Degradation of sodium dodecylbenzene sulfonate (SDBS) and high efficiency treatment of real grey water by TiO2-loaded stainless steel mesh under VUV irradiation

Reusing treated greywater indoors in buildings is an advanced strategy to increase the utilization of limited water resources , but currently there is a lack of feasible technologies for efficiently purifying greywater indoors. In this study, we construct the heterogeneous TiO 2 -stainless steel mesh (SSM) interface with photocatalytic degradation of sodium dodecylbenzene sulfonate (SDBS) by under vacuum ultraviolet (VUV) irradiation. At the initial SDBS of 10 mg/L, the degradation rates of SDBS with UV/TiO 2 -SSM and VUV/TiO 2 -SSM process were 53 % and 74 % respectively within 50 min. The results of specific scavengers experiments and EPR analysis revealed that the ·OH, h + and direct photolysis contributed to SDBS degradation and mineralization . The degradation rate of SDBS in VUV/TiO 2 -SSM process was higher at weak acid or weak alkali conditions, while the performance of UV/TiO 2 -SSM process was better at alkaline conditions. Both Cl − and HCO 3 − could inhibit SDBS degradation, while SO 4 2− slightly promoted the degradation. Active oxygen species mainly degrade SDBS in two ways: by attacking the α carbon, β carbon, or branched chain carbon on the alkane chain ; or by attacking the adjacent carbon on the alkane chain, resulting in the formation of three branch forms of products. The toxicity of the intermediate products shows a decreasing or stable trend. The experiment shows that UV or VUV photocatalytic TiO 2 -SSM has a good prospect of removing anionic surfactant in the real greywater. This study provides strategies for the development and design of indoor water reuse technologies and devices in buildings.