COPPER REMOVAL FROM AQUEOUS SYSTEMS: BIOSORPTION BY PSEUDOMONAS SYRINGAE

Zeolite Na-Y was prepared from kaolin located in Wadi-Hagul, Suez, Egypt. The synthetic zeolite prepared by the hydrothermal reaction of kaolin was characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM) and cation exchange capacity (CEC). Cadmium ion removal was investigated using the synthetic solution of Cd2+ ions with different concentrations at room temperature (25 °C ± 0.2), initial pH of the solution and contact times. The optimum contact time for removal of Cd2+ ion was 10 min, with 0.1g of synthetic zeolite and pH 7.57. The experimental data were correlated using Langmuir, Freundlich and Harkins-Jura adsorption isotherms. The maximum adsorption capacity Qm obtained from the Langmuir isotherm was 14.006 mg/g for Cd2+ ion. Kinetic studies reveal that synthetic zeolite is more effective as adsorbent for removing cadmium ions

Biosorption of azo-dye using marine macro-alga of Euchema Spinosum

Activated carbon from coconut coirpith as metal adsorbent: adsorption of Cd(II) from aqueous solution

Biosorption of lead(II) from aqueous solutions by non-living algal biomass Oedogonium sp. and Nostoc sp.—A comparative study

Olive cake obtained as a by-product from the olive oil industry has been evaluated as biosorbent of heavy metals from aqueous solutions in batch and continuous systems (fixed-bed columns). First, a complete study of effect of hydrothermal treatment with water on biosorption capacity of resulting solid was performed. Results showed that the values of biosorption capacity increased when the particle size of material decreased and the temperature of treatment increased. Then, hydrolyzed olive cake was treated by common chemicals (hot water, nitric acid, and sodium hydroxide) and the impact of chemical treatment was analyzed. The results were well reproduced by Langmuir and Freundlich isotherm models, getting maximum experimental biosorption capacities that changed between 42.34 mg/g obtained for the solid material modified by NaOH and 14.27 mg/g obtained for the solid material modified by nitric acid. Finally, laboratory tests in fixed-bed columns were performed with four different heavy metals and at three different inlet concentrations. The biosorption capacity increased from 2.83 mg/g (Cr), 4.51 mg/g (Cu), 12.30 mg/g (Pb), and 4.10 mg/g (Zn) to 3.08 mg/g (Cr), 5.17 mg/g (Cu), 13.21 mg/g (Pb), and 5.51 mg/g (Zn) when the concentration of metal ions increased, from 50 mg/L to 200 mg/L, respectively. Also, the experimental data obtained was successfully correlated with the Thomas, Yoon–Nelson, and dose–response models.

UPTAKE OF Cd2+ FROM AQUEOUS SOLUTIONS USING PROTONATED DRY ALGINATE BEADS

The potentiality of Saccharomyces cerevisiae SRCM 501804 to remove arsenite (As[III]) in an aqueous solution was investigated in this study. The S. cerevisiae SRCM 501804 was isolated from Korean turbid rice wine (Makgeolli). The S. cerevisiae SRCM 501804 was characterized by phylogenetic analysis, Fourier transform infrared (FT-IR) spectroscopy, visual minerals technologies (MINTEQ) model, and point of zero charge (pHpzc). The relationship between the factors (pH, biosorbent dosage, contact time, and concentration) and biosorption capacity was investigated. The S. cerevisiae SRCM 501804 was removed 31.1–90.1% of the As(III) depending on the initial biomass dosage within 1 h. Co-existing anions in aqueous solution showed a negative influence on the biosorption performance of As(III) in the order Cl− > NO3 − > SO4 2− > CO3 2−. The results of isotherms and kinetics suggested the Langmuir (R 2 > 0.95) and Pseudo-second order (R 2 > 0.99) models fit well with the equilibrium experimental data. The maximum biosorption capacity (qm ) of S. cerevisiae SRCM 501804 biomass for As(III) was found to be 113.9 mg/g from Langmuir isotherm. Based on the results, it can be concluded that the biomass of S. cerevisiae SRCM 501804 could be used as an effective bio-sorbent for As(III) biosorption in an aqueous solution.

The performances of nine biosorbents derived from dead fungal biomass were investigated for their ability to remove Reactive Black 5 from aqueous solution. The biosorption data for removal of Reactive Black 5 were readily modeled using the Langmuir adsorption isotherm. Kinetic analysis based on both pseudo-second-order and Weber-Morris models indicated intraparticle diffusion was the rate limiting step for biosorption of Reactive Black 5 on to the biosorbents. Sorption capacities of the biosorbents were not correlated with the initial biosorption rates. Sensitivity analysis of the factors affecting biosorption examined by an artificial neural network model showed that pH was the most important parameter, explaining 22%, followed by nitrogen content of biosorbents (16%), initial dye concentration (15%) and carbon content of biosorbents (10%). The biosorption capacities were not proportional to surface areas of the sorbents, but were instead influenced by their chemical element composition. The main functional groups contributing to dye sorption were amine, carboxylic, and alcohol moieties. The data further suggest that differences in carbon and nitrogen contents of biosorbents may be used as a selection index for identifying effective biosorbents from dead fungal biomass.

The biosorption properties of ethylenediaminetetraacetate (EDTA)-treated biomass of baker’s yeast (Saccharomyces cerevisiae) are studied for the removal of Cadmium(Cd), Lead(Pb), and Copper(Cu) from artificially prepared industrial wastewater. The metal ions are chosen for biosorption studies with regard to their availability in industry and potential pollution impact. The optimum biosorption capacity of these metal ions on the biomass is obtained at pH 5. It is observed that the sorption capacity of EDTA-treated biomass increases when the initial concentration of the metal ions is increased. Both Langmuir and Freundlich isotherm models are used to fit experimental biosorption equilibrium data. The maximum biosorption capacity as determined via the Langmuir isotherm is 32.26, 200.0, and 17.24 mg/g for Cd(II), Pb(II), and Cu(II) ions, respectively. The kinetics of biosorption is studied using both pseudo first order and pseudo second order models. Based on a linear regression correlation coefficie...

BackgroundCu(II) is considered to be a heavy metal ion that is quite hazardous to water.AimsZinc oxide‐montmorillonite composite (ZnO‐Mt) for the removal of Cu(II) from aqueous solutions.Materials & MethodsZnO‐Mt was prepared through ion exchange followed by heat treatment to form a highly effective adsorbent.ResultsThe structure and morphology of the composite were investigated by X‐ray diffraction, scanning electron microscope, and fourier transform infrared spectroscopy and it was found that Zinc oxide was successfully coated on montmorillonite. The composite has a superior removal effect on Cu(II) in an aqueous solution with an adsorption capacity of 192.89 mg·g−1. The adsorption kinetic model and the adsorption isotherm model are described by the pseudo‐second‐order kinetic equation and the Langmuir equation, respectively. The activation energy (Ea) was 84.18 kJ·mol−1, indicating that the adsorption was dominated by chemisorption. In addition, ZnO‐Mt can be applied in a wide pH range (3 ~ 8) and exhibits satisfactory selectivity for the adsorption of Cu(II) in the presence of coexisting cations. The removal efficiency of ZnO‐Mt for Cu(II) remains at 72% of the fresh adsorbent after five cycles.DiscussionA combination of experiment, characterization, and density functional theory analysis showed that the mechanism of Cu(II) removal was mainly surface complexation, ion exchange, and electrostatic attraction.ConclusionTherefore, the ZnO‐Mt composite is a promising and efficient adsorbent for the removal of Cu(II) from aqueous solutions.

Biosorption behavior and mechanism of beryllium from aqueous solution by aerobic granule

Peppers are very important foodstuffs in the world for direct and indirect consumption, so they are extensively used. The seeds of these peppers are waste materials that are disposed of from houses and factories. To evaluate the performance of this biomass in the treatment of wastewaters, a study was conducted to remove a textile dye, reactive blue 221, which is commercially used in textile mills. Raw seed materials were used without any pre-treatment. The effects of contact time, initial concentration of dye, pH and dose of biosorbent were studied to determine the optimum conditions for this biomass on color removal from wastewaters. The optimum pH value for dye biosorption was found to be 2.0. At an initial dye concentration of 217 mg L-1, treatment efficiency and biosorption capacity were 96.7% and 95.35 mg g-1, respectively. A maximum biosorption capacity of 142.86 mg g-1 was also obtained. Equilibrium biosorption of dye by capia seeds was well described by the Langmuir isotherm with a correlation coefficient above 99%. The biosorption process was also successfully explained with the pseudo-second order kinetic model. This biomass was found to be effective in terms of textile dye removal from aqueous solutions.

Environmental implications and the tendency of heavy metals to accumulate in selected tissues of plants and animals, as well as their overall potential to be toxic even at relatively minor levels of exposure, are a source of concern. The use of cheap and effective biological means for heavy metal remediation has been advocated. This study examines the biosorption and bioaccumulation of ferrous ion by Aspergillus terreus (A. terreus) and Trichoderma viride (T. viride) in a batch system. The effects of some important parameters, such as initial metal concentration, temperature and inoculum concentration on biosorption capacity were examined. Langmuir, Freudlinch, Temkin and Dubinin–Radushkevich models were applied to explain the biosorption isotherms of Fe(II) onto the biosorbents. The process fitted well into pseudo first order kinetic model and was best explained by the Langmuir isotherm with maximum absorption capacity of 6.33 and 7.50 mg/g for A. terreus and T. viride, respectively. The calculated thermodynamic parameters (ΔG W , ΔH W

Biosorption of chromium (VI) from aqueous solutions by the husk of Bengal gram (Cicer arientinum)

Residual biomass, produced by the thermophilic fungus, Talaromyces emersonii CBS 814.70, following growth on glucose-containing media, was examined for its ability to take up uranium from aqueous solution. It was found that the biomass had a relatively high observed biosorption capacity for the uranium (280 mg/g dry weight biomass). The calculated maximum biosorption capacity obtained by fitting the data to a Langmuir model was calculated to be 323 mg uranium/g dry weight biomass. Pretreatment of the biomass with either dilute HCl or NaOH brought about a significant decrease in biosorptive capacity for uranium. Studies on the effects of variation in temperature on the biosorptive capacity demonstrated no significant change in binding between 20 degrees C and 60 degrees C. However, a significant decrease in biosorptive capacity was observed at 5 degrees C. Binding of uranium to the biomass at all temperatures reached equilibrium within 2 min. While the routine binding assays were performed at pH 5.0, adjustment of the pH to 3.0 gave rise to a significant decrease in biosorption capacity by the biomass. The biosorptive capacity of the biomass for uranium was increased when extraction from solution in sea-water was examined.