Synthesis and application of lanthanum sulfide nanoparticles for removal of tetracycline from aqueous media

In the current study, lanthanum sulfide (La2S3) nanoparticles were synthesized and utilized to assess their potential as an adsorbent in a tetracycline adsorption/removal process. The adsorbent was characterized using different techniques such as field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy. To improve the adsorption capacity, several effective parameters on removal such as the adsorbent dosage, ionic strength, pH, contact time and initial solution concentration were studied. The validity of the experimental sorption and adsorption mechanism were investigated using isothermal and kinetic models. The Langmuir isotherm was best fitted to the experimental data, while the best-fitted kinetic model was pseudo-second-order. This indicated a monolayer sorption pattern for tetracycline with an appropriate adsorption capacity (56.81 mg g−1). Thermodynamic studies suggested a physisorption mechanism for tetracycline adsorption as ΔG° < − 18 kJ mol−1.