Thin polyamide films with controlled thickness are deposited directly on electrodes.
EIS measurements are made with varying polyamide film thicknesses and salt solutions.
Impedance spectra are fit with equivalent circuits containing resistors and capacitors.
Polyamide films exhibit a characteristic low-frequency impedance response.
Salt permeability is calculated from the characteristic polyamide membrane resistance.
Membrane transport behavior is directly observed during forward osmosis permeation.
Incomplete wetting of membrane polysulfone support layer is visually confirmed.
Draw solute concentration is quantified across feed and draw solution channels.
Permeation models are evaluated for describing observed concentration polarization.
Polyamide films and membranes are fabricated by molecular layer-by-layer deposition.
Polyamide surface chemistry is enriched with amine or carboxyl functional groups.
Gypsum scaling is compared for homogeneous and heterogeneous nucleation conditions.
Long-term gypsum scaling is similar for polyamide with different surface chemistry.
Commercial forward osmosis membranes are modified for organic fouling resistance.
Modification conditions for the poly(ethylene glycol) block copolymer are optimized.
Membranes show fouling resistance with an aggressive organic foulant mixture.
This post-fabrication technique compares favorably to other modification methods.
We present a critical review of the current state of forward osmosis (FO).
We analyze the energy efficiency of FO and emphasize relevant applications.
We discuss the key required membrane properties for FO and future implications.
We highlight fouling reversibility of FO and relevant benefits and applications.
We discuss applications where FO outperforms current technologies.
We present a low-fouling thin-film composite forward osmosis membrane.
An amine-rich polyamide active layer facilitates surface functionalization with PEG.
Improved organic fouling resistance at high (250 mg/L) alginate feed concentration
An analysis of an integrated forward and reverse osmosis desalination process is presented.
Integrated process can achieve boron and chloride levels suitable for agricultural irrigation.
Integrated forward and reverse osmosis process consumes less energy than a conventional two-pass RO process.
Challenges to further development of the integrated process are discussed.