Papers by Keyword: Water Flux

Abstract: This work shows the performance of cobalt-silica membranes through water desalination via pervaporation process. The aim of this work is to find out the performance of the cobalt oxide as a templating agent in the silica cobalt membranes for water desalination via pervaporation process. It also aims to investigate the water flux and salt rejection of silica cobalt membranes using artificial saline water. The concentration of cobalt oxide as a template for fabricating cobalt-silica membranes were 5 – 35 wt%. The feed solution applied during pervaporation process were 0.3 – 5 wt% NaCl with operating temperatures of 25, 40 and 60 °C. The silica xerogels were characterized using Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET). From the FTIR result, it is known that the higher the concentration of cobalt in the membrane, the more silanol and siloxane groups. Based on BET analysis, Si-Co 35 wt% membrane has largest pore volume (0.129387 cm³g^-1). In addition, the highest value of water flux (7.2660 kg.m^-2.h^-1) and salt rejection (100%) is achieved by Si-Co 5% membrane in 0.3% NaCl feed at 60 °C. The value of water flux decreases and the value of salt rejection increases with increasing feed concentration.

Abstract: In this study, FO membrane was fabricated by Layer-by-Layer (LbL) coating technique using Poly (sodium 4-styrene-sulfonate)(PSS) and Poly (diallyl-dimethylammoniumchloride) (PDADMAC) as the active polyelectrolytes. Different concentrations of polyelectrolytes and deposition time of polyelectrolytes were investigated. The success of the coated layer was confirmed using ATR-FTIR and FESEM images. The membrane performance was determined by water flux and reverse solute diffusion (RSD) using pure water and 1.75M Na₂SO₄ as feed and draw solution, respectively. It was observed that the highest water flux, 6.76 L/ was recorded at the lowest polyelectrolytes concentration and longer deposition time. Meanwhile, the minimum RSD was achieved by the membrane fabricated at the longest deposition time and highest polyelectrolyte concentration.

Abstract: In order to improve the performance of Poly(vinyl chloride)(PVC)/ polyethersulfone (PES) blended membranes, cellulose acetate (CA) was used as a hydrophilic enhancer to blend with PVC and PES for membrane preparation by phase inversion method. In this study, the results of equilibrium water content (EWC), contact angle and X-ray photoelectron spectroscopy (XPS) confirmed the addition of CA could effectively improve the hydrophilicity of PVC/PES blended membrane. It was also found that water flux of PVC/PES/CA blended membranes increased with the increase of CA concentration.

Abstract: The compatibility of polyvinylidene difluorid (PVDF) and polyurethane (PU), the thermodynamics of the PVDF/PU/DMF (N-N-Dimethylformamide) membrane-forming systems were studied, and the composite tubular membranes of PVDF/PU-PET knitted fabric tube were prepared by the immersion precipitation phase inversion method. The results showed that the PVDF/PU system was partly compatible by the measurements of the solubility parameter theory, the mixing enthalpy, the viscosity. With PU content increasing, the gelation values increased and the instantaneous liquid-liquid phase separation was preferred to occur. The water flux of the composite tubular membranes were enhanced from 1264.81 to 2165.35 L/m².h with PU content increasing from 10wt% to 40wt%, which resulted from the an increment of the membrane porosity and the improvement of the hydrophilicity.

Abstract: The polysulfone membranes surface modification by the low temperature air plasma for the study. The PS membranes surface composition, filtration, antifouling characteristics with the modification was characterized by water contact angle, water fluxes, interception rate. Polysulfone membranes hydrophilic has been greatly improved, by water contact angle decreased significantly with low temperature air plasma treatment .Optimal conditions for plasma processing are power 60W, 1.5min, vacuum 60Pa.The water fluxes for the modified PS were increased 2.3 times than the nascent one, the interception rate was little changed. Membrane pollution gradually increased as the wastewater permeation flux decreased with time.

Abstract: The hydrophilic and mechanical strength of the cellulose acetate microporous membrane (CAMM) were improved by dealt with TiO₂ nanoparticles, which were obtained by adding a super dispersant into TiO₂-aqueous dispersion. The influence of such factors as temperature, processing time and TiO₂ concentration on adsorption amount of CAMM were investigated. The experiment data indicated that water flux of the modified CAMM increased with the increase of the TiO₂ adsorption amount. It suggested that hydrophilic of the CAMM was improved than that of blank. Experiments data also showed that the modified CAMM was better in mechanical strength but was weaker in elastic deformation than those of the blank. Water flux stability of the modified CAMM has improved significantly. Better modified conditions are as follows:TiO₂ concentration 0.1mol·L^-1,temperature 35°C, processing time 6h, and adsorption amount 9.708mg/g.

Abstract: In order to grasp the effect of porous medium particle size on groundwater recharge clogging. Measure the water flux of porous medium with different particle, by indoor soil column experiment simulating the process of groundwater recharge clogging. The results show that porous medium particle size is proportional to the initial water flux and the clogging occurred time, and is negatively correlative to clogging degree. When lay out wells in the water source heat pump works, should give full consideration to the effect of local hydrogeological conditions on groundwater recharge. It provides a scientific reference to prevent groundwater recharge clogging and the choice of recharge wells location.

Abstract: Polypropylene/polysulfone composite ultrafiltration membrane was prepared though coating method using microporous polypropylene hollow fiber membrane as a support layer and polysulfone membrane as a functional layer. Membranes of different pore sizes were prepared by L-S phase translation though changing the concentration of PS. The properties of the composite membrane include water flux and rejections of PEG-2000 were studies. The flux of 78 L/m²h and 98 % rejection was achieved at PS concentration of 11%, Polyvinylpyrrolidone of 4 %, liquid phase coagulation time of 3 hours.

Abstract: Sulfonated poly(arylene ether sulfone)s (SPAES) with different sulfonation degree (DS) were synthesized through aromatic nucleophilic substitution polymerization, and subsequently used to prepare ultrafiltration membranes by the phase inversion method. The performance and morphological structures of the prepared SPAES membranes were investigated and evaluated for ultrafiltration applications. With DS of 3%, the prepared ultrafiltration membrane showed the largest water permeability with bovine serum albumin rejection over 99%.

Abstract: Poly(vinylidene fluoride)(PVDF), poly(vinyl chloride)(PVC), and poly(methyl methacrylate)(PMMA) were used as the main materials in the preparation of novel blend five-hole membrane. Dimethylacetamide (DMAC) and polyvinyl pyrrolidone (PVP) were used as solvent and additive, respectively. The effect of some external coagulation conditions on the property of five-hole membrane was studied. The external coagulation conditions investigated in the work were the coagulation temperature and the DMAC content in coagulation bath. The result showed that the flux increased along with the increase of coagulation bath temperature and could reach the max at 35°C, then decreased gradually. The effect of the DMAC content in coagulation bath on flux is very similar to that of the temperature. The cross-sectional structures were examined by scanning electron microscopy.