Feasibility of osmotic dilution for recycling spent dialysate: Process performance, scaling, and economic evaluation

(3-Aminopropyl)trimethoxysilane-Functionalized Titanium Dioxide Thin-Film Nanocomposite Membrane: Enhanced Rejection Performance for Unary and Binary High-Salt Wastewater

“…The APTMS-TFN0.05 reached a maximum water flux of 15.77 LMH at the KCl concentration of 1.5 M, while the pristine TFC reached its maximum of 15.26 LMH at 2 M. The initial increase in water flux for both membranes was mainly due to the higher KCl concentration and greater osmotic pressure on both sides of the membrane, which further increased the driving force of FO and led to an increase in the permeation flux . Due to concentration polarization and membrane fouling limitations, the membrane permeation flux reached a peak and, thereafter, a plateau with increasing KCl concentration. − As shown in the right part of Figure a, it can be found that when NaCl was selected as the draw solution, the water flux of APTMS-TFN0.05 first increased and then decreased with the increase in NaCl concentration, and APTMS-TFN0.05 reached the maximum water flux of 20.76 LMH when the NaCl concentration was 1.5 M. In the latter stage, with the increase in NaCl concentration, the concentration polarization and membrane fouling problems were exacerbated by the high concentration of NaCl, resulting in an extremely low permeation flux. As the concentration increased, the water flux of TFC gradually increased, reaching a maximum of 11.71 LMH at 2 M. Comparing the water flux of KCl and NaCl solutions as the draw, it can be clearly found that the 1 M NaCl solution exhibited a higher water flux as the draw.…”

APTMS‐Modified Silica as a Thin‐Film Nanocomposite Forward Osmosis Membranes: Towards Enhanced Selectivity and Dye Rejection Stability for Congo Red and Rhodamine B

“…Especially, the TFN membrane reached the maximum of 18.14 LMH at 1.5 M KCl concentration, while TFC reached the maximum of 15.26 LMH at 2 M. The upward trend in the former process was mainly because the rise of osmotic pressure difference across the FO membrane increases the driving force of FO process. [46] The latter process was stable because concentration polarization and membrane fouling prevent the passage of water molecular, [47][48][49] which can be alleviated by increasing the liquid flow rate. [50] It can be clearly seen from the right side of Figure 8 The SRSF for TFC and TFN reached the smallest when the KCl concentration was 1 M, which were 7.24 and 1.85 g/L, respectively (Figure 8(b)) while the minimum SRSF values of 1.77 and 0.17 g/L were obtained when the NaCl concentration was 1 M. Compared with the other influencing factors, draw solution concentrations had the greatest impact on the J w and SRSF of the FO membrane, which also reflected the sensitivity of the membrane to the concentration of the draw solution.…”

A Comprehensive Review on Forward Osmosis Water Treatment: Recent Advances and Prospects of Membranes and Draw Solutes

“…In such a system, the water molecules move from the feed solution side to the draw solution side; the FO process reduces with the decrease in the osmotic pressures and remains relatively static until the osmotic pressures on the respective sides are equal. The diluted draw solution can be reconstituted through secondary separation steps, such as nanofiltration (NF), RO, PRO, distillation, or the application of a thermal, magnetic, or electric field [17][18][19]. The following conditions must be met to realize the operation of the FO process [20]: (1) the draw solute must provide an effective driving force; (2) the selective permeable membrane or membrane module must allow the transport of the water molecules, while preventing the passage of the other solute molecules or ions.…”