Comparative adsorption of tetracyclines on biochars and stevensite: Looking for the most effective adsorbent

Abstract

Tetracyclines are one of the most widely used class of veterinary and human antibiotics. The conventional treatment of wastewater based on activated sludge is not effective to remove antibiotics and their residues are still biologically active, which represents a problem in terms of bacterial resistance. The main objective of this work is to assess ability of stevensite and two biochars to adsorb three tetracycline antibiotics from water. Batch adsorption experiments were carried out to test the ability of these materials to adsorb tetracyclines. Then desorption experiments were performed to determine the adsorption strength on stevensite. In order to elucidate the adsorption mechanism of tetracyclines on stevensite, cation exchange analysis and spectroscopic analyses by IR and XRD were performed. The adsorption of tetracyclines on stevensite was tested on continuous system with water artificially contaminated. Finally, the designed filter was validated with tetracyclines spiked wastewater. The two biochars and stevensite were able to adsorb between 60 and 100% of the tetracyclines present in the batch system. Stevensite was the material with the highest tetracyclines removal capacity (around 100% at low concentrations of tetracyclines). Biochars showed less affinity for tetracyclines adsorption (70%). Tetracyclines desorption from stevensite reached values lower than 10% for low tetracyclines concentrations. The IR spectroscopy suggested that cation exchange is the main mechanism of tetracyclines adsorption on clay and also proved the role of amide and amine groups in this adsorption. The cation exchange mechanism was confirmed by displacement of Ca and Mg from stevensite. A continuous wastewater flow through a system composed by stevensite leaved this system with no tetracyclines, indicating water purification by tetracyclines adsorption in clay.

Removal of Ciprofloxacin with Aluminum-Pillared Kaolin Sodium Alginate Beads (CA-Al-KABs): Kinetics, Isotherms, and BBD Model

“…Chemical oxidation, photocatalytic degradation, membrane filtration, adsorption, and so on were reported to be utilized for the removal of antibiotics [2]. Among them, adsorption was promising in terms of practical application for its high efficiency, easy operation, and low cost.…”

Performance and Microbial Community of Different Biofilm Membrane Bioreactors Treating Antibiotic-Containing Synthetic Mariculture Wastewater

“…The reason might be that adsorption played a main role in the early process. The adsorption of TC occurred quickly at the start and almost achieved the maximum adsorption capacity after 10 days [ 31 ]. With the increase in time, microorganisms gradually adapted to TC in the system, and then its biodegradation dominated later.…”

Efficient removal of tetracycline hydrochloride from aqueous solution by mesoporous cage MOF-818

“…For the MOF-818 infrared spectroscopy, the band at 1675 cm −1 could be attributed to the C=O stretching vibration of -COOH, and the band at 1553 cm −1 to C = N stretching vibration of pyrazole ring, respectively. The peaks at 1450 and 1294 cm −1 could be assigned to skeleton vibration of [54]. Compared with the FT-IR spectrum of MOF-818, the major infrared absorption peaks after adsorption (TC-MOF-818) were similar to that of MOF-818, with varying degrees of migration in wavenumber.…”