Evaluation of poly (aspartic acid sodium salt) as a draw solute for forward osmosis

• Published in: Water research (Oxford) Vol. 80; pp. 294 - 305
• Main Authors: Gwak, Gimun, Jung, Bokyung, Han, Sungsoo, Hong, Seungkwan
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2015
• Subjects: Antiscaling; Aspartic acid; Aspartic Acid - chemistry; Brackish; Brackish water desalination; Desalination; Distillation - instrumentation; Distillation - methods; Draw solution; Feasibility Studies; Flux; Forward osmosis (FO); Hydrodynamics; Membranes; Membranes, Artificial; Molecular dynamics; Osmosis; Osmotic Pressure; Peptides - chemistry; Recycling; Reproducibility of Results; Sodium - chemistry; Sodium salts; Solubility; Waste Disposal, Fluid - instrumentation; Waste Disposal, Fluid - methods; Waste water; Waste Water - chemistry; Wastewater reclamation; Water Purification - instrumentation; Water Purification - methods; Wastewater reclamation; Draw solution; Forward osmosis (FO); Antiscaling; Desalination
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2015.04.041

Poly (aspartic acid sodium salt) (PAspNa) was evaluated for its potential as a novel draw solute in forward osmosis (FO). The inherent advantages of PAspNa, such as good water solubility, high osmotic pressure, and nontoxicity, were first examined through a series of physicochemical analyses and atomic-scale molecular dynamics simulations. Then, lab-scale FO tests were performed to evaluate its suitability in practical processes. Compared to other conventional inorganic solutes, PAspNa showed comparable water flux but significantly lower reverse solute flux, demonstrating its suitability as a draw solute. Moreover, fouling experiments using synthetic wastewater as a feed solution demonstrated that PAspNa reversely flowed to the feed side reduced inorganic scaling on the membrane active layer. The recyclability of PAspNa was studied using both nanofiltration (NF) and membrane distillation (MD) processes, and the results exhibited its ease of recovery. This research reported the feasibility and applicability of FO-NF or FO-MD processes using PAspNa for wastewater reclamation and brackish water desalination. [Display omitted] •Poly (aspartic acid sodium salt) (PAspNa) was proposed as a novel draw solute in FO.•High osmotic pressure and large configuration of PAspNa were verified.•PAspNa exhibited superiority in high water flux and low reverse solute flux in FO.•The reversely flowed PAspNa in FO could act as an antiscalant.•Ease of PAspNa recovery was demonstrated by both NF and MD.