Zhang Li-Hong, Cheng Jian-Hua, You Xia, Liang Xiao-Yan, Hu Yong-You
Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou, 510006, China.
Hunan Key Laboratory of Applied Environmental Photocatalysis, Changsha University, Changsha, 410022, People's Republic of China.
Environ Sci Pollut Res Int. 2016 Jul;23(13):13531-42. doi: 10.1007/s11356-016-6539-y. Epub 2016 Mar 31.
Perfluorooctanoic acid (PFOA) is extremely persistent and bioaccumulative in the environment; thus, it is very urgent to investigate an effective and moderate technology to treat the pollution of PFOA. In this study, a process combined iron and granular activated carbon (Fe(0)/GAC) micro-electrolysis with VUV-Fenton system is employed for the remediation of PFOA. Approximately 50 % PFOA (10 mg L(-1)) could be efficiently defluorinated under the following conditions: pH 3.0, dosage of Fe 7.5 g L(-1), dosage of GAC 12.5 g L(-1), and concentration of H2O2 22.8 mmol L(-1). Meanwhile, during the process, evident defluorination was observed and the concentration of fluoride ion was eventually 3.23 mg L(-1). The intermediates including five shorter-chain perfluorinated carboxylic acids (PFCAs), i.e., C7, C6, C5, C4, and C3, were also analyzed by high-performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS) and defluorination mechanisms of PFOA was proposed, which involved photochemical of OH·, direct photolysis (185-nm VUV), and photocatalytic degradation of PFOA in the presence of Fe(3+) (254-nm UV).
全氟辛酸（PFOA）在环境中具有极强的持久性和生物累积性；因此，研究一种有效且适度的技术来处理PFOA污染迫在眉睫。在本研究中，采用铁与颗粒活性炭（Fe(0)/GAC）微电解与VUV-Fenton体系相结合的工艺对PFOA进行修复。在以下条件下，约50%的PFOA（10 mg L(-1)）可被有效脱氟：pH 3.0、铁用量7.5 g L(-1)、GAC用量12.5 g L(-1)以及H2O2浓度22.8 mmol L(-1)。同时，在此过程中观察到明显的脱氟现象，氟离子浓度最终为3.23 mg L(-1)。还通过高效液相色谱串联质谱（HPLC/MS/MS）分析了包括五种短链全氟羧酸（PFCAs），即C7、C6、C5、C4和C3在内的中间产物，并提出了PFOA的脱氟机制，其中涉及OH·的光化学作用、直接光解（185 nm VUV）以及在Fe(3+)（254 nm UV）存在下PFOA的光催化降解。
