Microbial Removal from Secondary Treated Wastewater Using a Hybrid System of Ultrafiltration and Reverse Osmosis

The efficiency of advanced membranes towards removal of general and specific microbes from wastewater was investigated. The treatment included a subsequent system of activated sludge, ultrafiltration （hollow fibre membranes with 100 kDa cut-off, and spiral wound membranes with 20 kDa cut-off）, and RO （reverse osmosis）. The removal evaluation of screened microbes present in treated wastewater showed that hollow fibre membrane rejected only 1 log （90% rejection） of the TPC （total microbial count）, TC （total coliforms）, and FC （faecal coliforms）. A higher effectiveness was observed with spiral wound, removing 2-3 logs （99%-99.9%） of TPC and complete rejection of TC and FC. The RO system was successful in total rejection of all received bacteria. The removal evaluation of inoculated specific types of bacteria showed that the hollow membranes removed 2 logs （99%） of inoculated E. coli （10^7-10^8 cfu/mL inoculum）, 2-3 logs （99%-99.9%） of Enterococus spp. （10^7-10^10 cfu/mL inoculum）, 1-2 logs （90%-99%） of Salmonella （10^8-10^10 cfu/mL inoculum） and 1-2 logs （90%-99%） of Shigella （10^5-10^6 cfu/mL inoculum）. The spiral wound was significantly efficient in rejecting further 3 logs of E. coil, 5 logs of Enterococus spp., 4 logs of Salmonella, and a complete rejection of all received bacteria was accomplished by RO membrane. The results indicate that Gram positive bacteria were removed much more efficiently compared to the Gram negative ones, the rationale behind such behaviour is based on cell walls elasticity.

Electrochemical performance of interfacially polymerized polyaniline nanofibres as electrode materials for non-aqueous redox supercapacitors

H+ doped polyaniline nanofibre(PH) was synthesized by interfacial polymerization and polyanilines doped with Li salt(PLI and PHLI) were prepared by immersing emeraldine base(EB) and H+ doped polyaniline in 1 mol/L LiPF6/(EC-EMC-DMC),respectively.PH,PLI and PHLI were all characterized by scanning electron microscopy(SEM) and Fourier transform infrared(FT-IR) spectrometry.With 1 mol/L LiPF6/(EC-EMC-DMC) as electrolyte,PH,PHLI and PLI were used as the active materials of symmetric non-aqueous redox supercapacitors.PLI shows the highest initial specific capacitance of 120 F/g(47 F/g for PH and 66 F/g for PHLI) among three samples.After 500 cycles,the specific capacitance of PLI remains 75 F/g,indicating the good cycleability.

Flexible fiber-shaped supercapacitors based on hierarchically nanostructured composite electrodes

A novel all-solid-state, coaxial, fiber-shaped asymmetric supercapacitor has been fabricated by wrapping a conducting carbon paper on a MnO2-modified nanoporous gold wire. This energy wire exhibits high capacitance of 12 mF.cm^-2 and energy density of 5.4 μW.h.cm^-2 with excellent cycling stability. Hierarchical nanostructures and coaxial architectural design facilitate effective contacts between the two core@sheath electrodes and active layers with high flexibility and high performance. This work provides the first example of coaxial fiber- shaped asymmetric supercapacitors with an operation voltage of 1.8 V, and holds great potential for future flexible electronic devices.

Amphiphilic core-sheath structured composite fiber for comprehensively performed supercapacitor

As an im portant branch of fiber-shaped energy storage devices, the fiber-shaped supercapacitor has been widely studied recently. However, it remains challenging to simultaneously achieve fast electron transport and excellent ion accessibility in one single fiber electrode of the fibershaped supercapacitor. Herein, a novel family of amphiphilic core-sheath structured carbon nanotube composite fibers has been developed and applied to the fiber-shaped supercapacitor to address the above challenge. The polyaniline-modified hydrophilic sheath of the composite fiber electrode effectively enhanced the electrochemical property via advancing ion accessibility, while Au-deposited hydrophobic core demonstrated improved electrical conductivity by fast electron supply. On the basis of a synergistic effect, a remarkable specific capacitance of 324 F cm^-3 at 0.5 A cm^-3 and greatly enhanced rate performance were achieved, i.e” a 79% retention (256 F cm 3) at 50 A cm^-3. The obtained fiber-shaped supercapacitor finally displayed remarkable energy and power densities of 7.2 mW h cm 3 and 10 W cm^-3, respectively. The strategy developed herein also presents a general pathway towards novel fiber electrodes for high-performance wearable devices.

An integrated nanocarbon–cellulose membrane for solid-state supercapacitors

In this work, we demonstrate the assembly of oxidised carbon nanohybrids(o CNHs) with a commercial cellulose membrane for solid-state supercapacitors. The o CNHs–cellulose membranes were prepared by filtering a water dispersion of o CNHs through the cellulose membrane. The o CNHs were derived from carbon nanotubes via a modified Hummer's method and contained both closed tubes and unzipped tubes, which indicated a hybrid geometrical structure. The solid-state supercapacitor based on the o CNHs–cellulose membranes showed a high areal capacitance of *75 m F/cm^2 at a low scan rate(5 m V/s)and excellent stability for 1,000 cycles.

Activated pyrolysed bacterial cellulose as electrodes for supercapacitors

In this paper, the bacterial celluloses(BCs) were pyrolysed in nitrogen and then activated by KOH to form a porous three- dimension-network electrode material for supercapacitor applications. Activated pyrolysed bacterial cellulose(APBC) samples with enlarged specific surface area and enhanced specific capacitances were obtained. In order to optimize electrochemical properties, APBC samples with different alkali-to-carbon ratios of 1, 2 and 3 were tested in two electrodes symmetrical capacitors. The optimized APBC sample holds the highest specific capacitance of 241.8 F/g, and the energy density of which is 5 times higher than that of PBC even at a current density of 5 A/g. This work presents a successful practice of preparing electrode material from environment-friendly biomass, bacterial cellulose.