Removal of antibiotic tetracycline using nano-fluid emulsion liquid membrane: Breakage, extraction and stripping studies

In this study, nano-fluid emulsion liquid membrane (NFELM) was used to extract tetracycline (TC) from simulated wastewater. The membrane phase comprises of n-heptane (diluent), Fe2O3 nanoparticles modified with oleic acid (stabilizing agent), and tri-butyl-phosphate (TBP, extractant) homogenized with hydrochloric acid (HCl) as the internal aqueous phase to create the nano-fluid emulsion. The effect of various experimental parameters, such as emulsification speeds and times, internal/membrane volume ratio, nanoparticles dosage, HCl and TBP concentration, and external phase pH were investigated to determine emulsion stability, extraction and stripping efficiency. More than 97 % of TC was effectively extracted by NFELM system at 12 min mixing time without significant emulsion breakage, and the stripping efficiency was 96.5 %. NFELM proved to be more stable, efficient, and has higher mass transfer coefficient of 7.344x10(-9) (m/s) than traditional ELM of 5.82x10(-9) (m/s). The membrane material and nanoparticles were successfully recycled five times in this work for the extraction of TC.