VOCs in fixed film processes. 2: Model studies

Journal Article · Mon Jul 01 04:00:00 EDT 1996 · Journal of Environmental Engineering

DOI:https://doi.org/10.1061/(ASCE)0733-9372(1996)122:7(564)· OSTI ID:267982

Parker, W J ^[1]; Monteith, H D ^[2]; Melcer, H ^[3]

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1. Carleton Univ., Ottawa, Ontario (Canada). Dept. of Civil and Environmental Engineering
2. Enviromega Ltd., Hamilton, Ontario (Canada)
3. Brown and Caldwell Consultants, Seattle, WA (United States)

Under the US Clean Air Act Amendments, fugitive emissions of volatile organic contaminants (VOCs) from waste-water-treatment facilities have been identified as a potentially significant source of air pollution. Models incorporating liquid-gas mass-transfer and biofilm mass-transfer resistances were developed for trickling filters (TF) and rotating biological contractors (RBC). Biodegradation and volatilization coefficients were estimated from the previously described pilot-scale studies. The volatilization coefficients of a given compound in the TF and RBC were generally constant across the experimental conditions investigated. While biodegradation-rate coefficients were constant in the TF across experimental conditions, in the RBC the biodegradation-rate coefficients appeared to be greatest under conditions of low loading and high disc rotation speed and lowest under conditions of high loading and low disk rotational speed. The biofilm was completely penetrated by most of the contaminants and diffusional resistance did not limit the rate of biodegradation of any of the compounds. In the RBC, diffusion in the biofilm appeared to be limiting the biodegradation of toluene, o-xylene, and 1,3,5-trimethylbenzene. The ratio of gas- and liquid-phase mass-transfer coefficients ranged from 91.4 for the TF to 5.6 for the RBC. Due to the relatively wide confidence intervals associated with these estimates, the values could not be statistically differentiated, however, the results suggest a significant contribution of gas-phase resistance to mass transfer in some cases.

• Sponsoring Organization: USDOE
• OSTI ID: 267982
• Journal Information: Journal of Environmental Engineering, Journal Name: Journal of Environmental Engineering Journal Issue: 7 Vol. 122; ISSN 0733-9372; ISSN JOEEDU
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION ABATEMENT
BIODEGRADATION
BIOREACTORS
CHEMICAL EFFLUENTS
CHLORINATED AROMATIC HYDROCARBONS
ENZYMES
MASS TRANSFER
MATHEMATICAL MODELS
PERFORMANCE
TOLUENE
WASTE PROCESSING
WASTE WATER