UV/H2O2/GAC工艺去除水中全氟化合物

全氟化合物(PFCs)持久存在于水环境中，难以通过传统的水处理工艺去除，提高水中PFCs的去除性能具有重要意义。本研究采用快速小柱实验探究了UV、H₂O₂和颗粒活性炭(GAC)组合工艺对水中4种PFCs的去除效果，并探究了UV照射时长和H₂O₂质量浓度对PFCs的直接去除效果及其对后续GAC吸附的影响。结果表明：不同工艺条件下，长链全氟辛酸(PFOA)和全氟辛烷磺酸(PFOS)始终表现出较短链全氟丁酸(PFBA)和全氟丁烷磺酸(PFBS)更高的去除率。单独GAC吸附对长链全氟PFOA和PFOS去除率为59.6%和64.3%，但对短链PFBA和PFBS去除率仅为11.7%和13.1%。单独UV或单独H₂O₂分别与GAC联用时，随着UV照射时长和H₂O₂质量浓度的增加，4种PFCs的去除率略有增加，且UV照射的增益效果较H₂O₂更优。UV/H₂O₂/GAC联用工艺对水中4种PFCs的去除效果最佳，30 min UV/H₂O₂处理后经GAC吸附可去除90％以上的PFOA和PFOS，短链PFBA和PFBS去除率也达到50%以上。UV/H₂O₂/GAC联工艺的良好效果是由于UV/H₂O₂高级氧化过程产生的羟基自由基氧化反应降低了水中大分子有机物的含量，从而减弱了有机物对PFCs的竞争吸附作用。本研究可为水中PFCs的高效处理提供技术参考。

Removal of PFCs from water by UV/ H2O2/GAC process

Perfluorinated compounds (PFCs) are persistently found in aquatic environment, which are difficult to be removed by the conventional water treatment process. Improving the removal effect of PFCs in water is of great significance. The removal efficacies of four kinds of PFCs in water by the combined process of UV, H2O2 and GAC were studied using the rapid small-scale column tests (RSSCT), and the effects of UV irradiation duration and H2O2 concentration on the direct oxidation of PFCs and the subsequent GAC adsorption were also explored. The results showed that long-chain perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) consistently exhibited higher removal rates than short-chain perfluorobutyric acid (PFBA) and perfluorobutane sulfonic acid (PFBS) under different process conditions. The removal rates of long chain perfluorinated PFOA and PFOS by GAC adsorption alone were 59.6% and 64.3%, respectively, but the removal rates of short chain perfluorinated PFBA and PFBS were only 11.7% and 13.1%, respectively. When UV or H2O2 were combined with GAC, the removal rates of the four PFCs slightly increased with the increase of UV irradiation time and H2O2 concentration, and the gain effect of UV irradiation was better than that of H2O2.The combined process of UV/H2O2/GAC presented the best removal effect of the four PFCs in water. After 30 minutes of UV/H2O2 treatment, GAC adsorption could remove higher than 90% of PFOA and PFOS, and the removal rates of short chain perfluorinated PFBA and PFBS were over 50%. After 30 min UV/H2O2/GAC treatment, more than 50% PFBA and PFBS were removed, and more than 90% of PFOA and PFOS can be removed. The excellent effect of the UV/H2O2/GAC combined process was due to the hydroxyl radical oxidation reaction generated by the advanced oxidation process of UV/H2O2, which weakened the competitive adsorption of organic matter on PFCs. This study can provide a technical guidance for the treatment of PFCs in water.