Public works . LTER. October 11, 1919 MUNICIPAL JOURNAL AND PUBLIC WORKS 221 It was found that Lake Ontariowaters varied greatly in pollution andthe purification effected under ap-parently the same physical conditionsvaried from time to time. Turbiditydid not seem to affect the purification,except that it was necessary to in-crease the alum to secure clarifica-tion. In the winter months pollutedwater requires at least Ihi to 2%grains of alum to obtain a satisfactoryeffluent. During the summer monthsit was found necessary to apply atleast 2% grains to a polluted waterwhich often was free from t
Public works . LTER. October 11, 1919 MUNICIPAL JOURNAL AND PUBLIC WORKS 221 It was found that Lake Ontariowaters varied greatly in pollution andthe purification effected under ap-parently the same physical conditionsvaried from time to time. Turbiditydid not seem to affect the purification,except that it was necessary to in-crease the alum to secure clarifica-tion. In the winter months pollutedwater requires at least Ihi to 2%grains of alum to obtain a satisfactoryeffluent. During the summer monthsit was found necessary to apply atleast 2% grains to a polluted waterwhich often was free from slightly polluted requiredabout one grain per gallon. Rawwater appears to coagulate slightlybetter in the summer months whenthe water temperature exceeds fiftydegrees, but the final purification ef-fected was lower than in the winterwhen the temperature ranged betweenthirty-three degrees and forty-six de-grees. The microscopic content andthat of the bacteria increased greatlyin the summer
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectmunicip, bookyear1896
