Han Hui-Li, Wang Hong-Jie, Dong Wen-Yi
Shenzhen Key Laboratory of Water Resource Application and Environmental Pollution Control, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055, China.
Huan Jing Ke Xue. 2017 Apr 8;38(4):1477-1482. doi: 10.13227/j.hjkx.201609204.
The objective of this experiment was to investigate the influence of SOdosage, pH value, initial perfluorooctane sulfonate(PFOS)concentration as well as coexisting substances on the degradation and defluorination of PFOS by VUV-SO process. The results indicated that the increase of SO dosage could lead to rise in the concentration of active species hydrated electron(e) and thus enhance the degradation and defluorination of PFOS. As the concentration of SO increased from 1 mmol·L to 20 mmol·L, the degradation and defluorination rates of PFOS increased from 45% and 40% to 97% and 63%, respectively. The degradation and defluorination of PFOS were also enhanced with the increment of the solution pH values, and the defluorination was more sensitive to the pH values. In addition, more PFOS was degraded with the increase of initial PFOS mass concentration, although the degradation and defluorination rates of PFOS were reduced. When the initial PFOS mass concentration changed from 1 mg·L to 50 mg·L, the degradation amount of PFOS after four hrs increased by about 50 times, probably due to the higher utilization proportion of e at high pollutants concentration. Last but not least, the influence of co-existing substances, Cl and HCO, on PFOS degradation could be neglected, whereas their effects on defluorination were observed. Defluorination of PFOS was enhanced with the increased Cl concentration, however, increased first and then decreased with the increment of HCO concentration. It was also found that the presence of humic acid(HA) lowered degradation as well as defluorination of PFOS owing to the blockage of effective UV light and trapping of active species for photochemical reaction.
本实验的目的是研究过硫酸钠（SO）投加量、pH值、全氟辛烷磺酸（PFOS）初始浓度以及共存物质对真空紫外光（VUV）-SO工艺降解PFOS及脱氟的影响。结果表明，增加SO投加量可导致活性物种水合电子（e）浓度升高，从而增强PFOS的降解和脱氟。当SO浓度从1 mmol·L增加到20 mmol·L时，PFOS的降解率和脱氟率分别从45%和40%提高到97%和63%。PFOS的降解和脱氟也随着溶液pH值的升高而增强，且脱氟对pH值更敏感。此外，尽管PFOS的降解率和脱氟率降低，但随着PFOS初始质量浓度的增加，更多的PFOS被降解。当PFOS初始质量浓度从1 mg·L变为50 mg·L时，4小时后PFOS的降解量增加了约50倍，这可能是由于在高污染物浓度下e的利用率较高。最后，共存物质Cl和HCO对PFOS降解的影响可忽略不计，但观察到它们对脱氟有影响。随着Cl浓度的增加，PFOS的脱氟增强，然而，随着HCO浓度的增加，脱氟先增加后降低。还发现腐殖酸（HA）的存在由于有效紫外光的阻挡和光化学反应活性物种的捕获而降低了PFOS的降解和脱氟。
