locations on the basin. Apparently GC chemical separation and air leaks were minimal for this sortie also. Considering all observations, the average flux was 3.4 ng/cmz * s with standard deviation of 1.7 ng/cm' * s.Conditions were not as ideal on the second trip to this site, where the average flux was 2.0 ng/cmPs with a standard deviation 1.3 ng/cmZ * s.
When all doubtful data is disregarded, the average flux at the site combining both visits is 3.8 ng/cm* s, with a range of 2.1-5.2 ng/cm' . s.
Conclusions
A field-sampling protocol and associated apparatus, referred to as the concentration-profile method (CPM) was developed and tested for volatile chemical emissions from surface impoundments. The method is based on obtaining samples of air, wind velocit , and temperature in a Turbulent-transport theory coupled with concentration and micrometeorological measurements is used to develop the flux-measurement algorithm for these area sources.
Volatile chemicals in the wastewater are emitted into the overlying air boundary layer. Air Sam les in a twometer re ion above the water surface ha uantities of higher than the back round. Concentrations in the layer make these measurements a method of trapping, concentrating, and analyzing low-molecular weight volatiles in the presence of excess water vapor was developed.
The flux rates of methanol, acetone, and total hydrocarbon, originating in aerated wastewater-treatment basins, were measured during field tests on the CPM.
Ranges of the average flux rates for the basins were: methanol, 1.4 to 3.8 n&mz . sec (11 to 29 lbs/acre * day); acetone, 0.28 to 0.10 ng/cmz * sec(.22 to 0.77 lbslacreday); and total hydrocarbon (FID), 3.0 to 4.3 ng/cmz. sec(23 to 33 lbs/acre day). Acetaldehyde was detected, but at extremely low concentration. two-meter boundary-layer region a B ove the water surface. methano, f acetone, and total hydrocarbon Bq in evels much decreased significant K y with height above the water. To