黄孢原毛平革菌210对稀土离子的吸附作用研究

通过电感耦合等离子体发射光谱(ICP-OES)、扫描电镜等手段研究了黄孢原毛平革菌210对镧离子(La3+)及其他稀土离子的吸附能力。结果表明,在pH=7,La3+浓度为40 mg.L-1,菌体投加量60 mg.L-1(以干重计),吸附时间120 min时,黄孢原毛平革菌210的吸附量最大,达141.5±4.72 mg.g-1。经盐酸预处理的菌体吸附能力有所提高,其他预处理则使菌体吸附能力下降。解吸剂柠檬酸和EDTA都能较好地解吸La3+。黄孢原毛平革菌210对单一稀土离子的吸附能力差异较大。在15种混合稀土离子溶液中,对Lu3+,Sm3+,Eu3+的吸附量较高,对混合稀土离子具有一定的富集、分离作用。扫描电镜发现La3+可能主要以盐的形式沉积在菌体表面上。     

Biosorption of Cadmium,Lead, and Uranium by Powder of Poplar Leaves and Branches

The removal of metal ions from aqueous solutions by biosorption plays an important role in water pollution control. In this study, dried leaves and branches of poplar trees were studied for removing some toxic elements (cadmium, lead, and uranium) from aqueous solutions. The equilibrium experiments were systematically carried out in a batch process, covering various process parameters that include agitation time, adsorbent size and dosage, initial cadmium, lead and uranium concentration, and pH of the aqueous solution. Adsorption behavior was found to follow Freundlich and Langmuir isotherms. The results have shown that both dried leaves and branches can be effectively used for removing uranium, while only branches were found to remove lead and cadmium completely from the aqueous solution. The maximum biosorption capacity of leaves for uranium was found to be 2.3 mg g⁻¹ and 1.7 mg g⁻¹ and 2.1 mg g⁻¹ for lead and cadmium on branches, respectively. In addition, the studied biomass materials were used in removing lead and cadmium from contaminated water and the method was found to be effective.     

Biosorption of Copper and Cadmium in Packed Bed Columns with Live Immobilized Fungal Biomass of <Emphasis Type="Italic">Phanerochaete chrysosporium</Emphasis>

Biosorption of copper (II) and cadmium (II) by live Phanerochaete chrysosporium immobilized by growing onto polyurethane foam material in individual packed bed columns over two successive cycles of sorption–desorption were investigated in this study. Initial pH and concentrations of the metals in their respective solutions were set optimum to each of those: 4.6 and 35 mg·l⁻¹ in case of copper and 5.3 and 11 mg·l⁻¹ for cadmium. The breakthrough curves obtained for the two metals during sorption in both the cycles exhibited a constant pattern at various bed depths in the columns. The maximum yield of the columns in removing these metals were found to be, respectively, 57% and 43% for copper and cadmium indicating that copper biosorption by the immobilized fungus in its column was better than for cadmium. Recovery values of the sorbed copper and cadmium metals from the respective loaded columns by using 0.1 N HCl as eluant was observed to be quite high at more than 65% and 75%, respectively, at the end of desorption in both the cycles. Breakthrough models of bed-depth service time, Adams–Bohart, Wolborska, and Clark were fitted to the experimental data on sorption of copper and cadmium in the columns, and only the Clark model could fit the sorption performance of the columns well over the entire range of ratios of concentrations of effluent to influent, i.e., C/C ₀ for both copper and cadmium biosorption. The kinetic coefficients of mass transfer and other suitable parameters in the system were determined by applying the experimental data at C/C ₀ ratios lower than 0.5 to the other three models.     

Biosorption of Lead,Copper, and Cadmium by <Emphasis Type="Italic">Phanerochaete chrysosporium</Emphasis> in Ternary Metal Mixtures: Statistical Analysis of Individual and Interaction Effects

Biosorption of three divalent metals, viz., lead, copper, and cadmium in ternary aqueous mixtures was studied using Phanerochaete chrysosporium in batch shake flasks. The mixtures were prepared containing the metals at their either varying optimum or equal initial concentration combinations in aqueous solution of pH optimum to each of the metals. Following were the optimum initial concentration ranges of the metals in mixture: lead, 60–100 mg/L; copper, 20–60 mg/L; and cadmium, 5–15 mg/L. And, for varying these optimum concentration levels of the metals, a 2³ full factorial design of experiments was employed. The results revealed that an increase in lead and cadmium concentrations helped in their better biosorption by the fungus, but an increase in initial copper concentration slightly diminished its removal. Statistical analysis of the results in the form of analysis of variance and Student t test gave a clear interpretation on the roles of both the individual metals and their interactions in the uptake of metals from mixture. Compared to the uptake of metals when presented individually, lead biosorption in mixture was found to be enhanced to a degree as high as 99%; on the other hand, copper and cadmium removals from mixtures were inhibited to the extent of 100% and 98%, respectively. However, this extent of inhibition or enhancement in the metal removals compared to the individual removals was less in mixtures containing all equal concentrations of the metals.     

海洋微藻富集微量元素研究进展

论述了微量元素对人体的重要作用,以及目前海洋微藻生物富集硒、铬、锌等的研究现状,同时探讨了微藻富集微量元素的前景。     

Biosorption of radioactive thorium by Sargassum filipendula

In the present work, the biosorption of radioactive thorium was investigated using a dry biomass of Sargassum filipendula as the biosorbent material. Radioactive solutions containing between 2.0 and 500.0μg thorium were tested by biosorption with S. filipendula, yielding uptake capacities from 20 to 100%, depending on the concentration of the solution. Kinetic studies indicated that equilibrium between the thorium solution and the solid fraction was achieved after three hours of contact and that a second-order model could express the equilibrium kinetics. In order to investigate the maximum biosorption capacity of the biomass an isotherm was done, based on the experimental data, which revealed the maximum uptake capacity to be 2.59 μmol thorium/g biomass. The experimental data fitted well to a Langmuir model, which provided a good correlation between the experimental and predicted thorium uptake values.     

Biosorption of americium-241 by Saccharomyces cerevisiae

The biosorption of radionuclide ²⁴¹Am from solution by Saccharomyces cerevisiae (S. cerevisiae), and the effects of experimental conditions on the adsorption were investigated. The preliminary results showed thatS. cerevisiae is a very efficient biosorbent. An average of more than 99% of the total ²⁴¹Am could be removed by S. cerevisiae of 2.1 g/l (dry weight) from ²⁴¹Am solutions of 17.54–4386.0 mg/l (2.22 MBq/l–555 MBq/l) with adsorption capacities of 7.45–1880.0 mg/g biomass (dry weight) (0.94 MBq/g–237.9 MBq/g). The adsorption equilibrium was achieved within 1 hour and the optimum pH ranged 1–3. No significant differences on ²⁴¹Am adsorption were observed at 10–45 °C, or in solutions containing Au³⁺ or Ag⁺, even 2000 times above ²⁴¹Am concentration. The relationship between concentrations and adsorption capacities of ²⁴¹Am indicated the biosorption process should be described by the Freundlich adsorption isotherm.     

Biosorption of copper by biomass of extremophilic algae

Copper and lead are among the most important chemical pollutants of the environment including hydrosphere. Interaction of these heavy metals with biomass of aquatic plant organisms including algae is an area of active research in ecological chemistry. We investigated the interaction of the biomass of unique extremophilic (thermophilic) algae Galdieria sulphuraria with these heavy metals in aquatic environment using stripping voltammetry. Biosorption of copper by the studied biomass from aquatic medium has been discovered; however, no biosorption of another heavy metal from aquatic environment with the biomass has been detected. The experiments with the mortmass of Galdieria sulphuraria have revealed no sorption of the heavy metals as measured by stripping voltammetry. The difference in the interaction of copper and lead with the algal biomass is important for deeper understanding of the biosorption phenomenon. The new data stimulated further interest to the concept of biogenic migration of chemical elements that was proposed by V.I. Vernadskii. The results contributed to the scientific basis for innovative biotechnology to decontaminate water.     

Biosorption of 241Am by immobilized Saccharomyces cerevisiae

More than half of the world's annual production of radionuclides is used for medical purposes such as diagnostic imaging of diseases and patient therapy. Using aqueous homogeneous solution reactor technology, production quantities of medical radioisotopes ⁹⁹Mo and⁸⁹Sr, can be extracted from one reactor cycle. ⁹⁹Mo may be produced directly from UO₂SO₄ uranyl sulfate in an aqueous homogeneous solution nuclear reactor in a manner that produces high purity radionuclides, making efficient use of the reactor's uranium fuel solution. The process is relatively simple, economical, and waste free, eliminating uranium targets. The short-lived radioisotope ^99mTc is eluted from ⁹⁹Mo for diagnostic imaging. Radioisotope ⁸⁹Sr infusion is a therapeutic modality that reduces reliance on narcotic analgesia through palliation of metastatic bone pain caused by metastases of the cancer to the bone. Painful disseminated osseous metastases are common with carcinomas of the lung, prostate, and breast. Synergistic interleaving of two manufacturing processes, one producing ⁹⁹Mo and another producing ⁸⁹Sr in the same production cycle of an aqueous homogeneous solution reactor makes full and efficient use of the time for both the neutron irradiation stage and the extraction stage of each radionuclide. Interleaving the capture of ⁸⁹Sr radioisotope with production processing of ⁹⁹Mo radioisotope is achieved, since the extraction and subsequent elimination of radionuclide impurities occurs during separate parts of the reactor cycle. The process applies to either HEU or LEU nuclear fuels in an aqueous homogeneous solution reactor.     

Biosorption of Metal Ions by Spirulina plantensis Microalga

Russian Journal of General Chemistry - The sorption of lead, nickel, zinc, chromium(III), and chromium(VI) ions by Spirulina platensis microalga was studied. The effects of pH, metal concentration,...     

Biosorption of precious metal ions by chicken feather

Chicken feather (C-feather) is an intricate network of stable and water-insoluble protein fibers with high surface area and is an abundant bioresource. C-feather protein was found to accumulate various precious metal ions (gold and platinum metals) selectively from their dilute aqueous solutions in high yield and in short contact time, depending on pH and characteristics of the individual precious metal ions. Under certain condition, the sequestering level of precious ions, Au(III), Pt(II), and Pd(II) approaches about 17, 13, and 7% of dry wt of C-feather, respectively. Gold(III) potassium cyanade was also accumulated up to 5.5% at pH 2.0. The presence of 100-fold (mol) of coexisting cations, such as Na⁺, Fe(III), Cu(II), and Ni(II), did not show a discernible effect on the precious metal uptake rate and capacity of C-feather. Experiment suggested C-feather is promising for use in the removal/recovery of precious metals as well as water pollution control. A qualitative discussion is given about the excellent adsorption behavior of C-feather.

     

Microbial mannosidation of bioactive chlorogentisyl alcohol by the marine-derived fungus Chrysosporium synchronum

The biological transformation of the biologically active chlorogentisyl alcohol (1), isolated from the marine-derived fungus Aspergillus sp., was studied. Preparative-scale fermentation of chlorogentisyl alcohol with marine-derived fungus Chrysosporium synchronum resulted in the isolation of a new glycosidic metabolite, 1-O-(α-D-mannopyranosyl)chlorogentisyl alcohol (2). The stereostructure of the new metabolite obtained was assigned on the basis of detailed spectroscopic data analyses, chemical reaction, and chemical synthesis. Compounds 1 and 2 exhibited significant radical-scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) with IC(50) values of 1.0 and 4.7 μM, respectively. The compounds 1 and 2 were more active than the positive control, L-ascorbic acid (IC(50), 20.0 μM).     

Heavy metal removal by biosorption using Phanerochaete chrysosporium

Biosorption using microbial cells as adsorbents is being seen as a cost-effective method for the removal of heavy metals from wastewaters. Biosorption studies with Phanerochaete chrysosporium were performed for copper (II), lead (II), and cadmium (II) to evaluate the effectiveness and to optimize the operational parameters using response surface methodology. The operational parameters chosen were initial metal ion concentration, pH, and biosorbent dosage. Using this method, the metal removal could be correlated to the operational parameters, and their values were optimized. The results showed fairly high adsorptive capacities for all the metals within the settings of the operational parameters. The removal efficiencies followed the order Pb>Cu>Cd. As a general trend, metal removal efficiency decreased as the initial metal ion concentration increased, and the results fitted the Langmuir and Freundlich isotherms well.     

Biosorption of uranium by immobilized cells of Rhodotorula glutinis

Biosorption of uranium ions from diluted solution (≤40 mg L^?1) onto immobilized cells of Rhodotorula glutinis was investigated in a batch system. Equilibrium, kinetic and thermodynamic studies were conducted by considering the effect of initial uranium concentration, contact time and temperature. Non-linear forms of Langmuir, Freundlich and Sips isotherm models were used to fit the equilibrium data, Sips model was designated as the best one. Kinetic data were simulated by non-linear pseudo-first-order, pseudo-second-order and intra-particle diffusion equations. Pseudo-first-order kinetic equation described the experimental data better than pseudo-second-order equation and intra-particle diffusion equation can fit the kinetic data with two independent curves. Thermodynamic parameters, including ?H ⁰, ?G ⁰ and ?S ⁰, were evaluated, the sorption process was determined to be spontaneous and endothermic. Uranium sorption from pure uranium solutions and uranium pit wastewater by immobilized biomass and blank beads, as well as the regeneration results indicated that immobilized R. glutinis can be use to recovery uranium from uranium pit wastewater.     

Transformation of Tetracycline by Manganese Peroxidase from Phanerochaete chrysosporium

The negative impacts on the ecosystem of antibiotic residues in the environment have become a global concern. However, little is known about the transformation mechanism of antibiotics by manganese peroxidase (MnP) from microorganisms. This work investigated the transformation characteristics, the antibacterial activity of byproducts, and the degradation mechanism of tetracycline (TC) by purified MnP from Phanerochaete chrysosporium. The results show that nitrogen-limited and high level of Mn²⁺ medium could obtain favorable MnP activity and inhibit the expression of lignin peroxidase by Phanerochaete chrysosporium. The purified MnP could transform 80% tetracycline in 3 h, and the threshold of reaction activator (H₂O₂) was about 0.045 mmol L⁻¹. After the 3rd cyclic run, the transformation rate was almost identical at the low initial concentration of TC (77.05–88.47%), while it decreased when the initial concentration was higher (49.36–60.00%). The antimicrobial potency of the TC transformation products by MnP decreased throughout reaction time. We identified seven possible degradation products and then proposed a potential TC transformation pathway, which included demethylation, oxidation of the dimethyl amino, decarbonylation, hydroxylation, and oxidative dehydrogenation. These findings provide a novel comprehension of the role of MnP on the fate of antibiotics in nature and may develop a potential technology for tetracycline removal.     

Characterization and Biosorption Performance of Silver by Bacillus Licheniformis

The demand of silver is increasing rapidly in recent decades, because silver and its related products are widely used in modern industry and decoration. It is necessary to recover silver from waste water using an efficient and environmental friendly method due to its environmental and economic benefits. In this paper, we eliminated the interference of Cl-and light conditions, and then studied the characterization and biosorption performance of silver by Bacillus licheniformis. The max biosorption amount was 87.4 mg/g(dry weight) with the initial Ag+concentration of 100 mg/L at pH 6.0. XRD pattern showed that the product was an amorphous compound. SEM/EDS-mapping and FT-IR results implied that phosphate, amino and carboxyl groups located on the cell walls involved in the biosorption of Ag~+. The XPS spectra result showed that the value of EB of Ag 3d_(5/2_(367.51 eV) corresponded to the energy values for Ag(Ⅰ), and indicated Ag~+ adsorbed to the surface of cell still maintained mono-valence. The results confirm that B. licheniformis just adsorb Ag+ but cannot covert soluble Ag~+ to silver nano-particles(AgNP).     

N-demethylation of methylene blue by lignin peroxidase from Phanerochaete chrysosporium

Applied Biochemistry and Biotechnology - Phanerochaete chrysosporium lignin peroxidase (LiP) can degrade synthetic dyes such as heterocyclic, azo, and triphenylmethane on its activation by H2O2....     

Biosorption of heavy metals by bacteria isolated from activated sludge

Twelve aerobic bacteria from activated sludge were isolated and identified. These included both Gram-positive (e.g., Bacillus) and Gram-negative (e.g., Pseudomonas) bacteria. The biosorption capacity of these strains for three different heavy metals (copper, nickel, and lead) was determined at pH 5.0 and initial metal concentration of 100 mg/L. Among these 12 isolates, Pseudomonas pseudoalcaligenes was selected for further investigation owing to its high metal biosorption capacity. The lead and copper biosorption of this strain followed the Langmuir isotherm model quite well with maximum biosorption capacity (q _max) reaching 271.7mg of Pb²⁺/g of dry cell and 46.8 mg of Cu²⁺/g of dry cell at pH 5.0. Study of the effect of pH on lead and copper removal indicated that the metal biosorption increased with increasing pH from 2.0 to 7.0. A mutual inhibitory effect was observed in the lead-copper system because the presence of either ion affected the sorption capacity of the other. Unequal inhibitions were observed in all the nickel binary systems. The increasing order of affinity of the three metals toward P. pseudoalcaligenes was Ni<Cu<Pb. The metal biosorptive potential of these isolates, especially P. pseudoalcaligenes, may have possible applications in the removal and recovery of metals from industrial effluents.     

Biosorption of heavy metal ions by immobilized zoogloea and zooglan

ImmobilizedZoogloea and zooglan in calcium alginate-silica matrix was shown to have a high adsorption capacity for Cu and Cd ions. Our results showed that Cu-ion uptake in the presence of Ca and Mg ions can be enhanced using immobilizedZoogloea and zooglan. Heavy metal ion adsorption efficiency decreased in the following order: Cu > Cd > Zn > Cr. The adsorbed metal ions were desorbed completely using sulfuric acid. ImmobilizedZoogloea and zooglan which was repetitively regenerated adsorbed heavy metal ions without a loss of adsorption capacity.