Water Treatment Method for Removal of Select Heavy Metals and Nutrient Ions Through Adsorption by Magnetite

Abstract

This study explored the removal of contaminants from surrogate solutions using magnetite particles. Commercially available magnetite was used for the removal of copper, lead, nitrate, and phosphate from surrogate solutions. Single-stage experiments with copper, lead, and phosphate surrogate solutions achieved over 98% removal, while nitrate removal experiments only achieved 7.47%, in 24 h at high (20 g/L) magnetite doses and initial concentrations of 100 mg contaminant/L. Two-stage experiments with copper showed over 99.9% cumulative removal after the second stage. Adsorption kinetics experiments for copper, lead, and phosphate demonstrate rapid uptake of contaminants with high doses of magnetite, removing over 90% of contaminants in 4 min or less and follow a pseudo-second-order model. Ultimately, this study aims to establish the minimum magnetite dose and/or minimum number of stages required to remove contaminants below water quality standards for human and/or aquatic life. Water pollution is a serious global issue, and this study poses a potential solution that can be modified for a variety of applications, including environmental contamination and industrial wastewater treatment.