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WE ,• s' argaratus at selrxted temperatures,the Henrv's Law Constants an,! direct t'asmeanecessary o! Hor%ii 6 law - 5olu6jlili�s constant•�s necessary for iticse sub- ovetall mass Iransler coefGcrents were stances because they may b:miscible ea.lculaled and the results interpreted Henry's law constants were measured with water and the conventional de,Gni- suct:essfully using the two•resistante ,Or a number of compounds,partin.larly tion of H as the ratio of vapor pressure to theory.The effects of solute molecular hydrocarbons and halogenated hyt.'ro- aqueous setubility is not applicable.A size and temperature wire adequately carbons in distilled water and in the simple test of the volatilization potential described and correlated using the presence of humic acid•fulvic acid and of a solute in water is 10 prepare a bentonite. A gas stripping Systerr. solution of the solute in water of solu'te's 5thmidt number, which con- method was used.and analysis was by concentration at about 10 mg/L distill ` tains information about the diffusivity. fluorescence or gas chromatography, half the water oft, and measure the The experimental system may be A number of solubility measurements concentration in the residue and in the suitable for screening new solutes !or were also made in the presence of co- distillate. if the concentration in the their volatilizaticn characteristics as a solutes such as lulvie acid using a distillate ii much higher than that of the functilin of concentration.temperature, genEV"or column system, and a cot- residue.than volatilization is likely to be i and presence of other compound: or relation was devatoped to calculate the an important environmental p.ahway, phases in the water that may influence effect of the-salubilization'•induced by r.: volatilization behavior. the dissolved organic matter.From the Valatiliratiort CaleuhlionS experiments conducted,it was concluded Wind Wave Tank Studies that at normal environmental concen- The repun concludes with a disc rssion stations of orginic matter there is A 6-m-long by 60-cm-deep wind unlikely to be sicnificant effect on solute of procedures for calculating environ- t wave lank wassonstructedandoperated solubility. and. therefore, on Henrys mental volatilization rates.including:he w r particularly at high wind speeds, to law constant. The e(Ject of the organic acquisition of physical and chemic.•1 determine the dependence of gas and material may bs 10 increase or decrease data.envitonmantal concentrations ono` liquid mass transfer coefficients an solubility, the estimation of mass transfer coeffi- + wind speed. Measurements of wind Anovel-relative votatitity"apparatus ciente as a function of environmental velocity profiles were also made to was developed that can be used to conditions and solute properties. acid measure Henry's law constants for the roles ofsedimentation and sorption- obtain friction velocities and surface substances shat have low Henry's law The carculation of concentration profiler. - roughnesses. The transfer rates of 1 i constants, i.e.,values close to that of _ of volatilizing solutes from rivers and organic solutes were measured at water. The system was tested with a lakes is discussed,including the use of various wind speeds. series of alcohols and ketunes.and the oxygen transfer data, (reaerA,-::-con- a tt was again found that the two- agreement with literature data was scants)for rivers as a means of resistance model adequately described satisfactory. It should be noted '.at • volatilization rates for othf:r Solute.. the mass transfer rates of the substances as inrluenced Sy Henry's law constant. The Schmidt number raised to an D.hlackar.W.Y.Shiu,A.Bobra,J.Billington E.Chau,A. Yeurr,C.Ng,and F. appropriate power was also found to Srato are with the University of Toronto, Toronto, Canada MSS fA4, be an appropriate determinant of S. W.lfarickhoffis the EPA Project Officer fseebelowl- ;'^ solute molecular size and temperature. The complete report.entitled••VulatilirationOforganic Pcllwantsfrom Warer,•' A number of correlaiions were developed 10rderNo.P882.23093°:Cost;518.00,subject to chan;_I will be available in which the mass transfer coefficients only from: were expressed as a function of friction National Technicallnformation Service " velocity (which can be related to the 52d5 Port Royal Road actual wind velocity) or to roughness- Springfield VA 22161 Reynold's Number (a dimensionless Telephone:703-487-4650 parameter indicative of the :urbulen, )he EPA Project Officer can be conracred at: ` conditions as the air-water :nterface). Envirortinentaf Research Laboratory Given the quality of existing zxperimen- U.S.j nvjranmental Protection Agency W data, the friction velociry alone may Athens,GA 30613 be an adequate descriptor of masa transfer coelficienL corrected by Schmidt Number for solute size,diffusivity and temperature.Anoutcome of this analysis us cvv:;.r.•cn7snW:.rc orr'c�tree_1SfafSr77w is the suggestion that mass transfer coefficients measured in the laboratory may be higher than those applying in the environment,because laboratory conditions tend to result in higher friction velocities at the sante wind velocity.This may help to explain some reported inconsistencies between vola- .• tilita•Raratescalvrlatedintheenviron- 6" mens and measured is the laboratory. 3 ra.