In the present study, a simple, inexpensive, nontoxic, and environmentally friendly polyethylene glycol (PEG) polymer was used to enhance the hydrophilicity of the forward osmosis (FO) membrane using various PEG concentrations as a pore forming agent in the casting solution of polyethersulfone/polysulfone (PES/PSF) blend membranes. A nonwoven PES/PSF FO blend membrane was fabricated via the immersion precipitation phase inversion technique. The membrane dope solution was cast on polyethylene terephthalate (PET) nonwoven fabric. The results revealed that PEG is a pore forming agent and that adding PEG promotes membrane hydrophilicity. The membrane with 1 wt% PEG (PEG1) had about 27% lower contact angle than the pristine blend membrane. The PEG1 membrane has less tortuosity (which reduces from 3.4–2.73), resulting in a smaller structure parameter (S value) of 277 μm, due to the presence of open pores on the bottom surface structure, which results in diminished ICP. Using 1 M NaCl as the draw solution and distilled water as the feed solution, the PEG1 membrane exhibited higher water flux (136 L m−2 h−1) and lower reverse salt flux (1.94 g m−2 h−1). Also, the selectivity of the membrane, specific reverse salt flux, (Js/Jw) showed lower values (0.014 g/L). Actually, the PEG1 membrane has a 34.6% higher water flux than the commercial nonwoven‐cellulose triacetate (NW‐CTA) membrane. By means of varied concentrations of NaCl salt solution (0.6, 1, 1.5, and 2 M), the membrane with 1 wt% PEG showed improved FO separation performance with permeate water fluxes of 108, 136, 142, and 163 L m−2 h−1. In this work, we extend a promising gate for designing fast water flux PES/PSF/PEG FO blend membranes for water desalination.
This paper was focused on the investigation of a forward osmosis- (FO-) reverse osmosis (RO) hybrid process to cotreat seawater and impaired water from steel industry. By using this hybrid process, seawater can be diluted before desalination, hence reducing the energy cost of desalination, and simultaneously contaminants present in the impaired water are prevented from migrating into the product water through the FO and RO membranes. The main objective of this work was to investigate on pilot-scale system the performance of the combined FO pretreatment and RO desalination hybrid system and specifically its effects on membrane fouling and overall solute rejection. Firstly, optimization of the pilot-scale FO process to obtain the most suitable and stable operating conditions for practical application was investigated. Secondly, pilot-scale RO process performance as a posttreatment to FO process was evaluated in terms of water flux and rejection. The results indicated that the salinity of seawater reduced from 35000 to 13000 mg/L after 3 hrs using FO system, while after 6 hrs it approached 10000 mg/L. Finally, FO/RO system was tested on continuous operation for 15 hrs and it was demonstrated that no pollutant was detected neither in draw solution nor in RO permeate after the end of operating time.
A B S T R A C TThe Al-Alamia Dye Company in Cairo, Egypt faces a variety of problems due to unhealthy conditions resulting from the discharge of dye wastewater into sewer systems. These dyes not only cause enormous environmental pollution problems, but they also interfere with treatment system operations. From study the characterization of the dye wastewater resulting from the company, a physiochemical pretreatment for the wastewater dye effluents as a pretreatment step prior to membrane separation was suggested. The aim of the present work is to characterize the dye wastewater resulting from the dye processes of cotton and polyester and evaluate a proposed physiochemical treatment process for reducing pollution prior to membrane separation. Physiochemical analyses of composite samples for both cotton and polyester wastewater dyes were investigated. The characteristics of the cotton dye wastewater proved high TDS concentration (5,400-14,000 mg/L) and low COD concentration (154-684 mg/L). The analyses of the polyester dye wastewater proved low TDS concentration (350-2,561 mg/L) and high COD concentration (354-3,051 mg/L). A remarkable suspended solids concentration (SS) and heavy metals for both polyester and cotton dye wastewater were determined. The pretreatment proved that aluminum sulfate with 200 mg/L dose is the optimum for reducing SS concentration and COD concentration for cotton wastewater dyeing. Also it was found that a 600 mg/L does of ferric chloride is the optimum for reducing the SS and COD concentration for polyester wastewater dyeing.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.