Decolorisation of H‐acid manufacturing process wastewater by anion exchange resin

Anion exchange resin was employed to examine the feasibility to treat the H‐acid manufacturing wastewater by column experiment. Besides the acidity recovery, the decoloring efficiency and chemical oxygen demand (COD) removal efficiency of the anion exchange resin was investigated in the experiments. The results revealed that the anion exchange resin was able to remove colourful pollutants and degrade a part of COD effectively, and at the same time reserve acidity in the wastewater solution. The resin regenerated by a 10% NaCl aqueous solution had the same ability to discolour and remove the COD from the wastewater as the new resin had. The resin regenerated by 3% w/w NaCl aqueous solution, which was the same concentration as seawater, also had, to some extent, the same effect on decolorisation and the removal of COD; however, its colour and COD removal performance was not as efficient as the resin regenerated by 10% w/w NaCl and the new resin. H‐acid (0.25%) was also successfully recovered from the regenerating solutions.