Optimization of the configuration of the anion selectrodialysis stack for fractionation of phosphate from UASB effluent in batch mode on lab scale and pilot scale

•With anion selectrodialysis phosphate can be recovered from nitrified UASB effluent.•The standard anion exchange (SA) membrane determines the phosphate concentrations.•HPO42- is the actual migrating ion through the SA membrane.•Fujifilm Type 1 and PC-Acid 100 OT membranes perform better than PC-SA membranes.•Similar results were obtained at lab scale and pilot scale.