Selective and high-efficient removal of tetracycline from antibiotic-containing aqueous solution via combining adsorption with membrane pre-concentration

Abstract

The antibiotics in the livestock sewerage are responsible for antimicrobial resistance, causing a global public health crisis and necessitating high-efficient and environmental-friendly antibiotic treatment processes. Herein, one membrane pre-concentration and MOF-based selective adsorption hybrid system is proposed to high-efficiently remove tetracycline (TC) from the aqueous solution containing other two representative antibiotics (sulfamethoxazole (SMZ), and trimethoprim (TMP)) in the livestock sewage. In this work, two common MOFs-based materials (MIL-101-Fe and NH2-MIL-101-Fe) are employed as the adsorbents to selectively remove TC from the solution. Adsorption experiments showed that the selective coefficient of NH2-MIL-101-Fe for TC could reach up to 95 %, because of stronger interaction between TC and MIL-101s calculated via the theoretical simulation. Also, experimental results demonstrated that the desired operating conditions necessitated thermal input and pre-concentration operation. Accordingly, temperature-enhanced forward osmosis (T-FO) and temperature-enhanced osmotic membrane distillation (T-OMD) were proposed to concentrate the solution containing these three antibiotics in the cost-effective way where the fertilizer solution (KCl in this work) was used as the draw solution (DS) and diluted DS solution could be used in agricultural fertigation. Membrane pre-concentration experiments showed that TC, TMP, and SMZ could be theoretically concentrated in T-FO, but high TC and KCl leakage and inevitable water flux decline behavior significantly sacrificed the concentration efficiency, thereby initiating the application of T-OMD. Higher and more stable water flux occurred in T-OMD, and 99.76 % of antibiotic and KCl leakage could be mitigated compared to T-FO, thereby providing one option to high-efficiently remove antibiotics in livestock sewerage and achieve agricultural fertigation.