آب و فاضلاب (Jan 2016)
Arsenic Removal from Aqueous Solutions Using Modified and Unmodified Oak Sawdust
Abstract
In this research, oak sawdust, in both modified and unmodified forms, was used as an economical and low-cost material for the removal of arsenic from aqueous solutions. For this purpose, arsenic synthetic samples were prepared using NaAsO2 in distilled water and the effects of pH, adsorbent dosage, contact time, and initial As(V) concentration were investigated on As(V) adsorption using the adsorbents prepared. The results showed that modified sawdust achieved the highest efficiency (>91%) over a contact time of 60 min and at pH 7 when the adsorbent dosage was 4gr/L and the initial As(V) concentration was 150 µg/L. The data from both adsorbents fitted well to the Langmuir isotherm. Under optimum conditions (an initial As(V) concentration of 150 µg/L and optimal absorption pH, contact time, and adsorbent dosage), maximum As(V) removal efficiencies were 93.85% and 91.034% with the modified and unmodified sawdust adsorbents, respectively. Given the availability and low cost of the adsorbent used and the high removal efficiency obtained at lower adsorbent dosages and contact times, the modified oak sawdust may be recommended as an effective adsorbent for the removal of arsenic (v) from aqueous solutions, especially since it requires no need for pH modification.
