Personal Research Database

Full Text: 1994\J Env Eng-ASCE120, 1470.pdf

Abstract: A process was developed using fly ash adsorption and cement fixation of the metal-laden adsorbent for the treatment of industrial wastewater containing heavy metals. Heavy metal industrial pollution is environmentally persistent and toxic. Industrial wastewaters containing Cd(II) and Zn(II) were chosen. A fly ash sample collected from a power plant was employed as the metal adsorbent. The metal-laden fly ash was fixed with cement and found to have the same or even greater 56-day strength than cement alone. Leachate from the fixed metal-laden fly ash was found to have metal concentrations lower than the drinking water standards. Further evaluation of the properties is needed before a conclusive recommendation can be made on the use of the mortar for construction purposes.

Nasserzadeh, V., Swithenbank, J., Schofield, C., Scott, D.W., Loader, A. and Leonard, A. (1994), Design optimization of coventry municipal solid-waste incinerator. Journal of Environmental Engineering-ASCE, 120 (6), 1615-1629.

Full Text: 1994\J Env Eng-ASCE120, 1615.pdf

Abstract: This paper discusses a number of design modifications and changes in operational conditions that have a major influence on the overall performance of the large Coventry municipal incinerator plant (65 MW), which incorporates a heat recovery system for district heating. Four different secondary air-injection systems and various primary air-distribution patterns along the grate were investigated using a computational fluid dynamic model, in an attempt to obtain optimum combustion conditions that would minimize potential emissions of toxic pollutants and reduce maintenance costs at the plant. The modeling work showed that the use of four large high-speed secondary air jets firing toward a common center, together with optimizing the primary air distribution along the grate, produces substantially longer residence times and improves temperature profile at the exit. The novel feature of the proposed secondary air-injection system is the formation of a large and significantly strong recirculation zone, located above the burning refuse bed, in the middle of the furnace shaft. This strong recirculation zone improves the overall performance of the incinerator due to intensive mixing of hot gaseous products evolving from the refuse bed with the combustion air supplied as the secondary air, and greatly improves the gas phase combustion and helps to reduce emissions of chlorinated organic compounds. Results obtained clearly demonstrate that the proposed secondary air-injection system has an excellent potential to satisfy most requirements for emissions levels and gas resident times specified by the European Directives (EEC) for municipal incinerators with a vertical radiation shaft.

Davis, A.P. and Singh, I. (1995), Washing of zinc(II) from contaminated soil column. Journal of Environmental Engineering-ASCE, 121, 174-185.

Full Text: J\J Env Eng-ASCE121, 174.pdf

Abstract: Several chemical washing procedures were applied to a zinc(II) contaminated (artificially) soil column to determine metal-extraction efficiency. Specific extractants examined include acid solution, ethylenediaminetetraacetic acid (EDTA) and diethylenetriamine pentaacetic acid (DTPA) organic complexing agents and chlorine, all at various concentrations. Effects of ionic strength, flow rate and type of zinc contamination were also determined. These parameters affect metal removal via various physicochemical mechanisms. The most efficient washing occurred using the organic chelating agents at the lowest flow rate (essentially complete zinc removal), although nearly as much zinc could be removed at higher flow rates, requiring less washing time. The washing efficiency is strongly dependent on the form of the zinc contamination in the soil.

Rael, J., Shelton, S. and Dayaye, R. (1995), Permeable barriers to remove benzene: Candidate media evaluation. Journal of Environmental Engineering-ASCE, 121 (5), 411-415.

Full Text: J\J Env Eng-ASCE121, 411.pdf

Abstract: This laboratory investigation evaluated candidate permeable- barrier media designed to remove benzene from in-situ ground water. There are many obvious potential permeable-barrier media, such as granular-activated carbon or ion-exchange resins; however, these are prohibitively expensive for most potential barrier applications. Therefore, developing low cost, yet effective, barrier materials would expand the breadth of potential applications. This investigation considered the effectiveness of several common materials including coal, powder-activated carbon (PAC), peat, sawdust, and zeolite. These materials were mixed with silica sand, then used in a bottle paint isotherm procedure. The PAC and sand mixture was selected as the media for a column investigation, based on the results of batch sample investigations. The evaluation of this mixture in the column investigation showed that batch study efficiency projections were exceeded by 37%. Possible reasons for that finding are proposed. Eventually, these data will be used to design field barriers

Keywords: Adsorption, Column, GAC, Groundwater, Ion Exchange, Sawdust

Tiwari, D.P., Singh, D.K. and Saksena, D.N. (1995), Hg(II) adsorption from aqueous solutions using rice-husk ash. Journal of Environmental Engineering-ASCE, 121 (6), 479-481.

Full Text: J\J Env Eng-ASCE121, 479.pdf

Abstract: Rice-husk ash (RHA) was found to be a good adsorbent for Hg(II) in aqueous solutions. Batch studies indicated that the percent adsorption decreased with increasing initial concentration of Hg(II) and particle size of adsorbent. Twenty g/L of RHA (diameter 37-50 µm) in an aqueous solution of Hg(II) with an initial concentration of 100 mg/L removed 98% of Hg(II). A contact time of 3 hr was found to be optimum. Maximum Hg(II) removal was observed near a pH of 6.0. Adsorption conformed to the Langmuir isotherm. Column experiments indicated that the adsorbed amount of Hg(II) decreased with increasing flow rate and decreasing bed height.

Keywords: Mercury(II), Water, Coal

Reed, B.E., Robertson, J. and Jamil, M. (1995), Regeneration of granular activated carbon (GAC) columns used for removal of lead. Journal of Environmental Engineering-ASCE, 121, 653-662.

Full Text: J\J Env Eng-ASCE121, 653.pdf

Abstract: Granular activated carbon (GAC) columns that were used for Pb removal were regenerated using several regeneration schemes. Acid type (HCl and HNO₃), regenerant concentration (0.1 N or 1 N), acid reuse and a NaOH-only rinse were studied. Column performance was assessed using the Pb surface loading (X/M) at exhaustion and the number of bed volumes (BVs) treated at breakthrough and exhaustion. The type of acid used did not affect column performance. Increasing the regenerant concentrations from 0.1 N to 1 N increased the surface loading at exhaustion and the BVs treated at breakthrough by 20% and 25%, respectively. Acid reuse did not significantly affect column performance, although desorption efficiencies decreased with the run number. The insensitivity of Pb removal to desorption efficiency indicates that the dominant removal mechanism is precipitation on the carbon surface or in the carbon pore, not adsorption. All measures of column performance deteriorated slightly when base-only regeneration was employed. However, column performance for the 1 N NaOH experiments were similar to the 0.1 N HCl-0.1 N NaOH studies.

Kapoor, A. and Viraraghavan, T. (1995), U.S. drinking-water regulations: Treatment technologies and cost. Journal of Environmental Engineering-ASCE, 121, 678.

Full Text: J\J Env Eng-ASCE121, 678.pdf

Cline, S.R. and Reed, B.E. (1995), Lead removal from soils via bench-scale soil washing techniques. Journal of Environmental Engineering-ASCE, 121, 700-705.

Full Text: J\J Env Eng-ASCE121, 700.pdf

Abstract: The retention and release of lead from eight different soils collected from the eastern United States were investigated. After characterization using well-established test procedures, the study soils were artificially contaminated with lead. Upon contamination, the lead-retention capacity of the study soils was statistically correlated with their physical and chemical properties. Lead capacity of the eight study soils was best correlated with the parameters of soil pH and the organic soil fraction. The efficiencies of six washing solutions in removing lead from the contaminated soils were then investigated via batch washing experiments. Unlike conventional field-scale soil washing, all particle size fractions were washed and recovered in these bench-scale experiments. HCl and EDTA obtained the best Pb-removal efficiencies. Removals tended to be independent of soil type and washing solution concentration. In addition to the physical/chemical properties of the washing solutions and of the study soils, the effects of the initial lead contamination level and washing solution concentration upon lead removals were examined. Lead-retention and release kinetic studies were performed to confirm equilibration between the aqueous and solid phases. Kinetics of both lead retention and release were very rapid for most study soils.

Bormann, N.E. and Kincanon, E. (1996), Strange attractors and chaos in wastewater flow: Discussion. Journal of Environmental Engineering-ASCE, 122 (3), 240.

Full Text: J\J Env Eng-ASCE122, 240.pdf

Fernandez, G. and Garbrecht, J. (1996), Strange attractors and chaos in wastewater flow: Discussion. Journal of Environmental Engineering-ASCE, 122 (3), 240-242.

Full Text: J\J Env Eng-ASCE122, 240-242.pdf

Angelbeck, D.I. and Minkara, R.Y. (1996), Strange attractors and chaos in wastewater flow: Closure. Journal of Environmental Engineering-ASCE, 122 (3), 242-243.

Full Text: J\J Env Eng-ASCE122, 242.pdf

Kapoor, A. and Viraraghavan, T. (1996), Treatment of metal industrial waste-water by fly-ash and cement fixation: Discussion. Journal of Environmental Engineering-ASCE, 122, 243.

Full Text: J\J Env Eng-ASCE122, 243.pdf

Weng, C.H. and Huang, C.P. (1996), Treatment of metal industrial waste-water by fly-ash and cement fixation: Closure. Journal of Environmental Engineering-ASCE, 122, 243-244.

Full Text: J\J Env Eng-ASCE122, 243-244.pdf

Chung, S.S. and Poon, C.S. (1997), Quantifying externalities in solid waste management in Hong Kong. Journal of Environmental Engineering-ASCE, 123, 282-289.

Full Text: J\J Env Eng-ASCE123, 282.pdf

Abstract: The solid waste management plan of 1989 stipulates that landfilling is the chief waste disposal method in Hong Kong. Although currently no charge is involved in solid waste disposal a landfill charge, covering the capital, operation and maintenance costs but not the external environmental costs, will soon be introduced. This paper aims to identify the minimum size of the external costs involved with landfilling and incineration in Kong Kong with respect to global and local air pollution, water pollution, noise and pollution from waste transport. It is found that landfilling results in a slightly lower external cost than incineration. However, factors not included in this paper, such as road casualties that arise from hauling waste and disamenities (a term coined to embrace negative impacts such as eyesores and loss of amenity values) may affect the preference of landfilling over incineration. The present study also shows that the external costs of landfilling are much greater than its capital, operation and maintenance costs. The considerable size of the estimated external costs of traditional waste management methods demonstrates the need for in-depth and comprehensive research to develop local data.

? Yu, H.Q., Gu, G.W. and Song, L.P. (1997), Posttreatment of effluent from coke-plant wastewater treatment system in sequencing batch reactors. Journal of Environmental Engineering-ASCE, 123 (3), 305-308.

Full Text: 1997\J Env Eng-ASCE123, 305.pdf

Abstract: The performance of sequencing batch reactors (SBRs) for the treatment of effluent from a conventional coke-plant wastewater biological treatment system has been evaluated. The results showed that an operating mode that incorporated two anoxic portions, one ahead of the aeration period and one after the aeration, was superior to the other modes (prearranged denitrification and postarranged denitrification) for nitrogen removal. The 4-h anoxic fill probably allowed some substrates in the influent to be stored in the biomass and led to subsequent storage-induced denitrification in the second anoxic portion during the reaction period. Under these conditions, the ammonia nitrogen (NH₃-N) and chemical oxygen demand (COD) reductions were 82.5 and 65.2%, respectively. During the fill period of an SBR, the organics concentration was reduced, probably due to the adsorption of organics onto activated sludge and dilution of the mixed liquor. Some readily biodegradable organics in the influent, such as phenol and o-cresol, were utilized by denitrifiers as a carbon source. A 16-h aeration significantly reduced the concentrations of o-cresol, 3,4-dimethyl phenol, and 2-quinoline alcohol, while reductions in quinoline, isoquinoline, indol, and methyl quinoline were limited.

Keywords: Activated Sludge, Adsorption, Ammonia, Ammonia-Nitrogen, Anoxic, Biological Treatment, Coke Plant, Coke Plant Wastewater, Coke-Plant Wastewater, Denitrification, Quinoline, Removal, Sbr, Treatment, Wastewater, Wastewater Treatment

Kapoor, A. and Viraraghavan, T. (1997), Nitrate removal from drinking water: Review. Journal of Environmental Engineering-ASCE, 123 (4), 371-380.

Full Text: J\J Env Eng-ASCE123, 371.pdf

Abstract: Nitrate concentrations in surface water and especially in ground water have increased in Canada, the United States, Europe, and other areas of the world. This trend has raised concern because nitrates cause methemoglobinemia in infants. Several treatment processes including ion exchange, biological denitrification, chemical denitrification, reverse osmosis, electrodialysis, and catalytic denitrification can remove nitrates from water with varying degrees of efficiency, cost, and ease of operation. Available technical data, experience, and economics indicate that ion exchange and biological denitrification are more acceptable for nitrate removal than reverse osmosis. Ion exchange is more viable for ground water while biological denitrification is the preferred alternative for surface water. This paper reviews the developments in the field of nitrate removal processes.

Keywords: Methylotrophic Fluidized-Bed, Ion-Exchange, Biological Denitrification, Ground-Water, Well Water, Supplies, Plant, Performance, Regenerant, Technology

Srivastava, S.K., Gupta, V.K. and Mohan, D. (1997), Removal of lead and chromium by activated slag: A blast-furnace waste. Journal of Environmental Engineering-ASCE, 123 (5), 461-468.

Full Text: J\J Env Eng-ASCE123, 461.pdf

Abstract: The blast-furnace waste generated in steel plants has been converted into a low-cost adsorbent. The resulting activated slag has been characterized and used for the removal of lead and chromium. The effect of pH, sorbent dosage, adsorbate concentrations, presence of other metal ions, temperature, and contact time on the sorption of lead and chromium were studied in batch experiments. Kinetic studies were undertaken to have an idea of the mechanistic aspects of the process. The uptake of lead is found to be greater than that of chromium. Adsorption on activated slag follows both Freundlich and Langmuir models. In addition, a series of fixed-bed experiments were performed in an attempt to simulate industrial conditions. The bed-depth-service-time (BDST) model proposed by Hutchins was successfully applied to the sorptive removal of lead. Some experiments were also performed with a view to recover Pb²⁺ and chemically regenerate the spent slag columns in situ.

Keywords: Toxic Metal-Ions, Aqueous-Solutions, Industrial-Waste, Earth Elements, Fly-Ash, Adsorption, Cadmium, Water, Carbon, Adsorbents

? Mirpuri, R., Sharp, W., Villaverde, S., Jones, W., Lewandowski, Z. and Cunningham, A. (1997), Predictive model for toluene degradation and microbial phenotypic profiles in flat plate vapor phase bioreactor. Journal of Environmental Engineering-ASCE, 123 (6), 586-592.

Full Text: 1997\J Env Eng-ASCE123, 586.pdf

Abstract: A predictive model has been developed to describe degradation of toluene in a flat-plate vapor phase bioreactor (VPBR). The VPBR model incorporates kinetic, stoichiometric, injury, and irreversible loss coefficients from suspended culture studies for toluene degradation by P. putida 54G and measured values of Henry’s law constant and boundary layer thickness at the gas-liquid and liquid-biofilm interface. The model is used to estimate the performance of the reactor with respect to toluene degradation and to predict profiles of toluene concentration and bacterial physiological state within the biofilm. These results have been compared with experimentally determined values from a flat plate VPBR under electron acceptor and electron donor limiting conditions. The model accurately predicts toluene concentrations in the vapor phase and toluene degradation rate by adjusting only three parameters: biomass density and rates of death and endogenous decay. Qualitatively, the model also predicts gradients in the physiological state cells in the biofilm. This model provides a rational design for predicting an upper limit of toluene degradation capability in a VPBR and is currently being tested to assess applications for predicting performance of bench and pilot-scale column reactors.

Keywords: Biofiltration, Verification, Aquasim

Brown, L.C. and Berthouex, P.M. (1997), Multiresponse parameter estimation of SVOCs in activated sludge process. Journal of Environmental Engineering-ASCE, 123, 767-775.

Full Text: J\J Env Eng-ASCE123, 767.pdf

Hering, J.G., Chen, P.Y., Wilkie, J.A. and Elimelech, M. (1997), Arsenic removal from drinking water during coagulation. Journal of Environmental Engineering-ASCE, 123 (8), 800-807.

Full Text: J\J Env Eng-ASCE123, 800.pdf

Abstract: The efficiency of arsenic removal from source waters and artificial freshwaters during coagulation with ferric chloride and alum was examined in bench-scale studies. Arsenic(V) removal by either ferric chloride or alum was relatively insensitive to variations in source water composition below pH 8. At pH 8 and 9, the efficiency of arsenic(V) removal by ferric chloride was decreased in the presence of natural organic matter. The pH range for arsenic(V) removal with alum was more restricted than with ferric chloride. For source waters spiked with 20 µg/L arsenic(V), final dissolved arsenic(V) concentrations in the product water of less than 2 µg/L were achieved with both coagulants at neutral pH. Removal of arsenic(III) from source waters by ferric chloride was both less efficient and more strongly influenced by source water composition than removal of arsenic(V). The presence of sulfate (at pH 4 and 5) and natural organic matter (at pH 4 through 9) adversely affected the efficiency of arsenic(III) removal by ferric chloride. Arsenic(III) could not be removed from source waters by coagulation with alum.

Keywords: Adsorption, Chemistry, Aluminum, Rule

? Zhang, M., Tay, J.H., Qian, Y. and Gu, X.S. (1997), Comparison between anaerobic-anoxic-oxic and anoxic-oxic systems for coke plant wastewater treatment. Journal of Environmental Engineering-ASCE, 123 (9), 876-883.

Full Text: 1997\J Env Eng-ASCE123, 876.pdf

Abstract: Coke plant wastewater produces severe pollution throughout china because coal is the main energy resource. The anoxic-oxic (A(2)-O) system can be used to treat this type of wastewater for simultaneous removal of NH₃-N and GOD. A comparative study between an anaerobic-anoxic-oxic (A(1)-A(2)-O) system and an A(2)-O system for coke plant wastewater treatment under the same operational conditions was undertaken to examine removal efficiencies of COD and NH₃-N, denitrification performance, and transformation of organic pollutants in each system. The experimental results showed that the A(1)-A(2)-O system was comparatively more effective not only in nitrification but also in denitrification performance, The total NH₃-N removal efficiency and the anoxic NOx-N removal rate of the A(1)-A(2)-O system were about 20% higher and more than twice that of the A(2)-O system, respectively. Coke plant wastewater subjected to anaerobic treatment resulted in less inhibitory effect on the subsequent nitrification process, and provided a more biodegradable and suitable carbon substrate far denitrifying bacteria. The anaerobic stage played an important role in nitrogen reduction in coke plant wastewater treatment.

Keywords: Anaerobic, Anoxic, Coal, Coke Plant Wastewater, Denitrification, NH₃-N Removal, Nitrification, Wastewater, Wastewater Treatment, Water

Swithenbank, J., Nasserzadeh, V., Taib, R., Stagg, D., Moore, D., Ward, M. and Bone, J. (1997), Incineration of wastes in novel high-efficiency tumbling and rotating, fluidized bed incinerator. Journal of Environmental Engineering-ASCE, 123 (10), 1047-1052.

Full Text: J\J Env Eng-ASCE123, 1047.pdf

Lim, T.T., Tay, J.H. and Teh, C.I. (1997), Sorption and speciation of heavy metals from incinerator fly ash in a marine clay. Journal of Environmental Engineering-ASCE, 123 (11), 1107-1115.

Full Text: J\J Env Eng-ASCE123, 1107.pdf

Chen, K.S. and Tong, C.H. (1997), Modeling of turbulent burning flow and performance evaluation of municipal solid incinerator. Journal of Environmental Engineering-ASCE, 123 (11), 1150-1157.

Full Text: J\J Env Eng-ASCE123, 1150.pdf

? Jayasundera, S. and Torrents, A. (1997), Natural organic matter sorption by kaolinite: Modified Langmuir isotherm. Journal of Environmental Engineering-ASCE, 123 (11), 1162-1165.

Full Text: 1997\J Env Eng-ASCE123, 1162.pdf

Abstract: This technical note describes the use of the modified Langmuir isotherm (MLI) model recently introduced by Gu and coworkers to describe the adsorption and desorption of natural organic matter (NOM) onto Kaolinite. The MLI was able to describe the adsorption of two different NOM samples with the use of three adjustable parameters. A commercial humic acid adsorbed to a much larger extent than a NOM sample collected from a swamp. The hysteresis coefficient was used to describe adsorption-desorption reversibility. Both samples had similar hysteresis coefficients. Such affinity parameters, however, determined from adsorption and desorption experiments, varied significantly. This study concludes that the new MLI model is better than the traditionally used Langmuir isotherm in describing adsorption-desorption of NOM to Kaolinite and desorption parameters may be considered to describe dissolved organic carbon concentrations in subsurface environments.

Keywords: Acid, Adsorption, Adsorption-Desorption, Carbon, Desorption, Dissolved, Dissolved Organic Carbon, Humic, Humic Acid, Humic Substances, Isotherm, Langmuir Isotherm, Matter, Model, Models, Modified, Natural, Natural Organic Matter, Organic, Organic Carbon, Organic Matter, Oxide Water Interface, Parameters, Sorption, Subsurface Systems, Surfaces, Transport

Kapoor, A. and Viraraghavan, T. (1998), Nitrate removal from drinking water: Review-Closure. Journal of Environmental Engineering-ASCE, 124 (9), 903.

Full Text: J\J Env Eng-ASCE124, 903.pdf

Smith, E.H. (1998), Surface complexation modeling of metal removal by recycled iron sorbent. Journal of Environmental Engineering-ASCE,