Biocompatible amino acid-based ionic liquids for extracting hormones and antibiotics from swine effluents

The generalized use of antibiotics and hormones in swine feed has triggered a growing concern on their presence in wastewater effluents and manure. Therefore, the implementation of strategies for their removal is a matter of practical significance and the synthesis of biocompatible ionic liquids to be used as segregation agents in aqueous waste effluents could be a suitable means for removing these emerging contaminants. In this work, the salting out capacity of cholinium alaninate, (N(1112OH)Ala) in aqueous streams containing surfactants (Triton X-100) was demonstrated. Afterwards, its ability to separate a hormone (17-beta estradiol) and antibiotics belonging to tetracycline and fluoroquinolone families was investigated in an aqueous synthetic swine effluent at environmental conditions. It was checked that the cautious selection of the feed compositions allowed high levels of hormone extraction (E) and partition coefficients (K): E > 90% and K > 13.86, in surfactant rich-phase. Antibiotics migrated to any of the two phases depending on system compositions. However, the decisive addition of a cationic surfactant (2% CTAB) led to increased extraction efficiencies of chlortetracycline (K = 15.77 and E = 92.5%), proving the versatility of the process.