添加凹凸棒土和钠基蒙脱石对铜锌镉污染红壤的改良效应研究

通过温室盆栽试验.开展了凹凸棒土和钠基蒙脱石处理对铜锌镉污染红壤的改良效应研究.结果表明:添加凹凸棒土和钠基蒙脱石处理能显著增加黑麦草(Lolium multiflorum Lam)两茬的地上部生物量(鲜重).未施入改良剂时,两茬黑麦草地上部的生物量分别为是7.60 g/盆和5.67 g/盆,添加80 g/kg 凹凸棒土处理的两茬地上部生物量分别增加了184%和15%添加80 g/kg钠基蒙脱石处理的两茬地上部生物量分别增加了113%和99.3%.黏土矿物的加入使土壤的pH提高了0.26～1.02个单位.从而降低了植株对Cu、Zn、Cd的生物有效性.随着添加量从20 g/kg增加到80 g/kg,黑麦草地上部Cu、Zn、Cd的含量降低,钠基蒙脱石钝化Cu、Cd的效果好于凹凸棒土,但两者钝化Zn的效果没有显著差异性.添加40 g/kg和80 g/kg的凹凸棒土或钠基蒙脱石处理都显著降低了污染上壤TCLP提取液中Cu、Zn的浓度,对于TCLP提取液中Cd浓度的显著降低只有添加80 g/kg的凹凸棒上这一种处理达到.     

蚓粪对黑麦草吸收污染土壤重金属铜的影响

在长江冲积物形成的高沙土中加入CuSO4.5H2O模拟土壤污染,使Cu污染浓度分别为200、400、600 mg kg-1,并设置加蚓粪(15%)和加原土(15%)处理,二处理各设种植黑麦草(Lolium multiflorum)和不种黑麦草培养试验,研究蚓粪对黑麦草生长及对Cu吸收的影响,以揭示蚓粪在Cu污染土壤植物修复中的作用。结果表明:蚓粪显著增加了黑麦草的地上部和地下部的生物量(p<0.001**)以及根系的长度、表面积、体积和根尖数(p<0.05*),在Cu浓度为200 mg kg-1时促进作用最大;蚓粪还显著提高了黑麦草地上部Cu的浓度及累积量,但显著降低了地下部的Cu浓度(p<0.05*),而对地下部的铜累积量没有影响,显示蚓粪能促进Cu从根系向地上部的运移及在地上部的富集。通过对土壤的pH和Cu的形态特征分析,发现种植黑麦草处理降低了土壤的pH并增加了可交换态铜的含量,而且这种作用在加入蚓粪后更加明显。推测蚓粪主要通过促进黑麦草根系的生长和活性而影响根系周围环境,提高重金属铜的生物有效性进而增加植物对铜的吸收。     

钝化剂对铅锌尾矿砂中重金属的固化作用

铅锌尾矿砂重金属含量高,对环境危害大。为了减缓铅锌尾矿砂的重金属污染风险,采用室内培养实验方法,在铅锌尾矿砂中添加油菜秸秆、芒草秸秆、水稻秸秆、石灰和磷酸一铵等钝化剂,并通过DTPA及Tessier连续提取铅、锌、镉的化学形态,评价钝化剂对铅、锌、镉的移动性和生物有效性的影响。结果表明,油菜秸秆、芒草秸秆、水稻秸秆、石灰和磷酸一铵均显著地降低Cd的生物有效性及其迁移能力;磷酸一铵、油菜秸秆均能有效地降低尾矿砂中Pb的生物有效性及其迁移能力,尤其是磷酸一铵有极显著的效果;油菜秸秆、芒草秸秆、水稻秸秆和磷酸一铵均能有效地降低尾矿砂中Zn的生物有效性及其迁移能力。尾矿砂中DTPA态Cd、Zn与交换态、碳酸盐结合态Cd、Zn极显著正相关,DTPA态Pb与碳酸盐结合态Pb极显著正相关。从Pb、Cd、Zn生物有效态含量的减少方面考虑,油菜秸秆和磷酸一铵是较好的铅锌尾矿砂原位钝化剂。     

石灰用量对污染红壤和黄泥土中有效态铜锌含量的影响

采用外源加入重金属铜锌硝酸盐的方法,制成铜、锌单一及复合污染的三级污染红壤和黄泥土（Cu 200mg/kg、Zn 400 mg/kg）,稳定一个月,施入低（0.50 g/kg）、中（1.50 g/kg）和高（2.50 g/kg）3种不同用量的石灰,稳定两个月后测定土壤有效态铜、锌含量和pH值,以阐明石灰用量对不同污染土壤中重金属有效态含量的影响。结果表明,随石灰用量的增加,复合污染红壤中有效态铜含量较对照依次降低31%、76%和87%;而石灰用量对黄泥土中有效态铜影响的差异不显著;两种土壤中有效态锌含量均随石灰用量的增加而显著减少;复合污染较单一污染相比,有效态铜及有效态锌的含量差异不显著。在复合污染下,低、中量石灰使黄泥土中有效态铜含量较红壤减少89%和63%,有效态锌减少27%和65%。但加入高量石灰,两种土壤差异不显著。石灰能够降低单一与复合污染铜、锌有效态的含量,但其效果因土壤类型而异,在红壤上选择施用高量石灰而在黄泥土上则适宜施用低中量石灰,以取得最佳的修复效果和效益。     

酸度对土壤溶液中铜形态的影响及其与黑麦草生长关系的研究

研究了酸度对土壤溶液中铜形态的影响以及不同形态铜与黑麦草吸收及其生长的关系。结果表明：酸度强烈地影响土壤溶液中铜的化学形态，随着酸度的增加，土壤溶液中各种形态铜的含量包括水溶态铜、离子态铜及与易溶有机物结合的铜都相应增加，而且随处理铜浓度的增加不同酸度土壤上的差异更大。酸度能影响黑麦草对铜的吸收，随酸度的增加，黑麦草对铜的吸收增加。其中在对照及低铜处理中两种土壤的差异不显著，而在处理铜浓度高于50mg／kg以后两种土壤上的黑麦草铜含量差异都达显著水平。黑麦草的生长随土壤酸度的增加而变差，随处理铜浓度的增加，两种土壤的差异逐步达显著水平。黑麦草的生物量与黑麦萆体内铜含量、土壤水溶态铜、有机结合态铜及离子态铜都呈极显著的负相关关系。酸度也影响土壤溶液中易溶有机碳的含量，随酸度的降低有机碳的水平呈增加的趋势．在部分铜处理水平间差异达显著水平。     

四种改良剂对铜和镉复合污染土壤的田间原位修复研究

研究了石灰、磷灰石、蒙脱石和凹凸棒石对冶炼厂周边Cu、Cd污染土壤的原位修复效果。以黑麦草(Lolium perenne L.)作为田间修复植物,采用植物重金属吸收性、土壤重金属化学提取性及土壤溶液重金属浓度变化等作指标来评价修复效果,并研究了黑麦草对Cu、Cd的吸收与土壤、土壤溶液中Cu、Cd含量的相关性。结果表明,石灰高添加剂量(石灰占污染土壤耕作层质量的0.4%)处理黑麦草对重金属的富集效果最好,显著降低了重金属毒性,促进了黑麦草的生长及其对重金属的富集;石灰和磷灰石各添加剂量均显著降低了污染土壤交换态Cu含量;石灰、磷灰石和蒙脱石各添加剂量均显著提高了土壤溶液pH并显著降低了其Cu、Cd浓度。黑麦草地上部、根中Cu浓度与土壤交换态Cu及土壤溶液Cu浓度呈显著或极显著正相关关系。     

铁和不同形态氮素对玉米植株吸收矿质元素及其在体内分布的影响 Ⅱ.对铁、锰、铜、锌等营养元素的影响

用营养液培养方法研究了铁和两种形态氮素对玉米植株吸收铁、锰、铜、锌等微量元素及其在体内分布的影响。结果表明:与硝态氮(NO3--N)相比,铵态氮(NH4+-N)显著提高了玉米对铁的吸收,降低了对锰、铜及锌的吸收。供铁也明显提高了植株地上部铁的吸收总量,降低了锰及锌的吸收量,尤其是在供应No3--N时这种作用更为明显。在缺铁条件下,NH4+-N处理的玉米新叶中铁的含量明显高于NO3--N处理;而新叶、老叶、茎中锰、锌、铜含量以及根中锰、锌含量都明显低于NO3--N处理。但使用NH4+-N时,根中铜的含量较高。在供铁条件下,NH4+-N处理的玉米植株四个不同器官中锰和锌的含量显著低于NO3--N处理的植株,而铜的含量正好相反。在缺铁条件下,玉米新叶中活性锰、活性锌的含量显著高于供铁处理;与NO3--N相比,NH4+-N的供应也显著降低了玉米新叶中活性锰以及活性锌的含量。     

轮作提高土壤磷生物有效性改善后茬作物磷素营养

  【目的】  豆科作物与禾本科作物轮作能够提高轮作体系的磷效率,本研究调查了前茬作物收获后的土壤磷状况,并尝试采用基于生物有效性的磷素分级方法 (BBP) 评价其对后茬玉米磷营养状况的影响。  【方法】  设置室内模拟盆栽试验,前茬作物处理包括蚕豆 (Vicia faba)、小麦(Triticum aestivum)、黑麦草 (Lolium perenne) 和毛叶苕子 (Vicia villosa Roth),以不种植作物为对照。作物收获后,后茬均轮作玉米。每个轮作前茬作物处理均分为基施P₂O₅ 60 mg/kg和不施磷肥两个处理。在前茬作物收获后,测定土壤Olsen-P含量,并将土壤磷分为CaCl₂-P、Citrate-P、Enzyme-P、HCl-P,评价土壤的有效磷状况。玉米收获后,测定产量和植株地上部磷含量及吸收累积量。  【结果】  轮作显著提高了后茬玉米地上部生物量,前茬不施磷肥处理对后茬玉米的增产效果高于施用磷肥处理。不施磷肥条件下,与对照相比,蚕豆后茬玉米的地上部生物量增加最多 (185.7%),且增幅显著高于小麦和毛叶苕子的后茬;施磷条件下,蚕豆、黑麦草后茬玉米的地上部生物量之间没有显著差异,但均显著高于小麦和毛叶苕子后茬。不施磷条件下,轮作显著提高了后茬玉米地上部含磷量,以黑麦草茬口的增幅最高,达到66.7%,且显著高于蚕豆和毛叶苕子;施磷条件下,4个茬口玉米地上部磷含量与无前茬作物对照没有显著差异,但黑麦草茬口仍显著高于蚕豆、小麦和毛叶苕子茬口的。前茬不施磷肥条件下,Enzyme-P在蚕豆、小麦、黑麦草和毛叶苕子茬土壤显著高于对照土壤;施磷肥条件下,只有蚕豆和黑麦草茬土壤显著高于对照土壤,这与轮作处理的促生效应相吻合。不施磷蚕豆、小麦、黑麦草和毛叶苕子土壤Citrate-P含量比其对照显著低20.99%、13.30%、5.05%和10.66%,而施磷土壤降幅更大,分别比对照低32.56%、22.86%、20.32%和27.62%。不论是否施磷肥,蚕豆与毛叶苕子均显著降低了土壤的HCl-P含量,而小麦茬对土壤的HCl-P含量无显著影响。  【结论】  不论是否施用磷肥,轮作显著降低了土壤中Olsen-P的含量,但是却显著促进了后茬玉米的生长。依据BBP分级方法,轮作不同程度地降低了土壤中Citrate-P和HCl-P含量,而增加了Enzyme-P的含量,进而提高了土壤中磷的生物有效性,增加了玉米吸磷量。在4种前茬作物中,黑麦草挖掘土壤供磷能力的潜力最大。     

巨大芽孢杆菌LY02对黑麦草修复重金属污染土壤的影响

采用盆栽试验方法,研究了接种巨大芽孢杆菌LY02对黑麦草修复Cd、Cu污染土壤以及二者复合污染土壤效果的影响。结果表明:在Cd、Cu污染土壤及复合污染土壤中接种巨大芽孢杆菌LY02,可显著提高黑麦草地上部生物量,增幅达65.0%~108.3%;促进了黑麦草在3种污染土壤中对重金属的吸收,其中对Cd污染土壤中黑麦草吸收Cd的影响最为显著,地上部Cd吸收量较对照组增加了45.8%(P0.05);3种污染土壤中黑麦草根际土壤有效磷含量显著升高,较对照组分别增加了18.2%,26.7%,16.2%;黑麦草根际土壤中有效态Fe含量显著提高,Cu单一污染土壤中增幅最大,达到152.5%;3种污染土壤中有效态重金属含量升高,在Cu污染土壤中,有效态Cu增幅达到49.7%(P0.05)。综上所述,巨大芽孢杆菌LY02通过增加污染土壤中生物可利用态P和Fe,促进黑麦草生长;通过提高有效态Cd和Cu的含量,增加黑麦草对其吸收,从而提高了黑麦草对Cu、Cd污染土壤的修复效率。     

不同修复方式对铅锌尾矿砂微生态环境的改良作用

采用盆栽试验方法研究黑麦草、黑麦草联合改良剂等不同修复方式对铅锌尾矿砂的理化性质和微生物性状的改良作用。结果表明,不同处理使铅锌尾矿砂中有机质、碱解氮、速效磷含量显著提高,其中黑麦草联合10%菜园土和1%赤泥处理(CN1)对铅锌尾矿砂中有机质、碱解氮、速效磷含量明显提高,分别比对照提高了51.82%,300.00%和901.29%。添加改良剂显著增加了黑麦草的生物量,减少了黑麦草根部重金属的含量。不同处理使铅锌尾矿砂中微生物数量,微生物C、N含量显著增加,其中CN1处理使细菌、真菌、放线菌数量和微生物C、N含量增加效果最好,分别比对照增加了33.78,5.99,21.82,6.34,6.35倍。各处理显著提高了尾矿砂中脲酶、磷酸酶、蔗糖酶、纤维素酶活性,其中CN1处理使脲酶、磷酸酶、蔗糖酶、纤维素酶活性分别比对照提高了18.43,12.58,5.00,9.15倍。黑麦草联合10%菜园土和1%赤泥较其他处理有利于提高铅锌尾矿砂的肥力,改良尾矿砂的微生态环境,促进植物生长。     

不同改良剂对黑麦草在铜矿尾矿砂上生长的影响

Montmorillonite, rice straw, organic manure and chemical fertilizer were used as amendment materials for copper mine tailings, and their effects on mine tailing pH, nutrients and metal availability to ryegrass were investigated. Chemical fertilization was the most effective one in improving ryegrass growth in mine tailings among the amendment materials examined. It was found that montmorillonite raised biomass of ryegrass at the 1st and 2nd cuts, but it did not give further positive effects at the 3rd and 4th cuts. The effect of organic materials on ryegrass growth was not so good as expected, mainly due to their slow decomposition in mine tailings with less soil microorganisms. Available Cu and Zn contents in mine tailings decreased in the presence of montmorillonite but increased when rice straw and organic manure were used as amendments. Cu and Zn contents in ryegrass decreased with increasing the rate of montmorillonite application but increased with the rate of rice straw. Zn showed much stronger mobility from soil to ryegrass than Cu, and almost all the available N and P in mine tailings, except for the treatments with organic manure, were completely consumed after ryegrass had grown in mine tailings for more than four months and been harvested for four times. Owing to its large biomass and high metal uptake, ryegrass is a potential plant for remediation of metal contaminated soils in practice.     

Revegetation of copper mine tailings with ryegrass and willow

To restore vegetation on metal mine tailings is very difficult because they often contain high concentrations of heavy metals, low nutrient content and low water retention capacity. This study involved 3 experiments that evaluated the effects of 4 treatment amendments: montmorillonite, rice straw, organic manure and chemical fertilizer on the growth of ryegrass (Loliurn perenne L.) and willow (Salix virninalis L.) with Cu and Zn mine tailings from two mining areas. The results showed that ryegrass was the most tolerant of 4 crops to Cu toxicity. Also when organic manure, which contained high concentrations of inorganic salts, was added to the mine tailings, it significantly hindered ryegrass growth (P=0.05).Meanwhile, with ryegrass organic manure significantly increased (P=0.05) the extractable Cu concentration in both mine tallings. When montmorillonite was used as a mine tailings amendment with willow, the height and tress number at the 1st cut were significantly greater (P = 0.05) than a control without montmorillonite. However there was no significant difference for height, tress number, dry weight or root dry weight at the 2nd cut. So, amendment applications to reduce metal toxicity and increase nutrients retention in mine tailings were essential during revegetation of mine tailings.     

Zinc Uptake by Spinach (Spinacia oleracea L.) as Affected by Zn Application Rate,Zeolite, and Vermicompost

Zinc deficiency in calcareous soils is a serious problem, which may be ameliorated by the application of some soil amendments. A completely randomized factorial experiment was done to investigate the effect of zeolite, vermicompost, zeolite + vermicompost, and Zn application to a calcareous soil on Zn availability, dry weight of spinach (Spinacia oleracea L.), and Zn concen-tration in spinach. Results indicated that zeolite had no effect on soil Zn availability, dry weight, and Zn concentration in spinach. Vermicompost significantly increased dry weight (1.33 g pot^?1) and decreased Zn concentration in spinach (16 mg kg^?1). Application of zeolite + vermicompost significantly increased dry weight (by 2.8 times) and Zn uptake in spinach and it also decreased Zn concentration in spinach less than vermicompost. Zinc application increased Zn concentration in spinach (up to 496 mg kg^?1), but did not affect dry weight except in soils treated with zeolite + vermicompost. Generally, application of zeolite + vermicompost is recommended instead of separate zeolite or vermicompost application for improvement of soil Zn fertility and Zn uptake by spinach.     

德兴铜矿尾矿库植被重建后的土壤肥力状况和重金属污染初探

德兴铜矿是我国的超大型铜矿,尾矿砂的排放是其主要的环境问题之一,目前主要堆积于尾矿库中。1号尾矿库于1986年服役期满后共堆积矿砂2.15×107 m3,面积约210 hm2。20世纪90年代后期,在坝坡约30 hm2覆有客土的地区进行了一系列植被重建的试验研究工作,本文报道了1998年开始在旱稻(OryzaLinn.)、花生(Arachis Linn.)、香根草(Vetiveria zizanioidesNash)和湿地松(Pinuselliottii Engelm.)等18种不同植被组合条件下的土壤基本农化性状(pH、有机质(OM)、铵态氮、速效P、速效K)以及0.05 mol L-1 HCl可提取态重金属在3~4年时间内的变化情况,结果表明,坝坡土壤N、P、K严重不足,且保水、保肥能力弱,需要不断地进行培肥和改良。三年多来,土壤pH总体上无显著变化;OM第三年有显著上升,约为第一年的127%;NH4 N成直线下降,第二年和第三年分别为第一年的72.9%和43.0%;随着耕作实践的推移,速效P和速效K显著上升,但仍旧处于较低水平。重金属(主要是Cu)污染严重,Cu、Zn、Pb、Cd在植物中有明显积累。研究结果强调了试验区在植被重建中不宜种植食用植物,以避免食物链的污染。     

Trace Metal Availability in Soils Amended with Metal-Fixing Inorganic Materials

Immobilization of metals by two materials (zeolite, AZ, and a synthetic, carbonate-rich material, “slovakite”, SL) was tested in a pot experiment with two soils from urban areas of Sevilla and two soils affected by a mine spill. Barley (Hordeum vulgare L. Hispanic) was grown in the pots, and metal contents were measured after 31 days in shoots and roots. Available metal was estimated by extraction with CaCl₂ (readily soluble), ethylenediaminetetraacetic acid (EDTA; plant available), a mixture of organic acids (soluble by root exudates), and glycine (bioaccessible by ingestion). Neither treatment caused significant differences on plant growth or metal contents of shoots, whereas roots contained more Cu in the SL treatments. Root Zn uptake was reduced in all cases, but reduction of Pb in roots was observed only in AZ treatments of the mine-spill soils. The effects on metal availability were often method-dependent. Decrease of CaCl₂ data were observed only in the mine-spill soils. EDTA-soluble metals were clearly decreased by both materials. Bioaccessible Zn were decreased by either material in several cases (but not in the most heavily polluted soil), whereas Cu or Pb data were less conclusive.     

矸石添加对铜尾矿中香根草生长及生理生态的影响

为了探索矸石作为改良剂用于尾矿生态修复,通过盆栽试验,将矸石按一定比例(0,1%,2.5%,5%,10%和15%)添加入铜尾砂,基于铜尾砂理化性质变化,探索矸石对尾砂中香根草生理生态的作用特点。结果表明:矸石添加入铜尾砂后,提高了基质pH、有机质和营养元素含量,降低了有效态重金属浓度(Cd、Cu、Pb和Zn),改善了尾矿贫瘠环境。随矸石添加比例增加,香根草体内重金属浓度呈下降趋势,生物量和光合色素含量呈现低促高抑性变化。同时,可溶性蛋白质和脯氨酸含量随矸石添加比例增加而增加,MDA随添加比例增加而降低,低添加比例的矸石选择性提升了SOD和CAT酶活性,增强了香根草清除体内多余活性氧的能力。矸石加入铜尾砂可稳定铜尾矿中有效态重金属,也能在一定添加比例内,提高香根草抵御铜尾矿胁迫环境的能力。     

铅锌矿废弃地尾矿砂对银合欢幼苗定居的影响

研究了广东省仁化县韶关凡口铅锌矿废弃地尾矿砂对银合欢(Leucaena glauca)幼苗定居的影响。结果表明，尾矿砂中Pb、Zn、Cu、Cd等重金属含量极高，Pb、Zn比对照土壤高100倍左右，Cu、Cd高4～5倍，植物对重金属的吸收、积累量较大，且多集中于根部。尾矿砂中硝态氮(NO^-₃-N)和铵态氮(NH⁺₄-N)含量很低，仅为对照土壤的13%～23%。银合欢幼苗在尾矿砂中能生长，但其叶片光合色素含量较少，株高、复叶数、植株干物质量等生物量显著降低，这主要是由于重金属含量过高导致根系活力降低，限制了植物对水分和营养物质的吸收，其次是土壤贫瘠的影响。     

A Laboratory Study on Revegetation and Metal Uptake in Native Plant Species from Neutral Mine Tailings

Lygeum spartum, Zygophyllum fabago and Piptatherum miliaceum are typical plant species that grow in mine tailings in semiarid Mediterranean areas. The aim of this work was to investigate metal uptake of these species growing on neutral mine tailings under controlled conditions and their response to fertilizer additions. A neutral mine tailing (pH of soil solution of 7.1–7.2) with high total metal concentrations (9,100 and 5,200 mg kg^?1 Zn and Pb, respectively) from Southern Spain was used. Soluble Zn and Pb were low (0.5 and <0.1 mg l^?1, respectively) but the major cations and anions reached relatively high levels (e.g. 2,600 and 1,400 mg l^?1 Cl and Na). Fertilization caused a significant increase of the plant weight for the three species and decreased metal accumulation with the exception of Cd. Roots accumulated much higher metal concentrations for the three plants than shoots, except Cd in L. spartum. Shoot concentrations for the three plants were 3–14 mg kg^?1 Cd, 150–300 mg kg^?1 Zn, 4–11 mg kg^?1 Cu, and 1–10 mg kg^?1 As, and 6–110 mg kg^?1 Pb. The results indicate that neutral pH mine tailings present a suitable substrate for establishment of these native plants species and fertilizer favors this establishment. Metal accumulation in plants is relatively low despite high total soil concentrations.