Personal Research Database

Full Text: W\Was Man21, 435.pdf

Abstract: Metal capture experiments were carried out in an atmospheric fluidized bed incinerator to investigate the effect of sulfur and chlorine on metal capture efficiency and the potential for simultaneous capture of metal, sulfur and chlorine by sorbents. In addition to experimental investigation, the effect of sulfur and chlorine on the metal capture process was also theoretically investigated through performing equilibrium calculations based on the minimization of system free energy. The observed results have indicated that, in general, the existence of sulfur and chlorine enhances the efficiency of metal capture especially at low to medium combustion temperatures. The capture mechanisms appear to include particulate scrubbing and chemisorption depending on the type of sorbents. Among the three sorbents tested, calcined limestone is capable of capturing all the three air pollutants simultaneously. The results also indicate that a mixture of the three sorbents, in general, captures more metals than a single sorbent during the process. In addition, the existence of sulfur and chlorine apparently enhances the metal capture process. (C) 2001 Elsevier Science Ltd. All rights reserved.

Keywords: Metal Capture, Emission Control, Fluidized Bed, Sorbent, Adsorption, Chemisorption

Nishida, K., Nagayoshi, Y., Ota, H. and Nagasawa, H. (2001), Melting and stone production using MSW incinerated ash. Waste Management, 21 (5), 443-449.

Full Text: W\Was Man21, 443.pdf

Abstract: Most of the municipal solid waste (MSW) in Japan is incinerated and the generated ash is landfilled. However, environmental pollution problems have increased and Japan has decreased final disposal sites for landfills. With the application of a melting system, the volume of incinerated ash can be reduced and the effective use of melted slag is being developed for use in civil engineering works. However, the low strength of melted slag as a vitreous structure has limited its effective use. As a solution for this deficiency, a technology to crystallize melted slag into higher strength produced stones was developed. With the joint cooperation of Chiba Prefecture and Kamagaya City, a demonstration plant for melting and stone production with a capacity of 4.8 tons of incinerator ash per day was constructed. The demonstration test was conducted from May 1998 to June 1999 with satisfactory results stated below. Long-term stable operation and performance of the plant have been confirmed and effective applications of produced stones have been demonstrated on a commercial scale. The results are as follows.

1. A stable, continuous operation and good quality produced stones have been confirmed by treating more than 750 tons of MSW incinerated ash.

2. More than 99.9% of dioxins contained in the incinerated ash were decomposed, and the concentration of dioxins in produced stones were less than the detection limit set by Japanese environmental standards.

3. Leaching values of hazardous heavy metals of produced stones sufficiently met the environmental standard on soil pollution of the Environment Agency with superior leaching behavior for the Vitreous slag, thus confirming their safe applications.

4. The effective application of produced stones for aggregate was tested based on Japanese Industrial Standards and every figure of test results met the Japanese standard values. The use of produced stones as raw materials for permeable pavement blocks has been confirmed in commercial construction for a park in Chiba Prefecture. Asphalt use was also demonstrated by paving a commercial roadway in Kamagaya City. (C) 2001 Elsevier Science Ltd. All rights reserved.

Keywords: Melting System, Ash Treatment, Msw, Incinerated Ash, Slag, Crystallization, Effective Use

Riley, C.E. (2001), Method development and implementation for co-planar polychlorinated biphenyls (PCBs). Waste Management, 21 (5), 465-470.

Full Text: W\Was Man21, 465.pdf

Abstract: The Emission Measurement Center (EMG) in the Environmental Protection Agency’s Office of Air Quality Planning and Standards was directed to conduct an emissions test program at a sewage sludge incinerator in support of a Maximum Achievable Control Technology (MACT) standard. One pollutant category of concern at these facilities was polychlorinated biphenyls, or PCBs. An objective of the test program was to measure co-planar PCBs in the incinerator emissions, the sewage sludge introduced to the incinerator, and the scrubber water effluent used in controlling the incinerator emissions. Co-planar PCB congeners are those having four or more chlorine atoms with only a few substitutions in the ortho positions, i.e. positions designated 2,2’,6, and 6’. Thirteen PCB compounds are sometimes referred to as the ‘WHO PCBs,’ because the World Health Organization (WHO) has derived toxic equivalency factors for these congeners. Studies have shown that these dioxin-like compounds can react with the aryl hydrocarbon receptor. This same reaction is believed to initiate adverse health effects for dioxin and furan congeners. In order to conduct the co-planer PCB testing, the EMG had to develop analytical methods that could measure the 13 co-planar PCBs. The purpose of the test program was to develop, evaluate, and implement analytical test methods capable of measuring co-planar PGBs in three matrices: incinerator stack gases, sewage sludge, and scrubber water effluents. The paper summarizes the initial development work that was performed in preparation of analytical test protocols that could measure co-planar PCBs in air, water, and sludge matrices. Following the method development, a MACT emissions test program was conducted at a sewage sludge facility in July 1999 and these data are also summarized in the paper. (C) 2001 Published by Elsevier Science Ltd.

Keywords: Polychlorinated Biphenyls (PCBs), Sewage Sludge, Incinerator, Analytical Tests

Hinshaw, G.D. and Trenholm, A.R. (2001), Hazardous waste incineration emissions in perspective. Waste Management, 21 (5), 471-475.

Full Text: W\Was Man21, 471.pdf

Abstract: There has been increasing concern over the stack emissions of toxic substances from hazardous waste incinerators, and with improved sampling and analytical technology, measurements are being made at lower and lower levels to support risk assessment and various types of decision-making. However, it is generally difficult to visualize these levels of emissions, which span many orders of magnitude. Data on stack emissions were compiled from various research and compliance testing programs, and representative examples of various types of emissions were plotted on a series of graphs that spans the entire range of concentrations that may be encountered. The result is an illustrative tool for communication as to what emissions from hazardous waste incinerators are actually like. (C) 2001 Published by Elsevier Science Ltd.

Keywords: Harzardous Waste Incinerators, Stack Emissions, MACT

Sørensen, M.A., Mogensen, E.P.B., Lundtorp, K., Jensen, D.L. and Christensen, T.H. (2001), High temperature co-treatment of bottom ash and stabilized fly ashes from waste incineration. Waste Management, 21 (6), 555-562.

Full Text: W\Was Man21, 555.pdf

Abstract: Bottom ashes from two Danish municipal solid waste incineration plants were heated at 900 degreesC with iron oxide stabilized air pollution control residues at actual mass flow ratios (9: 1), simulating a treating method for the residues. The two residues were cotreated, producing one combined stream that may be utilized as a secondary road construction material. Scanning electron microscope analysis and grain size distribution analysis indicated that sintering of the particles did not occur. Batch leaching tests at liquid/solid 10 I/kg at a range of pH-values (6-10) quantified with respect to Cd, Cr and Pb revealed significant positive effects of co-heating the ashes, although Pb showed slightly increased leaching. At a liquid/solid ratio of 10 I/kg the leachate concentrations were still low at pH 7-10 and the release of Pb was, thus, not expected to limit the utilization of the mixed ashes. The process, thus, fixates the metals in the solid residues without altering the leaching properties of the bottom ash too significantly. (C) 2001 Elsevier Science Ltd. All rights reserved.

Keywords: Waste Incineration, Heavy Metals, Leaching, Thermal Treatment, Bottom Ash, APC Residues, Stabilization, Element Behavior, Metals

Rodriguez, A. and Hall, M.J. (2001), Removal of an airborne low volatility metal under fuel-rich and fuel lean conditions through condensation onto soot and/or sorbent particles. Waste Management, 21 (7), 589-607.

Full Text: W\Was Man21, 589.pdf

Abstract: The removal by a sorbent of a low volatility heavy metal, barium, from a combustor exhaust stream was investigated experimentally. The barium was introduced into the gas phase through a combustion process simulating incineration of waste materials. Sorbent- and metal-feed-rate, temperature and air intake were varied to study the impact on the gas-to-particle conversion and the metal condensation process. Peak temperature and subsequent temperature drop were found to be the dominant factors affecting the condensation process. Fuel-rich and fuel-lean conditions result in lower peak temperatures and a more rapid temperature drop relative to stoichiometric conditions. Since the metal vapor saturation pressure falls exponentially with temperature a larger condensation rate was observed, as long as nucleation was suppressed. Fuel-rich conditions promote the formation of soot particles. These particles function as sites for subsequent metal-species condensation. Chlorine was injected into the flow, to study the effect on metal vaporization. Chlorine promoted the volatilization of barium and therefore the subsequent condensation capture was made more effective. (C) 2001 Elsevier Science Ltd. All rights reserved.

Keywords: Sorbent, Chlorine, Barium, Aerosol, Condensation Capture, Cl/Ba Ratio, Incinerator Fly-Ash, Heavy-Metals, Flame Incinerator, Aerosol Formation, Fluidized-Bed, Behavior, Growth, Vapor, Emissions, Dynamics

Ortiz, N., Pires, M.A.F. and Bressiani, J.C. (2001), Use of steel converter slag as nickel adsorber to wastewater treatment. Waste Management, 21 (7), 631-635.

Full Text: W\Was Man21, 631.pdf

Abstract: Magnetite, the main component of converter slag in the steel industry, can be used for the adsorption of Ni(II) from aqueous solutions, over a range of conditions: initial metal concentration (10-100 mg l^-1), stirring times (2-240 min); adsorbent dosage (1 g for 0.5 1 of metal solution) and temperatures (20, 30 and 38 degreesC). The adsorption rate increased with initial concentration but decreased with increase in temperature, due to competition of the dissolution process. The adsorption process obeyed the Freundlich isotherm model. (C) 2001 Elsevier Science Ltd. All rights reserved.

Keywords: Heavy Metals, Adsorption, Converter Slag, Solid Residue, Magnetite Slag, Nickel Adsorption, Fe(III)/Cr(III) Hydroxide, Adsorption, Removal

Tenório, J.A.S. and Espinosa, D.C.R. (2001), Treatment of chromium plating process effluents with ion exchange resins. Waste Management, 21 (7), 637-642.

Full Text: W\Was Man21, 637.pdf

Abstract: The surface treatment industry deals with various heavy metals, including the elements Cr, Zn, Ni, Cd, and Cu. Conventional treatments of effluents generate class I solid residue. The aim of this investigation was to study the viability of ion exchange as an alternative process for treatment of rinse water and to determine the efficacy of two ion exchange systems, System 1: ‘strong’ cationic resin- ‘strong’ anionic resin and System 2: ‘strong’ cationic resin- ‘weak’ anionic resin. Commercial resins and solutions taken from rinse tanks of chromium plating companies were used in this investigation. A two-column system, one for the cationic resin and another for the anionic resin, both with 150 ml capacity was mounted. The solution was percolated at a rate of 10 ml/min. The following solutions were used for regeneration of the resins: 2% H₂SO₄ for the cationic and 4% NaOH for the anionic. The percolated solutions revealed chromium contents of less than 0.25 mg/l, independent of the system used. The ‘strong’ cationic resin- ‘weak’ anionic resin gave excellent regeneration results. The ‘strong’ cationic- ‘strong’ anionic resin presented problems during regeneration, and did not release the retained ions after percolation of 2000 ml of 4% NaOH solution. It is concluded that for this type of treatment, the system composed of ‘strong’ cationic resin and ‘weak’ anionic resin is more appropriate. (C) 2001 Elsevier Science Ltd. All rights reserved.

Keywords: Chromium, Ion Exchange, Plating Industry Effluents

Cioffi, R., Maffucci, L., Santoro, L. and Glasser, F.P. (2001), Stabilization of chloro-organics using organophilic bentonite in a cement-blast furnace slag matrix. Waste Management, 21 (7), 651-660.

Full Text: W\Was Man21, 651.pdf

Abstract: The application of cement-based stabilisation/solidification treatment to organic-containing wastes is made difficult by the adverse effect of organics on cement hydration. The use of organophilic clays as pre-solidification adsorbents of the organic compounds can reduce this problem because of the high adsorption power of these clays and their compatibility with the cementitious matrix. This work presents an investigation of the effect on hydration kinetics, physico-mechanical properties and leaching behaviour of cement-based solidified waste forms containing 2-chlorophenol and 1-chloronapthalene adsorbed on organophilic bentonites. These were prepared by cation exchange with benzyldimethyloctadecylammonium chloride and trimethyloctadecylammonium chloride. The binder was a 30% pozzolanic cement, 70% granulated blast furnace slag mixture. Several binder-to-bentonite ratios and different concentrations of the organics on the bentonite were used. Kinetics of hydration were studied by measurement of chemically bound water and by means of thermal and calorimetric analyses. Microstructure and other physico-mechanical properties of the solidified forms were studied by means of mercury intrusion porosimetry, scanning electron microscopy and unconfined compressive strength measurement. Leaching was checked by two different leaching tests: one dynamic, on monolithic samples, and the other static, on powdered samples. This study indicates that the incorporation of the organic-loaded bentonite in the binder matrix causes modifications in the hardened samples by altering cement hydration. The effects of the two organic contaminants are differentiated. (C) 2001 Elsevier Science Ltd. All rights reserved.

Keywords: Organophilic Bentonite, Chloro-Organics, Adsorption, Stabilization, Slag Cement, Hydrophobic Layer Silicates, Alcohol-Benzene Mixtures, Industrial-Wastes, Clay-Minerals, Adsorption, Solidification, Adsorbents, Isotherms, Sorption, Surface

Panayotova, M.I. (2001), Kinetics and thermodynamics of copper ions removal from wastewater by use of zeolite. Waste Management, 21 (7), 671-676.

Full Text: W\Was Man21, 671.pdf

Abstract: Natural Bulgarian zeolite was tested for its ability to remove Cu²⁺ from model wastewater. Influence of process variables was investigated. It was found that the optimum wastewater to zeolite ratio is 100: 1 and the optimum pH value of water to be treated is 5.5 to 7.5. Zeolite with finer particles shows a higher uptake capacity. The simultaneous presence of Ca²⁺ and Mg²⁺ in concentrations similar to their concentrations in Bulgarian natural water does not significantly influence the uptake of Cu²⁺. Zeolite modification by treating it with NaCl, CH₃COONa and NaOH increases its uptake ability. Copper ions are strongly immobilized by modified zeolite and secondary pollution of water caused by its contact with preloaded zeolite is very low (1.5-2.5% of Cu²⁺ preliminary immobilized have been released back into acidified water). Contacting with 2 mol dm^-3 NaCl can easily regenerate loaded zeolite; best results were obtained for zeolite modified with NaCl. Requirements of Bulgarian standards for industrial wastewater can be met by a one-stage process for an initial Cu²⁺ concentration of 10 mg dm^-3, and by a two stage process for an initial Cu²⁺ concentration of 50 mg dm^-3. Uptake of Cu²⁺ by zeolite from neutral wastewater has proved to be as effective as Cu²⁺ removal by precipitation of copper hydroxide. The process of Cu²⁺ uptake by natural zeolite is best described by the kinetic equation for adsorption. This fact, together with the correlation found between the Cu²⁺ uptake and the amount of Na⁺, Ca²⁺ and K⁺ released into solution by zeolite shows that the ion exchange sorption plays the basic role in Cu²⁺ uptake by natural zeolite. The value obtained for the apparent activation energy (26.112 kJ mol^-1) implies that the process can be easily carried out with a satisfactory rate. The uptake equilibrium is best described by the Langmuir adsorption isotherm, with Langmuir constants K_L = 6.4×10^-2 dm³ mg^-1 and M = 6.74 mg g^-1. The apparent equilibrium constant found shows moderate affinity of zeolite for Cu²⁺. Values of G° and H° found show the spontaneous and endothermic nature of the process of Cu²⁺ uptake by natural zeolite. (C) 2001 Elsevier Science Ltd. All rights reserved.

Keywords: Natural and Modified Zeolite, Wastewater Treatment, Copper Ions Removal, Adsorption, Bentonite, Exchange

Aksu, Z. and Yener, J. (2001), A comparative adsorption/biosorption study of mono-chlorinated phenols onto various sorbents. Waste Management, 21 (8), 695-702.

Full Text: W\Was Man21, 695.pdf

Abstract: The potential use of dried activated sludge and fly ash as a substitute for granular activated carbon for removing mono-chlorinated phenols (o-chlorophenol and p-chlorophenol) was examined. The pollutant binding capacity of the adsorbent/biosorbent was shown to be a function of substituted group, initial pH and initial mono-chlorinated phenol concentration. The working sorption pH value was determined as 1.0 and the equilibrium uptake increased with increasing initial mono-chlorinated phenol concentration up to 500 mg dm^-3 for all the mono-chlorinated phenol-sorbent systems. The suitability of the Freundlich, Langmuir and Redlich-Peterson adsorption models to the equilibrium data were investigated for each mono-chlorinated phenol-sorbent system. The results showed that the equilibrium data for all the mono-chlorinated phenol-sorbent systems fitted the Redlich-Peterson model best within the concentration range studied. (C) 2001 Elsevier Science Ltd. All rights reserved.

Keywords: O-Chlorophenol, P-Chlorophenol, Adsorption/Biosorption, Dried Activated Sludge, Fly Ash, Granular Activated Carbon, Activated Carbon, Fly-Ash, Aqueous-Solutions, Waste-Water, Adsorption, Removal, Biosorption, Desorption, Pentachlorophenol, Chlorophenols

? Martin-Garin, A., Gaudet, J.P., Charlet, L. and Vitart, X. (2002), A dynamic study of the sorption and the transport processes of cadmium in calcareous sandy soils. Waste Management, 22 (2), 201-207.

Full Text: 2002\Was Man22, 201.pdf

Abstract: The interactions of Cd²⁺ with silica and calcite were observed through laboratory dynamic experiments. Cd²⁺ sorption processes were characterised as a function of reaction kinetics in aqueous solutions saturated or not with respect to calcite. Chromatographic column experiments show that Cd²⁺ sorption on silica can be considered as a reversible equilibrate reaction which depends on water composition and pH. For a porous medium composed by a mixture of silica and calcite, the Cd²⁺ migration behaviours are predominantly controlled by calcite. The amount and the reversibility of sorbed Cd on calcite are strongly affected by kinetic limitations. Stirred flow through reactor experiments provide an original method to separate and characterise the ‘fast’ and ‘slow’ Cd sorption on calcite processes. The ‘fast’ Cd reversible adsorption isotherms and the rate of Cd subsequent uptake by ‘slow’ reactions are determined. In addition, the inhibition of calcite dissolution is observed as a function of sorbed Cd in order to provide a complete mechanistic database for coupled transport-geochemistry models. (C) 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Adsorption, Adsorption Isotherms, Cadmium, Calcite, Cd²⁺, Dissolution, Ion-Exchange, Isotherms, Kinetic, Kinetics, Migration, Soils, Solid-Solution, Sorption, Surface, Transport, Water

Kazi, F.K.M. and Cooper, P.A. (2002), Rapid-extraction oxidation process to recover and reuse copper chromium and arsenic from industrial wood preservative sludge. Waste Management, 22 (3), 293-301.

Full Text: W\Was Man22, 293.pdf

Abstract: Chromated copper arsenate (CCA) wood preservative can form insoluble sludges when the hexavalent chromium component is reduced by wood extractives, wood particles and preservative additives in the solution. This sludge accumulates in treating solution work tanks, sumps and in-line filters and must be disposed of as hazardous wastes by waste disposal companies at high costs. A number of commercial sludges were investigated and found to contain 18-94% copper, chromium and arsenic as oxides combined with sand, oil, wood particles, additives and wood extractives. We have developed a multi-stage recycling process whereby approximately 97% of the CCA components are recovered from the sludge. It involves extraction with sodium hypochlorite to remove and oxidize chromium (more than 90%) and extract most of the arsenic (approx. 80%) followed by extraction of the copper and remaining arsenic and chromium with phosphoric acid. The phosphoric acid extract contains some trivalent chromium, which is subsequently oxidized by sodium hypochlorite. The combined oxidized extract containing Cr-VI, Cu-II and As-v was compatible with CCA treating solutions and could be re-used commercially for treating wood without having a significant effect on the preservative fixation rate or the leach resistance of the treated wood. A cost analysis showed that the economic savings from recovery of CCA chemicals and reduced landfill costs exceeded the variable costs for materials and energy for the process by as much as Can $966 per tonne of sludge if sodium sulfite can be acquired in bulk quantities for the process. (C) 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Arsenic, Behavior, Cca Fixation, Chromium, Compatibility, Copper, Extraction, Fixation, Kinetic-Model, Leaching, Oxidation, Preservative, Reaction Zone, Recovery, Recycle, Sludge, Soils, Waste, Wood

? Ho, T.C., Kobayashi, N. and Lee, Y.K. (2002), Modeling of mercury sorption by activated carbon in a confined, a semi-fluidized, and a fluidized bed. Waste Management, 22 (4), 391-398.

Full Text: 2002\Was Man22, 391.pdf

Abstract: A process model was developed to simulate elemental mercury sorption by activated carbon in three distinct beds, namely a confined, a semi-fluidized, and a fluidized bed. The model involved the coupling of a kinetic model based on the mechanisms of surface equilibrium and external mass transfer, and a material balance model based on the tank-in-series approach. For surface equilibrium, three different equilibrium laws were used in the model, namely the Henry’s Law, the Langmuir isotherm and the Freundlich isotherm. Literature mercury sorption data were used to determine the best-fit values of parameters for these equilibrium expressions, The parameter-fitted model was then used to simulate mercury sorption processes in the three distinct beds. The simulation parameters were mercury concentration, gas flow rate, adsorption temperature and the degree of semi-fluidization. The simulation results have indicated that the model is capable of describing the literature available mercury sorption data. All the three surface equilibrium laws appear to simulate the adsorption profiles equally well mainly because the sorption process occurs in an extremely low concentration range. The simulation results for the three distinct beds have suggested that the confined bed has the best mercury control performance; however, it generates the highest pressure-drop across the bed. A fluidized bed creates the least pressure drop; however, its sorption performance is poor. A semi-fluidized bed offers acceptable performance with affordable pressure-drops and can be a practical candidate for the process. (C) 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Activated Carbon, Adsorption, Carbon, Equilibrium, Isotherm, Kinetic, Langmuir Isotherm, Literature, Mass Transfer, Mechanisms, Mercury, Mercury Control, Pressure Drop, Semi-Fluidized, Sorption, Temperature

Johnson, P.D., Watson, M.A., Brown, J. and Jefcoat, I.A. (2002), Peanut hull pellets as a single use sorbent for the capture of Cu(II) from wastewater. Waste Management,