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An electro‐responsive hydrogel with semi‐interpenetrating polymer networks (semi‐IPN) composed of crosslinked poly(2‐acrylamido‐2‐methyl‐l‐propanesulfonic acid‐co‐acrylamide) (P(AMPS‐AM)) and linear polyelectrolyte polyacrylic acid (PAA) was explored. The semi‐IPN hydrogel was characterized with different methods and then used as advanced draw agent toward high water recovery for forward osmosis (FO) desalination. The swelling kinetics of the semi‐IPN hydrogel was investigated, and the electro‐responsive nature of the hydrogel under electric stimulus (in direct contact with electrodes) was determined. Results indicated that in comparison with pure P(AMPS‐AM) hydrogel, the semi‐IPN hydrogel exhibited a loose network structure with more pores. In addition, a higher equilibrium swelling capacity and more pronounced deswelling under electric stimulus can be observed for the semi‐IPN hydrogel. Furthermore, the semi‐IPN hydrogel displayed a similar initial water flux of 2.20 L m−2 h−1 (LMH) from 2 g/L NaCl solution of a lab‐scale FO process. Importantly, the semi‐IPN hydrogel had a 25% increase in water recovery efficiency under the electric stimulus of 15 V, and showed better recyclability during three cycles of regeneration compared with pure P(AMPS‐AM). The mechanism of enhanced dewatering nature for the semi‐IPN hydrogel under electric stimulus was elucidated. These results indicate this new hydrogel's potential as a promising candidate for improving FO performance. [ABSTRACT FROM AUTHOR]

Amino‐functionalized magnetic zirconium alginate beads with an interpenetrating network (Fe3O4/PAM/SA–Zr) were prepared, characterized, and then tested as a novel biomass adsorbent for phosphate removal and recovery. The hydrogel beads exhibited outstanding thermostability and possessed a magnetic response. The effects of the pH, dosage, initial phosphate concentration, interference ions, and temperature on the removal of phosphate were investigated. The kinetics, isotherms, and thermodynamics of the adsorption were studied. Notably, the adsorption of phosphate was endothermic, feasible, and spontaneous with a maximum uptake capacity of 42.23 mg‐P/g at an optimized pH of 2.0. The phosphate could be desorbed effectively with a 0.2 mol/L NaOH solution, and the adsorbent exhibited a good reusability. The possible adsorption mechanisms were verified by zeta potential, Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy analyses. Continuous phosphate‐adsorption tests were conducted in a fixed‐bed columns packed with Fe3O4/PAM/SA–Zr, and the breakthrough curves were predicted by the Adams–Bohart, Thomas, and Yoon–Nelson models, respectively. The suitability of the hydrogel beads for the treatment of real wastewater was also tested. These hydrogel beads should be a promising adsorbent for phosphate removal and recovery from aqueous solutions, with the advantages of a high uptake capacity, good reusability, and easy magnetic separation. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 46897. [ABSTRACT FROM AUTHOR]