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Ho Kyong Shon - One of the best experts on this subject based on the ideXlab platform.
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sulfur containing air pollutants as draw solution for fertilizer drawn forward osmosis desalination process for irrigation use
Desalination, 2017Co-Authors: Van Huy Tran, Sherub Phuntsho, Hyunwoong Park, Dong Suk Han, Ho Kyong ShonAbstract:Abstract This study investigated suitability and performance of the sulfur-based seed solution (SBSS) as a draw solution (DS), a byproduct taken from the photoelectrochemical (PEC) process where the SBSS is used as an electrolyte for H 2 production. This SBSS DS is composed of a mixture of ammonium sulfate ((NH 4 ) 2 SO 4 ) and ammonium sulfite ((NH 4 ) 2 SO 3 ), and it can be utilized as fertilizer for fertilizer drawn forward osmosis (FDFO) desalination of saline water. The FDFO process employed with thin-film composite (TFC) membrane and showed that the process performance (i.e. water Flux and reverse Salt Flux) is better than that with cellulose triacetate (CTA) membrane. In addition, it produced high water Flux of 19 LMH using SBSS as DS at equivalent concentration at 1 M and 5 g/L NaCl of feed solution (model saline water). Experimental results showed that the reverse Salt Flux of SBSS increased with the increase in pH of the DS and that lowering the concentration of ammonium sulfite in the SBSS led to the higher water Flux of feed solution. The result also demonstrated that this SBSS is practically suitable for the FDFO process toward development of water-energy-food nexus technology using sulfur chemicals-containing air pollutant.
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methane production in an anaerobic osmotic membrane bioreactor using forward osmosis effect of reverse Salt Flux
Bioresource Technology, 2017Co-Authors: Youngjin Kim, Sherub Phuntsho, Laura Chekli, Ho Kyong Shon, Torove Leiknes, Noreddine GhaffourAbstract:Abstract This study investigated the impact of reverse Salt Flux (RSF) on microbe community and bio-methane production in a simulated fertilizer driven FO-AnMBR system using KCl, KNO3 and KH2PO4 as draw solutes. Results showed that KH2PO4 exhibited the lowest RSF in terms of molar concentration 19.1 mM/(m2.h), while for KCl and KNO3 it was 32.2 and 120.8 mM/(m2.h), respectively. Interestingly, bio-methane production displayed an opposite order with KH2PO4, followed by KCl and KNO3. Pyrosequencing results revealed the presence of different bacterial communities among the tested fertilizers. Bacterial community of sludge exposed to KH2PO4 was very similar to that of DI-water and KCl. However, results with KNO3 were different since the denitrifying bacteria were found to have a higher percentage than the sludge with other fertilizers. This study demonstrated that RSF has a negative effect on bio-methane production, probably by influencing the sludge bacterial community via environment modification.
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selection of suitable fertilizer draw solute for a novel fertilizer drawn forward osmosis anaerobic membrane bioreactor hybrid system
Bioresource Technology, 2016Co-Authors: Youngjin Kim, Sherub Phuntsho, Laura Chekli, Torove Leiknes, Noreddine Ghaffour, Wanggeun Shim, Ho Kyong ShonAbstract:In this study, a protocol for selecting suitable fertilizer draw solute for anaerobic fertilizer-drawn forward osmosis membrane bioreactor (AnFDFOMBR) was proposed. Among eleven commercial fertilizer candidates, six fertilizers were screened further for their FO performance tests and evaluated in terms of water Flux and reverse Salt Flux. Using selected fertilizers, bio-methane potential experiments were conducted to examine the effect of fertilizers on anaerobic activity due to reverse diffusion. Mono-ammonium phosphate (MAP) showed the highest biogas production while other fertilizers exhibited an inhibition effect on anaerobic activity with solute accumulation. Salt accumulation in the bioreactor was also simulated using mass balance simulation models. Results showed that ammonium sulfate and MAP were the most appropriate for AnFDFOMBR since they demonstrated less Salt accumulation, relatively higher water Flux, and higher dilution capacity of draw solution. Given toxicity of sulfate to anaerobic microorganisms, MAP appears to be the most suitable draw solution for AnFDFOMBR.
Tai-shung Chung - One of the best experts on this subject based on the ideXlab platform.
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robust outer selective thin film composite polyethersulfone hollow fiber membranes with low reverse Salt Flux for renewable salinity gradient energy generation
Journal of Membrane Science, 2016Co-Authors: Zhen Lei Cheng, Tai-shung Chung, Ying Da LiuAbstract:Abstract This study reports outer-selective thin-film composite (TFC) hollow fiber membranes with extremely low reverse Salt Fluxes and robustness for harvesting salinity-gradient energy from pressure retarded osmosis (PRO) processes. Almost defect-free polyamide layers with impressive low Salt permeabilities were synthesized on top of robust polyethersulfone porous supports. The newly developed TFC-II membrane shows a maximum power density of 7.81 W m−2 using 1 M NaCl and DI water as feeds at 20 bar. Reproducible data obtained in the 2nd and 3rd runs confirm its stability under high hydraulic pressure differences. Comparing to other PRO membranes reported in the literature, the newly developed membrane exhibits not only the smallest slope between water Flux decline and Δ P increase but also the lowest ratio of reverse Salt Flux to water Flux. Thus, the effective osmotic driving force could be well maintained even under high pressure operations. For the first time, the effect of feed pressure buildup induced by feed flowrate was evaluated towards PRO performance. A slight increment in feed pressure buildup was found to be beneficial to water Flux and power density up to 10.06 W m−2 without comprising the reverse Salt Flux. We believe this study may open up new perspectives on outer-selective PRO hollow fiber membranes and provide useful insights to understand and design next-generation outer-selective TFC hollow fiber membranes for osmotic power generation.
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advanced fo membranes from newly synthesized cap polymer for wastewater reclamation through an integrated fo md hybrid system
Aiche Journal, 2013Co-Authors: Rui Chin Ong, Tai-shung Chung, Peng Wang, Bradley James Helmer, Jos S De WitAbstract:A new cellulose acetate propionate (CAP) polymer has been synthesized and used to prepare high-performance forward osmosis (FO) membranes. With an almost equal degree of substitution of acetyl and propionyl groups, the CAP-based dense membranes show more balanced physicochemical properties than conventional cellulose acetate (CA)-based membranes for FO applications. The former have a lower equilibrium water content (6.6 wt. %), a lower Salt diffusivity (1.6×1014 m2 s−1) and a much lower Salt partition coefficient (0.013) compared with the latter. The as-prepared and annealed CAP-based hollow fibers have a rough surface with an average pore radius of 0.31 nm and a molecular weight cut off of 226 Da. At a transmembrane pressure of 1 bar, the dual-layer CAP-CA hollow fibers show a pure water permeability of 0.80 L m−2 h−1 bar−1 (LMH/bar) and a rejection of 75.5% to NaCl. The CAP-CA hollow fibers were first tested for their FO performance using 2.0 M NaCl draw solution and deionized water feed. An impressive water Flux of 17.5 L m−2 h−1 (LMH) and a reverse Salt Flux of 2.5 g m−2 h−1 (gMH) were achieved with the draw solution running against the active CAP layer in the FO tests. The very low reverse Salt Flux is mainly resulting from the low Salt diffusivity and Salt partition coefficient of the CAP material. In a hybrid system combining FO and membrane distillation for wastewater reclamation, the newly developed hollow fibers show very encouraging results, that is, water production rate being 13–13.7 LMH, with a MgCl2 draw solution of only 0.5 M and an operating temperature of 343 K due to the incorporation of bulky propionyl groups with balanced physiochemical properties. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1245–1254, 2013
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double skinned forward osmosis membranes for reducing internal concentration polarization within the porous sublayer
Industrial & Engineering Chemistry Research, 2010Co-Authors: Kai Yu Wang, Tai-shung ChungAbstract:A scheme to fabricate forward osmosis membranes comprising a highly porous sublayer sandwiched between two selective skin layers via phase inversion was proposed. One severe deficiency of existing composite and asymmetric membranes used in forward osmosis is the presence of unfavorable internal concentration polarization within the porous support layer that hinders both (i) separation (Salt Flux) and (ii) the performance (water Flux). The double skin layers of the tailored membrane may mitigate the internal concentration polarization by preventing the Salt and other solutes in the draw solution from penetrating into the membrane porous support. The prototype double-skinned cellulose acetate membrane displayed a water Flux of 48.2 L·m−2·h−1 and lower reverse Salt transport of 6.5 g·m−2·h−1 using 5.0 M MgCl2 as the draw solution in a forward osmosis process performed at 22 °C. This can be attributed to the effective Salt rejection by the double skin layers and the low water transport resistance within the p...
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dual layer hollow fibers with enhanced Flux as novel forward osmosis membranes for water production
Environmental Science & Technology, 2009Co-Authors: Qian Yang, Kai Yu Wang, Tai-shung ChungAbstract:We have demonstrated in this work the prospect of dual-layer polybenzimidazole-polyethersulfone (PBI-PES) nanofiltration (NF) hollow fiber membranes in the forward osmosis (FO) process for water production: The state-of-the-art for dual-layer membrane fabrication via coextrusion technology could produce the resultant membrane consisting of an ultrathin selective skin, fully porous water channels underneath, and a microporous sponge-like support structure. Together with its sharp pore size distribution and self-charged PBI selective membrane surface, the dual-layer hollow fiber forward osmosis membrane can achieve a water Flux as high as 33.8 L·m−2·hr−1 and a Salt Flux less than 1.0 g·m−2·hr−1 at room temperature of 23 °C using 5 M MgCl2 as the draw solution. A comprehensive literature review of previous efforts on identifying suitable membranes and appropriate draw solutions in the FO process for water production and seawater desalination have also been conducted. It shows that the water Fluxes of the dua...
Youngjin Kim - One of the best experts on this subject based on the ideXlab platform.
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methane production in an anaerobic osmotic membrane bioreactor using forward osmosis effect of reverse Salt Flux
Bioresource Technology, 2017Co-Authors: Youngjin Kim, Sherub Phuntsho, Laura Chekli, Ho Kyong Shon, Torove Leiknes, Noreddine GhaffourAbstract:Abstract This study investigated the impact of reverse Salt Flux (RSF) on microbe community and bio-methane production in a simulated fertilizer driven FO-AnMBR system using KCl, KNO3 and KH2PO4 as draw solutes. Results showed that KH2PO4 exhibited the lowest RSF in terms of molar concentration 19.1 mM/(m2.h), while for KCl and KNO3 it was 32.2 and 120.8 mM/(m2.h), respectively. Interestingly, bio-methane production displayed an opposite order with KH2PO4, followed by KCl and KNO3. Pyrosequencing results revealed the presence of different bacterial communities among the tested fertilizers. Bacterial community of sludge exposed to KH2PO4 was very similar to that of DI-water and KCl. However, results with KNO3 were different since the denitrifying bacteria were found to have a higher percentage than the sludge with other fertilizers. This study demonstrated that RSF has a negative effect on bio-methane production, probably by influencing the sludge bacterial community via environment modification.
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selection of suitable fertilizer draw solute for a novel fertilizer drawn forward osmosis anaerobic membrane bioreactor hybrid system
Bioresource Technology, 2016Co-Authors: Youngjin Kim, Sherub Phuntsho, Laura Chekli, Torove Leiknes, Noreddine Ghaffour, Wanggeun Shim, Ho Kyong ShonAbstract:In this study, a protocol for selecting suitable fertilizer draw solute for anaerobic fertilizer-drawn forward osmosis membrane bioreactor (AnFDFOMBR) was proposed. Among eleven commercial fertilizer candidates, six fertilizers were screened further for their FO performance tests and evaluated in terms of water Flux and reverse Salt Flux. Using selected fertilizers, bio-methane potential experiments were conducted to examine the effect of fertilizers on anaerobic activity due to reverse diffusion. Mono-ammonium phosphate (MAP) showed the highest biogas production while other fertilizers exhibited an inhibition effect on anaerobic activity with solute accumulation. Salt accumulation in the bioreactor was also simulated using mass balance simulation models. Results showed that ammonium sulfate and MAP were the most appropriate for AnFDFOMBR since they demonstrated less Salt accumulation, relatively higher water Flux, and higher dilution capacity of draw solution. Given toxicity of sulfate to anaerobic microorganisms, MAP appears to be the most suitable draw solution for AnFDFOMBR.
Hansconrad Zur Loye - One of the best experts on this subject based on the ideXlab platform.
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Salt Flux synthesis crystal structure and theoretical characterization of rb0 74ga6 62ti0 38o11
Solid State Sciences, 2020Co-Authors: Mohammad Usman, Mark D Smith, Vancho Kocevski, Theodore M Besmann, Hansconrad Zur LoyeAbstract:Abstract Single crystals of Rb0.74Ga6.62Ti0·38O11 (RGTO) were grown from a mixed RbCl–RbF Flux at 850 °C. The compound crystallizes in the RbGa7O11 structure type, which is reminiscent of the hollandite and β-Ga2O3 structure types. RGTO crystallizes in the monoclinic space group P2/m with lattice parameters a = 8.3355 (8) A, b = 3.0286 (3) A, c = 9.5028 (9) A, and β = 114.620 (3)°. The crystal structure of RGTO is comprised of GaO6 and mixed (Ga/Ti)O6 octahedra and GaO4 tetrahedra connected in a complex three-dimensional, anionic framework exhibiting eight-sided channels that are occupied by disordered Rb cations required for charge balance. First-principles calculations in the form of density functional theory were performed, which indicated the complex to be a charge transfer semiconductor.
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oxygen anion solubility as a factor in molten Flux crystal growth synthesis and characterization of four new reduced lanthanide molybdenum oxides ce4 918 3 mo3o16 pr4 880 3 mo3o16 nd4 910 3 mo3o16 and sm4 952 3 mo3o16
Crystal Growth & Design, 2016Co-Authors: Anthony J Cortese, Dileka Abeysinghe, Branford Wilkins, Mark D Smith, Vitaly A Rassolov, Hansconrad Zur LoyeAbstract:Four new reduced lanthanide molybdenum oxides containing mixed valent Mo(V/VI)O4 tetrahedra were prepared in single crystal form by utilizing a high temperature molten Salt Flux synthesis involving an in situ reduction step. Calculations support the experimentally observed result that large alkali metal cations such as cesium are superior compared to the smaller alkali metal cations such as sodium in solvating O2– to facilitate oxide crystal growth in halide melts. All four compounds were structurally characterized by single crystal and powder X-ray diffraction methods and were found to crystallize in the cubic space group Pn3n. The temperature dependence of the magnetic susceptibility of these compounds was measured, and all were found to exhibit simple paramagnetism.
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high temperature Salt Flux crystal growth of new lanthanide molybdenum oxides ln5mo2o12 ln eu tb dy ho and er magnetic coupling within mixed valent mo iv v rutile like chains
Inorganic Chemistry, 2015Co-Authors: Anthony J Cortese, Dileka Abeysinghe, Branford Wilkins, Mark D Smith, Gregory Morrison, Hansconrad Zur LoyeAbstract:Five new lanthanide molybdenum oxides containing mixed valent Mo(IV/V) rutile-like chains, Ln5Mo2O12 Ln = Eu, Tb, Dy, Ho, and Er, were prepared utilizing a high-temperature molten Salt Flux synthesis involving an in situ reduction utilizing metallic reducing agents. All five compounds were structurally characterized by single-crystal and powder X-ray diffraction methods and were found to crystallize in the monoclinic space group C2/m. The molybdates all contain rare infinite chains consisting of MoO2O4/2 edge-sharing octahedra. The chains exhibit alternating long and short separations between octahedra caused by the presence of Mo–Mo bonds to form Mo2O10 units containing one unpaired electron. The temperature dependence of the magnetic susceptibility of these compounds was measured, and antiferromagnetic ordering was observed in all cases.
Nidal Hilal - One of the best experts on this subject based on the ideXlab platform.
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brackish water desalination for agriculture assessing the performance of inorganic fertilizer draw solutions
Desalination, 2019Co-Authors: Wafa Suwaileh, Daniel Johnson, Nidal HilalAbstract:Abstract Fertilizer drawn forward osmosis (FDFO) is a cost-effective technology for brackish water desalination. The diluted fertilizer draw solution can be used to supply nutrients to crops instead of separating it from the desalinated water. This work evaluates the performance of the FDFO using four fertilizer draw solutions with various concentrations (1.0, 1.5, 2.0 mol/L) and a polyamide thin film composite (TFC) FO membrane for brackish water desalination. The results revealed that KCl fertilizer draw solution achieved the highest water Flux and adequate reverse Salt Flux as compared to other fertilizer draw solution. The mixture KCl + KNO3 and KH2PO4 fertilizer draw solution generated the lowest water permeation and reverse Salt Flux. KH2PO4 draw solute promoted the growth of Salt scaling which affected the membrane productivity in terms of water Flux. The negatively charge of the membrane surface was responsible for precipitation of Salt on the selective layer. This influenced the performance and resulted in low water permeation and minimum loss of nutrients in the fertilizer draw solution. The advantage of FDFO is in not needing a recovery step to reconcentrate the draw solution, instead using diluted draw solution as a supplement to irrigation water via fertigation.
