The advanced peracetic acid (PAA) oxidation technology has a wide application prospect in the field of wastewater treatment for its high efficiency, environmental protection and wide application. In this work, cobalt tetraferrote (CoFe 2 O 4 ) was used to activate PAA to degrade acid red B. The effects of CoFe 2 O 4 catalyst dosage, PAA concentration, initial pH value and anion on the decolorization efficiency of acid red B were investigated by intermittent single factor experiments. The optimal reaction conditions for the degradation of 0.1 mM acid red B in the CoFe 2 O 4 /PAA system were as follows: catalyst dosage of 0.008 g, PAA concentration of 1 mM, and initial pH = 7. After 30 min of reaction, the degradation rate of acid red B reached was as high as 99.5%. The coexistence of CoFe 2 O 4 /PAA with low concentrations of anions and humic acid (HA) had negligible effects on the catalysis of acid red B, while the coexistence with higher concentrations of HCO 3 − , H 2 PO 4 − and HA inhibited the degradation behaviors. Quenching experiments confirmed that there were a large amount of R-O• and a small amount of •OH in the CoFe 2 O 4 /PAA system, and 1 O 2 played an important role in the degradation process. After 6 cycles, the catalytic performance of CoFe 2 O 4 remained above 98.6%, showing stable catalytic performance, which were also confirmed by FTIR and XPS. This work provided a new way for effectively treating azo dye containing waste water.
This study focused on the application of a thin-film composite nanofiltration (NF) hollow fiber membrane formed by interfacial polymerization on a polysulfone/polyethersulfone supporting membrane for dye desalination and concentration. The fabricated NF hollow fiber membrane had a hydrophilic skin layer with an isoelectric point at a pH value of approximately 6.6. Permeation tests revealed that the membrane possessed a molecular weight cut-off (MWCO) of approximately 520 Da and a pure water flux of 47.5 L/m 2 h at 0.4 MPa. Rejections of different salts followed in the order of MgSO 4 > Na 2 SO 4 > MgCl 2 > NaCl at a pH value of 6.8, with up to 96.20% rejection for MgSO 4 . Additionally, due to the negative charge on the membrane surface, rejections of the anionic dyes reactive brilliant blue X-BR and acid red B were 99.99% and 99.90%, respectively. The dye rejection and permeate flux were affected by the dye concentration as well as the presence of NaCl in the X-BR aqueous solutions. Both the dye rejection and permeate flux would decline with the increase of feed dye and salt concentration. The fabricated NF hollow fiber membrane was applied to the process of dye desalination and concentration using an X-BR and NaCl mixed aqueous solution as the pollutant. After finishing the process, the volume of retentate was concentrated 6.25 times, and the dye concentration in the retentate reached 2854.8 mg/L. Moreover, the recovery rate of dye was up to 91.4%, and over 95.3% NaCl was removed from the dye/salt mixtures, which indicated that the fabricated composite NF hollow fiber membrane could be successfully applied to the dye desalination and concentration process.
危险品化学品经营许可证（带存储）