Personal Research Database

Full Text: 2010\J Haz Mat181, 315.pdf

Abstract: Bioaugmentation is a promising technology to clean up sites contaminated with recalcitrant chemicals. White-rot fungi have proven to be effective in the degradation of pentachlorophenol. Here, we report the bioremediation of soil contaminated with pentachlorophenol (PCP) by Anthracophyllum discolor and its impact on the soil microbial community. In this study three types of microcosms were established: fresh soil (C-0), fresh soil plus wheat straw (WS0) and, fresh soil plus wheat straw inoculated with A. discolor (WSAD(0)). Additionally, similar treatments and a control of sterile soil spiked with PCP (C-250, WS250 and WSAD(250)) were used to evaluate the remediation and adsorption of PCP. The PCP removal, total microbial activity, and enzymatic activities were evaluated. This study also investigated the structure of soil microbial community by denaturing gradient gel electrophoresis (DGGE), identifying some of the dominant bacterial and fungal species. The results showed that PCP was effectively degraded in soils by A. discolor and by indigenous soil microorganisms. The addition of wheat straw increased the PCP degradation and enzymatic activities. Only laccase activity was negatively affected by PCP contamination. The PCP degradation was associated with changes in microbial communities, mainly stimulation of members of bacterial phylum Proteobacteria (Xanthomonadaceae, Burkholderiaceae and Enterobacteriaceae), and fungal phylum Ascomycota and Basidiomycota. This study shows the ability of A. discolor to degrade PCP from contaminated soil, and demonstrates that agricultural residues, such as wheat straw, can be used as growth substrate by microorganisms in PCP-contaminated soil, demonstrating a great potential of autochthonous microorganisms for soil remediation. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Anthracophyllum Discolor, Bacterial Community, Behavior, Biodegradation, Bioremediation, Degradation, Dgge, Diversity, Laccase, Microbial Community, Microorganisms, Pentachlorophenol, Primers, Remediation, Removal, Soil, Soil Remediation, Soils, Technology, Tyrosinase, White Rot Fungi, White-Rot Fungi

? Sun, D.H., Zhang, X.D., Wu, Y.D. and Liu, X. (2010), Adsorption of anionic dyes from aqueous solution on fly ash. Journal of Hazardous Materials, 181 (1-3), 335-342.

Full Text: 2010\J Haz Mat181, 335.pdf

Abstract: The adsorption behavior of two reactive dyes (Reactive Red 23 and Reactive Blue 171) and two acid dyes (Acid Black 1 and Acid Blue193) from aqueous solution on fly ash was investigated in order to identify the ability of this waste-material to remove colored textile dyes from wastewater. For this purpose a series of batch tests were carried out as a function of solution pH value, contact time, dye concentration and adsorption temperature. The experimental findings showed that the removal of four dyes on fly ash was a pH-dependent process with the maximum adsorption capacity at the initial solution pH of 7.5-8.5 for reactive dyes and 5-6 for acid dyes. Adsorption equilibriums of each anionic dye on fly ash could be reached within 60 min at respective optimum pH at 293 K. An increase in the initial dye concentration enhanced the adsorption capacity, but failed to increase the dye removal efficiency. The adsorption capacity for Reactive Red 23, Reactive Blue 171, Acid Blue193 and Acid Black 1 was found to be 2.102, 1.860, 10.937 and 10.331 mg g^-1, respectively. Kinetic studies of four dyes followed the pseudo-second-order modal. Freundlich isotherm described the equilibrium data of acid dyes on fly ash better than Langmuir isotherm, but Langmuir isotherm showed better fit to the equilibrium data of reactive dyes. Different thermodynamic parameters such as the free energy, enthalpy and entropy of adsorption of the dye-fly ash systems were evaluated and it was found that the reaction was spontaneous and endothermic in nature. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Acid Dye, Acid Dyes, Activated Carbons, Adsorbent, Adsorption, Adsorption Behavior, Adsorption Capacity, Anionic Dye, Anionic Dyes, Aqueous Solution, Batch, Batch Tests, Behavior, Capacity, Chitosan, Concentration, Data, Dye, Dye Removal, Dyes, Efficiency, Endothermic, Energy, Enthalpy, Entropy, Equilibrium, Experimental, Fly Ash, Freundlich, Freundlich Isotherm, Function, Isotherm, Kinetic, Kinetic Studies, Langmuir, Langmuir Isotherm, pH, pH Value, pH-Dependent, Pseudo Second Order, Pseudo-Second-Order, Purpose, Reactive Dye, Reactive Dyes, Removal, Removal Efficiency, Rice Husk, Rights, Solution, Sorption, Systems, Temperature, Thermodynamic, Thermodynamic Parameters, Value, Wastewater

? Ghimici, L., Constantin, M. and Fundueanu, G. (2010), Novel biodegradable flocculanting agents based on pullulan. Journal of Hazardous Materials, 181 (1-3), 351-358.

Full Text: 2010\J Haz Mat181, 351.pdf

Abstract: New copolymers with different grafted cationic chain content and length were synthesized by graft-polymerization of (3-acrylamidopropyl)-trimethylammonium chloride onto pullulan in aqueous solution, using potassium persulfate as an initiator. Their flocculation efficiency was studied in a clay suspension as a function of the grafted chains content and length as well as of some flocculation parameters: the polycation dose, the settling time, the parent solution concentration of polycation. All the polysaccharide samples showed flocculation ability: the higher the grafted cationic chain content and length the lower the amount of pullulan derivative was required for reaching the maximum clarity degree (of about 100%). This finding together with the negative value of the zeta potential and floc size measurements, at the optimum polymer dose, point to contributions from both neutralization and bridging mechanisms for flocculation process. The residual turbidity values also varied with the settling time and the parent solution concentration of polymer. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Behavior, Cationic Polysaccharides, Charge-Density, Chitosan, Clay, Flocculation, Flocculation Characteristics, Graft Copolymer, Graft-Copolymerization, Metal-Ion Sorption, Polyacrylamide, Pullulan, Starch Derivatives, Turbidimetry, Water-Treatment, Zeta Potential

? Royer, B., Cardoso, N.F., Lima, E.C., Macedo, T.R. and Airoldi, C. (2010), A useful organofunctionalized layered silicate for textile dye removal. Journal of Hazardous Materials, 181 (1-3), 366-374.

Full Text: 2010\J Haz Mat181, 366.pdf

Abstract: The octosilicate Na-RUB-18 has the ability to exchange its original sodium with cetyltrimethylammonium cations. This procedure leads to interlayer space expansion, with the aim of obtaining inorganic-organic nanostructured hybrids by chemical modification reactions. The silylating agent 3-trimethoxysilylpropylurea was attached to the inorganic layer using heterogeneous methodology. The new organofunctionalized material was characterized by elemental analysis, X-ray diffraction, C-13 and Si-29 nuclear magnetic resonances in the solid state, infrared spectroscopy, thermogravimetry and scanning electron microscopy. The amount of silylating agent immobilized on surface was 2.03 mmol g^-1, with a basal distance of 2.43 nm. Nuclear magnetic resonance of C-13 and Si-29 nuclei evidenced covalent bond formation between organosilyl and silanol groups at the surface. The new synthesized nanostructured layered material was able to remove the textile dye Reactive Black 5 from aqueous solution, followed through a batchwise process. The effects of stirring time, adsorbent dosage and pH on the adsorption capacity demonstrated that 150 min is enough to reach equilibrium at 298±1 K at pH 3.0. Based on error function values the data were best fitted to fractional-order kinetic models and compared to pseudo-first-order, pseudo-second-order and chemisorption kinetic models. The equilibrium data were better fitted to the Sips isotherm models. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorbent Dosage, Adsorption, Adsorption Capacity, Analysis, Aqueous Solution, Aqueous-Solution, Biosorbent, C-13, Capacity, Chemical, Chemical Modification, Chemisorption, Cu(II), Data, Dye, Dye Removal, Electron Microscopy, Equilibrium, Error, Function, Immobilized, Infrared Spectroscopy, Intercalation, Isotherm, Kinetic, Kinetic Models, Kinetic-Parameters, Layered Material, Magnetic, Magnetic Resonance, Methodology, Methylene-Blue, Models, Modification, Organofunctionalization, Pecan Nutshell, pH, Pine-Fruit Shell, Procedure, Pseudo First Order, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Reactive Black 5, Reactive Black 5 Dye, Removal, Rights, Rub-18, Scanning Electron Microscopy, Silicate, Sodium, Solution, Spectroscopy, State, Surface, Textile Dye, Thermogravimetry, Thin Chitosan Membranes, X-Ray, X-Ray Diffraction

? de Vicente, I., Merino-Martos, A., Cruz-Pizarro, L. and de Vicente, J. (2010), On the use of magnetic nano and microparticles for lake restoration. Journal of Hazardous Materials, 181 (1-3), 375-381.

Full Text: 2010\J Haz Mat181, 375.pdf

Abstract: Innovative approaches are of outstanding importance to devise technologies for dealing with eutrophication of inland waters. This study provides a quantitative estimate showing the convenience of using magnetic nano- and micronsized particles as phosphate absorbents and their later removal from solution by high gradient magnetic separation. Two different materials are investigated (iron and magnetite) having a controlled shape and size well in the colloidal domain. Magnetite particles adsorb more phosphate (empirical saturation constant = 27.15 mg P g(-1) Fe) than iron particles (empirical saturation constant = 18.83 mg P g(-1) Fe) as a consequence of the different particle size (average values for particle diameters of 90.6 +/- 1.2 and 805 +/- 10 nm for magnetite and for iron. respectively). A protocol is established for the successful reutilization of these magnetic particles by repeated washing with NaOH and therefore, optimizing the economic cost of this technology. Magnetic particles are also surface treated with amino silane groups (APTS) to counteract magnetic and van der Waals attractive interactions and promote kinetic stability. APTS-coated iron particles experience a notable increase in phosphate maximum adsorption capacity which could be explained by a remarkable increase in electrophoretic mobility. We propose the use of APTS-coated iron particles which are less-expensive and easy to obtain as a promising technique for lake restoration. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Capacity, Chitosan, Cobalt Ferrite, Eutrophication, Failures, Ions, Kinetic, Lake Restoration, Magnetic, Magnetic Particles, Magnetic Separation, Mobility, Nanoparticles, Particles, Phosphate Adsorption, Phosphorus, Precipitation, Removal, Technology, Water

? Rao, R.A.K. and Rehman, F. (2010), Adsorption studies on fruits of Gular (Ficus glomerata): Removal of Cr(VI) from synthetic wastewater. Journal of Hazardous Materials, 181 (1-3), 405-412.

Full Text: 2010\J Haz Mat181, 405.pdf

Abstract: The adsorption of Cr(VI) was studied in batch system using fruits of Ficus glomerata as adsorbent. The effect of temperature, pH, initial Cr(VI) concentration and time was investigated. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) was used to investigate surface morphology and active functional groups present on the adsorbent surface. Thermodynamic parameters like free energy change (ΔG(0)), enthalpy (ΔH-0) and entropy (ΔS-0) indicate the spontaneous, endothermic and increased randomness nature of Cr(VI) adsorption. Equilibrium data were fitted well with Langmuir isotherm at 50ºC. The magnitude of mean free energy indicates chemical nature of adsorption. The breakthrough and exhaustive capacities were found to be 5 and 23.1 mg g^-1 respectively. The applicability of the adsorbent has been demonstrated by removing Cr(VI) from electroplating wastewater. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorption, Agricultural Waste, Aqueous-Solution, Batch, Batch System, Biosorption, Breakthrough, Breakthrough Capacity, Chemical, Chromium(VI) Removal, Concentration, Cr(III), Cr(VI), Cr(VI) Adsorption, Data, Electron Microscopy, Electroplating Waste, Endothermic, Energy, Enthalpy, Entropy, Equilibrium, FTIR, Functional Groups, Heavy-Metals, Hexavalent Chromium, Infrared Spectroscopy, Ion-Exchange, Isotherm, Kinetics, Langmuir, Langmuir Isotherm, Mean Free Energy, Morphology, pH, Randomness, Removal, Rights, SEM, Spectroscopy, Surface, Temperature, Thermodynamic, Thermodynamic Parameters, Wastewater

? Kashiwakura, S., Ohno, H., Matsubae-Yokoyarna, K., Kumagai, Y., Kubo, H. and Nagasaka, T. (2010), Removal of arsenic in coal fly ash by acid washing process using dilute H₂SO₄ solvent. Journal of Hazardous Materials, 181 (1-3), 419-425.

Full Text: 2010\J Haz Mat181, 419.pdf

Abstract: Coal fly ash emitted from coal thermal power plants generally contains tens ppm of arsenic, one of the hazardous elements in coal, during combustion and their elution to soil or water has become a public concern. In this study, the acid washing process developed by the authors was applied to the removal of arsenic from coal fly ash. Laboratory- and bench-scale investigations on the dissolution behavior of arsenic from various coal fly ash samples into dilute H2SO4 were conducted. Arsenic in the coal fly ash samples were dissolved into H2SO4 solutions rapidly. However, its concentrations decreased with an increase in the pH of H2SO4 solution in some cases. The species of arsenic in the dilute H2SO4 was estimated as H3AsO4, and its anionic species was considered to adsorb with the elevation of pH under the presence of ash particle. Such adsorption behavior was enhanced under the presence of Fe ion in the solution. The sufficient removal of arsenic was achieved by controlling pH and avoiding the adsorption of arsenic on the surface of coal fly ash particles, and the elution of arsenic from coal fly ash sample was successfully below the regulation limit. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Acid Washing, Adsorption, Arsenic, Coal Fly Ash, Combustion System, Dependence, Dissolution Mechanism, FeAsO₄.2H₂O, Fired Power-Plant, Leaching Test, Particle-Size, pH, Removal, Selenium, Soil, Solubility, Speciation, Spectroscopy, Trace-Elements, Water

? Li, K.Q., Zheng, Z. and Li, Y. (2010), Characterization and lead adsorption properties of activated carbons prepared from cotton stalk by one-step H₃PO₄ activation. Journal of Hazardous Materials, 181 (1-3), 440-447.

Full Text: 2010\J Haz Mat181, 440.pdf

Abstract: Activated carbons were prepared from cotton stalk by one-step H3PO4 activation and used as adsorbent for the removal of Lead(II). Taguchi experimental design method was used to optimize the preparation of the adsorbents. The results showed that the optimized conditions were: impregnation with a 50% (w/v) phosphoric acid solution with a mass ratio of 3:2 and activation temperature at 500 degrees C for 60 min with the rate of achieving the activation temperature equal to 10 degrees C min(-1). The cotton stalk activated carbon (CSAC) prepared at these conditions have 1.43 mmol g(-1) acidic surface groups and 1570 m(2) g(-1) BET surface area. Adsorption isotherms for Lead(II) on the adsorbents were measured by conducting a series of batch adsorption experiments. The Langmuir maximum adsorption amount of Lead(II) on CSAC was more than 119 mg g(-1), which was superior to the ordinary commercial activated carbon (CAC) on the market. Compared with the CAC. the CSAC had a wider applicable pH range from 3.5 to 6.5 for Lead(II) uptake. The final pH values at equilibrium after adsorption were lower than the initial pH value, indicating that the ion-exchange process was involved in the adsorption. This is also confirmed by the result that the increase of acidic surface groups favored the adsorption process. Thermodynamic study indicated that the adsorption was a spontaneous and endothermic process. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Activated Carbons, Adsorption, Adsorption Isotherms, Adsorption Mechanism, Aqueous-Solutions, Batch, Characterization, Cotton Stalk, Equilibrium, H₃PO₄, Heavy-Metals, Ion Exchange, Ions, Isotherm, Isotherms, Langmuir, Lead, Packed-Bed, Pecan Shell, pH, Phosphoric-Acid Activation, Removal, Surface, Taguchi, Thermodynamic, Waste, Water

? Dong, A.Q., Xie, J., Wang, W.M., Yu, L.P., Liu, Q.A. and Yin, Y.P. (2010), A novel method for amino starch preparation and its adsorption for Cu(II) and Cr(VI). Journal of Hazardous Materials, 181 (1-3), 448-454.

Full Text: 2010\J Haz Mat181, 448.pdf

Abstract: A novel method was proposed to prepare amino starch by reacting ethylenediamine with previously synthesized dialdehyde starch. Different factors affecting the preparation, i.e., ethylenediamine concentration, ethylenediamine:dialdehyde starch molar ratio, pH, duration and temperature have been studied. The modified starch was characterized by IR spectroscopy, elemental analysis, X-ray diffraction and differential scanning calorimetry. The amino starch derivatives were evaluated as adsorbents. The adsorption activity for heavy metals such as Cu(II) and Cr(VI) by crosslinked amino starch was studied in terms of adsorption amount, kinetics and isotherm; and adsorbent reuse were also studied. Adsorption processes for Cu(II) and Cr(VI) on crosslinked amino starch fit a Langmuir isotherm, and adsorption for Cu(II) and Cr(VI) from aqueous solution was endothermic reactions. Crosslinked amino starch was very effective for the adsorption of Cu(II) and Cr(VI), and efficient in capacity, recycled. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Analysis, Cr(VI), Derivatives, Heavy Metal Ions, Heavy Metals, Isotherm, Kinetics, Langmuir, Langmuir Isotherm, Metal-Ions, pH, Preparation, Removal, Reuse, Starch, Water, X-Ray Diffraction

? Wang, L., Liu, Y., Li, J., Liu, X.A., Dai, R.H., Zhang, Y., Zhang, S.Y. and Li, J.R. (2010), Effects of Ni²⁺ on the characteristics of bulking activated sludge. Journal of Hazardous Materials, 181 (1-3), 460-467.

Full Text: 2010\J Haz Mat181, 460.pdf

Abstract: This study investigated effects of the continuous addition of a high-concentration of Ni2+ on the characteristics of bulking activated sludge as well as on the variety and recovery of their ability removing organic pollutants and ammonia in a sequencing batch reactor (SBR). To the knowledge of the authors, this is the first study to examine the changes in quantity and composition of the extracellular polymeric substances (EPS) in bulking activated sludge before and after the addition of a high-concentration of Ni2+. The correlation between these changes and the sludge characteristics was also investigated. The results showed that after a 40-day acclimation to the addition of 60 mg/L Ni2+, the ability to remove organic pollutants was recovered; but the ability to remove ammonia was not. The addition of Ni2+ made a great change in the quantity and composition of the EPS in bulking sludge, including both exterior soluble EPS (EPSs) and interior bound EPS (EPSb), showing a slight increase followed by a large decrease before reaching a steady state. The difference between the change in the amounts of EPSs and EPSb was not significant. However, among the component fractions, the change in protein content was obvious than that of polysaccharide and humic acid. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Activated Sludge, Adsorption, Ammonia-Nitrogen, Batch, Biosorption Properties, Bulking, Cadmium, EPS, Extracellular Polymeric Substances, Extracellular Polymeric Substances (EPS), Heavy-Metals, Metal Toxicity, Ni²⁺, Nickel, Nitrification Inhibition, Speciation

? Zhang, W., Li, C.Y., Mei, L.A., Geng, Y.M. and Lu, C.H. (2010), Preparation of carboxylate-functionalized cellulose via solvent-free mechanochemistry and its characterization as a biosorbent for removal of Pb²⁺ from aqueous solution. Journal of Hazardous Materials, 181 (1-3), 468-473.

Full Text: 2010\J Haz Mat181, 468.pdf

Abstract: Carboxylate-functionalized cellulose can be used as a low cost but effective biosorbent for heavy metals remediation. In this study, it was simply fabricated from wood cellulose and succinic anhydride via solvent-free mechanochemistry in the absence of catalyst at ambient temperature through pan-milling. Fourier transform infrared spectra (FT-IR) confirmed the realization of mechanochemical esterification of cellulose. Reaction kinetics study showed that this solid-state mechanochemical reaction was governed by “slow followed by fast” kinetics model. The reaction sites were mainly at the new surface of cellulose powder where hydrogen bondings in cellulose were broken up and hydroxyl groups were activated due to the fairly strong forces imposed by the pan-mill. X-ray photoelectron spectroscopy (XPS) indicated that the mechanochemical succinylation of cellulose occurred even in a short milling time. The exponential increment of surface area of cellulose during pan-milling was correlated to the increasing substitution degree. Preliminary adsorption studies showed that the modified cellulose possessed excellent adsorption capacity towards Pb2+, with lead ion uptake value of 422 mg/g and 84.4% metal removal from a 500 mg/g Pb2+ solution, significantly higher than those values for unmodified cellulose. (C) 2010 Published by Elsevier B.V.

Keywords: Adsorption, Adsorption Capacity, Agents, Anhydride, Biosorbent, Biosorption, Cd(II), Cellulose, Coir Pith, Cu(II), Fourier Transform Infrared, FTIR, Hardwood, Heavy Metals, Infrared, Infrared Spectra, Kinetics, Lead, Mechanochemistry, Metal Removal, Preparation, Remediation, Removal, Solid-State, Sugarcane Bagasse, Surface Modification, X-Ray Photoelectron Spectroscopy, XPS

? Hena, S. (2010), Removal of chromium hexavalent ion from aqueous solutions using biopolymer chitosan coated with poly 3-methyl thiophene polymer. Journal of Hazardous Materials, 181 (1-3), 474-479.

Full Text: 2010\J Haz Mat181, 474.pdf

Abstract: Adsorption capacity of Cr(VI) onto chitosan coated with poly 3-methyl thiophene synthesized chemically was investigated in a batch system by considering the effects of various parameters like contact time, initial concentration, pH and temperature. Cr(VI) removal is pH dependent and found to be maximum at pH 2.0. Increases in adsorption capacity with increase in temperature indicate that the adsorption reaction is endothermic. Based on this study, the thermodynamic parameters like standard Gibbs free energy (ΔGº), standard enthalpy (ΔHº) and standard entropy (ΔSº) were evaluated. Adsorption kinetics of Cr(VI) ions onto chitosan coated with poly 3-methyl thiophene were analyzed by pseudo-first-order and pseudo-second-order models. The Langmuir, Freundlich and Temkin isotherms were used to describe the adsorption equilibrium studies of chitosan coated with poly 3-methyl thiophene at different temperatures. Langmuir isotherm shows better fit than Freundlich and Temkin isotherms in the temperature range studied. The results show that the chitosan coated with poly 3-methyl thiophene can be efficiently used for the treatment of wastewaters containing chromium as a low cost alternative compared to commercial activated carbon and other adsorbents reported. In order to find out the possibility of regeneration and reuse of exhausted adsorbent, desorption studies were also performed. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorbents, Adsorption, Adsorption Capacity, Adsorption Equilibrium, Adsorption Kinetics, Alternative, Aqueous Solutions, Batch, Batch System, Capacity, Carbon, Chitosan, Chromium, Chromium(VI) Removal, Coated, Concentration, Cost, Cr(VI), Cr(VI) Removal, Desorption, Desorption Studies, Endothermic, Energy, Enthalpy, Entropy, Equilibrium, Equilibrium Studies, Freundlich, Gibbs Free Energy, Ions, Isotherm, Isotherms, Kinetics, Langmuir, Langmuir Isotherm, Low Cost, Models, pH, pH-Dependent, Poly 3-Methyl Thiophene, Polymer, Pseudo First Order, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Regeneration, Removal, Reuse, Rights, Sawdust, Shell, Solutions, Sorption, Standard, Temperature, Thermodynamic, Thermodynamic Parameters, Thermodynamics, Thiophene, Treatment, Wastewaters

? Silva, A.M., Cruz, F.L.S., Lima, R.M.F., Teixeira, M.C. and Leão, V.A. (2010), Manganese and limestone interactions during mine water treatment. Journal of Hazardous Materials,