The Application of Polytetrafluoroethylene (PTFE) Fiber Grafted Acrylic Acid as a Cation Exchanger for Removing Cu^(12)

The polytetrafluoroethylene fiber grafted acrylic acid was used as a cation exchanger. The exchange capacity of the cation fiber is 3.06 mmol/g. The maximum Cu2+ adsorption capacity is 107.48 mg/g. It could be desorbed completely by 1mol/L HCl.

Fabrication of supported acid catalytic composite fibers by a simple and low-cost method and their application on the synthesis of liquid biofuel 5-ethoxymethylfurfural

In this paper,sulfonic groups functionalized annealed bio-based carbon microspheres loaded polytetrafluoroethylene(A-BCMSs-SO_(3)H@PTFE)fibers with high activity,high stability,and easy regeneration were successfully fabricated by a simple method using low-cost raw materials.The characterization results showed that the annealed biomass carbon microspheres derived from waste Camellia oleifera shells were evenly distributed on the polytetrafluoroethylene fibers and the sulfonic groups can be successfully loaded on the surface of annealed biomass carbon microspheres by room temperature sulfonation.Subsequently,the as-prepared A-BCMSs-SO_(3)H@PTFE fibers were applied to the acidcatalyzed synthesis of liquid biofuel 5-ethoxymethylfurfural.The catalytic experiment results indicated that the annealing temperature and time during catalyst preparation have a significant effect on the activity and selectivity of A-BCMSs-SO_(3)H@PTFE fibers.The results of catalytic reaction kinetics showed that the yield of 5-ethoxymethylfurfural can reach more than 60%after 72 h of acid-catalyzed reaction.The stability test showed that the as-prepared A-BCMSs-SO_(3)H@PTFE fibers still maintained a stable acid catalytic activity after four recycles.

Energy reduction of a submerged membrane bioreactor using a polytetrafluoroethylene （PTFE） hollow-fiber membrane

In this study, we modified a polytetrafluoroethylene （PTFE） hollow-fiber membrane element used for submerged membrane bioreactors （MBRs） to reduce the energy consumption during MBR processes. The high mechanical strength of the PTFE membrane made it possible to increase the effective length of the membrane fiber from 2 to 3 m. In addition, the packing density was increased by 20% by optimizing the membrane element configuration. These modifications improve the efficiency of membrane cleaning associated with aeration. The target of specific energy consumption was less than 0.4 kWh·m^-3 in this study. The continuous operation of a pilot MBR treating real municipal wastewater revealed that the MBR utilizing the modified membrane element can be stably operated under a specific air demand per membrane surface area （SADm） of 0.13 m^3·m^-2. hr I when the daily- averaged membrane fluxes for the constant flow rate and flow rate fluctuating modes of operation were set to 0,6 and 0.5m^3·m^-2·d^-1 respectively. The specific energy consumption under these operating conditions was estimated to be less than 0.37 kWh.m^-3. These results strongly suggest that operating an MBR equipped with the modified membrane element with a specific energy consumption of less than 0.4 kWh·m^-3 is highly possible.