Personal Research Database

Full Text: J\J Haz Mat89, 185.pdf

Abstract: Activated carbon prepared from rubber seed coat (RSCC), an agricultural waste by-product, has been used for the adsorption of phenol from aqueous solution. In this work, adsorption of phenol on rubber seed coat activated carbon has been studied by using batch and column studies. The equilibrium adsorption level was determined to be a function of the solution pH, adsorbent dosage and contact time. The equilibrium adsorption capacity of rubber seed coat activated carbon for phenol removal was obtained by using linear Freundlich isotherm. The adsorption of phenol on rubber seed coat activated carbon follows first order reversible kinetics. The suitability of RSCC for treating phenol based resin manufacturing industry wastewater was also tested. A comparative study with a commercial activated carbon (CAC) showed that RSCC is 2.25 times more efficient compared to CAC based on column adsorption study for phenolic wastewater treatment. (C) 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Activated Carbon, Rubber Seed Coat, Adsorption, Phenol, Wastewater

Leyva Ramos, R., Bernal Jacome, L.A., Mendoza Barron, J., Fuentes Rubio, L. and Guerrero Coronado, R.M. (2002), Adsorption of zinc(II) from an aqueous solution onto activated carbon. Journal of Hazardous Materials, 90 (1), 27-38.

Full Text: J\J Haz Mat90, 27.pdf

Abstract: Adsorption isotherms were measured experimentally for Zn(II) adsorption from aqueous solution onto commercial activated carbons C, F-400, F-300 and Centaur HSL in a batch adsorber. The effects of carbon type and solution pH on adsorption isotherms were evaluated in this work. Nearly three times as much Zn(II) adsorbed onto C carbon as on the other three carbon types. The adsorption isotherm for Zn(II) was dependent on solution pH since Zn(II) did not adsorb to carbon below pH 2, and the adsorption isotherm increased as pH increased from 3 to 7. The adsorption isotherm of Zn(II) on C carbon was temperature independent while on F-400 the isotherm showed unusual behavior as temperature increased. (C) 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Activated Carbon, Adsorption, Aqueous Solution, Zinc(II)

Chu, K.H. (2002), Removal of copper from aqueous solution by chitosan in prawn shell: Adsorption equilibrium and kinetics. Journal of Hazardous Materials, 90 (1), 77-95.

Full Text: J\J Haz Mat90, 77.pdf

Abstract: The metal removal capability of prawn shell is evaluated in this study using copper as a model sorbate. A mild deacetylation method was used to convert chitin on the periphery of the shell to chitosan. The equilibrium and kinetic characteristics of copper adsorption on partially deacetylated prawn shell are studied in batch stirred-tank experiments. The extent of copper removal increases with an increase in pH. Both the Langmuir model with pH-dependent parameters and the extended Langmuir-Freundlich model with pH-independent parameters account very well for the measured equilibrium data. Modeling studies using two different second order surface reaction models demonstrate that transient profiles obtained experimentally for a range of initial metal concentrations (C-0) and adsorbent dosage are in good agreement with calculated curves of both models. The two rate models can be used for an accurate description of measured kinetic data so long as their rate constants are properly correlated with the two system variables. In contrast, deviation exists between experimental data and theoretical curves calculated from a diffusion-based model. Crown Copyright (C) 2002 Published by Elsevier Science B.V. All rights reserved.

Keywords: Adsorption, Chitosan, Heavy Metals, Crustacean Shell, Kinetics, Chelating-Agents, Chitin, Sorbents, Sorption, Beads

Mohan, S.V., Rao, N.C. and Karthikeyan, J. (2002), Adsorptive removal of direct azo dye from aqueous phase onto coal based sorbents: A kinetic and mechanistic study. Journal of Hazardous Materials, 90 (2), 189-204.

Full Text: J\J Haz Mat90, 189.pdf

Abstract: This communication presents the results pertaining to the investigation conducted on color removal of trisazo direct dye, C.I.Direct Brown 1:1 by adsorption onto coal based sorbents viz. charfines, lignite coal, bituminous coal and comparing results with activated carbon (Filtrasorb-400). The kinetic sorption data indicated the sorption capacity of the different coal based sorbents. The sorption interaction of direct dye on to coal based sorbents obeys first-order irreversible rate equation and activated carbon fits with the first-order reversible rate equation. Intraparticle diffusion studies revealed the dye sorption interaction was complex and intraparticle diffusion was not only the rate limiting step. Isothermal data fit well with the rearranged Langmuir adsorption model. R-L factor revealed the favorable nature of the isotherm of the dye-coal system. Neutral solution pH yielded maximum dye color removal. Desorption and interruption studies further indicated that the coal based sorbents facilitated chemisorption in the process of dye sorption while, activated carbon resulted in physisorption interaction. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: Adsorption, Direct Azo Dye, Coal Based Sorbents, Kinetics Study, First-Order Rate Reaction, Intraparticle Diffusion, Langmuir Isotherm, Chemisorption and Physisorption, Waste-Water, Triphenylmethane Dyes, Color, Silica, Adsorbents, Sorption

? Lin, S.H. and Wang, C.S. (2002), Treatment of high-strength phenolic wastewater by a new two-step method. Journal of Hazardous Materials, 90 (2), 205-216.

Full Text: 2002\J Haz Mat90, 205.pdf

Abstract: Treatment of high-strength phenolic wastewater by a novel two-step method was investigated in the present study. The two-step treatment method consisted of chemical coagulation of the wastewater by metal chloride followed by further phenol reduction by resin adsorption. The present combined treatment was found to be highly efficient in removing the phenol concentration from the aqueous solution and was proved capable of lowering the initial phenol concentration from over 10,000 mg/l to below direct discharge level (1 mg/l). In the experimental tests, appropriate conditions were identified for optimum treatment operation. Theoretical investigations were also performed for batch equilibrium adsorption and column adsorption of phenol by macroreticular resin. The empirical Freundlich isotherm was found to represent well the equilibrium phenol adsorption. The column model with appropriately identified model parameters could accurately predict the breakthrough times. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: 2-Chlorophenol, Adsorption, Adsorption Isotherm, Aqueous Solution, Aqueous-Solution, Batch, Breakthrough, Chemical Coagulation, Chemical Precipitation, Coagulation, Column, Column Adsorption, Column Adsorption Model, Combined Treatment, Discharge, Equilibrium, Extraction, Freundlich, Freundlich Isotherm, Granular Activated Carbon, High-Strength Phenolic Wastewater, Isotherm, Metal, Metal Chlorides, Novel, Phenol, Phenol Adsorption, Reduction, Resin, Rights, Treatment, Wastewater, Water, Wet Air Oxidation

Koumanova, B. and Peeva-Antova, P. (2002), Adsorption of p-chlorophenol from aqueous solutions on bentonite and perlite. Journal of Hazardous Materials, 90 (3), 229-234.

Full Text: J\J Haz Mat90, 229.pdf

Abstract: The adsorption of p-chlorophenol (p-CP) from aqueous solutions on bentonite and perlite was studied. These materials are available in large quantities in Bulgaria. Model solutions of various concentrations (1-50 mg dm^-3) were shaken with certain amounts of adsorbent to determine the adsorption capacity of p-CP on bentonite and perlite as well. The influence of several individual variables (initial adsorbate concentration, adsorbent mass) on the rate of uptake of the studied compound on the adsorbent was determined by carrying out experiments at different contact times using the batch adsorber vessel designed according to the standard tank configuration. Rapid adsorption was observed 20-30 min after the beginning for every experiment. After that, the concentration of p-CP in the liquid phase remained constant. The adsorption equilibrium of p-CP on bentonite and perlite was described by the Langmuir and the Freundlich models. A higher adsorption capacity was observed for bentonite (10.63 mg g^-1 compared to that for perlite (5.84 mg g^-1). (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: Adsorption, Bentonite, Perlite, P-Chlorophenol, Isotherms, Waste-Water, Expanded Perlite, Sorption

? Mohamed, A.M.O. (2002), Development of a novel electro-dialysis based technique for lead removal from silty clay polluted soil. Journal of Hazardous Materials, 90 (3), 297-310.

Full Text: 2002\J Haz Mat90, 297.pdf

Abstract: In this study, a novel electro-dialysis based technique has been developed and used to treat a silty clay soil polluted by lead. The effect of chemical reagents, i.e. tap water at pH 4 (reagent 1) and sodium acetate at pH 5 (reagent 2), on enhancing electro-dialysis extraction of lead from the tested soil was examined. Specimens were prepared by mixing soil with 1000 ppm of lead and were compacted in the dialysate at predetermined dry density and moisture content. Then, specimens were subjected to a predetermined level of current. In the dialysate compartment, anions and cations were removed by charge transport in opposite directions to the anodic and cathodic cells. Meanwhile, in the anodic and cathodic cells, ion concentrations were increased. Thus, concentrated electrolyte streams were produced in alternating cells and cleaned soils were obtained in the dialysate. Both soil pH and lead concentrations were uniformly distributed within the compacted soil specimen during testing. Total lead removal of 80 and 92% was obtained for reagents I and 2, respectively. The high removal efficiency was attributed to the separation of electrode reactions from the soil and inclusion of ion selective membranes (ISM), which restrict the movement of counter charged species. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: Acetate, Adsorption, Anions, Anode, Cadmium, Cathode, Cations, Charge, Clay, Contaminated Soils, Current, Development, Dialysate, Efficiency, Electrodialysis, Extraction, Inclusion, Ion Selective Membranes, Lead, Lead Removal, Membranes, Novel, pH, Remediation, Removal, Removal Efficiency, Rights, Separation, Soil, Soils, Speciation, Technique, Testing, Transport, Voltage, Water

? Gardea-Torresdey, J., Hejazi, M., Tiemann, K., Parsons, J.G., Duarte-Gardea, M. and Henning, J. (2002), Use of hop (Humulus lupulus) agricultural by-products for the reduction of aqueous Lead(II) environmental health hazards. Journal of Hazardous Materials, 91 (1-3), 95-112.

Full Text: 2002\J Haz Mat91, 95.pdf

Abstract: The agricultural by-products of the hop plant (Humulus lupulus L.) were investigated to determine their potential for use in the removal of heavy Lead(II) ions from contaminated aqueous solutions. Separate batch laboratory experiments were performed to establish the optimal binding pH, time exposures, and capacity of the metal adsorption for Lead(II) ions by dried and ground hop leaves and stems biomass. Results from these studies have shown a pH dependent binding trend from pH 2-6, with optimum binding occurring around pH 5.0. Time dependency experiments showed a rapid adsorption of Lead(II) ions within the first 5 min of contact. Binding capacity experiments demonstrated that 74.2 mg of Lead(II) were bound per gram of leaf biomass. Similarly overall capacity was seen for the leaves and stems. Desorption of 99% of the bound Lead(II) ions was achieved by exposing the metal laden biomass to 0.5 M sodium citrate. Further experiments were performed with silica-immobilized hop tissues to determine the Lead(II) binding ability under flow conditions. Comparison studies were performed with ion-exchange resins to evaluate the binding ability and to gain further insight into the metal binding mechanism. X-ray absorption spectroscopy experiments were also utilized to gain further insight into the possible Lead(II) binding mechanism by the hop plant tissue. Results from these studies indicate that carboxyl ligands are involved in the binding of Lead(II) from aqueous solution. These findings show that the use of hop agricultural waste products may be a viable alternative, for the removal and recovery of aqueous Lead(II) ions from contaminated waters. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: Ability, Achieved, Adsorption, Agricultural By-Products, Agricultural Waste, Aqueous Solution, Aqueous Solutions, Batch, Binding Mechanism, Biomass, Bioremediation, Capacity, Chromium, Citrate, Comparison, Contact, Copper Adsorption, Cr(III), Dependency, Desorption, Environmental, Environmental Health, Esterification, Experiments, Hazards, Health, Hops, Insight, Ion Exchange, Ion Exchange Resins, Ion-Exchange, Ions, Lead Binding, Lead(II), Mechanism, Medicago-Sativa Alfalfa, Metal, Metal Adsorption, Metal Binding, Metal-Ion Binding, pH, Phytofiltration, Phytoremediation, Recovery, Reduction, Removal, Resins, Rights, Waste, Waters

? Kim, Y. and Lee, D. (2002), Solubility enhancement of PCDD/F in the presence of dissolved humic matter. Journal of Hazardous Materials, 91 (1-3), 113-127.

Full Text: 2002\J Haz Mat91, 113.pdf

Abstract: From previous studies, we, the authors collected and arranged the octanol-water partition coefficients (K_ow), water solubility (S₀), and dissolved humic matter (DHM)-water partition coefficients (K_oc) for 95 organic compounds, and presented the correlations between each physical property. The K_oc and K_ow of dioxins estimated were significantly increased while S₀ was decreased on increasing the chlorine number. In the presence of DHM, solubility enhancement (S_w/S₀, S_w is the actual solubility in the presence of DHM) in highly chlorinated PCDD/F such as HpCDDs and OCDD is higher than that in low chlorinated ones. It means that dioxins abundant wastes (fly ash) should not be codisposed with organic abundant wastes (sewage sludge, food waste or bottom ash, etc.) to minimize the leachability of dioxins. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: Bottom Ash, Coefficients, Dibenzofurans, Dioxins, Dissolved Humic Matter (DHM), Enhancement, Fly Ash, Fly-Ash, Food, Food Waste, K_oe, K_ow, Leachability, Organic Compounds, Partition, Partition Coefficients, PCDD, F, Polynuclear Aromatic-Hydrocarbons, Presence, Rights, Sediments, Sewage, Sewage Sludge, Sludge, Soils, Solubility Enhancement, Sorption, Substances, Water

Galiatsatou, P., Metaxas, M. and Kasselouri-Rigopoulou, V. (2002), Adsorption of zinc by activated carbons prepared from solvent extracted olive pulp. Journal of Hazardous Materials, 91 (1-3), 187-203.

Full Text: J\J Haz Mat91, 187.pdf

Abstract: Activated carbons have been prepared by a two-step physical activation with steam at different burn-off levels to study the porosity development and its effect in zinc adsorption from aqueous solutions. The main material used was the residual from the extraction with solvent of the kernel-oil [solvent extracted olive pulp (SEOP)]. Olive, apricot and peach stone have been also used as different precursors. The products were characterized by N₂ at 77K adsorption, Hg porosimetry and iodine number determination. The influence of surface complexes and pH has been investigated in an attempt to elucidate the adsorption phenomena. The effect of different treatments [demineralization with H₂SO₄ and oxidation with (NH₄)₂S₂O₈] was also evaluated for the adsorption of zinc species.

Both basic and acidic carbons, originated from SEOP, show remarkable adsorption ability at solution pH=7. Their adsorption ability mainly depends on the content and nature of functional surface groups, the ash content of the precursors and the pH of the solution. These activated carbons were proved to be efficient adsorbents for the removal of water pollutants and contaminants.

Keywords: Zinc, Adsorption, Olive Pulp, Activated Carbon, Surface Groups

Manju, G.N., Krishnan, K.A., Vinod, V.P. and Anirudhan, T.S. (2002), An investigation into the sorption of heavy metals from wastewaters by polyacrylamide-grafted iron(III) oxide. Journal of Hazardous Materials, 91 (1-3), 221-238.

Full Text: J\J Haz Mat91, 221.pdf

Abstract: An adsorbent for heavy metals was synthesized by introducing carboxylate functional group into polyacrylamide-grafted hydrous iron(III) oxide. The product exhibits a very high adsorption potential for Pb(II), Hg(II) and Cd(II). The removal of metal ions by adsorption on adsorbent has been found to be contact time, concentration, pH and temperature dependent. The process follows first-order reversible kinetics. The intraparticle diffusion of metal ions through pores in the adsorbent was shown to be the main rate-limiting step. The optimum pH range for the removal of metal ions was found to be 5.0-6.0. The thermodynamic parameters such as free energy change, enthalpy change and entropy change have been calculated to predict the nature of adsorption. The adsorption data were fitted using the Langmuir equation and maximum adsorption for each metal was estimated using their respective Langmuir equation constants. The method was applied for synthetic wastewaters. NaCl regeneration has been tried for several cycles with a view to recover the adsorbed metal ions and also to restore the sorbent to its original state. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: Polymer-Grafted Metal Oxide, Metal Removal and Recovery, Adsorption Isotherm, Thermodynamic Parameters, Wastewater, Aqueous-Solution, Bituminous Coal, Ion-Exchange, Silica-Gel, Adsorption, Removal, Kinetics, Pb(II), Chitosan

? Ritchie, S.M.C. and Bhattacharyya, D. (2002), Membrane-based hybrid processes for high water recovery and selective inorganic pollutant separation. Journal of Hazardous Materials, 92 (1), 21-32.

Full Text: 2002\J Haz Mat92, 21.pdf

Abstract: The removal of heavy metals (e.g. Pb(II), Cd(II), Cu(II), etc.) and oxyanions (e.g. nitrate, As(III, V), Cr(VI), etc.) is of immense interest for treatment of groundwater and other dilute aqueous systems. However, the presence of non-toxic components, such as hardness (Ca, Mg) and sulfate, can interfere with the separation of toxic species. For example, pressure-driven membrane processes, such as reverse osmosis (RO), have been limited for water treatment due to problems that these extraneous components cause with water recovery and ionic strength (osmotic pressure) of the retentate. In addition, nitrate rejection by RO is considerably lower than NaCl rejection, resulting in permeate concentrations that may be too high for groundwater recharging. Other separation systems that rely solely on sorption of toxic species (e.g. ion exchange resins) may not have sufficient selectivity for efficient use in the presence of competing ions. Hence, implementation of pressure-driven membrane separations and high capacity sorbents in hybrid processes shows much promise for remedying these difficulties. For example, selective separation of nitrate may be achieved by combining nanofiltration (NF) for sulfate removal, followed by RO or ion exchange for nitrate removal (see example 1). When small concentrations of toxic metals are present, the large retentate volumes of RO processes may be reduced by selective removal of toxic species with a high capacity sorbent, thus permitting disposal of a lower volume, non-toxic stream (see example 2). The use of microfiltration membrane-based sorbents containing multiple polymeric functional groups is a novel technique to achieve high metal sorption capacity under convective flow conditions. These sorbents are formed by the attachment of various polyamino acids (MW: 2500-10,000), such as polyaspartic acid (cation sorption), polyarginine (oxyanion sorption), and polycysteine (chelation exchange), directly on the membrane pore surfaces. Since these sorbents have also been found to have high selectivity over non-toxic metals, such as calcium, they are ideal candidates for hybrid processing with RO/NF. (C) 2002 Elsevier Science B.V All rights reserved.

Keywords: Achieved, Acid, Attachment, Calcium, Capacity, Cation Sorption, Cd(II), Cr(VI), Cu(II), Disposal, Exchange, Functional Groups, Functionalized Microfiltration Membranes, Groundwater, Heavy Metals, Heavy-Metals, Hollow Fiber Membrane, Hybrid Processes, Implementation, Inorganics, Ion Exchange, Ion Exchange Resins, Ion-Exchange, Ionic Strength, Ions, Landfill Leachate, Low-Pressure Nanofiltration, Membrane, Membranes, Metal, Metal Sorption, Metals, Microfiltration, Nanofiltration, Nitrate, Nitrate Removal, Novel, Pb(II), Presence, Pressure, Problems, Recovery, Rejection, Removal, Resins, Reverse-Osmosis, Rights, Selectivity, Separation, Sorbent, Sorbents, Sorption, Sorption Capacity, Sulfate, Systems, Technique, Technology, Toxic Metals, Treatment, Water, Water Treatment

? Maloney, S.W., Adrian, N.R., Hickey, R.F. and Heine, R.L. (2002), Anaerobic treatment of pinkwater in a fluidized bed reactor containing GAC. Journal of Hazardous Materials, 92 (1), 77-88.

Full Text: 2002\J Haz Mat92, 77.pdf

Abstract: Pinkwater is generated during the handling and demilitarization of conventional explosives. This listed hazardous waste contains dissolved trinitrotoluene (TNT) and cyclo trimethylene trinitramine (RDX), as well as some by-products. It represents the largest quantity of hazardous waste generated by the operations support command, and its treatment produces a by-product hazardous waste-spent granular activated carbon (GAC). Anaerobic treatment in a fluidized bed reactor (FBR) containing GAC is an emerging technology for organic compounds resistant to aerobic biological treatment. Bench scale batch studies using an anaerobic consortium of bacteria fed ethanol as the sole electron donor demonstrated the transformation of TNT to triaminotoluene (TAT), which then degrades to undetectable end products. RDX is sequentially degraded to nitroso-, dinitroso-, trinitroso- and hydroxylaminodinitroso-RDX before the triazine ring is presumably cleaved, forming methanol and formaldehyde as major end products. The bacterial members of the anaerobic consortia are typically found in sludge digesters at municipal or industrial wastewater treatment plants. The results of a pilot scale evaluation of this process that was conducted at McAlester Army Ammunition Plant (MCAAP, OK) over a 1 year period are reported in this paper. The pilot test experienced wide fluctuations in influent concentrations, representative of true field conditions. The FBR was a 20 in. (51 em) diameter column with an overall height of 15 ft (4.9 m) and a bed of GAC occupying 11 ft (3.4 m). Water was recirculated through the column continuously at 30 gpm (1141/min) to keep the GAC fluidized, and pinkwater for treatment was pumped into the recirculation line. Several flowrates were evaluated to determine the proper mass loading rate (mass of TNT and RDX per reactor volume per time, kg/m³ per day) which the reactor could handle while meeting the discharge limitations. Based on the tests performed, a 1 gpm (3.785 1/min) rate in the 188 gal (7101) volume of the fluidized GAC bed was determined to consistently meet the discharge requirements. This information was used to develop a cost estimate for a system capable of treating the total effluent currently produced at MCAAR The cost of installing and operating this system was compared to the cost of GAC adsorption for MCAAP at current pinkwater generation rates. The GAC-FBR system had an annual operating cost of approximately US$ 19K, compared to US$ 71K annually for GAC adsorption. When including the amortization of the capital equipment required for the GAC-FBR, the payback period for installation of this new process was estimated at 3.7 years. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: 2,4-Dinitrotoluene, Activated Carbon, Adsorption, Aerobic, Anaerobic, Anaerobic Wastewater Treatment, Bacteria, Batch, Biological Treatment, Biotransformation, Carbon, Column, Cost, Discharge, Effluent, Evaluation, Explosives, Fluidized Bed, Fluidized Bed Reactor, Formaldehyde, GAC, Generation, Granular Activated Carbon, Hazardous Waste, Industrial Wastewater, Industrial Wastewater Treatment, Information, Limitations, Munitions Wastewater, Organic Compounds, Pinkwater, Process, Recirculation, Rights, Scale, Sludge, Support, Technology, Test, TNT, Transformation, Treatment, Trinitrotoluene, Waste-Water, Wastewater, Wastewater Treatment, Wastewater Treatment Plants, Water

Krishnan, K.A. and Anirudhan, T.S. (2002), Removal of mercury(II) from aqueous solutions and chlor-alkali industry effluent by steam activated and sulphurised activated carbons prepared from bagasse pith: Kinetics and equilibrium studies. Journal of Hazardous Materials,