利用粉煤灰污泥混料改良石灰岩质土壤后的重金属累积状况

通过盆栽试验研究以粉煤灰和污泥混合物为主料,改良石灰岩质土壤后对玉米生长发育的影响,根据重金属富集系数,探讨重金属在土壤和玉米中的累积状况。试验结果表明:石灰岩质土壤中添加粉煤灰污泥混合物后能显著促进玉米的生长和提高玉米的干物重,其中以1:1重量比处理玉米的平均株高、株径及根部、地上部、总干物重分别是对照样的1.56、1.71、1.36、3.81和2.37倍。以不同配比添加混合物后的土壤相对于国家土壤背景值和国家土壤环境质量标准,Hg和Cd表现强烈富集,整体符合国家二级土壤质量标准,且玉米根部几乎所有有害元素的含量均高于对照组,而地上部分除Cu、Zn外均显著低于对照组,但均未达到玉米毒害浓度。另外,在土壤中添加混合物后玉米中几乎所有的有害元素主要累积在根部,有利于其地上部分的生长,减少了通过食物链危害人类的机率。     

重金属Cu的土壤微生物毒性研究

Cu进入土壤后的早期阶段 ,低浓度对土壤微生物生物量有刺激作用 ,而高浓度则起抑制作用 ;表现在微生物呼吸强度升高 ,微生物生理生态参数代谢商 qCO2 增大 ,微生物生物量碳与有机碳的比值 (Cmic/Corg)降低 ;但土壤对Cu高强的结合容量导致该效应随时间而变得不显著 ;Biolog数据表明 ,在Cu的胁迫下 ,不仅微生物的群落结构有所改变 ,而且对碳源的优先利用种类发生了转移 ,碳源消耗量增加 ,消耗速度变快 ,同时这样的损伤效应具有长期性。     

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。     

沼渣与水分的耦合对温室土壤N积累及重金属污染状况的研究

采用完全随机区组田间试验设计的方法,以番茄为供试作物,研究了沼渣与水分的耦合对温室土壤N积累及重金属污染状况.结果表明,低灌溉量下,沼渣与化肥配合使用有利于土壤中重金属累积量的减少;就土壤中N积累状况而言,S2F2为较适宜的水肥组合.综合两方面得知,S2F2水肥组合有利于土壤环境的改善,为后续作物的栽培提供足够的N源,即3000 m3/hm2灌水量+40%沼渣+60%化肥为较适宜的水肥组合.     

铵饱和沸石对几种重金属离子的吸附解吸特性影响研究

通过室内分析的方法比较了天然沸石及铵饱和沸石对重金属离子Cd2+、Zn2+、Cu2+、Pb2+的吸附及解吸特性。研究结果表明:铵饱和沸石对4种重金属离子的吸附量大小顺序依次为Pb>Cu>Zn>Cd,而解吸量和解吸率的大小顺序为Cd>Zn>Cu>Pb,这主要与四种金属离子的水合离子半径和水合能密切相关。与天然沸石相比,铵饱和沸石一方面增加了对4种重金属离子的吸附,同时又降低了其解吸率。原因是铵饱和沸石的阳离子交换量和比表面积有所增加,同时铵饱和沸石的孔穴和通道也较天然沸石更加均一和畅通。因此,铵饱和沸石在农业生产实践中,特别是土壤污染治理方面具有广阔的应用前景。     

Heavy Metal Accumulation in Soil Amended with Roadside Pond Sediment and Uptake by Rice (Oryza sativa L.)

The effect of addition of roadside pond sediments on heavy metal contents of flooded rice paddies was studied to investigate the yield of rice and uptake of heavy metal by rice straw and grain. Sequential extraction of heavy metals on sediments shows that the percentage contribution of metals in the labile fraction follows the order lead (Pb, 48%) > copper (Cu, 42%) > zinc (Zn, 31%) > cadmium (Cd, 16%) > chromium (Cr, 9%) > nickel (Ni, 6%). The risk assessment code (RAC) for pond sediment revealed that Cr and Ni were found in the low-risk zone, Zn and Cd in the medium-risk zone, and Cu and Pb in the high-risk zone. However, though the heavy metal concentration in rice grain does not exceed the range acceptable for human consumption, it still represents a significant additional source of heavy metals in the diet. The addition of pond sediment significantly increased the rice yield over control. Therefore, pond sediment would be a valuable resource for agriculture if it is properly used.     

Heavy Metal Accumulation in Plants on Mn Mine Tailings

The Xiangtan Manganese （Mn） Mine in the middle of Hunan Province, China, has been mined since 1913 with mine tailings including excavated wastes, wastewater, and smelting wastes. A survey was conducted on the Mn mine tailing soils and eight plants on the Mn mine tailings. The concentrations of soil Mn, Pb, and Cd and the metal-enrichment traits of these eight plants were analyzed simultaneously. Exceptionally high concentrations of these three metals were found in the soils, especially on the tailing dam. Each plant investigated in this study accumulated the three heavy metals, but no hyperaccumulator of these metals was found. However, analysis indicated that Poa pratensis Linn., Gnaphalium affine D. Don, Pteris vittata L., Conyza canadensis （L.） Cronq., and Phytolacca acinosa Roxb. possessed specially good metalenrichment and metal-tolerant traits. P. pratensis, G. affine, and P. vittata were Pb-tolerant plants; and C. canadensis, P. pratensis, and G. affine were Cd-tolerant plants. P acinosa had a great tolerance to Mn, and it was a valuable plant for on-site phytoremediation. Phragmites communis Trin. was found to have high metal tolerance and economic benefit as a raw material for paper and should be considered for soil remediation. G. affine and C. canadensis had excessive accumulation of Mn and could be useful in phytoremediation. However, although P. pratensis was a good accumulator, it was not a suitable plant for soil remediation because its biomass was too little.     

砂姜黑土中重金属Cu、Cd、Zn形态分布与土壤酶活性研究

采用小麦农田取样,对土壤中的重金属运用连续提取方法,研究了皖北砂姜黑土中Cu、Cd、Zn的化学形态特征及其与四种土壤酶(过氧化氢酶、脲酶、蔗糖酶、中性磷酸酶)活性间的关系。结果表明:在砂姜黑土中,残留态Cu、Cd、Zn在总量中所占比例很高,交换态、有机态、碳酸盐结合态含量明显低于残留态。在三种元素中,Zn的化学形态变化趋势最为一致,表现为残留态>碳酸盐结合态>铁锰结合态>有机态>交换态;砂姜黑土中交换态Cu、Cd、Zn对脲酶活性有显著抑制作用,有机态Cu、Cd、Zn对过氧化氢酶表现为一定程度的促进作用。因此,在砂姜黑土壤中,把交换态Cu、Cd、Zn和脲酶以及中性磷酸酶的活性共同作为评价土壤Cu、Cd、Zn污染程度的主要生化指标是可行的。     

土壤重金属污染背景下的任豆修复试验

为寻找适合矿业尾矿坝人工生态恢复的植物,以广西南丹长坡矿堆存 50 a之久的尾矿坝为背景,通过盆栽模拟,运用室内土培和水培两种试验方法,研究了不同矿土比例（尾矿样与泥土比例分别为5∶0、4∶1、3∶2、2∶3、1∶4、0∶5）以及不同浓度（0、2.5、5、10、25、50、100、150、200、250 mg·L^-1）Pb^2＋、Cu^2＋、Zn^2＋在任豆苗体内的吸收、积累和分布的动态变化规律。结果表明,任豆对Pb、Cu、Zn都具有一定的吸收能力,任豆幼苗可以在一定的重金属胁迫环境下存活,任豆对重金属Pb的耐性最大,在高浓度下依然可以存活。任豆对不同类型的重金属的吸收及转运能力存在较大差异,从任豆对Pb、Cu、Zn的转运能力来看,任豆并非这3种重金属的超累积植物。试验表明,任豆在矿业尾矿坝的人工生态恢复（植物修复）中有一定的应用价值,但能否大规模采用任豆作为尾矿坝的生态修复物种,尚需进一步研究验证。     

重金属铅在河道及滩地中的积累规律

基于山西省汾河3个代表性断面处河道与滩地分层土壤中重金属铅含量的测定资料,分析了土壤铅含量沿河道与滩地横向及垂向的分布特征及其机理.结果表明:重金属铅在沿横断面的水平方向上,随着距离河道主槽水平距离增加,铅含量减小;与山西土壤背景值相比较,表层土壤、地下水位处土壤和深层土壤受污染河水的影响范围分别是距河道主槽100m,80 m和60 m;在河道垂向上,随着土层深度的增加,铅含量也呈下降的趋势,但在个别土层稍有起伏;在非饱和土壤中,其运移动力依次是对流作用,分子扩散作用,机械弥散;在饱和土壤中,运移动力依次是对流作用,机械弥散,分子扩散作用.     

中国耕地土壤重金属污染概况

依托收集的耕地土壤重金属污染案例资料,建立了我国138个典型区域的耕地土壤重金属污染数据库,并利用《土壤环境质量标准》(GB15618-1995)中的二级标准作为评价标准,测算了我国耕地的土壤重金属污染概况.研究表明:(1)我国耕地的土壤重金属污染概率为16.67％左右,据此推断我国耕地重金属污染的面积占耕地总量的1 /6左右;(2)耕地土壤重金属污染等别中,尚清洁、清洁、轻污染、中污染、重污染比重分别为68.12％,15.22％,14.49％,1.45％,0.72％;(3)8种土壤重金属元素中,Cd污染概率为25.20％,远超过其他几种土壤重金属元素;此外,也有一些区域发生Ni,Hg,As和Pb土壤污染,但是Zn、Cr和Cu元素发生污染的概率较小;(4)辽宁、河北、江苏、广东、山西、湖南、河南、贵州、陕西、云南、重庆、新疆、四川和广西14个省、市和自治区可能是我国耕地重金属污染的多发区域,特别是辽宁和山西的耕地土壤重金属污染可能尤其严重.     

Factors Affecting Microbial Biomass and Dehydrogenasc Activity in Apple Orchard Soils with Heavy Metal Accumulation

The size of the microbial biomass and dehydrogenase activity were measured in air-dried and rewetted apple orchard surface soils with accumulation of Cu, Pb, and As due to the application of Bordeaux mixtures and lead arsenate. The largest amounts of total Cu, Pb, and As found in the soils used were 1,108, 1,271, and 209 mg kg^-1 soil, respectively. The amounts of 0.1 M HCl-extractable heavy metals were strongly correlated with the total amounts, while those of 0.1 M CaCl₂-extractable heavy metals, except for As, increased significantly with decreasing soil pH. The amounts of microbial biomass C and N, expressed on a soil organic C and total N basis, respectively, were each negatively correlated with the amounts of total and 0.1 M HCl-extractable Cu. On the other hand, the dehydrogenase activity was not affected by the amounts of total and 0.1 M HCl-extractable heavy metals, and was negatively correlated with the amount of 0.1 M CaCl₂-extractable Cu and positively with the soil pH. Higher significant correlations were observed when the dehydrogenase activity was calculated per unit of soil organic C. Thus the microbial biomass was adversely affected by the slightly soluble fractions of Cu accumulated in apple orchard soils, whereas the dehydrogenase activity was affected by the water-soluble and exchangeable Cu of which amount depended on the soil pH. It is suggested that the microbial biomass and dehydrogenase activity expressed on a soil organic matter basis could become useful indicators for assessing the effects of heavy metals on the size and activity of the microbial biomass in soils differing in organic matter contents.     

小麦季磷肥施用对后作玉米的效果及土壤中无机磷形态转化的影响

在河北衡水潮土上进行田间试验,研究小麦/玉米轮作体系下,小麦季施用磷肥对玉米的后效及土壤中无机磷形态转化的影响。结果表明,与高施磷量(187.5 kg hm-2 P2O5)相比,小麦季磷肥施用量减少20%或40%,甚至当年不施磷,对后作玉米籽粒产量、生物量、植株吸磷量均无明显影响。从玉米苗期到成熟期,土壤中各形态无机磷下降幅度表现为Ca2-P最大,其次是Ca8-P,再次为Al-P。随着施磷量的减少,土壤Olsen-P、Ca2-P含量开始呈现下降趋势。与单施无机磷肥150.0 kg hm-2 P2O5相比,用有机肥猪粪磷替代其中20%无机磷肥,显著提高了土壤Olsen-P、Ca2-P和Ca8-P含量。本文结论认为在高肥力的华北地区小麦/玉米一个轮作周期中,小麦季减少磷肥用量,对后作玉米生长和产量尚未产生明显的影响。适当配施猪粪,减少无机磷肥,可以提高土壤中的Olsen-P和Ca2-P含量,较好地维持玉米季土壤中磷素肥力水平。     

不同粒径磷矿粉钝化土壤重金属Cd、Pb的机制研究

采用盆栽试验,研究磷矿粉不同粒径(0.1、1.5、150μm)的3种不同用量(1、2、4 g·kg-1土)钝化土壤重金属Cd和Pb的效应及机制。结果表明,磷矿粉的粒径越小、用量越大,上海青产量越高,叶面积越大,植物体内Cd、Pb的含量越低,土壤中交换态Cd、Pb的含量越低,残渣态Cd、Pb的含量越高。与对照相比,0.1μm磷矿粉高用量(4 g·kg-1土)的处理上海青的产量和叶面积分别显著增加87.3%和147.9%,叶中Cd和Pb含量分别显著降低46.9%和61.9%,根中Cd和Pb含量分别显著降低47.9%和35.3%,土壤交换态Cd和Pb含量分别降低44.8%和44.9%。150μm磷矿粉低用量(1 g·kg-1土)处理叶面积、植物体内Cd、Pb含量与对照都没有达到显著差异。1.5μm磷矿粉处理效果介于0.1μm和150μm磷矿粉处理之间。可见,0.1μm磷矿粉钝化土壤重金属效果最好,其机制是降低了植物容易吸收的交换态Cd和Pb的含量。     

细菌溶磷作用与磷矿粉伴生性重金属元素的释放

以4株溶磷细菌和5种磷矿粉为材料,对细菌溶磷作用与磷矿粉伴生性重金属元素释放间的关系进行了研究。结果表明,溶磷细菌在促进磷矿粉中磷溶出的同时,还促进了磷矿粉中伴生性重金属的释放,在测定的6种伴生性金属元素(Zn、Pb、Cu、Co、Ni、Cd)中,Zn最容易随细菌溶磷作用而释放,最多可占该磷矿粉中总Zn量的97.0%,Pb和Cd随细菌溶磷释放率皆低于10%;细菌溶磷作用强度与磷矿粉中各伴生性重金属释放量间的关系因磷矿粉产地和伴生性重金属种类而异。细菌作用于湖南石门磷矿粉和四川马边磷矿粉的溶磷量与Zn、Cu、Co、Ni释放量间(四川马边磷矿粉中Co除外)正相关,但未达到显著水平(r=0.50~0.95,P>0.05),但在溶解贵州开阳磷矿粉时,Zn、Co、Ni的释放量都与溶磷量显著正相关(r>0.88,P<0.05)。     

城市土壤重金属污染特征分析

目前越来越多的大城市的土壤受到不同程度的重金属污染,这将深刻影响到城市环境质量和人体健康。因受人类活动的强烈扰动,城市土壤重金属污染特征与传统意义上的土壤重金属污染特征差别很大,文章就城市土壤重金属污染特征做了详细的分析,并提出了一些相应的管理对策。     

Heavy Metal and Nutrient Ion Accumulation by Two Black Gram Cultivars Treated with Copper and Lead

ABSTRACT

A pot experiment was conducted to examine the uptake of nutrients (K⁺ (potassium) and Ca²⁺ (calsium)) and heavy metal (Cu²⁺ (copper) and Pb²⁺ (lead)) ions by leaves, seeds, and roots of two black gram [Vigna mungo (L.) Hepper] cultivars, ‘Mash-95018’(V₁) and ‘Mash-97’(V₂) treated with copper (Cu) and lead (Pb) at 25mg L^?1 and 50mg L^?1. This study was conducted in a greenhouse in the Botanical Garden, University of Agriculture, Faisalabad, Pakistan, during the spring of 2003. Heavy-metal treatments were applied 30 d after germination, and nutrient and heavy-metal ion uptake data were collected 10 d after treatment application. Both heavy metals in both cultivars substantially reduced nutrient ion accumulation and its translocation to seeds. Leaves had proportionately more K⁺ and Ca²⁺ than that recorded for roots and seeds after heavy-metal treatments. Nevertheless, both heavy metal (Cu²⁺ and Pb²⁺) ions ware predominantly sequestered in the roots, rather than in leaves and seeds, under their respective treatments. As the external concentrations of heavy metals increased, their uptake by the respective treated plants also increased, but nutrient ion (K⁺ and Ca²⁺) uptake was gradually reduced. This result suggests a concentration-dependent phenomenon. Overall, lead (Pb²⁺) showed more toxic effects on the uptake of essential nutrients compared with Ca²⁺, while ‘Mash-97’proved more sensitive to heavy metals than ‘Mash-95018.'     

重金属Cd、Zn、Cu、Pb复合污染对土壤微生物和酶活性的影响

通过野外土样采集及室内测定,研究了云南东川铜矿区土壤酶和微生物特征,并采用盆栽试验研究了重金属Cd、Zn、Cu、Pb复合污染对土壤微生物和酶活性的影响。结果表明,距离矿口越近,土壤有机质、有效N、P、K的含量、土壤pH值亦越低,土壤酶活性和土壤微生物数量、微生物生物量C和N受到的抑制程度也增强,其中土壤酶中的酸性磷酸酶和过氧化氢酶,土壤微生物中的细菌对重金属污染较为敏感。盆栽试验中,Cd、Zn、Cu、Pb复合污染使白菜(Brassica rapapekinensis)生物量明显下降,且随复合污染程度的增加,白菜生物量下降幅度增加。Cd与Zn、Cu、Pb,Zn与Cd、Cu、Pb,Cu与Cd、Zn、Pb的复合效应机制为协同效应,而Pb与Cd、Zn、Cu的复合效应机制为拮抗效应。重金属Cu、Zn、Pb、Cd复合污染使土壤酶活性显著降低,但低量的Cd、Zn、Cu、Pb复合污染刺激了细菌、真菌、放线菌、微生物生物量C和N。重金属Cd、Zn、Cu、Pb对土壤酶活性和土壤微生物数量及微生物生物量C和N的复合效应机制表现出协同和拮抗效应。     

新乡市大棚菜田土壤重金属积累特征及污染评价

采用微波消解-ICP-AES技术,测定不同种植年限大棚菜田土壤样品中As、Pb、Zn、Cd、Cr、Mn、Ni、Cu等重金属的含量,研究不同种植年限与大棚菜田土壤重金属累积的相关性以及大棚菜田土壤重金属累积特征,并利用地积累指数法进行污染评价。结果表明:大棚菜田土壤重金属Zn、Pb、Ni、Mn和Cu的含量与种植年限具有极显著相关性;大棚菜田土壤中重金属Cd和Cr的含量与种植年限不相关。重金属元素间相关性分析表明,Zn与Pb、Cd、Ni、Mn、Cr、Cu,Pb与Cd、Ni、Mn、Cr、Cu,Cd与Ni、Mn、Cr,Ni与Mn、Cr、Cu,Mn与Cr、Cu具有污染同源性,Cu与Cd、Cr不具有污染同源性。地积累指数法污染评价结果显示Cd的污染等级达到了6级,已构成了极严重污染;Zn和Cu的污染等级达到2级,已构成了中度污染;Pb、Mn的污染等级达到1级,已经构成了轻~中度污染;As、Ni、Cr均未构成污染。     

The Applicability of Needle Chemistry for Diagnosing Heavy Metal Toxicity to Trees

Water, Air, &; Soil Pollution - To estimate the validity of needle chemistry as a tool for diagnosing heavy metal toxicity, we collected needle samples from mature pines and young seedlings and...