Personal Research Database

184 (1-3), 147-155.

Full Text: 2010\J Haz Mat184, 147.pdf

Abstract: In this study, a novel Zn-Al-O binary metal oxide adsorbent was prepared and used to remove the emerging polar contaminant benzotriazole from water. The adsorption behavior, kinetics and mechanism were systemically studied. Results showed that benzotriazole was rapidly and effectively adsorbed by the adsorbent. Instantaneous adsorption was observed under each studied condition, and the adsorption reached equilibrium within 30 min. High initial benzotriazole concentration enhanced the adsorption. The amount of absorbed benzotriazole increased with increasing adsorbent dosage, but decreased with increasing ionic strength. Solution pH had little effect on benzotriazole adsorption. The adsorption isotherm was consistent with S-type. Langmuir isotherm model fitted the equilibrium data better than Freundlich, Dubinin-Radushkevich and Temkin isotherm models. The maximum monolayer adsorptive capacity of benzotriazole with and without electrolytes was 7.30 mg g(-1) and 9.51 mg g(-1). respectively. Elovich and pseudo-second-order models were most suitable for describing the adsorption kinetics. Interactions between the surface sites of the adsorbent and benzotriazole may be a combination of electrostatic interaction, ion exchange and hydrogen bond. (c) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption, Adsorption Isotherm, Adsorption Kinetics, Aqueous-Solution, Benzotriazole, Cadmium, Capacity, Contaminants, Corrosion-Inhibitors, Data, Dubinin-Radushkevich, Elovich, Equilibrium, Exchange, Fluoride, Freundlich, Hydrogen, Hydroxide, Ion Exchange, Isotherm, Isotherm Models, Kinetics, Langmuir, Langmuir Isotherm, Mechanism, Mixed-Oxide, Model, Models, Oxide, pH, Polar Contaminant, Pseudo Second Order, Pseudo-Second-Order, Removal, Sorption, Temkin, Temkin Isotherm, Waste-Water, Water, Zn-Al-O Binary Metal Oxide

? Sismanoglu, T., Kismir, Y. and Karakus, S. (2010), Single and binary adsorption of reactive dyes from aqueous solutions onto clinoptilolite. Journal of Hazardous Materials, 184 (1-3), 164-169.

Full Text: 2010\J Haz Mat184, 164.pdf

Abstract: The adsorption of Reactive Blue 21 (RB21) and Reactive Red 195 (RR195) onto clinoptilolite type natural zeolite (ZEC) has been investigated at 298.15K. The uptake of single and binary reactive dyes from aqueous solutions has been determined by UV-vis spectroscopy. Two mono-component (RB21 and RR195) and binary component (RB21 with RR195, and RR195 with RB21), isotherms were determined. The mono-component Langmuir isotherm model was applied to experimental data and the isotherm constants were calculated for RB21 and RR195 dyes. The monolayer coverage capacities of clinoptilolite for RB21 and RR195 dyes in single solution system were found as 9.652 and 3.186 mg/g, respectively. Equilibrium adsorption for binary systems was analyzed by using the extended Langmuir models. The rate of kinetic processes of single and binary dye systems onto clinoptilolite was described by using two kinetics adsorption models. The pseudo-second-order model was the best choice among the kinetic models to describe the adsorption behaviour of single and binary dyes onto clinoptilolite. (c) 2010 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Adsorption Isotherms, Aqueous Solutions, Biopolymer Chitin, Clinoptilolite, Data, Degradation, Dye, Dyes, Equilibrium, Equilibrium Adsorption, Isotherm, Isotherms, Kinetic, Kinetic Models, Kinetics, Kinetics Models, Langmuir, Langmuir Isotherm, Model, Models, Natural Zeolite, Processes, Pseudo Second Order, Pseudo-Second-Order, Reactive Dyes, Reactive Red 195, Removal, Single And Binary Adsorption, Sorption, System, Uptake, Wastes, Zeolite

? Hao, Y.M., Chen, M. and Hu, Z.B. (2010), Effective removal of Cu(II) ions from aqueous solution by amino-functionalized magnetic nanoparticles. Journal of Hazardous Materials, 184 (1-3), 392-399.

Full Text: 2010\J Haz Mat184, 392.pdf

Abstract: A novel magnetic nano-adsorbent (MNP-NH2) has been developed by the covalent binding of 1,6-hexadiamine on the surface of Fe3O4 nanoparticles for removal of Cu2+ ions from aqueous solution. Various factors affecting the uptake behavior such as contact time, temperature, pH, salinity, amount of MNP-NH2 and initial concentration of Cu2+ were investigated. The kinetics was evaluated utilizing the Lagergren pseudo-first-order, pseudo-second-order, Elovich and intra-particle diffusion models. The equilibrium data were analyzed using Langmuir. Freundlich, and Dubinin-Radushkevich isotherms. The adsorption was relatively fast and the equilibrium was established within 5 min, and its kinetics followed the pseudo-second-order mechanism, evidencing chemical sorption as the rate-limiting step of sorption mechanism. The best interpretation for the equilibrium data was given by Langmuir isotherm, and the maximum adsorption capacities was 25.77 mg g(-1) at pH 6, and 298 K. Thermodynamic parameters showed that the adsorption process was spontaneous, endothermic and chemical in nature. The successive adsorption-desorption studies indicated that the MNP-NH2 sorbent kept its adsorption and desorption efficiencies constant over 15 cycles. Importantly, MNP-NH2 was able to remove 98% of Cu2+ from polluted river and tap water. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Properties, Amino-Functionalized, Carbon Nanotubes, Composite Adsorbent, Contact Time, Copper, Copper Ions, Cu, Cu(II) Ions, Cu2+, Cycles, Data, Desorption, Diffusion, Dubinin-Radushkevich, Elovich, Equilibrium, Freundlich, Heavy-Metals, Intra Particle Diffusion, Intra-Particle Diffusion, Intraparticle Diffusion, Isotherm, Isotherms, Kinetics, Langmuir, Langmuir Isotherm, Magnetic Nanoparticle, Mechanism, Metal-Ions, Models, Nano-Adsorbent, Nanoparticles, pH, Process, Pseudo Second Order, Pseudo-Second-Order, Removal, Salinity, Sorbent, Sorption, Sorption Mechanism, Temperature, Thermodynamic, Thermodynamic Parameters, Uptake, Waste-Water, Water

? Recillas, S., Colón, J., Casals, E., González, E., Puntes, V., Sánchez, A. and Font, X. (2010), Chromium VI adsorption on cerium oxide nanoparticles and morphology changes during the process. Journal of Hazardous Materials, 184 (1-3), 425-431.

Full Text: 2010\J Haz Mat184, 425.pdf

Abstract: In this study, suspended cerium oxide nanoparticles stabilized with hexamethylenetetramine were used for the removal of dissolved chromium VI in pure water. Several concentrations of adsorbent and adsorbate were tested, trying to cover a large range of possible real conditions. Results showed that the Freundlich isotherm represented well the adsorption equilibrium reached between nanoparticles and chromium, whereas adsorption kinetics could be modeled by a pseudo-second-order expression. The separation of chromium-cerium nanoparticles from the medium and the desorption of chromium using sodium hydroxide without cerium losses was obtained. Nanoparticles agglomeration and morphological changes during the adsorption-desorption process were observed by TEM. Another remarkable result obtained in this study is the low toxicity in the water treated by nanoparticles measured by the Microtox (R) commercial method. These results can be used to propose this treatment sequence for a clean and simple removal of drinking water or wastewater re-use when a high toxicity heavy metal such as chromium VI is the responsible for water pollution. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Equilibrium, Adsorption Kinetics, Aqueous-Solution, CeO₂ Nanoparticles, CeO₂ Nanoparticles, Chromium, Chromium Vi, Cr(VI), Desorption, Drinking Water, Equilibrium, Freundlich, Freundlich Isotherm, Gold Nanoparticles, Heavy Metal, Heavy-Metals, Isotherm, Kinetics, Mechanism, Morphology, Nanoparticles, Oxide, Pollution, Process, Pseudo Second Order, Pseudo-Second-Order, Removal, Reuse, Separation, Sodium Hydroxide, TEM, Toxicity, Toxicity, Treatment, Vi, Wastewater, Water, Water Pollution, Water-Treatment

? Magriotis, Z.M., Leal, P.V.B., Sales, P.F., Papini, R.M. and Viana, P.R.M. (2010), Adsorption of etheramine on kaolinite: A cheap alternative for the treatment of mining effluents. Journal of Hazardous Materials, 184 (1-3), 465-471.

Full Text: 2010\J Haz Mat184, 465.pdf

Abstract: The results of laboratory experiments aimed at determining the influence of physicochemical parameters on the adsorption of etheramine (adsorbate) on white, pink and yellow kaolinites (adsorbent) are presented. The adsorption of etheramine was favoured at pH 10.0 under conditions where the initial concentration of etheramine was 200 mg l(-1) and the ratio of adsorbent to volume of etheramine solution was 1:100 g ml(-1). Equilibrium adsorption was attained within 30 min and the efficiencies of removal of etheramine by white, pink and yellow kaolinite were 77%, 80% and 69%, respectively. The adsorption isotherms of the kaolinites were determined under optimum conditions and with adsorbate in the concentration range of 0-4000 mg l(-1). The amounts of etheramine adsorbed per unit mass of adsorbent were 33.03, 34.32 and 23.11 mg g(-1) for white, pink and yellow kaolinites, respectively. The adsorption of etheramine on kaolinites was better fitted to the Langmuir rather than the Freundlich isotherm, and could be explained by a pseudo-second-order kinetic model. It is concluded that kaolinites offer significant potential in the treatment of effluents originating from the processing of lower grade iron ores by froth flotation. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Isotherms, Aqueous-Solutions, Clay, Copper, Design, Effluents, Equilibrium, Equilibrium Adsorption, Etheramine Removal, Flotation, Freundlich, Freundlich Isotherm, Iron, Iron Ore, Isotherm, Isotherms, Kaolinite, Kinetic, Kinetic Model, Langmuir, Methylene-Blue, Model, Montmorillonite, pH, Polyacrylamide, Pseudo Second Order, Pseudo-Second-Order, Removal, Sorption, Treatment, Volume

? Ahmed, I.A.M., Young, S.D. and Crout, N.M.J. (2010), Ageing and structural effects on the sorption characteristics of Cd²⁺ by clinoptilolite and Y-type zeolite studied using isotope exchange technique. Journal of Hazardous Materials, 184 (1-3), 574-584.

Full Text: 2010\J Haz Mat184, 574.pdf

Abstract: This research investigates the long-term kinetics of Cd(2+) sorption and desorption by calcium-exchanged clinoptilolite (CaCpt) and Y-type (CaY) zeolite using isotopic exchange with (109)Cd while maintaining pH at circumneutral values. The effects of Si/Al ratio and crystal structure of these zeolitic materials on intracrystalline transport of Cd are discussed. A first-order kinetic model was developed to describe the progressive transfer of Cd(2+) to a less reactive form within the zeolite structure, following initial sorption and subsequent desorption of Cd subject to different initial contact times. The kinetic model differentiates between two forms of sorbed Cd(2+) designated ‘labile’ and ‘non-labile’ in which the labile form is in immediate equilibrium with the free Cd(2+) ion activity in solution. A model combining diffusion and first-order kinetics for cation exchange was also employed to determine Cd(2+) diffusivity and intracrystalline exchange rates in CaY and CaCpt. The efficiency of Permeable Reactive Barriers (PRBs) containing zeolitic materials in protecting water systems against lateral flow of metal-contaminated leachate was simulated for three contrasting zeolites. The slow transfer of Cd between labile and non-labile forms was particularly important in moderating high concentration pulses of Cd traversing the PRB. In addition, the reversibility of Cd fixation effectively restored the sorption capability of the zeolite through slow leakage to drainage water. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Cadmium, Cadmium, Cation Exchange, Cd²⁺, Clinoptilolite, Crystal-Structure, Cu²⁺, Desorption, Diffusion, Equilibrium, First Order, First-Order Kinetics, Fixation, Ion-Exchange, Isotopic Exchange, Kinetic, Kinetic Model, Kinetics, Leachate, Lead, Leakage, Model, Natural Clinoptilolite, Pb²⁺, Permeable Reactive Barriers, pH, Ratio, Removal, Research, Sodium, Sorption, Thermal-Stability, Zeolite

? Rathinam, A. and Zou, L. (2010), Biosorption of bovine serum albumin by Ulva lactuca biomass from industrial wastewater: Equilibrium, kinetic and thermodynamic study. Journal of Hazardous Materials, 184 (1-3), 597-602.

Full Text: 2010\J Haz Mat184, 597.pdf

Abstract: Batch biosorption experiments have been carried out for the removal of bovine serum albumin (BSA) from simulated industrial wastewater onto Ulva lactuca seaweed. Various vital parameters influencing the biosorption process such as initial concentration of BSA. pH of the solution, adsorbent dosage and temperature have been determined. The biosorption kinetics follows a pseudo-second order kinetic model. Equilibrium isotherm studies demonstrate that the biosorption followed the Freundlich isotherm model, which implies a heterogeneous sorption phenomenon. Various thermodynamic parameters such as changes in enthalpy, free energy and entropy have been calculated. The positive value of Delta H degrees and the negative value of Delta G degrees show that the sorption process is endothermic and spontaneous. The positive value of change in entropy Delta S degrees shows increased randomness at the solid-liquid interface during the biosorption of BSA onto U. lactuca seaweed. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Alga, Aqueous-Solution, Biomass, Biosorbent, Biosorption, BSA, Dye, Equilibrium, Equilibrium Isotherm, Freundlich, Freundlich Isotherm, Industrial, Industrial Wastewater, Isotherm, Isotherm Studies, Kinetic, Kinetic Model, Kinetics, Model, pH, Process, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second-Order, Removal, Seaweed, Sorption, Temperature, Thermodynamic, Thermodynamic Parameters, Thermodynamics, Ulva Lactuca, Wastewater

? Bouzidi, A., Souahi, F. and Hanini, S. (2010), Sorption behavior of cesium on Ain Oussera soil under different physicochemical conditions. Journal of Hazardous Materials, 184 (1-3), 640-646.

Full Text: 2010\J Haz Mat184, 640.pdf

Abstract: In the present study, the sorption behavior of cesium was investigated in Ain Oussera soil around the Es-Salam reactor facility. This study was conducted using batch method under different physicochemical conditions including contact time, ionic strength, pH, solid/liquid ratio and temperature. The results showed that sorption followed pseudo-second-order kinetics with a good regression coefficients (R-2=0.999). The activation energies were 11.26 and 15.21 kJ mol(-1) which correspond to ion-exchange-type sorption mechanism. The adsorption was favored at low temperature and it was exothermic (Delta H-0 <0, with average value of -1.97 kJ mol(-1)) and spontaneous (Delta G degrees < 0, with average value of -11.97 kJ mol(-1) at 23 degrees C and -13.2 kJ mol(-1) at 60 degrees C). The presence of competing cations such as K+ and Ca2+ ions in groundwater can significantly reduce the Cs adsorption onto soil. Desorption reaction was also investigated using three reagents with different ionic strengths (deionized water, groundwater and 0.1 M KCl solution). The results showed that Cs ions were preferentially distributed onto high affinity sorption sites. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Activation, Adsorption, Ain Oussera Soil, Batch, Bentonite, Ca²⁺, Cesium, Contact Time, Desorption, Exchange, Granite, Hanford Site, Illite, Ions, Kinetics, Mechanism, Minerals, pH, Pseudo Second Order, Pseudo-Second-Order, Reactor, Soil, Sorption, Sorption Mechanism, Subsurface Sediments, Temperature, Water

? Yazdanbakhsh, M., Khosravi, I., Goharshadi, E.K. and Youssefi, A. (2010), Fabrication of nanospinel ZnCr₂O₄ using sol-gel method and its application on removal of azo dye from aqueous solution. Journal of Hazardous Materials, 184 (1-3), 684-689.

Full Text: 2010\J Haz Mat184, 684.pdf

Abstract: For the first time, nanoparticles of zinc chromite, spinel ZnCr2O4 have been fabricated by the thermal decomposition of Zn-Cr gel prepared by sol-gel method in the presence of oxalic acid as a chelating agent. It was shown that the well-crystallized spinel structure is formed after calcination at 450 degrees C. The nanospinel has been characterized by differential thermal analysis (DTA). X-ray powder diffraction (XRD), infrared spectroscopy (IR), and transmission electron microscope (TEM). The average particle size is approximately 13 nm according to the TEM image. The nanoparticles of zinc chromites showed excellent adsorption properties towards reactive dye, reactive blue 5 (RB5). The adsorption studies have been carried out for contact time, different pH values, different temperatures, and adsorbent doses. The investigation of removal kinetics of RB5 indicates that the removal process obeys the rate of second-order kinetic equation. The results indicate that the Langmuir adsorption isotherm fitted the data better than the Freundlich. Also, the photocatalytic degradation of RB5 using spinel ZnCr2O4 under UV irradiation at pH = 1 has been also examined. The results showed that the degradation of RB5 dye follows merely an adsorption process. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Isotherm, Analysis, Azo Dye, Azo-Dye Removal, Catalytic Combustion, Co, Contact Time, Cr, Data, Degradation, Dye, Freundlich, Infrared, IR, Irradiation, Isotherm, Kinetic, Kinetics, Langmuir, Langmuir Adsorption, Langmuir Adsorption Isotherm, Nanoparticles, Nanostructures, Oxide, pH, Powders, Process, Properties, Reactive Blue 5, Reactive Dye, Removal, Second-Order, Sensing Properties, Sol-Gel, Sol-Gel Growth, System, TEM, UV, X-Ray, XRD, Zinc, ZnCr₂O₄

? Wang, G.H., Zhou, Y.M., Wang, X.G., Chai, X.J., Huang, L. and Deng, N.S. (2010), Simultaneous removal of phenanthrene and lead from artificially contaminated soils with glycine-beta-cyclodextrin. Journal of Hazardous Materials, 184 (1-3), 690-695.

Full Text: 2010\J Haz Mat184, 690.pdf

Abstract: Preparation of glycine-beta-cyclodextrin (GCD) was carried out by the reaction of beta-cyclodextrin with glycine in the presence of KOH and epichlorohydrin. The enhanced solubilization behavior of phenanthrene and lead carbonate by GCD was studied, and the desorption behavior of phenanthrene and lead from co-contaminated soil was also investigated. The results showed that GCD has obvious solubilization for phenanthrene and lead carbonate. The solubility of phenanthrene in 30 g/L of GCD was enhanced about 30-fold. And the apparent aqueous solubilities of lead carbonate are also obviously increased with increasing GCD concentration, when the concentration of GCD reached 20 g/L, the aqueous lead concentration was 2945 mg/L GCD could simultaneously increase the apparent aqueous solubility of phenanthrene and complex with lead. The desorption process of GCD for phenanthrene and lead from co-contaminated soil followed the pseudo-second-order kinetic model. The removal efficiencies of phenanthrene and lead in soil increased dramatically with increasing GCD concentrations. At concentration of 40 g/L, GCD has a removal efficiency of 85.8% and 78.8% for lead and phenanthrene, respectively, from the combined contaminated soil. The use of GCD as an extractant to enhance the removal of heavy and hydrophobic organic contaminants (HOCs) from co-contaminated soils appears as a promising remediation method. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Cadmium, Co-Contaminated Soil, Complex, Desorption, Glycine, Glycine-Beta-Cyclodextrin, Heavy-Metals, Hydrophobic, Kinetic, Kinetic Model, KOH, Lead, Model, Phenanthrene, Polarity Organic-Compounds, Preparation, Process, Pseudo Second Order, Pseudo-Second-Order, Remediation, Remediation, Removal, Removal Efficiency, Soil, Soils, Solubility, Water

? Liu, T.Y., Zhao, L., Sun, D.S. and Tan, X. (2010), Entrapment of nanoscale zero-valent iron in chitosan beads for hexavalent chromium removal from wastewater. Journal of Hazardous Materials, 184 (1-3), 724-730.

Full Text: 2010\J Haz Mat184, 724.pdf

Abstract: Nanoscale zero-valent iron (NZVI) was successfully entrapped in chitosan (CS) beads for reduction of Cr(VI) from wastewater. The removal mechanism may include both physical adsorption of Cr(VI) on the surface or inside of CS-NZVI beads and subsequent reduction of Cr(VI) to Cr(III). The free amino groups and hydroxyl groups on CS may contribute little to hinder the formation of Fe(III)-Cr(III) precipitate. Entrapment of NZVI in CS beads prevents the particles from aggregation and oxidation. The results indicate that there is no significant difference between the reaction rates of bare NZVI and entrapped NZVI. Cr(VI) reduction kinetics follows a pseudo-first-order rate expression. The reduction capacity for Cr(VI) increases with increasing temperature and NZVI dosage but decreases with the increase in initial concentration of Cr(VI) and pH values. This study demonstrates that entrapment of NZVI in CS beads has the potential to become a promising technique for in situ groundwater remediation. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.

Keywords: Adsorption, Capacity, Chitosan, Chromium, Chromium Removal, Copyright, Cr(VI), Cs, Cs-NZVI Beads, Groundwater, Hexavalent, Hexavalent Chromium, Hydrogel Beads, Iron, Kinetics, Mechanism, Metal, Nanoparticles, Nanoscale Zero-Valent Iron (NZVI), Oxidation, pH, Pseudo-First-Order, Ray Photoelectron-Spectroscopy, Reaction Rates, Reduction, Remediation, Removal, Wastewater, Zero-Valent Iron, Zerovalent Iron

? Olu-Owolabi, B.I. and Unuabonah, E.I. (2010), Kinetic and thermodynamics of the removal of Zn²⁺ and Cu²⁺ from aqueous solution by sulphate and phosphate-modified Bentonite clay. Journal of Hazardous Materials, 184 (1-3), 731-738.

Full Text: 2010\J Haz Mat184, 731.pdf

Abstract: The modification of pristine Bentonite clay with sulphate and phosphate anions was found to increase its cation-exchange capacity (CEC), adsorption capacity and overall pseudo-second order kinetic rate constant for the adsorption of Cu2+ and Zn2+. Modification with sulphate and phosphate anion decreased the specific surface area of pristine Bentonite clay. Phosphate-modified Bentonite clay was found to give the highest adsorption capacity for both metal ions. The adsorption process was observed to be endothermic and spontaneous in nature for both metal ions with Zn2+ being more adsorbed. Modification with phosphate anion increased the spontaneity of the adsorption process. The effective modification of pristine Bentonite clay with sulphate anion was confirmed from hypochromic shifts in the range of 13-18 cm(-1) which is typical of physisorption while modification with phosphate anion was confirmed by its hyperchromic shifts typical of chemisorption in the infrared red region using Fourier transformed infrared spectroscopy (FTIR). Using the model efficiency indicator, kinetic data were found to show very strong fit to the pseudo-second order kinetic model implying that the adsorption of Cu2+ and Zn2+ were basically by chemisorption. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption, Adsorption Capacity, Bentonite, Bentonite Clay, Cadmium Ions, Capacity, Cation Exchange, Cation Exchange Capacity, Chemisorption, Clay, Cu²⁺, Data, FTIR, Heavy-Metals, Infrared, Kaolinite Clay, Kinetic, Kinetic Model, Kinetics, Lead, Mechanism, Metal Ions, Minerals, Model, Modification, Montmorillonite, Phosphate, Process, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second-Order, Rate Constant, Removal, Sulphate, Surface Area, Thermodynamics, Titration, Zinc, Zn²⁺

? Das, D., Das, N. and Mathew, L. (2010), Kinetics, equilibrium and thermodynamic studies on biosorption of Ag(I) from aqueous solution by macrofungus Pleurotus platypus. Journal of Hazardous Materials,