Modified powder of Corchorus capsularis as a new adsorbent for removal of tetracycline group antibiotic from water

This study prepared a novel adsorbent from Corchorus capsularis modified powder for the removal of the tetracycline group (tetracycline -TC, oxytetracycline -OTC, chlortetracycline -CTC) in aqueous solution. Corchorus capsularis powder was pre-treated with 15% sodium hydroxide (COC), then reformed by a mixture of 0.15 mol L-1 sodium bisulfide (SB) and 0.2 mol L-1 ammonium peroxydisulfate (APS). This adsorbent was embedded with monoacrylamide (AM) at ratio AM/COC = 1/1 at 60 degrees C for 2.5 h. After modification with AM (BTA), the surface area of the adsorbents increased from 1.53 to 2.79 m(2) g(-1), while the pore size of the adsorbents decreased from 36.95 to 11.85 nm. The study also investigated the effects of pH, adsorbent dose and temperature on the adsorptive removal process. Tetracycline concentrations were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The kinetics and isotherms of adsorption performance were examined using a variety of models, including pseudo-first-order kinetic (PFO), pseudo-second-order kinetic (PSO), Freundlich, Langmuir, and Dubinin-Radushkevich isotherms (DRM). The experimental data fitted very well with the pseudo-second-order kinetic model. The maximum adsorption bulks of TC, OTC, CTC following Langmuir isotherm model were 1.25, 0.83, 1.43 mg g(-1), respectively. The adsorption constants Kp of TC, OTC, and CTC from the Freundlich isotherm model were 15.36, 21.80, and 22.08 mg1-nLng(-1), respectively. The mean free energy E (kJ mol(-1)) of TC, OTC, and CTC from DRM was 4.35, 4.20, and 4.57, respectively. The results indicated that modified Corchorus capsularis powder had significant potential as a new adsorbent material for removing antibiotics from aqueous solutions.