Oxacillin antibiotic removal from aqueous solution using nonionic micellar system or ionic liquid: a comparative study based upon experimental optimization and response surface methodology

Oxacillin antibiotic was removed from aqueous effluents using the biodegradable nonionic surfactant Triton X-114 (TX-114) and the ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate ([C4C1im]PF6). The experimental results of oxacillin extraction from aqueous solution according to the surfactant (X-t) or ionic liquid (X-IL) concentration and temperature (T) were expressed by the following parameters: antibiotic extraction extent (E%), remaining antibiotic concentration (X-s,X-w), residual surfactant (X-t,X-w) or ionic liquid (X-IL,X-w) concentration in aqueous phase after extraction, and volume fraction of coacervate at equilibrium (phi(c)). High extraction yields were reached under optimal conditions: 99% for TX-114 and 89% using [C4C1im]PF6. The concentration of antibiotic in effluent was reduced by about 7-fold and 6-fold using TX-114 and [C4C1im]PF6, respectively. Sodium sulfate addition (3 wt%) increased E% from 20% to 88% at only 2 wt% of TX-114. Finally, solute stripping from the micellar phase using Winsor II microemulsion extraction was investigated. Thereby, 90% of the TX-114 in the micelle-rich phase was separated into the organic phase (Om).