THE EFFECT OF WATER HARDNESS AND TEMPERATURE ON WATER STERILIZATION BY MIXTURES OF DETERGENTS AND QUATERNARY AMMONIUM COMPOUNDS

Abstract
SUMMARY: Six QAC detergent mixtures and the QACs alone were tested for bactericidal efficiency in hard and distilled water, using E. coli as test organism, contact times of 1, 2 and 5 min and temperatures of 5, 10 and 17°.The efficiencies of the unformulated QACs were dissimilar. With all, 200 p/m in hard water was less efficient than 50 p/m in distilled water. The efficiencies of the QAC detergent mixtures were not related to that of the pure QAC, the efficiency of a QAC being increased by one detergent formulation and decreased by another. All materials were least efficient at 5°.