Specific chemical permeation through a cellulose acetate membrane has also been reported (Hindin, Bennett and Narayanan 1969). The membranes were immersed in water at 82°C for 30 min prior to use. At a pressure differential of 100 atm, a temperature of 25°C, flux rates on the order of 15 gal/sq ft/day, and feed concentrations of about 500 mg/l, reduction of lindane was 73% while DDT and TDE (DDD) were rejected above 99%. High reductions were obtained for those chemical species existing primarily in the colloidal, aggregate, micelle, or macro-molecular form. If the chemical species existed both as an aggregate in dispersion and as a discrete molecule in true solution where vapor pressure of the discrete molecule in true solution was appreciably greater than that of water, the range of reduction was 50-80%. Where discrete molecules more volatile than water were tested, range of reductions was 14-40%.
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