Investigation of liquid carryover in the girdler-sulfide process for production of heavy water at the AEC Savannah River Plant

"An investigation of the causes of liquid carryover in the Girdler-Sulfide process for the production of heavy water was carried out using 12 samples of carbon collected over a one-year time period. Organic impurities from the feedwater were concentrated by adsorption on carbon. Studies of methods for the drying of carbon showed that freeze drying resulted in the minimum reproducible moisture retention without gross loss of the adsorbed organic materials. Rotary vacuum evaporation and air drying of beds of carbon were proven to be less efficient. A study was made of the variables which affect extraction efficiency by the Soxhlet method. The efficiency of extraction of the adsorbed materials with both water immiscible and water miscible solvents was shown to increase as the residual moisture content of the carbon decreased. Excess heat input to the Soxhlet boiling flask was shown to be a possible cause of degradation of organic compounds during the extraction process. The amount of organic material extracted from a given sample of carbon was found to be dependent upon the type of solvent used for the extraction. The amount of organic materials extracted from uniform samples (collected over the one-year time period) varied with the month the sample was collected and the extraction solvent. Specific correlations could not be made with changes in the river quality or plant water treatment variances. The extracted organic materials were analyzed by gas chromatography and mass spectrometry, and two of the materials were identified as ε-Caprolactam and 2-methoxy furan. The results of the analyses correspond to chemicals used by textile and paper processing plants upstream from the Savannah River Plant. Result s of the work show that the Carbon Chlorofrom Extract (CCE) method adopted by the U.S. Public Health Service as a standard for the determination of organic micropollutants in drinking water may be inadequate and unreliable. Analysis of the water treatment program at the Savannah River Plant showed the most probable cause of carryover is the hydrated aluminum oxide floc allowed to escape in the feedwater"--Abstract, pages ii-iii.