高锰酸钾对UV/PMS降解六氟双酚A影响

摘要

The aim of this work is to investigate the effect of potassium permanganate ( KMnO4 ) on the photocatalytic degradation of hexafluorobisphenol A (BPAF) by peroxymonosulfate (PMS). The influences of the experimental conditions such as PMS and permanganate dosage, solution pH were analyzed. Furthermore, the process for the oxidative removal of BPAF in natural water was confirmed and its efficiency compared with that of UV/PMS process. Results showed that KMnO4 had a positive effect on the BPAF degradation in the UV/PMS process. The degradation efficiency was increased with the increase of PMS dosage. With the dosage of KMnO4 increased from 0 to 1. 5 μmol/L, the optimum removal efficiency of BPA obtained when PMS was 1 mmol/L. Further addition of KMnO4, however, had no significant promotion on the extent of BPAF oxidation efficiency. BPAF degradation rate inhibited with increasing the pH under acidic condition, while promoted significantly under alkaline condition. The BPAF removal percentage in UV/PMS/KMnO4 was about 12%-14% higher than in UV/PMS system in actual water. The mechanism of the synergetic combination of PMS with KMnO4 for BPA degradation under the UV irradiation indicated that the catalytic oxidation of some reactive manganese intermediates generated in the UV/PMS/Mn( VII) process.%为考察高锰酸钾(KMnO4)耦合紫外催化过一硫酸盐(PMS)对六氟双酚A(BPAF)去除效能,研究水体pH、PMS浓度和KMnO4投加量对UV/PMS/KMnO4体系去除六氟双酚A的影响,并在实际水体中对比UV/PMS及UV/PMS/KMnO4对六氟双酚A的去除效果.结果表明,KMnO4能够有效地促进UV/PMS对BPAF的去除.UV/PMS/KMnO4对BPAF的去除率随PMS投加量的增加而增加.KMnO4投加量的增加(0~1.5μmol/L)能够促进BPAF的降解,但是当达到一定浓度时,其促进作用不再提高.在偏中酸性条件下,BPAF的去除率随着pH增加而降低,但是当pH在碱性条件下,BPAF的去除率随pH增加而显著增加.在4种实际水体中,UV/PMS/KMnO4工艺比UV/PMS对BPAF的去除率高12%~14%,这种促进可能是由于氧化体系中产生的中间价态锰的催化氧化作用.