Preparation and Application of Chitosan Membranes to Filter Silver from X-ray Film Processing Wastes

Chitosan is a natural polysaccharide biopolymer which has been widely used in different processes and applications. Chitosan based membranes have been used in reverse osmosis, gas separation, dialysis and pervaporation. The object of this research was investigating the possibility of chitosan membrane used as a filter for removing silver (Ag) from X-ray film processing wastes. Several of chitosan membranes such as M1, M2, M3 and M4 have been prepared for the purpose and filtration was done using dead end filtration method. The filtration experiments were performed on a flat sheet membrane using pure water and X-ray film processing wastes as feeds. The analysis of silver concentration has been done by atomic absorption spectrometers (AAS). The results show that chitosan membrane M2 gave the highest filtration capacity i.e. 99.9%, with the pure water flux (PWF) and product flux (PF) are 2972.56 L/m2h and 1761.18 L/m2h respectively. The filtration capacity of the membranes decreases with increasing the amount of chitosan, while the pure water flux and product flux are increased. The filtration capacities show that the chitosan membranes are able to filter silver from X-ray film processing wastes with performance dependent on their characteristic such as pores size. This suggests that, the chitosan membranes can be used to recover of silver from X-ray film processing wastes to improve the quality of treated to an acceptable quality level.