砷和铅对土壤酶活性的影响

研究了浙江省绍兴银山铅锌矿周围农田的污染情况及其对土壤酶活性的影响。该污染区域内主要的污染元素为砷和铅,其含量与区内土壤脱氢酶、过氧化氢酶、过氧化物酶、转化酶、脲酶和磷酸酶呈显著的复相关关系,其中砷的影响是主要的。土壤脱氢酶、过氧化氢酶和转化酶活性的变化能够反映供试土壤类型受砷和铅复合污染的程度。     

Effects of cadium, zinc and lead on soil enzyme activities

Heavy metal （HM） is a major hazard to the soil-plant system. This study investigated the combined effects of cadium （Cd）, zinc （Zn） and lead （Pb） on activities of four enzymes in soil, including calatase, urease, invertase and alkalin phosphatase. HM content in tops of canola and four enzymes activities in soil were analyzed at two months after the metal additions to the soil. Pb was not significantly inhibitory than the other heavy metals for the four enzyme activities and was shown to have a protective role on calatase activity in the combined presence of Cd, Zn and Pb; whereas Cd significantly inhibited the four enzyme activities, and Zn only inhibited urease and calatase activities. The inhibiting effect of Cd and Zn on urease and calatase activities can be intensified significantly by the additions of Zn and Cd. There was a negative synergistic inhibitory effect of Cd and Zn on the two enzymes in the presence of Cd, Zn and Pb. The urease activity was inhibited more by the HM combinations than by the metals alone and reduced approximately 20%--40% of urease activity. The intertase and alkaline phosphatase activities significantly decreased only with the increase of Cd concentration in the soil. It was shown that urease was much more sensitive to HM than the other enzymes. There was a obvious negative correlation between the ionic impulsion of HM in soil, the ionic impulsion of HM in canola plants tops and urease activity. It is concluded that the soil urease activity may be a sensitive tool for assessing additive toxic combination effect on soil biochemical parameters.     

Soil enzymatic activities and microbial community structure with di erent application rates of Cd and Pb

This study focused on the changes of soil microbial diversity and potential inhibitory effects of heavy metals on soil enzymatic activities at different application rates of Cd andor Pb. The soil used for experiments was collected from Beijing and classified as endoaquepts. Pots containing 500 g of the soil with different Cd andor Pb application rates were incubated for a period of 0, 2, 9, 12 weeks in a glasshouse and the soil samples were analyzed for individual enzymes, including catalase, alkaline phosphatase and dehydrogenase, and the changes of microbial community structure. Results showed that heavy metals slightly inhibited the enzymatic activities in all the samples spiked with heavy metals. The extent of inhibition increased significantly with increasing level of heavy metals, and varied with the incubation periods. The soil bacterial community structure, as determined by polymerase chain reaction-denaturing gradient gel electrophoresis techniques, was different in the contaminated samples as compared to the control. The highest community change was observed in the samples amended with high level of Cd. Positive correlations were observed among the three enzymatic activities, but negative correlations were found between the amounts of the heavy metals and the enzymatic activities.     

我国14种典型土壤脲酶、脱氢酶活性对汞胁迫的响应

Hg作为环境的主要污染重金属之一,其对土壤酶的影响是表征其环境效应的重要方面,结果可为土壤环境监测等提供生物学依据.因此,本文通过室内模拟试验,较系统地分析了全国14种主要类型18个土样的脲酶和脱氢酶活性在Hg胁迫下的响应.结果表明,Hg会抑制土壤酶活性,其降幅随土壤类型的不同有明显差异;随着Hg含量的升高,土壤脲酶和脱氢酶活性均显著降低;模型U=A/(1+B×C)可较好地拟合酶活性(U)与汞含量(C)之间的关系,揭示出土壤脲酶和脱氢酶在一定程度上可监测土壤Hg污染的程度,且机理为完全抑制(包括竞争性抑制和非竞争性抑制)作用.同时,实验获得的供试土样脲酶的生态剂量(ED10)范围为0.08~0.77 mg·kg-1,脱氢酶ED10范围为0.11~2.58mg·kg-1,从土壤酶角度获得的土壤汞轻度污染临界值为0.08 mg·kg-1,此值要小于国家土壤质量标准中的二级标准.有机质、pH、CEC和粘粒显著影响了汞与土壤脱氢酶的关系,上述4个土壤性状参数值越高,汞对土壤酶的毒害作用就越弱;酸性土壤中汞的毒害作用强于碱性土壤.表明在我国主要土壤类型上,土壤脲酶、脱氢酶对Hg毒性均较为敏感,可在更广范围内作为Hg污染程度的监测指标之一.     

Rhizobacteria helps to explain the enhanced efficiency of phytoextraction strengthened by Streptomyces pactum

The ultimate purpose of phytoextraction is not only to remove heavy metals from soil but also to improve soil quality. Here, we evaluated how the joint effect of Streptomyces pactum (strain Act12) and inorganic (Hoagland's solution) and organic (humic acid and peat) nutrients affected the phytoextraction practice of cadmium (Cd) and zinc (Zn) by potherb mustard, and the microbial community composition within rhizosphere was also investigated. The results indicated that the nutrients exerted synergistically with Act12, all increasing the plant biomass and Cd/Zn uptakes. The inoculation of Act12 alone significantly increased dehydrogenase activity of rhizosphere soil (P < 0.05), while urease and alkaline phosphatase activities varied in different dosage of Act12. Combined application of microbial strain with nutrients increased enzymatic activities with the elevated dosage of Act12. 16S ribosomal RNA high-throughput sequencing analysis revealed that Act12 inoculation reduced the diversity of rhizosphere bacteria. The Act12 and nutrients did not change dominant phyla i.e., Proteobacteria, Bacteroidetes, Gemmatimonadetes, Actinobacteria and Acidobacteria, but their relative abundance differed among the treatments with: Peat > Act12 > Humic acid > Hoagland's solution. Comparatively, Sphingomonas replaced Thiobacillus as dominant genus after Act12 application. The increase in the Sphingomonas and Flavisolibacter abundances under Act12 and nutrients treatments gave rise to growth-promoting effect on plant. Our results revealed the important role for rhizosphere microbiota in mediating soil biochemical traits and plant growth, and our approach charted a path toward the development of Act12 combined with soil nutrients to enhance soil quality and phytoextraction efficiency in Cd/Zn-contaminated soils.     

土壤的重金属污染与土壤酶活性

本文根据模拟研究,论述了不同用量的重金属Hg、Cd和Pb对不同肥力水平的棕壤和红壤的过氧化氢酶、转化酶、脲酶和磷酸酶活性的影响.重金属对土壤酶抑制作用的顺序为:Hg>Cd>Pb.且随金属浓度的增大而增强.实验表明,重金属对土壤酶活性的抑制是一种暂时现象、由于脲酶活性恢复得较少较慢,故建议用土壤的脲酶活性作为土壤Hg污染程度的指标.     

北京市密云水库上游金铁矿区土壤重金属污染特征及对比研究

不同金属矿山选冶活动造成的矿区及周边土壤中重金属的分布累积特征不同.为了解密云水库上游金矿和铁矿矿区土壤中重金属地球化学特征的异同及污染状况,对区域内典型的金矿和铁矿矿区进行土壤样品采集,应用地球化学方法研究了2种土壤中重金属的污染特征,并应用地累积指数法评价了其污染状况.结果表明,2种土壤中除As外的其它重金属含量明显高于北京市土壤重金属背景值,金矿矿区土壤重金属含量普遍高于铁矿矿区.相关性分析表明,金矿矿区土壤中Cu含量与Pb、Zn(p<0.01)及Cr、有机质(OM)含量(p<0.05)之间显著相关,pH值与Pb含量(p<0.01)及Hg含量(p<0.05)呈显著负相关,而铁矿矿区土壤中重金属含量之间的相关性不显著.金矿尾砂中重金属含量明显高于铁矿尾砂,与矿区土壤污染状况一致.地累积指数法评价结果显示,金铁矿区土壤中重金属的污染程度均已十分严重,金矿矿区土壤污染程度高于铁矿,金矿矿区土壤重金属的污染程度由高到低依次为:Pb>Hg>Cd>Cr>Cu>Zn>Co>As;铁矿矿区土壤重金属的污染程度由高到低依次为:Pb>Cd>Cr>Co>Cu>Zn>Hg>As.该研究数据可为同一区域内不同金属矿区重金属污染的有效监控与治理提供科学依据.     

Effects of plant species coexistence on soil enzyme activities and soil microbial community structure under Cd and Pb combined pollution

The relationship between plant species coexistence and soil microbial communities under heavy metal pollution has attracted much attention in ecology. However, whether plant species coexistence could o set the impacts of heavy metal combined pollution on soil microbial community structure and soil enzymes activities is not well studied. The modified ecological dose model and PCR-RAPD method were used to assess the e ects of two plant species coexistence on soil microbial community and enzymes activities subjected to Cd and Pb combined stress. The results indicated that monoculture and mixed culture would increased microbe populations under Cd and Pb combined stress, and the order of sensitivity of microbial community responding to heavy metal stress was: actinomycetes > bacteria > fungi. The respirations were significantly higher in planted soil than that in unplanted soil. The plant species coexistence could enhance soil enzyme activities under Cd and Pb combined. Furthermore, planted soil would be helpful to enhance soil genetic polymorphisms, but Cd and Pb pollution would cause a decrease on soil genetic polymorphisms. Mixed culture would increase the ecological dose 50% (ED50) values, and the ED50 values for soil enzyme activities decreased with increasing culture time. The dehydrogenase was most sensitive to metal addition and easily loses activity under low dose of heavy metal. However, it was di cult to fully inhibit the phoshpatase activity, and urease responded similarly with phosphatase.     

安徽铜陵矿区不同功能区域土壤中重金属对微生物及酶活性的影响

为揭示土壤微生物及酶活性与重金属污染的内在关系,并建立土壤重金属污染水平的酶活性及生物学参数表征体系,以安徽铜陵狮子山矿区周边土壤为研究对象,测定矿区内不同功能区域（采矿区、选矿区、堆矿区、尾矿库以及菜园）土壤中w（Cu）、w（Zn）、w（Cd）、w（Pb）和基础呼吸、微生物量碳含量、代谢熵等理化性质以及6种土壤酶（脲酶、蔗糖酶、纤维素酶、过氧化氢酶、中性磷酸酶和碱性磷酸酶）的活性.结果表明,所选矿区不同功能区域的内梅罗综合污染指数（P_N）依次为堆矿区（10.77）>采矿区（4.38）>选矿区（4.06）>尾矿库（2.55）>菜园（1.35）;4种重金属（Cu、Zn、Cd和Pb）的单因子指数（P_i）依次为Cd > Cu > Zn > Pb.不同功能区域内6种土壤酶活性之间有显著差异并呈不同程度变化,且均以菜园土壤酶活性为最大,其中,过氧化氢酶、中性磷酸酶和蔗糖酶活性均可以有效地表征w（Cu）、w（Zn）、w（Cd）和w（Pb）的水平.与基础呼吸或者微生物量碳含量指标相比,代谢熵能更好地表征土壤环境污染状况.研究显示,土壤酶活性、代谢熵与Cu、Zn、Cd、Pb这4种重金属含量均呈极显著相关,因此可通过测定土壤酶活性和代谢熵等生物学参数为矿区土壤环境质量评价及生态修复提供参考依据.      

重金属Cd、Zn、Pb复合污染对土壤酶活性的影响

采用回归正交设计方案 ,研究了潮褐土中Cd、Zn、Pb复合污染对 4种土壤酶活性 (过氧化氢酶、脲酶、碱性磷酸酶、转化酶 )的影响 .结果表明 ,在复合效应影响中 ,重金属对土壤酶活性的抑制效应顺次为Cd >Zn >Pb ;同时 ,Cd、Zn、Pb复合污染对 4种土壤酶活性的影响效应存在着明显差异 .其复合污染对脲酶表现出协同抑制负效应的特征 ;对过氧化氢酶表现出一定的屏蔽作用 ;对转化酶和碱性磷酸酶活性影响则主要随着Cd浓度的增加而显著降低 .离子冲量与土壤脲酶活性之间呈显著负相关 ,用脲酶活性作为预测土壤重金属Cd、Zn、Pb复合污染程度的主要生化指标具有一定的可行性     

海泡石对镉-铅复合污染钝化修复效应及其土壤环境质量影响研究

通过盆栽试验,开展了海泡石钝化修复Cd-Pb复合污染土壤对p H、重金属形态含量、水稻体内重金属累积特征以及土壤酶活性和微生物数量的影响研究.结果表明,添加海泡石提高了土壤p H值,污染土壤中Cd和Pb由活性较高的可提取态向活性低的有机结合态、铁锰氧化物结合态以及残渣态转化,可溶态Cd和Pb含量分别较对照降低了1.4%~72.9%和11.8%~51.4%.水稻体内各部分重金属含量总体上随海泡石含量增加而减少.与对照相比,水稻茎、叶、糙米和稻壳中Cd含量最大可降低39.8%、36.4%、55.2%和32.4%,而相对应部位的Pb含量最大降幅也分别达到了22.1%、54.6%、43.5%和17.8%.添加海泡石后在一定程度上改善了土壤环境质量,过氧化氢酶和脲酶活性、细菌和放线菌数量有所增加,蔗糖酶活性和真菌数目较对照有所降低,但不显著(P>0.05).p H、可溶态Cd、Pb含量以及脲酶和蔗糖酶活性与水稻体内Cd、Pb含量之间存在显著的相关关系,可以用来评价土壤Cd-Pb复合污染钝化修复效率.     

赣南某钨矿区土壤重金属污染状况研究

为研究钨矿区土壤重金属的污染现状,采集尾矿堆积区土壤样品,用ICP-MS测定土壤重金属(Cr、As、Mn和Pb)含量,采用Kriging插值法分析土壤重金属的空间分布特征,并分析测定土壤脲酶、过氧化氢酶、蔗糖酶的活性.结果表明土壤重金属的浓度均值高于背景值,Cr、As、Mn、Pb的均值分别是土壤背景值的2.26,3.06,1.85和2.59倍.空间分析表明Mn和Pb间两种元素具有较为相似的分布,Cr、As、Mn和Pb 4种重金属的空间分布相关性强,且呈条带状分布.土壤酶活性结果进一步验证重金属的污染状况,土壤酶活性低于对照样,土壤脲酶、过氧化氢酶、蔗糖酶分别是对照的7%~93%和5%~86%、11%~90%.逐步多元回归法分析表明,在Cr、As、Mn、Pb复合污染条件下,矿区土壤不同酶活性表现出抑制或者激活作用,但各重金属元素对不同的酶活性的影响系数是不一样的,蔗糖酶对复合重金属污染最为敏感. 主成分分析表明土壤酶活性的指标能较好地反映钨矿矿区土壤重金属复合污染状况.     

煤矿周围土壤中铜、锌污染状况及特征分析

以陕西省神木县西沟乡六道沟流域作为研究区域,对六道沟煤矿周围的土壤中的铜、锌的含量进行了研究,着重分析了煤矿开采是否对周围土壤造成重金属污染以及重金属在煤矿周围土壤中的分布特征。结果表明该区域仅有部分土壤遭受铜、锌的轻度污染,即煤矿开采会对周围土壤造成不同程度的污染,且铜、锌含量随着距煤矿距离的增大而递减,并随采样深度增加而递减。     

宝鸡市麟游县煤矿区周边农田土壤重金属污染安全评价

文章选取麟游县的北马坊煤矿、郭家河煤矿和北王煤矿为研究区域,对其周边的农田土壤进行野外采样和室内分析,测定Zn、Cr、Pb、Cu、Cd、Hg、As 7种重金属的污染状况。结果表明:测定的7种重金属元素的最大值均超过了陕西省土壤背景值和当地的土壤环境背景值。单因子污染指数评价得出,三矿区周边的土壤Hg元素的污染较严重,局部地区已经达到了重度污染;综合污染指数法评价得出,三矿区均达到了中度到重度污染水平,其中北王煤矿污染水平较高;地质累积指数法评价得出,三矿区Hg元素的累积程度属于中度污染到强污染等级,Cd元素次之。因此3矿区周边的耕地土壤已不同程度的受到重金属的污染,相关部门应该采取一定的措施治理该区的土壤。     

Cd胁迫下城郊农业土壤微生物活性对生物炭输入的响应

为了探究Cd胁迫下生物炭输入对城郊农业土壤微生物活性的影响,通过室内培养试验,分析CK处理(风干土壤)、Cd处理(风干土壤+外源Cd)、CdBC处理〔风干土壤+外源Cd+2%生物炭,即生物炭与土壤(以湿质量计)质量比为2%〕、BC处理(风干土壤+2%生物炭)对土壤呼吸、土壤微生物数量及土壤酶活性的影响. 结果表明:整个培养期(0~60 d)内,各处理下土壤CO₂累积释放量表现为CK处理＜Cd处理＜CdBC处理＜BC处理. 与CK处理相比,CdBC处理下生物炭输入能显著增加土壤CO₂累积释放量(P＜0.05),增幅为43.6%,并且土壤中细菌、放线菌、真菌数量也有显著增加(P＜0.05),增幅分别达到12.7%、62.7%、18.7%. Cd胁迫对土壤酶活性的抑制表现为蔗糖酶＜脲酶＜中性磷酸酶,抑制率分别为3.5%、6.8%、18.0%. 生物炭输入可使受Cd胁迫的土壤脲酶、蔗糖酶的活性有所增强,增幅分别为15.0%、18.4%. 可见,生物炭输入可在不同程度上缓解Cd胁迫对蔗糖酶、脲酶活性及土壤微生物数量的影响.      

某铜矿区土壤重金属污染状况研究

通过对某铜矿区土壤重金属含量及化学形态分布进行分析,探讨了采矿过程中的重金属在土壤中的积累特征。结果表明,该矿区的Cu、Zn、Pb、Cd、Ni在土壤中的积累程度相当高。各采样点的重金属综合污染递减顺序依次为:堆浸泥>最后沉淀池>堆浸矿>堆浸土>金矿排污口污泥>原生土壤>铜矿区下游江边土壤。堆浸矿土壤的重金属以残渣态、水溶态、有机质硫化态这三种组分为主,而堆浸泥土壤则以Fe-Mn氧化物结合态为主。     

陇东黄土高原石油污染土壤环境因子对金盏菊(Calendula officinalis)-微生物联合修复的响应

为筛选适合陇东黄土高原石油污染土壤修复植物,选取当地"适生"植物金盏菊(Calendula officinalis)联合微生物菌剂开展了为期5个月的原位修复实验.采用常规方法和PCR-DGGE技术分析了修复过程中土壤理化性质、酶活性及土壤微生物群落遗传多样性等15项土壤环境因子的动态变化情况及其对金盏菊生态修复的响应.结果表明,随着原位修复的进行,1土壤脲酶、多酚氧化酶、过氧化氢酶及脱氢酶活性均不同程度呈增加的趋势(p0.05).2土壤TPHs、p H、有机质、含盐率的变化情况不尽相同,但总体呈下降的趋势(p0.05);土壤碱解氮、速效磷及速效钾含量总体呈上升趋势(p0.05).3土壤微生物群落遗传多样性结果显示,Shannon-Wiener多样性指数和Pielou均匀度指数整体呈逐步增加的趋势.4PCA分析结果显示,土壤脲酶、脱氢酶及碱解氮等环境因子对金盏菊修复表现为促进作用,而有机质含量过高将不利于金盏菊的植物修复.金盏菊和微生物菌剂联合修复过程中,土壤多酚氧化酶、速效磷、脱氢酶及速效钾发挥主要作用,而土壤TPHs和含盐率过高则影响了联合修复效果.本研究旨在分析金盏菊用于陇东地区油污土壤的生态响应,结果有助于筛选出适合陇东黄土高原土壤类别-适生植物-土著降解菌群的组合,利用乡土物种的适生性降低修复成本,为陇东地区油污土壤生态修复提供新的技术方案和背景资料.     

湖南采矿区和冶炼区水稻土重金属污染及其潜在风险评价

对湖南省9个县市采矿区和冶炼区附近的水稻土中重金属Cd、As、Cu、Zn和Pb进行了调查和分析.结果表明,采矿区和冶炼区周围的水稻土中重金属Cd、As、Cu、Zn和Pb的含量呈对数正态分布.单因子污染指数法评价表明,在所调查的区域中,有6个县市矿区和冶炼区附近的水稻土受到Cd的严重污染,其它地区的水稻土分别受到Cd、As、Cu、Zn和Pb不同程度的污染,其中衡阳常宁市水口山铅锌矿区和株洲清水塘冶炼区附近的水稻土受到重金属的严重污染.潜在风险评价表明,采矿区和冶炼区周围的水稻土中Cd潜在风险参数最高,其次是Pb和As.衡阳常宁水口山铅锌矿、株洲清水塘冶炼区、娄底冷水江锡矿和湘潭锰矿附近的水稻土中重金属的潜在生态风险参数很高,具有很高潜在风险程度;永州道县冶炼区水稻土中重金属的潜在生态风险程度为较高程度;郴州柿竹园铅锌矿.常德石门雄磺矿、益阳赫山区金矿区和岳阳临湘铅锌矿区附近的水稻土的重金属潜在生态风险为中等程度.     

密云水库上游某铁矿区土壤重金属含量及形态研究

应用富集因子法(EF)和风险评估编码方法(RAC)对北京市密云水库上游某铁矿矿区及其周边土壤中重金属的分布状况和潜在生态风险进行了研究.结果表明,各重金属元素含量除As外,其余均明显高于北京市土壤重金属背景值,矿区的选冶活动已经对下游的水体和土壤环境造成一定的影响.富集因子法评价表明Cd、Pb、Cr富集较为严重,达到显著污染水平.形态分析表明,残渣态是重金属元素的主要存在形态, Cd元素可交换态所占比例(2.88%~21.15%)最高,RAC评价结果显示Cd基本处于中等风险水平,Pb为无风险,风险等级由强至弱的顺序为:Cd>Mn>Zn>Cu>Co>Cr>Pb.     

基于GIS的银川市不同功能区土壤重金属污染评价及分布特征

以银川市8种不同城市功能区表层土壤(0~20 cm)为研究对象,每个功能区各采集10个土样,共80个样.通过数理统计和地统计学方法,分析和评价银川市区不同功能区土壤重金属Zn、Cd、Pb、Mn、Cu和Cr污染现状及其来源,并在GIS支持下绘制土壤重金属含量空间分布图.结果表明,银川市Zn、Cd、Pb、Mn、Cu和Cr的平均值分别为74.87、0.15、29.02、553.55、40.37和80.79 mg·kg-1,均高于宁夏土壤背景值,呈现出重金属累积现象.通过单因子污染指数可知,银川市不同重金属污染程度依次为:CuPbZnCrCdMn.从空间分布可以看出,Zn、Cd、Pb和Cr在东北、西南和市区中部含量较高,Mn和Cu在东北方向和市区中部含量较高.通过内梅罗综合指数可知,银川市道路和工业区呈现中度污染,其它功能区均表现为轻度污染.不同功能区污染程度依次为:道路工业区商业区医疗区住宅区公园开发区科教区.说明伴随经济发展,银川市土壤重金属含量已受到城市中各种人类活动的影响.