In this study, efficient simultaneous degradation and dechlorination of the photo-recalcitrant emerging disinfection byproduct, 2-chlorophenol (2-CP), was achieved by vacuum-ultraviolet (VUV) system for the first time. Different from the conventional UV system, the combined action of direct photolysis and OH oxidation in VUV system led to a significantly higher removal efficiency for 2-CP. In UV system, 2-CP degradation rate constants was independent of the initial 2-CP concentration, and was increased with enhancing pH. To the contrary, in VUV system, higher initial concentration of 2-CP resulted in lower rate constant, and the degradation rates of 2-CP under both acidic and alkaline conditions were higher than that at the neutral pH. Moreover, humic acid could inhibit 2-CP degradation more prominently in VUV system than in UV system, owing to the scavenging effect of OH by it. The degradation pathways of 2-CP were proposed based on the identified main degradation products by GC–MS/MS. Furthermore, degradation of the other seven typical halogenated phenols by VUV irradiation in tap water, ultrafiltrated water and Mill-Q water were investigated to verify the feasibility of the system. Based on the systematic economic analysis, VUV process is economically feasible for the advanced treatment of tap water to remove halogenated phenols.

在这项研究中，首次通过真空-紫外线（VUV）系统实现了光顽固的新兴消毒副产物2-氯苯酚（2-CP）的高效同时降解和脱氯。与传统的紫外线系统不同，直接光解和VUV系统中的OH氧化导致2-CP的去除效率大大提高。在UV系统中，2-CP降解速率常数与初始2-CP浓度无关，并且随pH值的增加而增加。相反，在VUV系统中，较高的2-CP浓度导致较低的速率常数，并且2-CP在酸性和碱性条件下的降解速率均高于在中性pH下的降解速率。而且，由于腐殖酸的清除作用，腐殖酸在VUV系统中比在UV系统中更能抑制2-CP降解。哦。根据GC-MS / MS确定的主要降解产物，提出了2-CP的降解途径。此外，还研究了在自来水，超滤水和Mill-Q水中通过VUV辐照降解其他7种典型的卤代苯酚的方法，以验证该系统的可行性。基于系统的经济分析，VUV工艺对于自来水的高级处理以去除卤代酚类在经济上是可行的。