Premium
Aluminum Sulfate (Alum) for Precipitating Clay Turbidity from Fish Ponds
Author(s) -
Boyd Claude E.
Publication year - 1979
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1979)108<307:asafpc>2.0.co;2
Subject(s) - alum , turbidity , sulfate , fish <actinopterygii> , aluminium sulfate , fishery , environmental science , oceanography , geology , chemistry , biology , organic chemistry
Alum was more effective than ferric sulfate, hydrated lime, or gypsum in removing clay turbidity from laboratory suspensions of clay. A simple alum‐requirement test was developed to determine the amount of alum needed to floc clay particles in pond water. Alum applied to seven ponds at rates determined by this test removed 84 to 97% of the turbidity within 48 hours. Alum‐requirement values ranged from 10 to 30 mg/liter for 23 samples of pond waters containing clay turbidity. Each mg/liter of alum destroyed approximately 0.5 mg/liter of total alkalinity, and depressed pH. Fathead minnows (Pimephales promelas) were unharmed by 10–30 mg/liter alum if the total alkalinity was initially above 20 mg/liter, and were unharmed by floc resulting from alum treatment. In waters with total alkalinity below 20 mg/liter, hydrated lime or agricultural limestone may be applied to prevent severe depression of alkalinity and pH that would otherwise be caused by alum.