EFFECTS OF PH ON THE ALUMINUM, IRON AND CALCIUM-PHOSPHATE FRACTIONS OF LAKE-SEDIMENTS

A laboratory study was conducted to determine the effect of sediment pH on the amount of phosphorus bound in the aluminum, iron, calcium and saloid-bound fractions of sediments from Lake Carl Blackwell, Oklahoma. The pH of the lake sediment samples was experimentally altered by mixing them with distilled water with pH values ranging from 1 to 12. Once the pH of the sediment and overlying water had equilibrated, a one gram sample was fractionated using a modified Chang & Jackson procedure to determine the phosphorus bound in each fraction. The point of minimum fixation for this sediment was found to occur at a pH of 7.33. Aluminum and iron phosphate fractions were predominant in an acidic environment. There was more phosphorus found in the aluminum and iron fractions than in the calcium fraction and the amount of saloid bound phosphorus was minimal at every pH investigated. © 1979.