The capacity of Polyurethane Sponge to Adsorb Nitrate, Ammonium, and Phosphate

Abstract

Nitrate, ammonium, and phosphate are the main contaminants in agricultural runoff that can harm aquatic organisms if in high concentrations reaches water bodies, for that contamination must be controlled. Polyurethane sponge is a durable material and can be used for filtering those contaminants from wastewater, but studies on the mechanism of adsorption by this material are still rare. Therefore, the purpose of this study is to predict the adsorption capacity, removal efficiency, isotherm, and adsorption kinetics of polyurethane sponge on ammonium, nitrate, and phosphate removal. The results of the study show that polyurethane sponge can remove nitrate, ammonium, and phosphate by adsorption mechanism. The highest maximum adsorption capacity is nitrate in 5-hour mixing time, followed by ammonium in 2- hour mixing time, and the last one is phosphate in 3-hour mixing time. The isotherm that is suitable for presenting the removal of nitrate and ammonium is the Freundlich isotherm, while the Langmuir isotherm is more suitable for the removal of phosphate. The adsorption kinetics which fit to describe the mechanism of nitrate and ammonium adsorption is the intra-particle diffusion model, while the phosphate adsorption kinetics is more suitable to be described by the Pseudo first-order model.