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Porous P84 co-polyimide anion exchange membranes are prepared by phase inversion process using isopropanol (IPA) or water as the non-solvent. Membrane area resistances are in the range of 0.7–2.2 Ω cm 2 , lower than those of commercial anion exchange membrane AMX (2.0–3.5 Ω cm 2 ) and dense P84 membrane (>80 Ω cm 2 ). The ion exchange capacities (IECs) are in the range of 0.6–0.9 mmol/g and the water uptake (W R ) values are 100–160%, both of which are higher than those of dense P84 membrane. The porous P84 co-polyimide membranes are utilized in bipolar membrane electrodialysis (BMED) process to produce lactobionic acid (LBA) and NaOH from sodium lactobionic. The pore morphology and IECs influence the output of LBA significantly. Membrane with big tear-like pores shows higher W R value and can produce 0.0555–0.0565 mol/L LBA. Sponge-like pores with IEC of 0.9 mmol/g can yield 0.0724 mol/L LBA after 180 min running under 20 V, while sponge-like pores with IEC of 0.7 mmol/g yield reduced LBA concentration of 0.0593 mol/L, illustrating that higher IEC is in favour of the passage of LB − . The porous P84 membranes have improved efficiency as compared with commercial membrane AMX (0.0451 mol/L) and the dense P84 membrane (merely 0.0162 mol/L) in the production of LBA. Meanwhile, the Na + leakage through the porous membrane is similar to that of the commercial membrane. Hence, the porous membranes, due to their low resistances, can have high potential for producing organic acid with high molecular weight. [ABSTRACT FROM AUTHOR]

Diffusion dialysis (DD) technique is nowadays mainly utilized for recovering acid or alkali solutions, but the recovery of salts such as sodium chloride (NaCl) and sodium acetate (NaAc) is much more difficult due to their low diffusivity. Polyelectrolyte complexes (PECs)/polyvinyl alcohol (PVA) membranes containing functional groups of C OH, Si OH, N + (CH 3 ) 3 and SO 3 Na are pioneered for DD process of salts. The membranes have improved stability in water and salt solution. The dialysis coefficients of NaCl (U NaCl ) are in the range of 0.00196–0.00290 m/h, which are 6–30 times higher than the values of commercial DF-9010 and CJMCDD-1 membranes. The dialysis coefficients of NaAc (U NaAc ) are in the range of 0.00108–0.00503 m/h, which are 30–143 times higher than the value of CJMCDD-1 membrane, whereas DF-9010 membrane has poor stability in NaAc solution. Finally, PECs/PVA membranes are applied to NaCl/threonine (Thr) mixture and NaAc waste residue solution, showing their outstanding advantages for DD process of salts. The membranes show both high permeability and selectivity for NaCl/Thr mixture, with separation factor (S NaCl/Thr ) as high as 6.495 (DF-9010: 1.25; CJMCDD-1: 0.224). The U NaAc values for NaAc waste residue solution are 0.000602–0.00120 m/h, higher than that of commercial CJMCDD-1 membrane. [ABSTRACT FROM AUTHOR]

Large amounts of solid waste residue containing high salinity and a series of organic impurities are produced during the manufacturing process of dithianon in insecticide factories, posing a severe environmental pollution problem. Here sodium acetate (CH 3 COONa) waste residue is firstly tested by diffusion dialysis (DD) to investigate the permeability of different commercial ion exchange membranes. Selemion CMV and AMV membranes show low permeability to the organic impurities of the waste residue, and hence are chosen for the following bipolar membrane electrodialysis (BMED) experiments to regenerate acid and base. The BMED firstly uses a BP-A-C-BP configuration to select an optimized current density of ∼50 mA/cm 2 . Afterwards, four membrane stack configurations are compared including BP-A-C-BP, C-BP-A-C, BP-C-BP and BP-A-BP. In consideration of the high current efficiency, low energy consumption, and high concentrations of the produced acid/base, C-BP-A-C is a favorable configuration. Finally, the addition of a strong acid 001 ∗ 7 type of cation-exchange resin into acid compartment can substantially decrease the voltage drop across the stack and reduce the energy consumption. The C-BP-A-C configuration at 50 mA/cm 2 can have a high output (0.491 mol/L CH 3 COOH and 0.556 mol/L NaOH), high current efficiency (87.7% for CH 3 COOH and 99.0% for NaOH), and a relatively low energy consumption (22.3 kW h/kg CH 3 COOH and 29.7 kW h/kg NaOH). Overall, this study illustrates the practical significance of BMED process for treating sodium acetate waste residue, including reducing soil and water pollution and producing valuable products in insecticide industries. [ABSTRACT FROM AUTHOR]

[Display omitted] • WO 3 -CuFe 2 O 4 Z-scheme catalyst was constructed. • Quinoline removal was realized by persulfate-assisted photocatalytic process. • Photogenerated holes and ·OH were the main reactive species. • Degradation mechanism and pathways of quinoline were explored. Quinoline is a kind of organic pollutant difficult to be biodegraded, for which the photocatalysis technology is a commonly used removal method, but the degradation performance still needs to be improved. In this work, the WO 3 -CuFe 2 O 4 Z-scheme system was constructed, and the persulfate (PS)-assisted photocatalytic degradation of quinoline with WO 3 -CuFe 2 O 4 by adding persulfate in the photocatalytic systems was studied. The effects of different systems and key parameters such as catalyst dosage, PS concentration and initial pH value on the degradation efficiency of quinoline were investigated. With the addition of persulfate, the degradation efficiency of quinoline increased from 24.3% to 100% in 150 min, under the condition of [PS] = 3 mmol/L, [catalyst] = 3 g/L, temperature = 25 ± 2 °C, and pH = 9. And the WO 3 -CuFe 2 O 4 catalyst showed excellent reusability according to the result of 5-cycle repeated experiment. The possible degradation mechanism was studied by the quenching test and the identification of intermediates and products, which indicated the degradation of quinoline in WO 3 -CuFe 2 O 4 /VIS/PS system was realized via denitrification, dehydrogenation, hydroxylation and ring breaking processes. [ABSTRACT FROM AUTHOR]