Personal Research Database

Full Text: 2000\J Haz Mat73, 221.pdf

Abstract: Dissolved organic matter (DOM) in water is often characterized by aggregate parameters like dissolved organic carbon (DOC). DOM from conventional surface water treatment plant in Northern New Jersey was isolated and fractionated using resin adsorption chromatography into six different fractions, which were operationally categorized as hydrophobic acid, hydrophobic neutral, hydrophobic base, hydrophilic acid, hydrophilic neutral and hydrophilic base. The spectral fluorescent signatures (SFS) technique was developed for the quantitative identification of the six fractions by post-processing analysis that includes a statistical model. The SFS is the total sum of emission spectra of a sample at different excitation wavelengths, recorded as a matrix of fluorescent intensity in coordinates of excitation and emission wavelengths, in a definite spectral window. High sensitivity and rapid identification and quantification of DOM fractions are among the main features of the technique. Since hydrophobic and hydrophilic substances are considered more humic and non-humid in nature, respectively, the technique provided an opportunity to rapidly delineate source waters in terms of such categories. (C) 2000 Elsevier Science B.V. All rights reserved.

Keywords: Acid, Adsorption, Analysis, Base, Carbon, Categories, Diagnostics, Dissolved Organic Matter, Dissolved Organic Matter (DOM), DOC, DOM, Fluorescence, Fractionation, Hydrophilic, Hydrophobic, Model, Molecular-Weight, Opportunity, Organic Matter, Preparative Isolation, Quantitative, Rapid Delineation, Resin, Rights, Sensitivity, Substances, Surface, Surface Water, Technique, Treatment, Water, Water Treatment, Waters

? Olson, E.S., Miller, S.J., Sharma, R.K., Dunham, G.E. and Benson, S.A. (2000), Catalytic effects of carbon sorbents for mercury capture. Journal of Hazardous Materials, 74 (1-2), 61-79.

Full Text: 2000\J Haz Mat74, 61.pdf

Abstract: Activated carbon sorbents have the potential to be an effective means of mercury control in combustion systems. Reactions of activated carbons in flow systems with mercury and gas stream components were investigated to determine the types of chemical interactions that occur on the sorbent surface. The effects of carbon type, panicle size, temperature, and reactive gases were studied. Sorption kinetics and capacities for lignite- and bituminous-based carbons were compared with those for catalytic carbons at temperatures of 107 C, 150 C, and 163 C. In the air and baseline gas studies, the catalytic carbons exhibited far better sorption than the lignite- and bituminous-derived carbons. With the catalytic carbons, the greater sorption kinetics and capacity in an air stream or baseline gas composition compared with nitrogen provides a clear demonstration that O-2 is required in the gas stream for higher reactivities and capacities. Thus, a catalytic chemisorption mechanism predominates for the sorption of mercury at these conditions. The reaction kinetics are inversely proportional to the temperature, indicating that a preliminary physisorption step with mercury associating with a surface site is rate-determining. In synthetic flue gas streams containing HCl (50 ppm), the sorption kinetics of the catalytic carbon are slightly inferior to those of lignite-based carbon. Thus, the reaction is dominated by a different interaction, where HCl reacts with mercury on the carbon surface and the oxidation sites on the catalytic carbon apparently have no advantage. Granular and fine-particle carbons gave similar results in flue gas streams. (C) 2000 Elsevier Science B.V. All rights reserved.

Keywords: Activated Carbon, Activated Carbons, Capacity, Carbon, Catalytic Carbons, Chemisorption, Combustion, Composition, Control, Flue Gas, Flue-Gases, Interaction, Interactions, Kinetics, Lignite, Mechanism, Mercury, Mercury Capture, Mercury Sorption, Nitrogen, Oxidation, Reaction Kinetics, Removal, Rights, Sorbent, Sorbents, Sorption, Sorption Kinetics, Surface, Systems, Temperature

? Marhaba, T.F. and Van, D. (2000), The variation of mass and disinfection by-product formation potential of dissolved organic matter fractions along a conventional surface water treatment plant. Journal of Hazardous Materials, 74 (3), 133-147.

Full Text: 2000\J Haz Mat74, 133.pdf

Abstract: Dissolved organic matter (DOM) influences many aspects of water treatment, including the formation of potentially harmful disinfection by-products (DBPs) when disinfectants are applied. DOM from a conventional surface water treatment plant (WTP) in Northern New Jersey was isolated and fractionated using resin adsorption chromatography into six different fractions. These fractions are operationally categorized as hydrophobic acid, hydrophobic neutral, hydrophobic base, hydrophilic acid, hydrophilic neutral and hydrophilic base. The hydrophilic acid fraction was found to be the most abundant fraction in the source water. The hydrophilic neutral, hydrophilic acid and hydrophobic acid fractions had the highest removal efficiency through the WTP (about 65%). The variation and removal effectiveness of each fraction along the WTP was studied. Seven-day chlorine DBP formation potential (FP) tests were performed on all DOM fractions through the WTP. For the source water studied, the hydrophilic acid fraction was found to be the most reactive precursor to the trihalomethane (THM) formation. The hydrophobic neutral fraction was found to be the fraction of concern with respect to the FP of haloacetic acids (HAAs) class of DBPs. The FP of each fraction’s class of DBPs was found to be amenable for reduction along the treatment train, specifically by coagulation/sedimentation. The fractionated approach concept showed to be very beneficial in the study of DBP precursors and their effective removal by physical and chemical treatment. (C) 2000 Elsevier Science B.V. All rights reserved.

Keywords: Acid, Adsorption, Base, Carbon, Chemical Treatment, Chlorination, Class, Disinfection By-Product, Disinfection By-Products, Disinfection By-Products Formation Potential, Disinfection Byproducts, Dissolved Organic Matter, DOM, Drinking-Water, Effectiveness, Efficiency, Fraction, Fractionation, Humic Substances, Hydrophilic, Hydrophobic, Influences, Molecular-Weight, Natural-Waters, Organic Matter, Precursors, Preparative Isolation, Reduction, Removal, Removal Efficiency, Resin, Rights, Surface, Surface Water, THM, Treatment, Water, Water Treatment

? Watts, R.J., Haller, D.R., Jones, A.P. and Teel, A.L. (2000), A foundation for the risk-based treatment of gasoline-contaminated soils using modified Fenton’s reactions. Journal of Hazardous Materials, 76 (1), 73-89.

Full Text: 2000\J Haz Mat76, 73.pdf

Abstract: The relative oxidation of representative aromatic and aliphatic hydrocarbons found in gasoline was evaluated to provide the foundation for risk-based treatment of petroleum-contaminated soils and groundwater using modified Fenton’s reagent (catalyzed hydrogen peroxide). Aromatic components of gasoline are considered more hazardous than the aliphatic fractions due to their higher mobility in the subsurface and their higher acute and chronic toxicities. Benzene, toluene, and mixed xylenes (BTX) were selected as aromatic compounds representative of unleaded gasoline, while nonane, decane, and dodecane (NDD) were used as model aliphatic compounds. The effects of hydrogen peroxide (H₂O₂) concentration, iron catalyst concentration, and pH on the degree of treatment of the model compounds were investigated using central composite rotatable experimental designs. Oxidation of the aromatic compounds required less iron and less H₂O₂ than did oxidation of the aliphatic compounds, while proceeding more effectively at near-neutral pH. Greater than 95% of the BTX was treated at near-neutral pH using 2.5% H₂O₂ and 12.5 mM iron(III), while only 37% nonane, 7% decane, and 1% dodecane oxidation was achieved under the same conditions. The results show that the more toxic and mobile aromatic fraction was more effectively oxidized using less H₂O₂ and more economical conditions, including near-neutral pH, compared to the aliphatic fraction. A process design based on treating only the aromatic fraction of petroleum may provide significantly lower costs when using modified Fenton’s reagent for the treatment of contaminated soils and groundwater. (C) 2000 Elsevier Science B.V. All rights reserved.

Keywords: Achieved, Benzene, Bioremediation, BTX, Catalyst, Catalyzed Hydrogen-Peroxide, Chemical Oxidation, Complexes, Composite, Costs, Degradation, Design, Fenton’s Reagent, Fraction, Groundwater, H₂O₂, Hydrocarbons, Hydrogen Peroxide, Iron, Mixed, Mobility, Model, Modified, Oxidation, Petroleum, pH, Pollutants, Process, Process Design, Reagent, Remediation, Rights, Soil Remediation, Soils, Sorption, Toluene, Treatment

? Leist, M., Casey, R.J. and Caridi, D. (2000), The management of arsenic wastes: problems and prospects. Journal of Hazardous Materials, 76 (1), 125-138.

Full Text: 2000\J Haz Mat76, 125.pdf

Abstract: Arsenic has found widespread use in agriculture and industry to control a variety of insect and fungicidal pests. Most of these uses have been discontinued, but residues from such activities, together with the ongoing generation of arsenic wastes from the smelting of various ores, have left a legacy of a large number of arsenic-contaminated sites. The treatment and/or removal of arsenic is hindered by the fact that arsenic has a variety of valence states. Arsenic is most effectively removed or stabilized when it is present in the pentavalent arsenate form. For the removal of arsenic from wastewater, coagulation, normally using iron, is the preferred option. The solidification/stabilization of arsenic is not such a clear-cut process. Factors such as the waste’s interaction with the additives (e.g. iron or lime), as well as any effect on the cement matrix, all impact on the efficacy of the fixation. Currently, differentiation between available solidification/stabilization processes is speculative, partly due to the large number of differing leaching tests that have been utilized. Differences in the leaching fluid, liquid-to-solid ratio, and agitation time and method all impact significantly on the arsenic leachate concentrations. This paper reviews options available for dealing with arsenic wastes, both solid and aqueous through an investigation of the methods available for the removal of arsenic from wastewater as well as possible solidification/stabilization options for a variety of waste streams. (C) 2000 Elsevier Science B.V. All rights reserved.

Keywords: Activities, Adsorption, Agriculture, Aqueous-Solutions, Arsenate, Arsenic, Cement, Coagulation, Control, Differentiation, Efficacy, Fly-Ash, Generation, Immobilization, Impact, Interaction, Iron, Leachate, Leaching, Leaching Tests, Lime, Management, Methods, Precipitation, Problems, Process, Prospects, Recovery, Removal, Removal, Rights, Soils, Solidification, Solidification, Stabilization, States, Toxicity, Treatment, Wastewater

? Lin, S.H., Lai, S.L. and Leu, H.G. (2000), Removal of heavy metals from aqueous solution by chelating resin in a multistage adsorption process. Journal of Hazardous Materials, 76 (1), 139-153.

Full Text: 2000\J Haz Mat76, 139.pdf

Abstract: Copper and zinc removal from aqueous solution by chelating resin was investigated theoretically and experimentally in the present study. A multistage process was proposed as an alternative for enhancement of the heavy removal of the single-stage process. Heavy metal mass balance equations with empirical Freundlich adsorption isotherm were developed to represent the multistage process and the theoretical model permits determination of the inter-stage heavy metal concentrations and the total amount of chelating resin required for achieving a desired level of heavy metal removal. Optimization of the linearized theoretical model shows that equal division of the total amount of chelating resin among all stages of the multistage process yields the best results in terms of saving of chelating resin for a given heavy metal removal or enhanced heavy metal removal fur a given total amount of chelating resin. Experimental tests were also conducted to establish the equilibrium adsorption of heavy metal by the chelating resin and to empirically verify the advantages of the multistage adsorption process. (C) 2000 Elsevier Science B.V. All rights reserved.

Keywords: Adsorption, Adsorption Isotherm, Adsorption Process, Aqueous Solution, Chelating Resin, Copper, Enhancement, Equilibrium, Freundlich, Freundlich Adsorption Isotherm, Heavy Metal, Heavy Metal Removal, Heavy Metals, Heavy-Metal, Isotherm, Metal, Metal Removal, Metals, Model, Multistage Adsorption Process, Optimization, Process, Removal, Resin, Rights, Theoretical Model, Zinc, Zinc Removal

? Grubb, D.G., Guimaraes, M.S. and Valencia, R. (2000), Phosphate immobilization using an acidic type F fly ash. Journal of Hazardous Materials, 76 (2-3), 217-236.

Full Text: 2000\J Haz Mat76, 237.pdf

Abstract: Batch equilibration experiments using a low calcium (similar to 1 wt.% as CaO), acidic (pH similar to 4.5) Type F fly ash demonstrated phosphate immobilization on the order of 100% to 75% for 50 and 100 me; P/1 solutions, respectively. A loosely compacted column of fly ash similarly removed 10 mg P/1 for over 85 pore volumes, While the interactions between phosphate and calcium-rich (Type C) ashes are relatively well understood, insight into the mechanisms of phosphate immobilization in Type F ash necessitated a review of the phosphate chemistry and interactions with acidic geomedia. Phosphate adsorption was subsequently modeled using a constant capacitance model approach (CCM) excluding precipitation reactions. Our CCM predictions of total phosphate immobilization (20%) were substantially less than the results of the batch equilibration experiments and phosphate adsorption predicted by other researchers examining near pure natural and synthetic geomedia due to the compositional heterogeneity of the fly ash. Nevertheless, for the amorphous and crystalline phases studied, the immobilization of phosphate in the Type F fly ash is attributed to the formation of insoluble aluminum and iron phosphates at low to medium values of pH. (C) 2000 Elsevier Science B.V. All rights reserved.

Keywords: Acid Conditions, Adsorption, Aluminum, Anion Competition, Ashes, Batch, Calcium, Chemical-Model, Column, Constant Capacitance Model, Experiments, Fly Ash, Goethite, Heterogeneity, Hydrous Oxides, Immobilization, Insight, Interactions, Ions, Iron, Model, Natural, pH, Phosphate, Phosphate Adsorption, Phosphates, Precipitation, Removal, Review, Rights, Soils, Sorption, Sorption, Values

Kao, P.C., Tzeng, J.H. and Huang, T.L. (2000), Removal of chlorophenols from aqueous solution by fly ash. Journal of Hazardous Materials, 76 (2-3), 237-249.

Full Text: J\J Haz Mat76, 237.pdf

Abstract: Fly ash from coal-fired thermal power plants can be used for the removal of 2-chlorophenol (2-CP) and 2,4-dichlorophenol (2,4-dCP) with enthalpy changes of about-3 kcal/mol. The amounts of 2-CP and 2,3-DCP removed are affected by the pH value of the solution. The efficiency of removal improves when the pH value is less than the pK_a values of 2-CP and 2,4-dCP, respectively. The adsorbed amount of chlorophenol by fly ash is also affected by particle diameter, carbon content, and the specific surface area of the ash used in this study. As expected, more adsorption takes place with fly ash of higher carbon content and larger specific surface area. Moreover, the adsorbed amount of chlorophenol is not influenced by the matrix in the wastewater, as shown by studying the removal of 2-CP and 2,4-dCP in wastewater from a synthetic fiber plant. Chlorophenols in the wastewater were also removed efficiently through a fly ash column, with breakthrough times being inversely proportional to flow rates. (C) 2000 Elsevier Science B.V. All rights reserved

Keywords: Adsorption, Chlorophenol, Fly Ash, Wastewater

? Wey, M.Y., Chao, C.Y., Wei, M.C., Yu, L.J. and Liu, Z.S. (2000), The influence of heavy metals on partitioning of PAHs during incineration. Journal of Hazardous Materials, 77 (1-3), 77-87.

Full Text: 2000\J Haz Mat77, 77.pdf

Abstract: The presence of heavy metals (Cr, Cd, Pb and Zn) in feedstock increases the partitioning of polycyclic aromatic hydrocarbons (PAHs) in the solid as well as in the gaseous phases, which has been reported in our previous study. However, the partitioning of PAHs in air-pollution control equipment (APCE) has not been investigated thus far. Hence, the present work was conducted to study the partitioning of PAHs in APCE and the effect of heavy metals on PAHs formation by varying the target heavy metals in the feedstock. A fluidized bed incineration system which includes a primary combustion chamber (sand bed), a secondary combustion chamber (freeboard), and an APCE (cyclone and scrubber) was utilized in this study. The feedstock that contained various heavy metals was fed into the incinerator, and then the PAHs in the cyclone and scrubber were analyzed to determine the effect of heavy metals on PAHs partitioning. The results indicate that the presence of Pb and Zn in feedstock facilitates the formation of PAHs. (C) 2000 Elsevier Science B.V. All rights reserved.

Keywords: Adsorption, Air Pollution, APCE, Cd, Combustion, Control, Fluidized Bed, Fly-Ash, Heavy Metals, Hydrocarbons, Incineration, Influence, Metals, PAHs, Particles, Partitioning, Pb, Polycyclic Aromatic Hydrocarbons, Polycyclic Aromatic-Hydrocarbons, Presence, Rights, Sand, Secondary, Stack Ash, Work, Zn

? Theodoratos, P., Moirou, A., Xenidis, A. and Paspaliaris, I. (2000), The use of municipal sewage sludge for the stabilization of soil contaminated by mining activities. Journal of Hazardous Materials, 77 (1-3), 177-191.

Full Text: 2000\J Haz Mat77, 177.pdf

Abstract: The ability of municipal sewage sludge to immobilize Pb, Zn and Cd contained in contaminated soil originating from a former mining area in Lavrion, Greece was investigated. The soil was cured with sewage sludge in various proportions. The stabilization was evaluated primarily by applying chemical tests and complemented by the performance of additional biological tests. Application of the U.S. EPA Toxicity Characteristic Leaching Procedure (TCLP) on the stabilized mixtures proved that Pb, Zn and Cd solubility was reduced by 84%, 64% and 76%, respectively, at 15% w/w sludge addition, while a 10% w/w addition was sufficient to reduce Pb solubility below the U.S, EPA TCLP regulatory limit. The results of the extraction using EDTA solution showed the same trend, resulting in 26%, 36% and 53% reduction in the Pb, Zn and Cd extractable fractions, respectively. Speciation analysis of the treated soils revealed a significant decrease in the mobile fractions of heavy metals, which was attributed to their retention in sewage sludge by adsorption and organic complexation mechanisms. For the assessment of possible phytotoxicity, experiments including growing dwarf brans in the treated soil was carried out. It was Found that sewage sludge addition had a positive effect on plant growth. Furthermore, the Pb and Zn uptake of plant leaves and roots was reduced, while Cd uptake was unaffected by the sludge treatment. The results of this study support the hypothesis that municipal sewage sludge is a potential effective stabilizing agent for contaminated soil containing Pb, Zn and Cd. (C) 2000 Elsevier Science B.V. All rights reserved.

Keywords: Ability, Activities, Adsorption, Agent, Amended Soil, Analysis, Assessment, Cd, Complexation, Compost, Contaminated Soil, EDTA, Experiments, Extraction, Greece, Growth, Heavy Metals, Heavy-Metals, Leaching, Metals, Mining, Mixtures, Pb, Performance, Reduction, Retention, Rights, Sequential Extraction, Sewage, Sewage Sludge, Sludge, Soil, Soils, Speciation, Stabilization, Support, TCLP, Toxicity, Treatment, U.S, Zn

Ajmal, M., Rao, R.A.K., Ahmad, R. and Ahmad, J. (2000), Adsorption studies on Citrus reticulata (fruit peel of orange): Removal and recovery of Ni(II) from electroplating wastewater. Journal of Hazardous Materials, 79 (1-2), 117-131.

Full Text: J\J Haz Mat79, 117.pdf

Abstract: The ability of fruit peel of orange to remove Zn, Ni, Cu, Pb and Cr from aqueous solution by adsorption was studied. The adsorption was in the order of Ni(II) > Cu(II) > Pb(II) > Zn(II) > Cr(II). The extent of removal of NI(II) was found to be dependent on sorbent dose, initial concentration, pH and temperature. The adsorption follows first-order kinetics. The process is endothermic showing monolayer adsorption of Ni(II), with a maximum adsorption of 96% at 50 degreesC for an initial concentration of 50 mg l^-1 at pH 6. Thermodynamic parameters were also evaluated. Desorption was possible with 0.05 M HCl and was found to be 95.83% in column and 76% in batch process, respectively. The spent adsorbent was regenerated and recycled thrice. The removal and recovery was also done in wastewater and was found to be 89% and 93.33%, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.

Keywords: Endothermic, Adsorption, Isotherm, Desorption, Regeneration, Heavy-Metal Ions, Peanut Skins, Water, Binding

Yu, B., Zhang, Y., Shukla, A., Shukla, S.S. and Dorris, K.L. (2000), The removal of heavy metal from aqueous solutions by sawdust adsorption: Removal of copper. Journal of Hazardous Materials, 80 (1-3), 33-42.

Full Text: J\J Haz Mat80, 33.pdf

Abstract: Locally available sawdust, a byproduct of the world industry, was found to be a low cost and promising adsorbent for the removal of copper(II) from wastewater. In this work, adsorption of copper on sawdust has been studied by using batch techniques. The equilibrium adsorption level was determined to be a function of the solution pH, contact time, and sorbate concentration. The equilibrium adsorption capacity of sawdust for copper was obtained by using linear Freundlich and Langmuir isotherms. Ion exchange is probably one of the major adsorption mechanisms for binding divalent metal ions to the maple sawdust. The results provide strong evidence to support the hypothesis of adsorption mechanism. It also supplies significant sawdust operation capacity data for engineering design. (C) 2000 Elsevier Science B.V. All rights reserved.

Keywords: Sawdust, Metal Ions, Copper, Adsorption, Wastewater, Carbon

? Ku, Y. and Lee, K.C. (2000), Removal of phenols from aqueous solution by XAD-4 resin. Journal of Hazardous Materials, 80 (1-3), 59-68.

Full Text: J\J Haz Mat80, 59.pdf

Abstract: The experiments on the adsorption of phenols from aqueous solution by Amberlite XAD-4, a polystyrene-divinylbenzene resin without functional group, were carried out under different conditions. The phenols studied in this research include 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, 2-nitrophenol, 2,4-dinitrophenol, 2-methylphenol, and 2,4-dimethylphenol. The experimental observations indicate that adsorption behavior of various phenols by XAD-4 resin could be described by either Langmuir or Freundlich models. The removals of phenols by XAD-4 resin for solutions of different pH varied significantly and can be explained by the species distribution of phenols in aqueous solutions. Phenols were effectively removed by XAD-4 resin at acidic conditions where the presence of molecular phenol species dominates. The removal decreased sharply for alkaline solutions where the negatively-charged ionic species is the dominant phenol species. The proposed adsorption equilibrium model adequately describes the sorption behavior of phenols by XAD-4 resin. The presence of functional groups on the benzene ring of various phenols plays an important role on the extent of adsorption. The removals of phenols by adsorption were found to correlate with the octanol/water partition coefficients of various phenol compounds.

Keywords: Phenols, Adsorption, Resin

Gardea-Torresdey, J.L., Tiemann, K.J., Armendariz, V., Bess-Oberto, L., Chianelli, R.R., Rios, J., Parsons, J.G. and Gamez, G. (2000), Characterization of Cr(VI) binding and reduction to Cr(III) by the agricultural byproducts of Avena monida (Oat) biomass. Journal of Hazardous Materials,