5 - Metallurgical Slag as an Efficient and Economical Adsorbent of Arsenic

Abstract

Water contamination by arsenic has been recorded as an important health problem of global concern; even though the adsorption process has shown to be one of the best removal technologies, there are no adsorbents able to reduce its concentration to drinking water standards (0.010mg/l) when arsenic is present at high initial concentrations (>1mgAs/l), with an acceptable cost–benefit ratio. This study aims to demonstrate that metallurgical slag (SL) is an efficient and economical adsorbent of arsenic present in water at high initial concentrations by comparing removal efficiencies and treatment costs, using slags and zero-valent iron nanoparticles. Slag was less efficient, in terms of the maximum adsorption capacity, but it produced effluents meeting the limit (0.025mg/l) of the Mexican drinking water standards, when a 6mgAs/l solution was treated. Considering this, the use of SL instead of expensive commercial adsorbents will make the adsorption process of arsenic for water treatment feasible.