Competitive Potassium Adsorptions of Ferric Phosphate Precipitation in Activated Sludge

Ferric phosphate is the product of simultaneously chemical/biological phosphorus removal system,and the negatively charged ferric phosphate can adsorb potassium which also needed by biological phosphorus removal. In this paper, adsorption experiment was carried out in distilled water and wastewater respectively,which showed that adsorption rate increased with the increased concentration of ferric phosphate, while adsorption strength as weak. The proportion of potassium adsorption by ferric phosphate to adsorption by activated sludge ranged from 21 to 29%. It was also found that adsorption of potassium by activated sludge was adversely affected when content of FePO4was increased.