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A field scale evaluation of the airstripping of volatile organic compounds by surface aerators
Author(s) -
Parker Wayne J.,
Monteith Hugh D.,
Bell John P.,
Melcer Henryk
Publication year - 1996
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143096x128531
Subject(s) - aeration , mass transfer , chemistry , mass transfer coefficient , analytical chemistry (journal) , stripping (fiber) , chromatography , phase (matter) , range (aeronautics) , environmental chemistry , thermodynamics , materials science , organic chemistry , composite material , physics
The stripping of volatile organic compounds (VOCs) by surface aerators was evaluated in experiments performed at field scale. Each experiment consisted of dosing a tank containing tapwater with a selection of VOCs, activation of the aerator, and subsequent monitoring of the disappearance of the compounds. The tank contents were deoxygenated before the experiment thereby allowing concurrent measurement of the uptake of oxygen. Experiments were performed with two aerators with differing power inputs and aeration patterns and over a range of temperatures from 3 to 22°C. Overall mass transfer coefficients were calculated for each compound in each experiment. The impacts of temperature and aerator horsepower on the mass transfer coefficients of the candidate compounds were examined and relationships were calibrated with the experimental data. The fundamental gas and liquid mass transfer coefficients were calibrated and the ratio of gas to liquid phase mass transfer coefficient was estimated to range from 16 to 24. The estimated ratio of k g /k l was found to be relatively insensitive to variations in the Henry's Law coefficient over the range typically observed in the literature. The observed ratio was lower than that previously reported in the literature and would suggest a greater impact of gas phase resistance than previously thought. The lower value of the ratio may be attributed to mass transfer limitations caused by entrained air.