Recent innovative technologies have been introduced to lower the energy demand of this process, through short-circuiting the nitrification-denitrification pathway (e.g. Overall, this study highlights the potential of low-cost polymer hydrogels for achieving mainstream ammonium recovery from domestic wastewater.įor the past century, the conventional activated sludge process has been the preferred approach to treating domestic wastewater worldwide 1, in which ammonium is dissipated to atmospheric nitrogen by sequential oxidation and reduction through a nitrate intermediate (i.e. pH 4.0) was demonstrated with minimal loss in sorption performance following multiple sorption/desorption cycles. Importantly, effective regeneration of the hydrogels under mildly acidic conditions (i.e. It was, however, unaffected by changes in pH, as the sorption capacity remained constant from pH 5.0–8.0. The sorption capacity of the hydrogel was 8.8–32.2 mg NH 4–N/g, which corresponds to removal efficiencies ranging from 68% to 80% NH 4–N, increasing proportionally with the initial ammonium concentration. This paper reports on the use of polymer hydrogels for rapid sorption of ammonium from domestic wastewater coupled with efficient regeneration by mild acid washing. This is largely due to the low ammonium concentrations in these wastewater streams. To date, technologies to recover ammonium from domestic wastewater from the mainstream have not found widespread application.