Recovery of Phosphorus from Wastewater by Using Lime Precipitation-air Flotation

The factors influencing the recovery of phosphorus from simulated wastewater by using lime precipitation-air floatation was studied.The experiments include precipitation test and flotation test.The aim of the precipitation test is to discover the best dosages of CaO which is used to remove phosphorus by changing the pH,the influence of NH_4~+ and Mg~(2+) present in the wastewater.The removal rate of phosphorus was up to 99.88%.The test of flotation included changing the kinds of collector,the dosages of collector and pH.The results of flotation experiments showed that there were some differences among the floatation process with different collectors.The flotation results by using capric acid as collector is the best.The grade of phosphorus in the floated precipitate is 11.16% and its recovery is up to 94.93%.