Degradation of sodium dodecyl benzene sulfonate in aqueous solution by electron beam radiation and changes in surfactant micelle property

In this study, we investigated the degradation of surfactant sodium dodecyl benzene sulfonate (SDBS) in aqueous solution using electron beam radiation. The removal efficiency of SDBS approached nearly 100%, achieving a COD removal rate of 7-20% with an absorbed dose of 5.0 kGy. Upon irradiation, several notable changes in SDBS micelles were observed. The absolute value of zeta potential and the average diameter size decreased. SEM observations revealed that the clustered aggregates of SDBS micelles fragmented into irregular filamentous pieces. Moreover, the interfacial tension increased remarkably and approached the level of pure water at 2.5 kGy for SDBS in a pure water solution and 5.0 kGy for SDBS in a brine water solution. The foaming power disappeared for SDBS in pure water and decreased to 20 mm for SDBS in brine water at 10 kGy. The defoaming rate of SDBS solution increased incrementally from an initial range of 1-2 mm/min to 3.0-5.6 mm/min at 5.0 kGy. In summary, when SDBS is decomposed, new system is created with new properties. Electron beam radiation offers a clean and sustainable approach to degrade SDBS in wastewater.