红螺菌R-04吸附多种重金属的研究

研究了红螺菌R 0 4对重金属Cu2 + 、Ni2 + 和Cr6+ 的吸附行为。实验表明 ,菌体分别在含 1 0～ 5 0mg/LCu2 + 、Ni2 + 和Cr6+ 的培养液中培养 96h ,最高吸附率分别为 98 9%、90 %和 84 % ;且菌体对Cr6+ 的还原率均达 99%以上。另外 ,观察到 5 0mg/LCu2 + 的培养液 ,菌液褪色 ;而在Ni2 + 和Cr6+ 中没有出现这种现象。最后 ,探讨了共存离子对吸附的影响 ,3种金属离子两两组合、三者共存对菌体吸附Cu2 + 和Cr6+ 的影响不大 ,对Ni2 + 的影响较大     

利用污泥进行水体中重金属生物吸附研究现状及展望

对国内外利用废水处理等工业过程中所产生的污泥作为生物吸附剂吸附水体中重金属的研究现状进行了综述和分析,包括其预处理技术、反应机理、主要影响因素、处理效果以及反应器工艺等。同时,对该技术未来的发展趋势进行了展望,指出依托现有废水处理设施进行集约化开发将是该工艺的发展方向。     

Ionic strength effects in biosorption of metals by marine algae

Biosorption, the passive accumulation of metals by biomass, can be used as a cost-effective process for the treatment of metal polluted industrial effluents. The green alga Ulva fascia and the brown seaweeds Sargassum hemiphyllum, Petalonia fascia, and Colpomenia sinuosa were characterized in terms of their number of binding sites, their charge density and intrinsic proton binding constant (pKa) using pH titrations at different ionic strengths. The determined number of binding sites decreased in the order Petalonia > or = Sargassum > Colpomenia > Ulva. Due to their high number of binding sites Sargassum and Petalonia are most promising for biosorption applications. The decrease of proton binding with increasing ionic strength and pH as well as the increase of Cu and Ni binding with increasing pH and decreasing ionic strength could be described by the Donnan model in conjunction with an ion exchange biosorption isotherm.     

固定化鼠尾藻Sargassum thunbergii对水中重金属锌的生物吸附效应

采用海藻酸钠-聚乙烯醇联合固定鼠尾藻与活性炭的方法对废水中重金属Zn2+进行生物吸附研究。结果表明：当固定化材料配比为15 g·L-1鼠尾藻粉,2%海藻酸钠溶液、6%聚乙烯醇溶液,1.5%活性炭时,固定化小球对废水中Zn2+的吸附率最大。溶液在不同环境因素条件下吸附率不同,吸附率随着pH升高而升高,当pH为6时吸附率达到最大,随后开始下降;当温度为30 ℃,投放量为60 g·L-1时吸附率上升至最大值后趋于平衡,吸附率不再随着条件的增加而增加;前30 min吸附过程为快速吸附阶段,并在60 min后吸附率趋于平衡。在实验室规模的流化生物反应器中,固定化颗粒可以连续高效处理模拟矿山废水,同时经过多次吸附解吸循环后仍然具有较好的吸附效果,为固定化鼠尾藻的实际应用奠定了基础。     

Earthworm contamination by PCBs and heavy metals

A comparison is made of soil and earthworm contamination by PCBs and heavy metals between a nature reserve and two sites conditioned by the addition of sewage sludge and compost.The tissues and gut content of the earthworms shows a higher PCB concentration than that of the surrounding soil and also a difference in the fingerprint of some single PCB compounds.Earthworms display a selective accumulation of cadmium and zinc in their tissues and gut content.     

微生物沥浸法去除底泥中的重金属

以硫酸亚铁盐为底物,培养以氧化亚铁硫杆菌为主要菌种的土著沥滤微生物,采用批式方法对湘江长沙段底泥进行微生物沥浸实验。实验结果表明,底物投加量与底泥固体浓度比(Sd/Sc)为1.5时已能满足底泥的微生物沥浸要求,进一步研究发现底泥固体浓度为13%、底物投加量为19.5 g/L、沥浸时间为6 d时,底泥中超标重金属Cd、Zn和Cu的去除率可分别达到83.1%、75.3%和61.2%;沥浸后底泥中大部分重金属以残渣态存在,且含量低于农用污泥中污染物控制标准,其中硫化物有机结合态Cu浸出较Zn、Cd需更低的pH,且Cu以间接机理浸出为主;以Fe2+为底物的沥浸体系中,黄铁矾的重吸附或共沉淀是沥浸实验后期重金属浸出率下降的原因之一。     

活性炭上吸附态重金属稳定性

为评价吸附后活性炭上重金属稳定性,采用BCR（European Communities Bureau of Reference）连续浸提法对吸附于活性炭上的重金属形态进行分析,分为可交换态、可还原态、可氧化态和残渣态。结果表明：未改性、硝酸改性、氨改性活性炭上Cr（Ⅵ）、Pb（Ⅱ）、Cd（Ⅱ）以残渣态稳定态为主,均在80%左右,在环境中的迁移性低,且改性后活性炭上重金属残渣态含量高于未改性活性炭。研究表明,应用BCR连续提取法有助于确定活性炭中重金属的污染状况和潜在释放能力。     

Sorption of phenanthrene by soils contaminated with heavy metals

The fate of polycyclic aromatic hydrocarbons (PAHs) in soils with co-contaminants of heavy metals has yet to be elucidated. This study examined sorption of phenanthrene as a representative of PAHs by three soils contaminated with Pb, Zn or Cu. Phenanthrene sorption was clearly higher after the addition of heavy metals. The distribution coefficient (K(d)) and the organic carbon-normalized distribution coefficient (K(oc)) for phenanthrene sorption by soils spiked with Pb, Zn or Cu (0-1000 mg kg(-1)) were approximately 24% larger than those by unspiked ones, and the higher contents of heavy metals added into soils resulted in the larger K(d) and K(oc) values. The enhanced sorption of phenanthrene in the case of heavy metal-contaminated soils could be ascribed to the decreased dissolved organic matter (DOM) in solution and increased soil organic matter (SOM) as a consequence of DOM sorption onto soil solids. Concentrations of DOM in equilibrium solution for phenanthrene sorption were lower in the case of the heavy metal-spiked than unspiked soils. However, the decreased DOM in solution contributed little to the enhanced sorption of phenanthrene in the presence of metals. On the other hand, the sorbed DOM on soil solids after the addition of heavy metals in soils was found to be much more reactive and have far stronger capacity of phenanthrene uptake than the inherent SOM. The distribution coefficients of phenanthrene between water and the sorbed DOM on soil solids (K(ph/soc)) were about 2-3 magnitude larger than K(d) between water and inherent SOM, which may be the dominant mechanism of the enhanced sorption of phenanthrene by soils with the addition of heavy metals.     

Remediation of heavy metals contaminated soils by ball milling

In the present work, the use of ball milling reactors for the remediation of lead contaminated soils was investigated. Lead immobilization was achieved without the use of additional reactants but only through the exploitation of weak transformations induced on the treated soil by mechanical loads taking place during collisions among milling media. The degree of metal immobilization was evaluated by analyzing the leachable fraction of Pb(II) obtained through the "synthetic precipitation leaching procedure". The reduction of leachable Pb(II) from certain synthetic soils, i.e., bentonitic, sandy and kaolinitc ones, was obtained under specific milling regimes. For example, for the case of bentonitic soils characterized by a Pb(II) concentration in the solid phase equal to 954.4 mg kg(-1), leachable Pb(II) was reduced, after 7 h of mechanical treatment, from 1.3 mg l(-1) to a concentration lower than the USEPA regulatory threshold (i.e., 0.015 mg l(-1) for drinkable water). Similar results were obtained for sandy and kaolinitic soils. X-ray diffraction, scanning electron microscopy, electron dispersive spectroscopy and granulometric analyses revealed no significant alterations of the intrinsic character of sandy and bentonitic soils after milling except for a relatively small increase of particles size and a partial amorphization of the treated soil. On the other hand, the mechanical treatment caused the total amorphization of kaolinitic soil. The increase of immobilization efficiency can be probably ascribed to specific phenomena induced by mechanical treatment such as entrapment of Pb(II) into aggregates due to aggregation, solid diffusion of Pb(II) into crystalline reticulum of soil particles as well as the formation of new fresh surfaces (through particle breakage) onto which Pb(II) may be irreversibly adsorbed.     

Effects of heavy metals on sea urchin embryo development. 1. Tracing the cause by the effects

The toxicity of the polluted waters originating from a disused lead mine was evaluated using both sea urchin bioassays and heavy metal analysis. Samples from three polluted waters (a seawater and two freshwaters) were collected from the mine area and one seawater sample was taken from a non-contaminated reference site. The test waters contained higher concentrations of heavy metals such as manganese, lead, cadmium, zinc, chromium, nickel, iron, and copper than did ambient seawater. The three test waters had inhibitory effects, in a dose-dependent manner, on the first cleavage of sea urchin embryos and on pluteus formation during the development. Some malformations, such as a radialized pluteus, exo-gastrula, and spaceship Apollo-like embryos were induced by the test waters without dilution. Zinc alone also induced the same anomaly. Zinc in the test seawater was ascertained as one of the metals that caused the anomalies, but not all of the toxicity was caused by zinc. It was speculated that interactive effects, involving zinc and possibly manganese and nickel, were occurring.     

水培翅碱蓬对重金属吸收的研究

由于人类活动以及工业化的迅速发展,滩涂湿地正在遭受前所未有的污染和破坏,其中重金属污染是主要污染问题之一。生物修复技术是近年发展起来的新型环境污染治理方法,它在去除污染的同时还具有较高的环保价值,因此受到人们的广泛关注。以中国北方滩涂湿地的优势种植物翅碱蓬(Suaeda heteroptera kitag)为研究对象,通过测定翅碱蓬体内重金属的含量,分别探讨了翅碱蓬对单一Cu、Zn、Pb、Cd及Cu和Zn、Pb和Cd混合重金属的吸收规律、翅碱蓬不同部位对Cu的积累特性。实验结果表明,翅碱蓬对Cu、Zn、Pb、Cd的最大吸收速率分别为31、101、34、62mg/(kg.d);Cu的存在,促进了翅碱蓬对Zn的吸收,翅碱蓬各部位对Cu的积累量大小为根>茎>叶。     

Mapping heavy metals in polluted soil by disjunctive kriging

The soil of some 50 km(2) around the town of Weinfelden in north-east Switzerland has been sampled and analysed to estimate and map the concentrations of heavy metals before an incinerator for the canton's waste is built. Given that the estimates are subject to error, the probabilities that true values exceed the maximum tolerable concentrations of the Swiss federal guide have also been estimated by disjunctive kriging. These may now be used by the local planners for making decisions. Of the metals examined, lead exceeded the guide value at several sampling points, and a moderate probability of excess of lead is fairly widespread. Copper exceeded the guide value in vineyards and orchards, but also in a few places elsewhere, and the estimated probabilities of excess were not negligible. The other two metals of concern, cadmium (with one exception) and zinc, had concentrations much less than the guide values. The patterns of distribution of the four metals were similar, the product-moment correlations among them are substantial, except in the vineyards and orchards, and it seems likely that they had common sources.     

离子交换纤维对重金属的吸附研究

采用自制强酸性阳离子交换纤维对镉、铅离子的吸附性能进行了初步研究。实验结果表明 ,强酸性阳离子交换纤维对镉、铅离子具有较好的吸附能力 ,其最大吸附容量分别为 2 0 6.6mg g和 10 5 .5mg g ;吸附速度快 ,2 0min即可达到平衡。用Langmuir方程对其吸附等温线进行回归 ,结果显示实测值与理论方程具有较好的一致性     

TiO2光催化处理废水中贵重金属的研究进展

概述了TiO2光催化处理废水中贵重金属的原理、影响因素及应用研究.影响光催化处理水相中金属的因素包括TiO2的晶型、粒径和比表面积、TiO2的用量、改性剂、光源与光强、金属离子、溶液pH值、O2、空穴捕获剂、阴阳离子、固定化及光反应器.叙述了采用光催化法除去单一金属离子(Cr(Ⅵ)、Hg(Ⅱ)、Cd(Ⅱ))、选择性分离回收多种贵金属以及耦合协同处理金属与有机污染物.最后,指出了存在的问题及今后的研究趋势.     

植物修复重金属污染土壤的强化措施

植物修复技术作为一种新兴的绿色环保技术,有着高效、经济和生态协调等特点而成为当前研究的热点领域,而且由于其修复的彻底性和环境友好性而在治理污染土壤实地过程得到广泛应用.概述了当前植物修复研究的基本类型和修复机理,并着重从生物技术、农艺措施和物理化学等强化手段上阐述了利用超富集植物修复污染土壤,以进一步提高超富集植物的修复效率,为大规模治理重金属污染土壤和商业化应用提供技术途径和科学依据.     

Inhibition of heavy metals on fermentative hydrogen production by granular sludge

This study was conducted to investigate the toxicity of six electroplating metals on the H(2)-producing activity of a granular sludge sampled from an H(2)-producing upflow reactor treating sucrose-containing wastewater. The H(2) production activities of the sludge were measured in serum vials using wastewater containing not just sucrose and proper nutrient, but also individual heavy metals at concentrations ranging 0-5000 mg l(-1). The relative toxicity to H(2) production was found in the following order: Cu (most toxic)>Ni approximately Zn>Cr>Cd>Pb (least toxic). The C(I,50) values, at which the bioactivity of the sludge was reduced to 50% of the control, for individual heavy metals were Cu 30 mg l(-1), Ni and Zn 1600 mg l(-1), Cr 3000 mg l(-1), Cd 3500 mg l(-1), and Pb >5000 mg l(-1). Compared with the literature data, H(2)-producing sludge exhibited in general higher resistance to metal toxicity than methanogenic granular sludge.     

Monometal and competitive adsorption of heavy metals by sewage sludge-amended soil

Sewage sludge-amended soils may alter their ability to adsorb heavy metals over time, due to the decomposition of sludge-borne organic matter. Thus, we studied Cd, Ni, and Zn adsorption by a sewage sludge-amended soil (Typic Xerofluvent) before and after one-year incubation in both monometal and competitive systems. In the monometal system, the order of decreasing sorption was Zn>Cd>Ni. Competition significantly reduced metal K(d), especially that of Cd which decreased by nearly 50%. Over the course of the incubation there was a 31% reduction of soil organic matter content. At the same time, in competitive systems Cd K(d) significantly decreased, while Zn K(d) significantly increased, and Ni K(d) remained unaffected. This study shows that sewage sludge-amended soils may change in their ability to sorb heavy metals over time at high metal concentrations. The data suggest that Cd is likely to be of most environmental significance in such soils, since it exhibited decreased sorption under competitive conditions and as the organic matter content of the soil was reduced. The potential for long-term release of metals should be considered in the risk assessment associated with sewage sludge addition to soils, particularly in climates where degradation of organic matter is likely to be enhanced.     

淋洗法去除城市生活垃圾堆肥中重金属

采用淋洗法研究了淋洗剂酸度、螯合剂与表面活性剂对生活垃圾堆肥中重金属的去除效果.结果表明,淋洗剂的酸度对堆肥中重金属的淋出效果不明显,螯合剂与表面活性剂的影响较为显著.随着螫合剂、表面活性剂浓度增加,Mn、Zn和Cu的淋出量有增加的趋势,当DL-苹果酸、柠檬酸浓度为30 mmol/L,Mn的淋出量分别为对照的87和22...     

比较两种表面活性剂淋洗去除土壤中的重金属

以停车场和湿地2种土壤为研究对象,分别使用表面活性剂鼠李糖脂和月桂基醚硫酸钠对土壤样品进行淋洗,考察2种表面活性剂对这2种土壤中重金属的去除能力差异及形态分布的影响,并分析淋洗后残留在土壤中表面活性剂的生物毒性。结果表明,2种表面活性剂均可在一定程度上去除2种土壤中的Cu、Cd、Pb和Zn。与湿地土壤相比,2种表面活性剂对停车场土壤中重金属的去除率均较高,且月桂基醚硫酸钠的去除能力优于鼠李糖脂。2种表面活性剂对可交换态重金属的去除效果最好,对残渣态重金属去除率较低。淋洗后2种土样中残留的鼠李糖脂及停车场土样中残留的月桂基醚硫酸钠的生物毒性低,湿地土壤中残留的月桂基醚硫酸钠具有一定生物毒性。     

Biosorption of heavy metals from aqueous solution by UV-mutant Bacillus subtilis

To develop an efficient bio-immobilization approach for the remediation of heavy metal pollution in soil, a mutant species of Bacillus subtilis (B38) was obtained by ultraviolet irradiation and selection under high concentration of cadmium (Cd) in a previous study. In the present study, to check the applicability of this mutated species to the sorption and immobilization of other metals, the sorption of four heavy metals, Cd, chromium (Cr), mercury (Hg), and lead (Pb), on living and nonliving B38 in single- and multiple-component systems under different conditions was investigated using batch experiments. Rapid metal binding occurred on both living and nonliving B38 during the beginning of the biosorption. The sorption kinetics followed the exponential equation for living biomass and the pseudo-first-order Lagergren model for nonliving biomass, with r ² values in the range of 0.9004-0.9933. The maximum adsorptive quantity of the heavy metals on B38 changed with the solution pH, temperature, biomass dose, and ionic strength. The nonliving biomass generally showed greater or similar adsorptive capacities as compared with the living biomass and was not likely to be affected by the solution parameters. The bacterium had a stronger affinity to the cationic heavy metals than to the anionic one, and the equilibrium sorption amounts were 210.6, 332.3, and 420.9 mg/g for Cd(II), Hg(II), and Pb(II), respectively. The results of binary and ternary sorption experiments indicated that the metals with the higher sorption capacity in the single-component systems showed greater inhibitory effects on the biosorption of other metal ions in the multiple-component systems, but the sorption sites of Hg and Cd or Pb are likely to be different. The results of this study illustrated that the mutant species is a promising biosorbent for the remediation of multiple heavy metals.