Record Display for the EPA National Library Catalog


Main Title Calcium Phosphate Precipitation in Wastewater Treatment.
Author Mena, Arnold B. ; Jenkin, David ;
CORP Author California Univ., Berkeley. Sanitary Engineering Research Lab.
Year Published 1972
Report Number SERL-72-6; EPA-WQO-17080-DAR; 06038,; R2-72-064
Stock Number PB-216 605
Additional Subjects ( Chemical removal(Sewage treatment) ; Phosphorus) ; ( Precipitation(Chemistry) ; Phosphorus) ; ( Sewage treatment ; Chemical removal(Sewage treatment)) ; Calcium phosphates ; Magnesium hydroxides ; Calcium carbonates ; pH ; Settling ; Flocculation ; Colloids ; Solubility ; Crystal growth ; Water pollution control
Library Call Number Additional Info Location Last
NTIS  PB-216 605 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 100p
Precipitation of calcium phosphate from both synthetically derived wastewater and from actual wastewater was investigated. An amorphous tricalcium phosphate was the steady state solid phase that controlled dissolved phosphate residuals. The solubility of this phase determined from chemically defined systems was used with success to predict dissolved phosphate residuals from both chemically defined systems and actual wastewaters. Suspension settling was enhanced by magnesium hydroxide precipitation but not by calcium carbonate precipitation. In wastewater of moderate alkalinity and hardness, a phosphate removal in excess of 80% was consistently achieved at pH 9.5 with lime doses of at the most 200 mg/l as calcium carbonate. The overall phosphate removal performance was dictated by the performance of the precipitation reactor and its ensuing sedimentation basin. Phosphate containing particles that escaped sedimentation could not be removed by filtration because they dissolved rapidly during the recarbonation process that necessarily precedes the filtration step.