The Potential Use of Low-Grade Phosphate Rocks as Adsorbent (original) (raw)

This study evaluates the suitability of using low-grade phosphate for Cu 2+ removal. The study also investigates the effects of the presence of ethylene-diamine-tetra-acetic acid (EDTA), citric acid, tartaric acid and sodium chloride in a solution containing Cu 2+ on the adsorption capacity of Cu 2+ onto low-grade phosphate. For aqueous solutions with 100 ppm Cu 2+ , the percentage removal of Cu 2+ at pH 4 onto 0.2 g of 0.063 mm low-grade phosphate was found to be 96.6 % after one hour. Using one mmol of either Cu 2+ , Cu-NaCl, Cu-tartaric acid, Cu-EDTA, or Cu-citric acid aqueous solutions, the present work shows trend of the percentage removal of Cu 2+ at equilibrium time: Cu 2+ > Cu-NaCl > Cu-tartaric acid > Cu-EDTA > Cu-citric acid. It is also found that increasing the concentration of ligand to copper ratio decreases the percentage removal of Cu 2+ significantly. This means that the adsorption capacity is ligand type and concentration dependent.