酿酒酵母吸附重金属离子的研究进展

重金属污染成为当今最重要的环境问题之一。生物吸附法是处理大体积低浓度重金属废水的一种理想方法,近年来有关的研究报道不断增多,但尚未实现工业化应用。酿酒酵母(Saccharomyces cerevisiae)不仅是具有实用潜力的生物吸附剂,也是研究重金属生物吸附机理的良好材料。结合自己的研究成果,总结了酿酒酵母作为生物吸附材料的优点、研究中的表现形式和吸附性能,重点讨论了酿酒酵母生物吸附机理,介绍了等温吸附平衡模型和动力学模型在酵母生物吸附中的应用情况。最后提出生物吸附进一步的研究方向。     

霉菌吸附重金属离子的研究进展

介绍了目前国内外采用霉菌吸附分离废水中重金属离子的研究情况,总结了不同霉菌的吸附能力,讨论了霉菌吸附重金属离子的影响因素、机理以及固定化技术,最后展望了霉菌吸附重金属的发展趋势.     

活体微藻吸附水体中Cd2+的性能特征

【目的】藻类对重金属吸附和吸收是重金属进入食物链的重要渠道之一。研究活体微藻对水体中Cd~(2+)的吸附性能和吸附机理,旨在为Cd~(2+)等重金属离子进入水体后的去向及去除提供理论依据。【方法】选取地表水普遍存在的4种微藻:钝顶螺旋藻(Spirulina platensis)、铜绿微囊藻(Microcystis aeruginosa)、四尾栅藻(Scenedesmus quadricauda)和小球衣藻(Chlamydomonas microsphaera)作为试验材料,通过室内模拟实验,利用Langmuir、Freundlich和Dubinin-Radushkevich(D-R)3种等温吸附模型,研究4种活体微藻对Cd~(2+)的吸附规律及吸附参数。【结果】4种微藻对水体Cd~(2+)吸附均可以用Langmuir、Freundlich和D-R模型描述,其中用Langmuir模型拟合钝顶螺旋藻、Freundlich模型拟合小球衣藻、D-R模型拟合铜绿微囊藻和四尾栅藻的吸附效果最佳。四尾栅藻对Cd~(2+)的吸附量最高,而钝顶螺旋藻对Cd~(2+)的吸附量最低,但与Cd~(2+)的亲和力最强,4种微藻吸附Cd~(2+)主要是以离子代换为主的化学吸附。【结论】微藻对Cd~(2+)均有较强的吸附能力,会引起以微藻为食的水生动物Cd~(2+)富集;微藻也是去除水体Cd~(2+)的潜在吸附剂原料。     

盐土粘细菌NUST03的非活性菌体对重金属离子的吸附研究

研究盐土粘细菌NUST03对Cu2+、Cr3+、Ni2+的吸附能力及不同条件下菌体对离子的吸附。实验表明盐土粘细菌NUST03对Cu2+、Cr3+、Ni2+吸附能力为Cu2+>Cr3+>Ni2+,pH值对菌体吸附Cu2+、Ni2+影响较大,氯化钙和氯化镁的存在对菌体吸附Cu2+、Ni2+、Cr3+有一定的抑制作用。     

紫色土中砷、磷的吸附-解吸和竞争吸附

采用批培养法研究了As、P在三峡库区典型土壤紫色土中的吸附-解吸特点及竞争吸附对As、P迁移活化的影响.结果表明：3种紫色土中As、P的吸附-解吸特点相似,等温吸附均符合Langmuir和Freundlich方程,As在酸性、中性和石灰性紫色土中的最大吸附量分别为1428.6、1250.0和1111.1 mg·kg^-1;P在酸性、中性和石灰性紫色土中的最大吸附量分别为322.6、357.1和434.8 mg·kg^-1;As、P吸附动力学过程为先快后慢,均符合一级动力学方程与Elovich方程,快速吸附段符合一级动力学方程,为交换吸附;慢速吸附阶段满足Elovich方程,可能属于深层吸附或专性吸附.As、P竞争吸附试验表明,As、P共存时P的吸附速度和吸附量均增强,而As的吸附速度和吸附量均降低,表明As的存在能明显增强紫色土对P的吸附作用,P的存在则明显抑制紫色土对As的吸附.     

伊利石吸附-生物法处理重金属污水中伊利石吸附条件研究

本文考察了用伊利石吸附-生物法处理重金属污水时,伊利石吸附条件中添加量、转速、pH以及吸附时间对吸附率的影响。确定了伊利石吸附条件为:伊利石添加量0.45g·100mL-1、pH9、转速230r/min、吸附时间3h。在此条件下采用伊利石吸附-生物法处理重金属污水,结果表明,该方法不仅提高了处理污水的效果,而且缩短了反应时间。     

微生物在矿物表面吸附的研究进展

微生物在矿物表面的吸附是微生物与矿物表面深度作用的前提, 也是生物药剂在选矿中的应用的基础研究。本文综述了影响微生物在矿物表面吸附的环境因素, 微生物细胞与矿物表面之间的相互作用, 微生物细胞表面基团、表面成分及其胞外聚合物对吸附过程的影响, 并提出了今后的研究方向。     

从铅锌矿渣中分离的微生物对重金属吸附特性的研究

从铅锌矿渣中分离到 16种菌 (包括 7株细菌和 9株真菌 ) ,并研究了它们对Zn2 + ,Pb2 + ,Cu2 + 的吸附特性。发现大多数菌株对Pb2 + 与Zn2 + 有不同程度的吸附 ,但对Cu2 + 的吸附能力较小。菌株对Zn2 + 的吸附率大于对Pb2 + 的吸附 ,能吸附Pb2 + 的菌株也能吸附Zn2 + 。pH 4～ 6是真菌吸附金属离子的较好范围 ,细菌仅在pH =5 .0条件下 ,对Pb2 + 与Zn2 + 有吸附。在测试的不同金属离子浓度范围内 (5 0mg/L 相似文献   

微藻对污水中重金属的生物吸附(英文)

在我国,水源污染问题异常突出,特别是水体重金属污染情况非常严重,因此,如何有效治理水体重金属污染成为了摆在科技工作者面前十分紧迫的任务。利用微藻生物吸附来治理水体重金属污染是一种经济、简便、有效可行的方法,具有极其广阔的应用前景。论文介绍了我国近年水体污染的状况及水体重金属污染特点;综述了水体重金属污染对水体植物、水体动物以及人类潜在的危害;比较了几种常见治理重金属污染的方法;分析了微藻吸附水体重金属的优点,并阐述了微藻对重金属生物吸附的机理及影响生物吸附过程的外在因素;最后提出了今后的研究发展方向。     

乙酸对土壤胶体矿物吸附酸性磷酸酶的影响

研究了不同pH值、不同浓度乙酸对酸性磷酸酶在土壤胶体和矿物表面吸附的影响,结果表明,在pH2～8的乙酸体系中,酶在胶体矿物表面的最大吸附pH一般出现在蛋白的等电点和矿物的零电荷点(PZC)之间,各土壤胶体和粘粒矿物对酶的吸附量大小顺序为针铁矿》黄棕壤>砖红壤>高岭石>二氧化锰,乙酸浓度对酶在胶体矿物表面的吸附量和吸附结合能具有较显著影响,在0～200mmol·L^-1范围内,随着乙酸浓度的增加,酶吸附量呈现先升高、后降低、再稳定的趋势,而吸附结合能的变化与此相反,并就乙酸对酶在胶体矿物表面吸附影响的可能机理进行了初步探讨。     

Adsorption of heavy metal from aqueous solution by dehydrated root powder of long-root Eichhornia crassipes

The root powder of long-root Eichhornia crassipes, as a new kind of biodegradable adsorbent, has been tested for aqueous adsorption of Pb, Zn, Cu, and Cd. From FT-IR, we found that the absorption peaks of phosphorous compounds, carbonyl, and nitrogenous compounds displayed obvious changes before and after adsorption which illustrated that plant characteristics may play a role in binding with metals. Surface properties and morphology of the root powders have been characterized by means of SEM and BET. Energy spectrum analysis showed that the metals were adsorbed on root powders after adsorption. Then, optimum quantity of powder, pH values, and metal ion concentrations in single-system and multi-system were detected to discuss the characteristics and mechanisms of metal adsorption. Freundlich model and the second-order kinetics equation could well describe the adsorption of heavy metals in single-metal system. The adsorption of Pb, Zn, and Cd in the multi-metal system decreased with the concentration increased. At last, competitive adsorption of every two metals on root powder proved that Cu and Pb had suppressed the adsorption performance of Cd and Zn.     

NMR studies on heavy metal immobilization in biosorbents and mineral matrices

Magnetic resonance imaging and otherNMR methods have a potential for thenon-destructive observation of environmentallyrelevant processes with both spatial andtemporal resolution. Among other applications,such methods can be used to study transport andimmobilization of paramagnetic heavy metal ionsin biosorbents and other matrices. Thisoverview covers various NMR approaches to studysuch processes and illustrates them withexamples of imaging on alginate-basedbiosorbents and on heavy-metal doped gypsumpastes. Experimental challenges in studies ofother matrices are shortly addressed as well.     

Phytochelatins and heavy metal tolerance

The induction and heavy metal binding properties of phytochelatins in heavy metal tolerant (Silene vulgaris) and sensitive (tomato) cell cultures, in water cultures of these plants and in Silene vulgaris grown on a medieval copper mining dump were investigated. Application of heavy metals to cell suspension cultures and whole plants of Silene vulgaris and tomato induces the formation of heavy metal–phytochelatin-complexes with Cu and Cd and the binding of Zn and Pb to lower molecular weight substances. The binding of heavy metal ions to phytochelatins seems to play only a transient role in the heavy metal detoxification, because the Cd- and Cu-complexes disappear in the roots of water cultures of Silene vulgaris between 7 and 14 days after heavy metal exposition. Free heavy metal ions were not detectable in the extracts of all investigated plants and cell cultures. Silene vulgaris plants grown under natural conditions on a mining dump synthesize low molecular weight heavy metal binding compounds only and show no complexation of heavy metal ions to phytochelatins. The induction of phytochelatins is a general answer of higher plants to heavy metal exposition, but only some of the heavy metal ions are able to form stable complexes with phytochelatins. The investigation of tolerant plants from the copper mining dump shows that phytochelatins are not responsible for the development of the heavy metal tolerant phenotypes.     

食用菌生物修复重金属污染研究进展

生物修复是利用生物体及其衍生物对重金属进行吸收/吸附来处理环境中重金属污染的方法,具有成本低、来源广、无二次污染等特点.食用菌富集重金属是生物修复的一个重要研究方向,食用菌修复作用主要通过对重金属的吸收来降低其生态毒性,从而对重金属污染起到一定的修复作用.本文论述了食用菌对重金属Cu、Cd、Pb、Zn、As、Cr的富集作用,揭示了食用菌富集重金属的可能机理,并对采用食用菌富集重金属以治理环境污染的前景进行了展望.     

Effect of the clay minerals montmorillonite and kaolinite on the genetic transformation of competentBacillus subtilis cells

The effect of the clay minerals montmorillonite and kaolinite on the transformation of competentBacillus subtilis cells with chromosomal DNA was studied. Clay particles were found to substantially increase the transformation frequency of competent cells, as well as the rate of their spontaneous chromosomal and plasmid transformation. The effect was ascribed to the adsorption of bacterial cells on the surface of mineral particles.     

水体重金属污染植物修复研究进展

植物修复技术作为一种废水处理新技术,具有投资少、效果好、产出高、环境效益好等优点,现已得到迅速发展及广泛应用。介绍了水生超富集植物的3种生态类型,造成水体污染重金属元素类型,植物应答重金属污染的检测方法,并对植物修复水体重金属污染的发展前景提出展望。     

Selectivity in the heavy metal removal by exopolysaccharide-producing cyanobacteria

Aims:  The aim of this study was to assess the selective removal of Cu(II), Cr(III) and Ni(II) by strains of exopolysaccharide (EPS)-producing cyanobacteria, and to investigate the interaction of sorption in solutions with multiple-metals.
Methods and Results:  Nine EPS-producing cyanobacteria were tested for their ability to remove Cr, Cu and Ni in both single- and multiple-metal solutions. In the single-metal solutions, some of the strains showed very high values of metal uptake, however, only two of them showed the capability to selectively remove one or two of the metals present in the multiple-metal solutions. In multi-metal systems, the binding process was either noninteractive, synergistic or competitive between metal ions for different strains of cyanobacteria.
Conclusions:  Cyanothece 16Som 2 showed significantly greater sorptive capacity for Cu (1·5–20×) and Cr (2–50×) than all other strains tested. The Nostoc PCC 7936 strain showed high specific and almost exclusive selectivity towards Cu, which suggests its use aimed at recovering this metal from multiple-metal solutions.
Significance and Impact of the Study:  To find out microbial sorbents with good metal selectivity may be very useful for building up processes aimed to recover valuable metals from industrial wastewaters.     

Adsorption of heavy metal ion from aqueous single metal solution by chemically modified sugarcane bagasse

This work describes the preparation of new chelating materials derived from sugarcane bagasse for adsorption of heavy metal ions in aqueous solution. The first part of this report deals with the chemical modification of sugarcane bagasse with succinic anhydride. The carboxylic acid functions introduced into the material were used to anchor polyamines, which resulted in two yet unpublished modified sugarcane bagasse materials. The obtained materials were characterized by elemental analysis and infrared spectroscopy (IR). The second part of this reports features the comparative evaluation of the adsorption capacity of the modified sugarcane bagasse materials for Cu(2+), Cd(2+), and Pb(2+) ions in aqueous single metal solution by classical titration. Adsorption isotherms were studied by the Freundlich and Langmuir models.     

新型吡唑类化合物DL-1的硝化抑制效应初探

以国内外应用较为广泛的硝化抑制剂双氰胺（DCD）为参比对象,采用室内培养方法,对新型吡唑类化合物DL-1的硝化抑制效应进行初步探讨.结果表明,DL-1对土壤中铵的氧化过程具有显著的抑制效应,前3周的硝化抑制率可达70％以上,且硝化抑制能力在第14天至28天最强.与等量DCD相比,施用量为(NH₄)₂SO₄氮量1.0%的DL-1在14、21和28 d使土壤中的NO₃^--N含量分别下降 26.23%、33.27%和23.31%;与不加抑制剂的对照处理相比,土壤NO₃^--N含量则分别下降了71.12%、69.10%和55.14%.当DL-1用量为(NH₄)₂SO₄氮量的2。0%时,土壤的硝化作用受到了更强烈的抑制,到培养第90天试验结束,土壤中的NO₃^--N含量始终维持在较低水平.     

Enterovirus 71 adsorption on metal ion-composite chitosan beads

In this study, we developed composite chitosan beads combining various metal ions, including Ni(2+), Cu(2+), Zn(2+), and Fe(2+), for direct adsorption of enterovirus 71 (EV71). The metal-ion species had significant effects on the adsorption capacity of beads. Among these metal ion-composite chitosan beads, Ni(2+)-chitosan beads exhibited the best adsorption capacity of EV71. Using a concentration of 0.01-M Ni(2+) was found to best provide for bead formation and EV71 adsorption. The adsorption of EV71 for Ni(2+)-chitosan beads at neutral or alkaline pH was favored. Under a competitive condition with albumin proteins, Ni(2+)-chitosan beads exhibited significant capacity of EV71 adsorption in culture media. The adsorption of EV71 on the Ni(2+)-chitosan beads was attributed to the strong binding between Ni(2+) ions chelated to the surface amino acid of EV71 capsids and Ni(2+) ions chelated on the chitosan materials. Moreover, the adsorbed EV71 retained its antigenicity and infectivity after desorption. The Ni(2+)-chitosan beads exhibit a promising application to EV71 adsorption and removal.