Semi-continuous Magnetic Removal of Phosphate Using an Iron Oxide Hydroxide Adsorbent and Regeneration of Its Adsorbent

Phosphate removal from wastewater using fine-particles of schwertmannite was performed by use of a semi-continuous magnetic filtration. The effects of two main parameters of magnetization and drag forces on the performance of the magnetic filtration were investigated. By increasing the magnetic intensity from 0.4 to 4 T, the magnetic filter performance was increased from less than 0.7 up to 0.99 depending on the fluid velocity through the magnetic filter. The measured results in magnetic filtration tests were in consistence with the theoretical results applied in this study. It was revealed that the schwertmannite possessed a high regeneration ability with trivial loss of adsorption capacity. Moreover, the phosphate adsorption capacity in schwertmannite was remarkably increased by using an acid-modification method.