Anion exchange membranes used in diffusion dialysis for acid recovery from erosive and organic solutions

The membrane structures are damaged and their performances are reduced after the erosion of HCl-FeCl2, which are mainly attributed to the loss of -N+(CH3)3Br− and -OH groups. The weight loss percent is in the range of 10-21%, the ion exchange capacity decreases but the swelling degree increases. The dialysis coefficient of HCl (UH-1) and separation factor (S1) reduce to 0.006-0.010 m h−1 and 13.9-15.5 for commercial membranes, and 0.016-0.024 m h−1 and 33.2-47.6 for QPPO/PVA membranes, correspondingly. Besides, the membranes without erosion are used to separate organic solution containing HCl and glyphosate. The UH-2 is in the range of 0.0040-0.0062 m h−1 for commercial membranes, and 0.0094-0.0104 m h−1 for QPPO/PVA membranes. The UH-2 values are generally stable within 10 h, and the acid concentration in the feed side decreases from 5.82 to 3.16 mol L−1. Hence, the QPPO/PVA membranes can be potentially applied in DD process to recover acid from organic solution containing HCl and glyphosate.