine-grained soil from a large cemetery in Northwest Ohio. Metal analyses were performed by atomic absorption and inductively coupled plasma spectrometry. This preliminary investigation revealed numerous possible sources of contamination, and the data support the need for further research. The results of zinc, copper, lead, and iron reveal an increase in concentrations on-site as well as with depth, especially at the burial depth. Dramatic increases in arsenic indicate contamination from embalming fluids or wood preservatives. This study warrants a concern for the quality of soil, groundwater, and nearby surficial water systems.     

Dioxin Soil Contamination near Former Landfills

Eurasian Soil Science - Dioxin contamination levels and profiles of soils in New Moscow area were studied to identify the potential sources of contamination at a distance of 300 to 1000 m from the...     

Cost-Effectiveness Analysis for Soil Heavy Metal Contamination Treatments

Soil heavy metal contamination results in both huge economic loss and severe health problem. Many technologies, such as soil stabilization/solidification, soil excavation, soil washing, chemical extraction and phytoremediation, have been developed to treat soil heavy metal contamination. Among these methods, phytoremediation is usually regarded as a promising, environment-friendly, and cost-effective method. However, little information has been found to support this idea. Hence, in this study, we have conducted a cost-effectiveness analysis of three treatment methods (soil excavation and disposal, soil washing, and phytoextraction) in 16 scenarios of different soil texture, site scale, soil metal, and contamination levels with reviewed literature information. The results have showed that phytoextraction is more cost-effective when dealing with the slightly polluted soils, while soil washing is cost-effective for severely-contaminated scenarios.     

Extractability and Transformation of Copper and Zinc Added to Tropical Savanna Soil under Long-Term Pasture

The extractability and slow reactions of copper (Cu) and zinc (Zn) in a weathered savanna soil under Brachiaria decumbens, Digitaria smutsii, and Stylosanthes guianensis pastures were determined in a laboratory incubation study using a sequential extraction to remove operationally defined fractions of the metals, consisting of exchangeable, organically bound, precipitate [occluded in aluminum (Al) and iron (Fe) oxides], and residual metal fractions. The soils from the pasture fields were spiked with 100 mg Cu kg^–1 soil and 200 mg Zn kg^–1 soil for 24 weeks. Copper and Zn extractable with 1 N potassium nitrate (KNO₃) solution decreased exponentially with time but reached a steady state after 2–3 weeks. The concentrations of Cu and Zn exchangeable with potassium (K) were greater in the Digitaria smutsii field soil than Brachiaria decumbens and Stylosanthes guianensis field soils. The exchangeability of added Cu and Zn (indexed Mⁿ⁺ _(exch)) with time was described by a simple exponential decay equation: Mⁿ⁺ _(exch) = αe^βt, where α is a constant, β is a coefficient that defines the rate of transformation of added Cu and Zn from the exchangeable to nonexchangeable pools, and t is time. The β values for Cu (0.040–0.076 mg kg^–1 d^–1) were almost 10 times greater than those of Zn (0.005–0.007 mg kg^–1 d^–1). Sequential extraction of added Cu and Zn indicated that between 26 and 30% of the total Cu and between 19 and 30% of the total Zn were associated with organic matter. Similarly, between 35 and 38% of total Cu and between 47 and 60% of total Zn were associated with Fe, Al, and manganese (Mn) oxides. The differential capacity of the pasture fields to transform added Cu and Zn from exchangeable and labile form to nonlabile and nonexchangeable form appears to be governed by organic matter (OM), pH, and active Fe ratio in the pasture field soils.     

Migration of Copper with Wheat Straw in Soil under the Alternate Dry-Wet and Eluviation Conditions

ABSTRACT

The migration of heavy metals in soil relates to the soil type and cultivation practices. It is necessary to examine the migration changes of heavy metal under the specific areas of concern. Straw returning to the field is one essence of traditional agriculture; the migration of copper (Cu) in agricultural soil of Henan province, China, with and without wheat straw under alternate dry-wet and eluviation conditions was studied in this paper. Experiments examined the morphological changes of Cu among different bound fractions of exchangeable (EXC), carbonate (CAR), iron and manganese oxide (OX), organic matter (OM), and residual (RES) under different conditions. Results showed along with the addition of wheat straw in the soil, the CAR and OX fractions decreased while the OM and RES fractions increased, at the same time, the EXC fractions decreased at high Cu concentration and increased at low Cu concentration. In addition, the EXC and CAR fractions of Cu increased and the RES fractions decreased when the Cu concentration rose under dry-wet alternate conditions. In the eluviation experiment, the release amount and rate of Cu improved along with the addition of wheat straw. Although wheat straw could make the distribution of Cu turn into the more stable fractions such as RES, the heavy metal was unstable and much easier to dissolve into the leaching water in the course of heavy metal migration. According to the results, it was suggested the wheat straw returning to the field should comprehensively consider the local conditions.     

铜在土壤中的淋溶迁移特征研究

以棕壤为供试土壤,采用室内土柱淋溶模拟试验方法,研究了相当于泰安平均年降水量条件下铜在土壤垂直方向上的迁移转化特征.结果表明:各处理土壤中的铜在0～10 cm土层中均有不同程度的迁移转化.土壤铜含量越高,年降水量条件下表层土壤中铜的淋失量越大,沉淀态铜和矿物残留态铜所占的比例增加了28.57%～33.49%.高铜土壤中,钙含量的增加使交换态铜比例降低幅度为9.97%～10.48%,使铜的迁移量最大可减少15.54%;随褐煤施入量的增加,表层交换态铜含量减少,铜向5～10 cm土层中的淋溶量减少显著,有机结合态铜的含量增加22.76%～36.07%.     

棕壤对铜的吸附特性研究

棕壤对铜的吸附特性以及土壤条件对吸附的影响进行了研究，结果表明，棕壤对铜的吸附随溶液中铜的平衡浓度增加而增加，但在高浓度时增幅渐缓，与处于相同地区的褐土相比棕壤的吸附相对较弱，其吸附可用Langmiur、Frundlich、Temkin及米氏方程进行描述。土壤酸度增强，棕壤对铜的吸附降低，用H^＋浓度对Frundlich方程进行修饰，能更好地描述铜的吸附状况。此外，离子强度、陪伴离子对吸附都有影响，随离子强度增加及高价陪伴离子比例的上升吸附减弱。