Abstract
This study investigates the feasibility of zirconium loaded onto orange waste, a cheap and available agricultural waste material, utilization for phosphorus recovery from secondary effluent of piggery wastewater. Phosphorus removal using zirconium-loaded saponified orange juice residue (Zr-SOJR) gel increased with increasing solid/liquid ratio. Phosphate adsorption was found to be very efficient at pH of 2–6. The secondary effluent was treated in a column packed with Zr-SOJR gel, which attained a dynamic adsorption capacity of 1.06 mol-P/kg. The phosphorus adsorbed on the column was successfully eluted as pre-concentrated phosphorus with a small amount of 0.2 M NaOH. Throughout the elution process, zirconium was not leaked from the adsorption gel. The solution obtained after elution had high concentrations of potassium and phosphorus, which was precipitated as potassium–magnesium–phosphate with the addition of magnesium.
