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 (Xt) or ionic liquid (XIL) concentration and temperature (T) were expressed by the following parameters: antibiotic extraction extent (E%), remaining antibiotic concentration (Xs,w), residual surfactant (Xt,w) or ionic liquid (XIL,w) concentration in aqueous phase after extraction, and volume fraction of coacervate at equilibrium (ϕc). 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).