Aqueous phase thiosulfate removal using photo catalysis

Removal of thiosulfate (S ₂O ₃ ^2-, 200 mg/L) from simulated wastewater samples was investigated under varying co-pollutants and pH conditions employing the titanium dioxide (TiO ₂) mediated photocatalysis. For thiosulfate only studies higher substrate removal was noted at lower pH with a specific trend of pH 4 > pH 7 > pH 10. Furthermore, near complete thiosulfate removal was also achieved at pH 4. A similar thiosulfate removal trend was also noted for the binary thiosulfate & p-cresol and thiosulfate & thiocyanate systems at pH 4, indicating high photocatalysis process efficiency. However, thiosulfate removal from the mixed systems at pH greater than 4 was slower as compared to the respective thiosulfate only systems. Nevertheless for the binary thiosulfate & thiocyanate system, significant thiosulfate removal was noted even at pH 12 when the thiosulfate concentration was reduced to 40 mg/L.