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1.
Abstract

End of life waste Lead (Pb) acid batteries are one of the largest sources of secondary lead production globally. Recycling lead by melting down used batteries is a commercial trade all over the world; but, regrettably, reprocessing lead from end of life batteries is reported for anthropogenic lead exposures causing harsh human health consequence and environmental pollution. The current research intends to isolate and identify Lead (Pb) solubilizing bacteria from automobile waste deposits from Agartala city in Tripura state of India. Scanning Electron Microscope equipped with energy-dispersive X-ray characterization of the grounded lead sample was carried out, and the micrographs demonstrated scattered structures across the matrix. The X-ray diffraction (XRD) spectrum indicates the presence of Lead Oxide (PbO), Lead dioxide (PbO2), and Lead sulfate (PbSO4) in the collected samples. A single bacterium viewing observable growth on Pb supplemented plates was isolated and its Pb recovering capability was estimated through ICP AES analysis. Molecular characterization of the bacterium was investigated using 16S rRNA sequencing along with isolated culture was taxonomically grouped as Cupriavidus sp. The genomic DNA sequences were submitted in NCBI GenBank with the accession number MG171197. In the present case of inspection, the ability of the bacterial strain to recover Pb from end life battery waste was carried out in laboratory scale on a shake flask for 20?days. The experiment conducted under optimum bioleaching parameters with initial pH 6, 5% w/v of microbial culture, 2% pulp density and 2?g/100?mL dextrose concentration at 30?°C temperature with a speed of 200?RPM resulted in 67% Pb recovery from the battery sample. This investigation emphasizes the significance of Pb recycling ability of native bacterial isolate for efficient Pb bio-recovery from end of life waste batteries.  相似文献   

2.
周宁一 《微生物学通报》2016,43(6):1404-1404
正随着采矿业的迅速发展,越来越多的重金属通过多种途径进入土壤环境中,对生态环境造成了不可估量的破坏并严重威胁人类健康。铅锌在工业上具有非常重要的作用且其应用极为广泛,而他们具有的难去除、难迁移和生物累积等特性使得铅锌在环境中的污染尤为突出。通过微生物的生长代谢,有效降低土壤重金属毒性,是促进植物生长的重要步骤之一。同时也要求微生物自身具有抵抗重金属的功能,根际微生  相似文献   

3.
耐性真菌HA吸附铅、锌的影响因素及吸附机理研   总被引:1,自引:0,他引:1  
【目的】从铅锌矿区分离筛选出耐铅锌性菌株,并研究其吸附铅、锌的影响因素及吸附机理,为重金属污染微生物修复提供参考。【方法】以从铅锌矿区筛选出的耐铅锌真菌HA作为试验菌株,考察影响其对铅、锌去除能力的主要因素(初始浓度、pH、接种量),同时通过等温吸附模型、动力学分析及红外光谱分析探讨其相关的吸附机理。【结果】经鉴定,从矿区筛选的对Pb2+、Zn2+有较强耐性的菌株HA为米曲霉(Aspergillus oryzae);在初始铅、锌浓度的实验范围内(100-800mg/L),HA对铅、锌离子的去除率随着其初始浓度增加而减小,25h后HA的生长进入平稳期,且对铅、锌离子的去除率趋于稳定。当铅、锌初始浓度为100mg/L、pH为5.0时,HA对铅、锌离子的去除率均达到最高,分别为97.8%、54.1%;当HA接种量为1mL时,其对铅、锌去除率的增长率达到最大。HA对铅、锌的吸附过程满足Langmuir吸附模型,其吸附以单层吸附为主。在动态吸附过程中,HA对Pb2+、Zn2+离子吸附性能与准二级动力学吸附方程的拟合程度更高,且对Pb2+的吸附效果明显高于Zn2+。红外光谱分析表明,HA细胞中羟基、烷基、酰胺基、羰基、磷酸基等参与了Pb2+、Zn2+的吸附过程。【结论】HA是一株对铅、锌有较强吸附能力的真菌,其吸附铅、锌影响因素及吸附机理研究结果将为重金属污染微生物修复提供指导。  相似文献   

4.
The potential of nonliving biomass of Hydrilla verticillata to adsorb Pb(II) from an aqueous solution containing very low concentrations of Pb(II) was determined in this study. Effects of shaking time, contact time, biosorbent dosage, pH of the medium, and initial Pb(II) concentration on metal-biosorbent interactions were studied through batch adsorption experiments. Maximum Pb(II) removal was obtained after 2 h of shaking. Adsorption capacity at the equilibrium increased with increasing initial Pb(II) concentration, whereas it decreased with increasing biosorbent dosage. The optimum pH of the biosorption was 4.0. Surface titrations showed that the surface of the biosorbent was positively charged at low pH and negatively charged at pH higher than 3.6. Fourier transform infrared (FT-IR) spectra of the biosorbent confirmed the involvement of hydroxyl and C?O of acylamide functional groups on the biosorbent surface in the Pb(II) binding process. Kinetic and equilibrium data showed that the adsorption process followed the pseudo-second-order kinetic model and both Langmuir and Freundlich isothermal models. The mean adsorption energy showed that the adsorption of Pb(II) was physical in nature. The monolayer adsorption capacity of Pb(II) was 125 mg g?1. The desorption of Pb(II) from the biosorbent by selected desorbing solutions were HNO3 > Na2CO3 > NaOH > NaNO3.  相似文献   

5.
The present study deals with the sorption of Cd(II) and Pb(II) by exopolymeric substances (EPS) extracted from activated sludges or pure bacterial strains. The percentage of sorbed metal increases with the concentration of the EPS–water solution. Pb(II) always presents a higher affinity than Cd(II) for EPS. For the EPS extracted from pure bacterial strains, only one global binding constant from a simple equilibrium sorption model, may be used to assess the effect of microbial products such as EPS on Cd(II) and Pb(II) speciation or mobility in the environment. However, for EPS extracted from activated sludges, the wide variation of the global binding constants determined for Cd(II) and Pb(II) do not permit such a simple approach. The differences in sorption to metals between the two types of EPS (bacterial, activated sludges) could be explained by the differences in EPS composition: organic macromolecules, as well as the nature of the mineral fraction.  相似文献   

6.
Biosorption is the process of removal of any chemical molecules by the treatment of biological material. Industrialization resulted in the discharge of various toxic heavy metals into water bodies, which poses serious health hazards to humans and animals. In the present study, live Spirulina platensis was used as a biosorbent for the removal of the heavy metals chromium (Cr(VI)) and lead (Pb(II)) from the aqueous samples. S. platensis were cultured in the presence of different concentrations of heavy metals. The growth of the algal cells was found to be decreased by 59% and 36% in media containing 50 ppm Cr(VI) and Pb(II), respectively. To assess the biosorption of heavy metals, at different time intervals, the spent culture media were used to detect Cr(VI) by atomic absorption spectroscopy method and Pb(II) by 4-(2-pyridylazo)resorcinol indicator method. Results suggested that there was a significant uptake of Cr(VI) and Pb(II) from the medium by S. platensis, with corresponding decrease of metals in the medium. When metal salt solutions or industrial effluent samples were passed through the column containing immobilized live S. platensis in calcium alginate beads, the concentration of Cr(VI) was found to be reduced drastically. The present study indicates the application of S. platensis for the bioremediation of heavy metals from the samples obtained from industrial effluents.  相似文献   

7.
Previous studies revealed that Mn(II) is accumulated in cultured glial cells to concentrations far above those present in whole brain or in culture medium. The data indicated that Mn(II) moves across the plasma membrane into the cytoplasm by facilitated diffusion or counter-ion transport with Ca(II), then into mitochondria by active transport. The fact that 1–10 M Mn(II) ions activate brain glutamine synthetase makes important the regulation of Mn(II) transport in the CNS. Since Cu(II) and Zn(II) caused significant changes in the accumulation of Mn(II) by glia, the mechanisms by which these ions alter the uptake and efflux of Mn(II) ions has been investigated systematically under chemically defined conditions. The kinetics of [54MN]-Mn(II) uptake and efflux were determined and compared under four different sets of conditions: no adducts, Cu(II) or Zn(II) added externally, and with cells preloaded with Cu(II) or Zn(II) in the presence and absence of external added metal ions. Zn(II) ions inhibit the initial velocity of Mn(II) uptake, increase total Mn(II) accumulated, but do not alter the rate or extent Mn(II) efflux. Cu(II) ions increase both the initial velocity and the net Mn(II) accumulated by glia, with little effect on rate or extent of Mn(II) efflux. These results predict that increases in Cu(II) or Zn(II) levels may also increase the steady-state levels of Mn(II) in the cytoplasmic fraction of glial cells, which may in turn alter the activity of Mn(II)-sensitive enzymes in this cell compartment.  相似文献   

8.
Metal complexes of d-glucose (d-Glc) from large cation containing dibromo-dichloro salts of dipositive metals [NEt4]2[MBr2Cl2] (M = Mn, Co, Ni, Cu and Zn) and the disodium salt of glucose were synthesized from a MeOH:MeCN mixture. The complexes were characterized by UV-vis absorption, circular dichroism, IR and proton magnetic resonance spectroscopies, and by elemental analysis, and were found to be Na[M(d-Glc)(OMe)Cl]. Cyclic voltammetric studies of these complexes, in the acidic to neutral pH range, indicated no dissociation, even in highly acidic conditions.This paper is dedicated to Professor Richard H. Holm (Harvard University) on the occasion of his 60th birthday.  相似文献   

9.
Antitumor effects of a known bis(imino-quinolyl)palladium(II) complex 1 and its newly synthesized platinum(II) analogue 2 were evaluated against human breast (MCF-7) and human colon (HT-29) cancer cell lines. The complexes gave cytotoxicity profiles that were better than the reference drug cisplatin. The highest cytotoxic activities were pronounced in complex 2 across the two examined cancer cell lines. Both compounds represent potential active drugs based on bimetallic complexes.  相似文献   

10.
The processing of leaves in temperate streams has been the subject of numerous studies but equivalent tropical ecosystems have received little attention. We investigated leaf breakdown of a tropical tree species (Hura crepitans, Euphorbiaceae), in a tropical stream using leaf bags (0.5 mm mesh) over a period of 24 days. We followed the loss of mass and the changes in adenosine triphosphate (ATP) concentrations and respiration rates associated with the decomposing leaves. The breakdown rate was fast (k=?0.0672/d, kd=?0.0031/degree‐day), with 81 percent loss of the initial mass within 24 days. This high rate was probably related to the stable and high water temperature (22°C) favoring strong biological activity. Respiration rates increased until day 16 (1.1 mg O2/h/g AFDM), but maximum ATP concentrations were attained at day 9 (725 nmol ATP/g AFDM) when leaf mass remaining was 52 percent. To determine the relative importance of fungi and bacteria during leaf decomposition, ATP concentrations, and respiration rates were determined in samples treated with antibiotics, after incubation in the stream. The results of the samples treated with the antifungal or the bacterial antibiotic suggest a higher contribution of the fungal community for total microbial biomass and a higher contribution of the bacterial community for microbial respiration rates, especially during the later stages of leaf decomposition. However, these results should be analyzed with caution since both antibacterial and antifungal agents did not totally eliminate microbial activity and biomass.  相似文献   

11.
To develop conducting organic polymers (COPs) as luminescent sensors for determination of toxic heavy metals, a new benzene sulfonic acid‐doped polypyrrole (PPy‐BSA) thin film was electrochemically prepared by cyclic voltammetry (CV) on flexible indium tin oxide (ITO) electrode in aqueous solution. PPy‐BSA film was characterized by FTIR spectrometry, X‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The optical properties of PPy‐BSA were investigated by ultraviolet (UV)‐visible absorption and fluorescence spectrometry in dimethylsulfoxide (DMSO) diluted solutions. PPy‐BSA fluorescence spectra were strongly quenched upon increasing copper(II) ion (Cu2+) and lead(II) ion (Pb2+) concentrations in aqueous medium, and linear Stern–Volmer relationships were obtained, which indicated the existence of a main dynamic fluorescence quenching mechanism. BSA‐PPy sensor showed a high sensitivity for detection of both metallic ions, Cu2+ and Pb2+, with very low limit of detection values of 3.1 and 18.0 nM, respectively. The proposed quenching‐fluorimetric sensor might be applied to the determination of traces of toxic heavy metallic ions in water samples.  相似文献   

12.
微生物降解多环芳烃的研究进展   总被引:8,自引:0,他引:8  
多环芳烃(PAHs)是具有严重危害的环境污染物质。介绍PAHs的降解菌,降解机理和PAHs的生物修复方面的研究进展。土壤中PAHs的生物修复被认为是解决污染的有效方法,目前,菲的生物降解途径已经比较清楚,但对结构更为复杂的多环芳烃研究较少。文章还对消除环境中多环芳烃的相关生物技术提出展望。  相似文献   

13.
A great number of important chemical reactions that occur in the environment are microbially mediated. In order to understand the kinetics of these reactions it is necessary to develop methods to directly measure in situ reaction rates and to develop models to help elucidate the mechanisms of microbial catalysis. The oxidation of Mn(II) in a zone above the O2/H2S interface in Saanich Inlet, B.C., Canada is one such reaction. We present here a method by which in situ rates of microbial Mn(II) oxidation are measured and a model based on our experimental results to describe the general mechanism of Mn(H) oxidation. We propose a two step process in which Mn(II) is first bound by a site on the bacterial surface and then oxidized. The model is analogous to the Langmuir isotherm model for surface catalyzed gas reactions or the Michaelis-Menten model for enzyme kinetics. In situ Mn(II) oxidation rates were measured during five cruises to Saanich Inlet during the summers of 1983 and 1984. We use the model to calculate the apparent equilibrium binding constant (Ks 0.18 M), the apparent half saturation constant for biological Mn(H) oxidation (Km = 0.22 to 0.89 M), the maximum rate of Mn(II) oxidation (Vmax = 3.5 to 12.1 nM·h-1) and the total microbial surface binding site concentration ( E 51 nM). Vmax for Mn(II) oxidation agrees with the rates calculated from the value of the flux of Mn(II) to the oxidizing zone using the Mn(II) gradient and estimates of the eddy diffusion coefficient. This consistancy verifies our methodology and indicates that the rate of Mn(II) oxidation is nearly equal to the (Vmax for the reaction. We conclude that in this environment the Mn(II) oxidation rate is more a function of the total number of surface binding sites than the Mn(H) concentration.Contribution #1601 from the School of Oceanography, Univ. of Washingtoncorresponding author  相似文献   

14.
Two unique bimetalic Pt(II) coordination polymers of composition [Ni(hydeten)2Pt(CN)4] (Ni-Pt) and [Cu(hydeten)2Pt(CN)4] (Cu-Pt) [hydeten = N-(2-hydroxyethyl-ethylenediamine) or 2-(2-aminoethylamino)ethanol] have been synthesized and structurally characterized by various methods in this study. The crystal structure of Cu-Pt was determined by single-crystal X-ray diffraction analysis. The structure of Cu-Pt forms of infinite 2,2-TT type [-Cu(hydeten)2-NC-Pt(CN)2-CN-] chains containing paramagnetic copper atoms bridged by tetracyanoplatinate species. In this complex, Cu(II) centers display an axially elongated octahedron with two chelating hydeten molecules in the equatorial positions and N-bonded bridging cyano groups in the axial positions, whereas Pt(II) centers are four coordinate with four cyanide-carbon atoms in a square-planar arrangement. The decrease of the moments of these complexes in temperature range of 50 305 K can assigned to the antiferromagnetic interactions in the structures. The thermal decomposition of Cu-Pt comprise of five distinguished stages, while the thermal decomposition of Ni-Pt take place four different stages.  相似文献   

15.
Complex formation between Arsenazo III and Mn2+ and Co2+ at equilibrium has been investigated at pH 7.2, and the stoichiometry and stability of the complexes have been determined. The data indicate that Arsenazo III is suitable for determination of Mn2+ and Co2+ on the micromolar scale. The dissociation constants of the phosphate complexes of Mn2+ and Co2+ at pH 7.2 were estimated with Arsenazo III as 3.6 and 10 mM, respectively.  相似文献   

16.
The effect of copper(II), lead(II) and chromium(VI) ions on the growth and bioaccumulation properties of Aspergillus niger was investigated as a function of initial pH and initial metal ion concentration. The optimum pH values for growth and metal ion accumulation were determined as 5.0, 4.5 and 3.5 for copper(II), lead(II) and chromium(VI) ions, respectively. Although all metal ion concentrations caused an inhibition effect on the growth of A. niger, it was capable of removing of copper(II) and lead(II) with a maximum specific uptake capacity of 15.6 and 34.4 mg g−1 at 100 mg dm−3 initial copper(II) and lead(II) concentration, respectively. Growth of A. niger was highly effected by chromium(VI) ions and inhibited by 75 mg dm−3 initial chromium(VI) concentration since some inhibition occurred at lower concentrations.  相似文献   

17.
A new easily synthetic route with a 96% yield of ligand 2-(3,5-diphenyl-1H-pyrazol-1-yl)ethanol (L) is obtained. The reactivity of L against Pd(II), Zn(II) and Cu(II) leads to [PdCl2(L)2] (1), [ZnCl2(L)] (2) and [CuCl(L′)]2 (3) (L′ is the ligand L without alcoholic proton), respectively. According to the different geometries imposed by the metallic centre and the capability of L to present various coordination links, it has been obtained complexes with square planar (1 and 3) or tetrahedral (2) geometry and different nuclearity: monomeric (1 and 2) or dimeric (3). Complete characterisation by analytical and spectroscopic methods, resolution of L and 1-3 by single-crystal X-ray diffraction and magnetic studies for complex 3 are presented.  相似文献   

18.
A new nano-sized lead(II) one-dimensional coordination polymer with Pb?F interactions, [Pb(μ-TFPB)2]n (1) [TFPB = 4,4,4-trifluoro-1-phenyl-1,3-butandionate], has been synthesized and characterized by SEM, X-ray powder diffraction, IR spectroscopy and elemental analyses. The single-crystal X-ray data of compound 1 show that the Pb(II) atoms have a hemidirected coordination sphere with an environment of PbO6F2. The presence of a stereo-chemically active lone pair of the lead atom is apparently the reason that the neighboring bridging bond relative to gap of coordination sphere are so long. Therefore arrangement of “TFPB” ligands suggests a gap or hole in coordination geometry around the lead(II) ions. PbO nanoparticles were obtained by calcination of the nano-sized compound 1 at 600 °C.  相似文献   

19.
The 1:1 condensation of 1,2-diaminopropane and 1-phenylbutane-1,3-dione at high dilution gives a mixture of two positional isomers of terdentate mono-condensed Schiff bases 6-amino-3-methyl-1-phenyl-4-aza-2-hepten-1-one (HAMPAH) and 6-amino-3,5-dimethyl-1-phenyl-4-aza-2-hexen-1-one (HADPAH). The mixture of the terdentate ligands has been used for further condensation with pyridine-2-carboxaldehyde or 2-acetylpyridine to obtain the unsymmetrical tetradentate Schiff base ligands. The tetradentate Schiff bases are then allowed to react with the methanol solution of copper(II) and nickel(II) perchlorate separately. The X-ray diffraction confirms the structures of two of the complexes and shows that the condensation site of the diamine with 1-phenylbutane-1,3-dione is the same.  相似文献   

20.
An investigation into the feasibility of removing Cu(II) and Cr(IV) from solution with basidiomycete (Gloeophylum sepiarium, Pleurotus sp.)-colonized sawdust was undertaken. Obeche (Triplochyton scleroxylon) sawdust exposed to the basidiomycetes for 1–3 months reduced the concentration of the metals in the solution to 22.0–84.4 mg/l. The supernatant from the centrifuged mixture of a solution of 100 mg metal ions/l and aqueous extract of a 3-month basidiomycete-degraded obeche sawdust contained lower concentration of the metal ions (38.6–75.4 mg/l). Unextracted sawdust of pigmented tropical timbers, African mahogany (Khaya ivorensis), black afara (Terminalia ivorensis) and camwood (Baphia nitida) exposed to the test basidiomycetes, removed Cu and Cr significantly better than the extracted sawdust. It is hypothesised that some products of basidiomycete wood-degradative activities were ligands which immobilized the test metals.  相似文献   

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