Optimizing ferric sulfate coagulation of algae with streaming current measurements

摘要: This study sought to determine ferric sulfate coagulation conditions that lead effective removal of algae by conventional gravity sedimentation. Using laboratory-cultured Anabaena flos-aquae spiked into natural water, charge titrations and jar tests were conducted evaluate the effects streaming current value, pH, initial concentration on algae, turbidity, organic matter. At pH 6, doses corresponding point zero (PZC), as determined measurements, consistently produced low settled water concentrations when an anionic flocculant aid was added. In contrast, at 7.0 7.5 not for because algae's surface could be sufficiently neutralized. 6 PZC, concentrations, ultraviolet absorbance 254 nm similar 10,000 50,000 cells/mL, but a larger coagulant dose required reach PZC higher concentration. Thus, adjusting based value should maintaining quality in plants treat waters with rapidly varying influent and/or background quality. Experiments bloom sample confirmed removal.