Abstract
Chromium is one of the most widely used heavy metals in industry as it has enough advantages for tanneries, textiles, wood processing and agro-food industries. Chromium VI is highly toxic and highly soluble in water, which is the origin of its great mobility in the ecosystems. In this study, the forward osmosis (FO) process was investigated to remove chromium from aqueous solution using cellulose triacetate membrane and ammonium bicarbonate (NH4 HCO3) as draw solution. The effect of various operating parameters such as feed temperature, feed concentration, draw temperature and draw concentration on FO performance was evaluated. The experimental runs showed that the permeate flux was enhanced with draw temperature, and maximum permeate flux of 2.38 x 10(-6) m s(-1) was obtained at 55 degrees C. The permeate flux was found to decrease with feed concentration. Moreover, the flux reached 2.9 x 10(-6) m s(-1) at maximum draw concentration of 3 mol L-1. These operating parameters had insignificant effect on chromium rejection and reached, in all cases, more than 99%. The validation of the model, using McCutcheon and Elimelech model, shows a good agreement with the determined experiment alones.