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Rechargeable magnesium batteries have attracted much attention due to the high theoretical volumetric capacity, abundance, and safety. However, solid‐state Mg batteries have been rarely studied because of limited choices of solid‐state electrolyte materials. In this research, poly(vinylidene fluoride)/poly(propylene carbonate) (PVDF/PPC) as matrix were prepared using a simple solution casting method. Ethylene carbonate (EC), diethyl carbonate (DEC), and magnesium(II) bis(trifluoromethanesulfonyl) imide [Mg(TFSI)2] were selected to prepare liquid electrolyte. A classification of novel gel polymer electrolytes (GPEs), PVDF/PPC/Mg(TFSI)2, was synthesized and investigated. The electrochemical measurements show that PVDF/PPC/Mg(TFSI)2 polymer electrolytes exhibit a high ionic conductivity, close to 10−2 S cm−1, at room temperature. The electrochemical stability window of PVDF/PPC‐based GPE was up to 3 V (versus Mg2+/Mg). Materials characterization shows that these GPEs have a porous structure, providing a pathway for magnesium ion transport. Thermal analysis and crystal structure results indicate that PVDF crystallinity was affected by the addition of PPC. Additionally, the ion transport mechanism in the gel polymer electrolyte has been discussed. [ABSTRACT FROM AUTHOR]

Submerged membrane bioreactor system is commonly used for water and wastewater treatment processes. This system is a more economical alternative to conventional activated sludge process due to small footprint and better effluent quality. Nevertheless, membrane fouling is a major issue that requires further studies. This paper covers the use of an optical microscope to observe membrane fouling. Bentonite was used as model particles to simulate activated sludge. In-situ observation of particle deposition along the surface of hollow fiber membranes during filtration was performed at various operating conditions. Results from this studies indicated that the flux distribution was affected by the permeate flux and cross flow velocity. Lower CFV and higher flux caused the flux to be more non-uniformly distributed due to more severe fouling. These findings provided useful information to further improve the membrane module design to achieve more evenly distributed permeate flux.

In this study, a polyvinylidene difluoride (PVDF) hollow fiber membrane module incorporated with TiO2 was submerged into a photocatalytic reactor to create a hybrid photocatalysis with membrane separation process (a submerged membrane photoreactor, SMPR), for advanced dyes wastewater treatment. The SMPR performance was assessed by the degradation of single component Rhodamine B (RhB) and degradation of mixed dyes (RhB and Methyl orange (MO)) in a binary solution. Several operational parameters such as the amount of catalyst loading, permeate flux, and the effect of aeration were studied. Fouling tendency on the membrane was also investigated to determine the optimum operating conditions. The results show that the synergetic effect of the low catalyst loading and permeate flux creates the environment for optimum light penetration for high photocatalytic activity as the hybrid system with low catalyst loading (0.5 g/L) and 66 L/m²h of flux with aeration at 1.3 L/min has proven to increase the photocatalysis performance by 20% with additional catalyst recovery. In addition, applying the low catalyst loading and flux permeate with aeration brings minimal fouling problems. [ABSTRACT FROM AUTHOR]