Evaporation Reduction Research: Screening Tests of Evaporation Retardants

摘要

The procedures used in this 4-yr series of outdoor tests to screen materials as possible evaporation retardants are described. Experimental results include a listing of the relative efficiencies of 79 samples of 68 materials. The best material tested, in terms of efficiency or evaporation savings achieved, was an ethoxylated alcohol (long-chain ether). Much additional work needs to be done regarding the effect of temperature on the efficiencies of evaporation retarding materials. The best results were obtained from powdered materials. Thick water dispersions and water emulsions gave poor results. Generally, the materials with 20 to 22 carbon atoms were more efficient than those with 16 to 18 carbon atoms. The study concludes that outdoor evaporation pan tests provide a reasonably reliable and reproducible means of screening evaporation retardants. (Author)