Treatment of Wool Scouring Wastes with Colloidal Bentonite

Abstract

Results are presented of a laboratory-scale study to determine the effectiveness of various coagulants as supplementary additives in the conventional acid cracking of wool scouring wastes. It was observed that a dispersible-type bentonite produces a marked improvement in the extent of clarification of the waste effluent. In brief, the treatment involves first acidifying the scouring wastes with sulfuric acid to a pH level between 3 and 4 and then adding the required amount of bentonite as an aqueous dispersion. The amount of bentonite required depends upon the grease and suint content of the waste. A bentonite concentration of between 0.1 and 0.5% is generally sufficient. As an ex ample, treatment of a standard waste with acid and bentonite removed as much as 96% of the grease, compared with removal of 67% with acid alone. The chemical oxygen demand was reduced by approximately 60% by the combination treatment, compared with 33% reduction with acid alone.

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References

American Public Health Association , Standard Methods for the Examination of Water and Sewage, 9th ed., American Public Health Association, New York (1946).

Cabot, S., and Cohen, G. (Pacific Mills), U. S. Pat. 2,692,184 (October 19, 1954).

Evans, L.F. , and Ewers, W.E. , Australian J. Appl. Sci. 4, 552 (1953).

Faber, H.A. , and Howard, P.F. , Water & Sewage Works 93, 467 (1946).

McCarthy, J.A. , Sewage Works J. 21, 75 (1949).

Raymond, R.S. , and Mandell, S.L. , "Wool Grease: The Economics of Recovery and Utilization in the United States," Marketing Research Report No. 89 (report of contract research conducted by Lowell Technological Institute) ( U. S. Dept. Agriculture) (June, 1955).

Wilson, J.F. , Hilgardia 11, 149 (1938).