藻类吸附重金属的研究进展

藻类吸附技术在处理重金属废水方面有着广阔的应用前景.介绍藻类的基本特点,藻类对有毒重金属吸附的络合、离子交换等机理,以及影响生物吸附的pH值、吸附时间、共存离子和预处理等主要因素;讨论相关的生物吸附平衡模型和动力学方程,对藻类吸附重金属研究进行了展望.     

生物炭协同微生物修复四川某铜矿选冶渣重金属复合污染研究

为了解决四川某选冶渣多重金属复合污染问题,采用生物炭固化微生物试验和吸附动力学试验,研究生物炭与微生物的协同作用对多种重金属的修复效果、多种重金属在生物炭表面的吸附动力学行为。使用傅里叶红外光谱(FTIR)与扫描电镜(SEM),探究生物炭基团强化微生物修复重金属的界面机理。结果表明,在厌氧气氛下,硫酸盐还原菌(SBR)和嗜酸性氧化亚铁硫杆菌(At. f,pH=5.0)以体积比3∶2混合,接种量为20%,生物炭添加量10%,固化30 d后,选冶渣中铁、锌、铜、铅和铬的生物有效性降低率分别为98.37%、90.32%、90.81%、96.52%和100%,吸附动力学试验表明反应过程是化学反应。傅里叶红外光谱与扫描电镜分析表明,重金属与生物炭表面羟基和羧基等基团反应,以沉淀的形式将Zn、Cu等重金属固化/稳定化,降低其生物有效性。     

微波辅助改性褐煤-秸秆生物炭对Cr的吸附研究

重金属 Cr(Ⅵ)污染是目前亟需解决的突出环境问题,生物炭吸附法是一种最经济有效的方法之一.针对常规生物炭吸附率低的问题,以褐煤和稻秸秆为原材料制备生物炭,利用响应面设计法研究 NH４Cl、FeCl３、CaCl２ 在微波辅助条件下对生物炭进行改性,并通过 FTIR、XRD、SEM 等对生物炭进行表征,最后利用改性秸秆生物炭对重金属 Cr(Ⅵ)进行吸附研究.结果表明,采用 FeCl３改性,吸附时间为６h、温度６０℃、pH 为７的条件下吸附效果最佳,吸附率为９５．８％.在 FeCl３改性后,Langmuir比表面积由５２．２４ m２/g增加到１２７．５４m２/g,表面出现大量微孔,有利于对重金属的吸附.     

非金属天然矿物吸附材料在土壤重金属污染修复中的应用

随着土壤重金属污染日趋严重,非金属天然矿物吸附材料以其低价、无二次污染的独特优势,在土壤修复中得到应用。本文在介绍我国土壤重金属污染现状、天然矿物材料吸附性能的基础上,回顾了该类吸附材料的应用发展历程,着重突出了应用该吸附材料作为反应介质的渗透反应墙(PRB)、地球化学障(GB)技术,而水土一体化联合修复是一种较好的修复方式。对天然矿物吸附材料在土壤重金属污染修复中的应用研究提出了一些展望,包括吸附转化、影响条件、微观对比、多技术联合等。     

铜陵矿区铜、锌抗性菌体的吸附特征

选取铜陵矿区不同污染程度的土壤作为研究对象,培养、分离出重金属抗性菌;通过不同菌体对铜、锌的抗性大小和生长量试验,确定具有铜、锌抗性的优势菌种。将筛选出的优势菌进行培养,研究在不同的pH值、吸附时间、吸附剂浓度、金属离子初始浓度等条件下对Cu2＋和Zn2＋的生物吸附。结果反应所筛选的优势菌种在单因子为最佳状况下对Cu2＋和Zn2＋最大吸附量分别为22.89 mg/g和51.09 mg/g,表明该菌种在微生物治理重金属铜、锌污染土壤中具有较好的应用前景。     

三乙烯四胺基蔗渣纤维素的制备及其对Cu~(2+)、Cr~（6+)的吸附

工业废水中存在的铜、铬等重金属离子不仅污染土壤、水体,而且对人体危害极大,采用农业废弃物改性制备的重金属吸附剂吸附处理含重金属离子废水具有原料成本低、吸附性能好等优点。以蔗渣为原料提纯纤维素,再选择性氧化成双醛纤维素,并与三乙烯四胺进行席夫碱反应制备三乙烯四胺基蔗渣纤维素吸附剂。三乙烯四胺基蔗渣纤维素吸附剂对Cu2+、Cr6+进行的吸附试验表明:吸附过程符合Langmuir等温吸附模型和准二级吸附动力学吸附模型,三乙烯四胺基蔗渣纤维素对Cu2+、Cr6+的饱和吸附量分别为222.72 mg/g和10.86 mg/g;吸附自由能变ΔG均为负值,说明试验条件下吸附剂对Cu2+和Cr6+的吸附反应均能自发进行;吸附自由焓变ΔH均为负值,说明试验条件下吸附剂对Cu2+和Cr6+的吸附反应均为放热反应;吸附熵变ΔS均为负值,说明吸附过程体系趋于稳定。     

汞矿区土壤重金属迁移转化及治理技术研究综述

通过对汞矿区土壤重金属元素种类、来源、赋存形态及迁移转化的最新研究进展进行综述,发现汞矿区土壤污染主要来源于尾矿和冶炼废渣中重金属的释放,矿区周围土壤中的重金属形态具有相似的分布特征,都是以残渣态为主;汞矿区土壤中重金属主要发生溶解、吸附、氧化还原、沉淀、共沉淀、矿化等反应,其迁移转化受物理、化学和生物多方面因素影响;同时对目前的治理技术和研究动态进行了概述,明确植物修复是目前研究的热点,但尚需探究植物修复与土壤改良措施结合的联合修复技术,从而提出应充分关注土壤中多种重金属之间的拮抗和协同作用,以期为研究汞矿区重金属元素的迁移转化规律及汞污染土壤的治理提供理论指导。     

粉煤灰对煤矸石酸性重金属淋滤液的修复作用

采用批处理吸附实验和柱状淋溶模拟实验,分析粉煤灰吸附重金属、处理煤矸石酸性重金属淋滤液的效果及机理。结果表明：① 粉煤灰对Pb2+、Cu2+、Cd2+ 和Zn2+的吸附等温线符合Freundlich等温模式,吸附过程符合准二级反应动力学模型,且均在30 min内达到吸附平衡,随着pH增加,4种重金属离子吸附率逐渐增加并趋于平衡（Pb、Cu、Cd、Zn分别在pH=3.5、6.0、7.5、8.0时达到平衡）,在酸性环境下粉煤灰对4种金属离子具有较好的吸附性能;② 在重金属竞争性吸附中,共存离子的存在抑制了目标离子的吸附,其中Pb受共存离子的影响最小,粉煤灰吸附强弱顺序为Pb>Cu>Cd>Zn;③ 煤矸石柱状淋溶试验中,煤矸石淋滤液呈现较强酸性、较高重金属浓度的酸性矿山废水特征,而在粉煤灰处理中,淋滤液的pH值呈中性,重金属离子浓度显著下降,其主要机制为粉煤灰吸附、碱性中和、重金属与Fe共沉淀等。研究表明,实验用粉煤灰具有修复煤矸石酸性重金属淋滤液的潜力。     

钠基凹凸棒土对模拟废水中重金属Co(Ⅱ)离子的吸附研究

研究了钠基凹凸棒土对重金属Co(Ⅱ)离子吸附行为。考察了接触时间、吸附剂浓度、p H值、离子强度、不同电解质离子、腐植酸(FA)和温度等因素对吸附率的影响。结果表明,凹凸棒土对重金属Co(Ⅱ)离子的吸附在较短时间内即可达到平衡且吸附过程较好地符合假二级动力学方程,体系pH值和离子强度是影响吸附过程的主要因素;离子交换和表面络合是主要的反应机理。通过热力学参数(△G°、△S°和△H°)的计算,证明钠基凹凸棒土对重金属Co(Ⅱ)离子的吸附是一个自发的吸热过程,较高的温度有利于反应的进行;实验数据能较好地符合Langmuir热力学模型。     

两种生物炭对铅离子的吸附特性及其机制

为探索农林废弃物的资源化利用途径及对水体中重金属的处理应用,以花生壳和玉米芯为原料,于600℃下热解制备生物炭,就两种生物炭对Pb²⁺的吸附性能进行研究,利用等温吸附模型和吸附动力学模型研究了花生壳和玉米芯生物炭对Pb²⁺的吸附行为,分析了花生壳生物炭和玉米芯生物炭对Pb²⁺的吸附特性差异及其影响因素。同时,结合FTIR红外表征了生物炭吸附前后官能团的变化,探讨了两种生物炭吸附Pb²⁺的机制。结果表明：1)花生壳生物炭和玉米芯生物炭吸附Pb²⁺分别在480和360 min达到吸附平衡,理论最大吸附量分别为20.85、28.51 mg/g; 2)Langmuir-Freundlich模型能够很好地描述两种生物炭对Pb²⁺的等温吸附规律,表明吸附过程包括单分子层和多分子层的多相吸附;花生壳生物炭和玉米芯生物炭对Pb²⁺的吸附动力学均符合二级动力学模型,表明其对Pb²⁺的吸附主要是以化学吸附为主,Pb²⁺     

Effect of mining chemicals on biosorption of Cu(II) by the non-living biomass of the macrophyte Potamogeton lucens

The present work investigates the effect of some compounds commonly discharged from mineral processing plants on biosorption of heavy metals by the non-living biomass of the freshwater macrophyte Potamogeton lucens. Studies of sorption of Cu (II) in the presence of metal ions, surfactants, EDTA and cyanide were carried out at laboratory scale. The results show that copper adsorption by ion exchange on the biomass is not affected by equimolar concentrations of copper/sodium, copper/calcium or copper/iron. Non ionic surfactants (e.g. pine oil) do not modify biosorption, but the negative groups of anionic surfactants (e.g. sodium oleate) compete with the surface groups of the biomass for the free copper ions in solution. EDTA and cyanide react with copper ions producing soluble complexes that do not adsorb onto the biomass. The biosorption process is suitable for wastewater treatment when the heavy metal species are free in solution. Effluents containing metal sequestering compounds that produce soluble or precipitated species are not able to be treated by carboxyl groups based biosorbents.     

Biosorption of cadmium by green coconut shell powder

The effective removal of heavy metals from aqueous wastes is among the most important issues for many industrialized countries. The traditional treatment methods used to remove heavy metals from wastewaters have certain disadvantages such as incomplete metal removal, high reagent and energy requirements, generation of toxic sludge or other waste products that require disposal. The search for alternative and innovate treatment techniques has focused attention on the use of biological materials for metal removal and recovery technologies. Biosorption has gained important credibility during recent years because of its good performance and low cost.In the present study, the biosorption capacity of powder from coconut shell was studied for cadmium. The adsorption capacity of biomass was investigated by batch experiments. The influence of metal ion concentration and pH were evaluated and the results were fitted using adsorption isotherm models. The kinetic of cadmium biosorption was also investigated.     

Biosorption of Cu(II) and Pb(II) from aqueous solutions by dried activated sludge

The biosorption of Cu(II) and Pb(II) ions from aqueous solutions by dried activated sludge was investigated as a function of initial pH, initial metal ion concentration and temperature. The results showed that both the heavy metals uptake processes followed the pseudo-second-order equation. The equilibrium data fitted very well to both Langmuir and Freundlich adsorption models. The main mechanism of Cu(II) and Pb(II) biosorption on dried activated sludge was their binding with amide I group.     

Fundamental aspects of biosorption of lead (II) ions onto a Rhodococcus opacus strain for environmental applications

Lead is present in different types of industrial effluents, being responsible for environmental pollution. Biosorption of heavy metal ions by biological material is a promising technology with a potential for treating mineral processing wastewater. In this fundamental work, the biosorption of Pb(II) ions from aqueous solutions using the bacteria Rhodococcus opacus was investigated as a function of contact time, initial metal ion concentration and temperature. The equilibrium studies showed that the biosorption is well described through the Langmuir isotherm model in comparison to the Freundlich model in the concentration range studied (20–200 mg/L). The biosorption capacity obtained from Langmuir equation increased from 86.2 to 95.2 mg/g as the temperature was increased from 15 to 35 °C. Experimental data were also tested in terms of biosorption kinetics using pseudo-first order and pseudo-second-order kinetic models. The result showed that the biosorption processes of lead ions followed well pseudo-second-order kinetics and the adsorption rate constant increased with increasing temperature. The activation energy of biosorption (E_a) was determined (30.4 kJ/mol) using the pseudo-second-order rate constants. The positive values of both ΔH⁰ and ΔS⁰ obtained suggest that the biosorption of lead (II) ion on the R. opacus was spontaneous and endothermic in nature.     

Biological treatment of precious metal refinery wastewater: A review

The refining of platinum group metals (PGMs) generates large volumes of wastewater which is highly contaminated by organic solvents and contains trace amounts of heavy metals. Treatment to reduce chemical oxygen demand and metal concentration to levels allowing reuse in refinery processes can help to alleviate the demand for clean water in arid/semi arid mining regions of the world. Traditional physicochemical treatment options have been favoured in the past for treatment of PGM wastewater but biological treatment is becoming increasingly popular. This review examines the need for treatment of PGM wastewater and various physicochemical technologies that are available for treatment of organic solvents and heavy metals. It also introduces various activated sludge technologies that have been shown to remove 99% of certain solvents, while biosorption has been demonstrated to be very effective in removal of heavy metals. A combination of biological treatment and biosorption can be a viable technology for the treatment of complex and potentially toxic wastewaters. Improved treated wastewater quality can allow for reuse in refinery processes which could lead to significant cost reduction and prove to be environmentally beneficial.     

矿区土壤中抗镉菌株的分离筛选及其对镉的吸附特性

[目的]近年来,随着工业化的发展,重金属污染越来越严重,如何解决水体重金属污染是人们普遍关注的问题。镉(Cd)是生物毒性极强的重金属元素,本试验从受污染矿区中筛选出抗镉菌株,并对其形态学特性及其对水中Cd的吸附特性进行研究,旨在为抗性菌株修复Cd污染提供科学依据和试验材料。[方法]采用稀释平板分离技术,在培养基中加入不同浓度的Cd2 ,经过分离和驯化,筛选出耐Cd菌株E、M,采用革兰氏染色法对两菌株进行形态学初步鉴定,并利用摇床培养的方法对菌株的生长曲线、温度和pH值等特性进行了初步研究,除此之外,还利用能谱仪测定了菌株对Cd的生物吸附。[结果]两菌株对不同浓度的Cd2 溶液均有一定的吸附率,且菌株M较真菌E的吸附率更高一些。能谱检测表明,与对照相比吸附Cd后的E、M菌株均出现了明显的Cd峰。E为丝状革兰氏阳性菌;M为卵圆形革兰氏阳性菌。     

Application of synthetic principal component analysis model to mine area farmland heavy metal pollution assessment

Referring to GB5618-1995 about heavy metal pollution, and using statistical analysis SPSS, the major pollutants of mine area farmland heavy metal pollution were identified by variable clustering analysis. Assessment and classification were done to the mine area farmland heavy metal pollution situation by synthetic principal components analysis (PCA). The results show that variable clustering analysis is efficient to identify the principal components of mine area farmland heavy metal pollution. Sort and clustering were done to the synthetic principal components scores of soil sample, which is given by synthetic principal components analysis. Data structure of soil heavy metal contaminations, relationships and pollution level of different soil samples are discovered. The results of mine area farmland heavy metal pollution quality assessed and classified with synthetic component scores reflect the influence of both the major and compound heavy metal pollutants. Identification and assessment results of mine area farmland heavy metal pollution can provide reference and guide to propose control measures of mine area farmland heavy metal pollution and focus on the key treatment region.     

高岭土吸附废水中的重金属

介绍了目前国内外采用高岭土吸附处理废水中重金属离子的研究状况,总结了吸附效果,分析了pH值、吸附时间、重金属离子初始浓度、温度、改性方法及共存离子等对吸附效果的影响,探讨了高岭土的吸附机理、等温式与吸附热力学,展望了高岭土吸附重金属的发展趋势和应用前景.     

矿区煤矸石堆对土壤重金属污染时空特征研究

伴随着煤炭资源的大量回采,产生了大量的煤矸石经过地表堆积形成矸石山。矸石山侵占大量土地的同时会释放多种有害重金属元素,能够在周围土壤中进行富集,通过食物链在生态中传递,会对煤矸石周围人群造成伤害。煤矸石周围土壤中重金属分布规律对于矿区生态安全具有重要意义。以山西某矿区两个典型矿井矸石山堆积地为研究对象,基于数理统计方法,分析了周围环境和土壤中七种重金属的分布特征。研究结果表明:甲、乙煤矿的煤矸石七种重金属元素含量明显高于当地背景值,Cr的污染最大,污染最小的是Hg;下风向区域的重金属污染含量明显高于上风向的重金属含量;平面方向上,煤矿甲的土壤重金属污染明显高于煤矿乙对土壤的污染与煤矿矸石堆堆放时间有关;煤矿矸石堆周围重金属元素含量随着距矸石堆的距离增加而减少,其变化趋势存在差异;随着采矿活动的不断进行,矿区矸石堆周围土壤中能够明显的表现出重金属积累的特征;甲、乙煤矿矸石堆周围土壤重金属元素含量随着深度的增加呈递减趋势。土壤中的重金属元素主要集中在土壤表层。煤矿甲在剖面方向上重金属含量煤明显高于煤矿乙。      

锡采矿行业重金属污染现状、节点及治理技术

简述锡采矿行业重金属的污染现状,结合该行业重点企业,分析重金属污染节点,为污染防控提供重要依据。在此基础上概述矿山重金属典型污染防控技术,重点分析锡采矿行业重点企业较先进的清洁生产技术,为类似企业解决问题提供技术依据。