A sorption kinetics model for arsenic adsorption to magnetite nanoparticles.

INTRODUCTION: Arsenic is a well known water contaminant that causes toxicological and carcinogenic effects. In this work magnetite nanoparticles were examined as possible arsenic sorbents. The objective of this work was to develop a sorption kinetics model, which could be used to predict the amount of arsenic adsorbed by magnetite nanoparticles in the presence of naturally occurring species using a first-order rate equation, modified to include adsorption, described by a Langmuir isotherm. DISCUSSION: Arsenate and arsenite adsorption to magnetite nanoparticles was studied, including the effect of naturally occurring species (sulfate, silica, calcium magnesium, dissolved organic matter, bicarbonate, iron, and phosphate) on adsorption.
CONCLUSION: The model accurately predicts adsorption to magnetite nanoparticles used in a batch process to remove arsenic from spiked Houston, TX tap water, and contaminated Brownsville, TX groundwater.