Effective removal of tetracycline from wastewater using carbonaceous materials derived from Brassica oleracea plant: Experimental and computational perturbation

Abstract

This study aimed to convert low-cost agricultural biomass wastes from cabbage plant into biochar (BC) and active biochar carbon (ABC). They can be used for tetracycline (TC) removal from aqueous media that is a promising mean toward waste biomass utilization. Different analytical tools have been employed to fully characterize of the synthesized materials. Batch method was applied to investigate the kinetics and isotherms to illustrate the adsorption mechanisms. The model of pseudo second-order fit well for both biosorbents, according to kinetic measurements, indicating a chemisorption mechanism. The model of Freundlich isotherm was the well-described one, according to isotherm data. The TC adsorption capacity was found to be 163.93 mg/g for ABC, exceeding BC by a value of 3.7 times (43.48 mg/g). On both adsorbents, the spontaneous and exothermic nature of TC adsorption was validated by the negative values of ΔG and ΔH. Additionally, the BC and ABC could be effectively maintained at ∼ 80 % and 85 % of their respective capabilities following five regeneration cycles. Also, both structure and electronic properties of the TC-ABC were investigated via computational perturbation. Using DFT/GGA/PBE, a geometrically optimized method was applied to the system under study. Based on the same degree of computations, frontier molecular orbital (FMOs) and molecular electrostatic potential (MEP) investigation were considered. An identification of the atomic orbital as a major or minor electronic distribution by deducing the electronic density of states (DOS). The most accurate description of the adsorbed model’s stability over time was provided by a dynamic simulation analysis at high temperatures.