Tetracycline removal from aqueous solution by biochar derived from algae and modified with MnMoO4: effects of operating parameters, isotherm, kinetic, and thermodynamic study

Novelty statement In the present research, a novel biocomposite that could efficiently remove tetracycline (TC) from wastewater was synthesized. The biocomposite was fabricated by biochar of microalgae (BC) and MnMoO4 (MM) nanoparticles in different ratios to find a biocomposite with optimum characteristic as an efficient adsorbent. Finally, the optimum one was characterized to confirm its properties as an economical and efficient adsorbent for TC adsorption. Adsorption experiments including kinetic, isotherm and thermodynamic modeling were conducted to verify the high potential of novel biocomposite for TC adsorption. TC as an antibiotic frequently is found in soil, sediment, and aquatic environments which may lead to adverse side effects on human health including bacterial resistance and change in the microbial ecological functions. This makes the present study comprehensive and allows us to reach a strong conclusion on selecting biomaterial for biosorption purposes. Therefore, the present study will add unique knowledge to the science of biosorption. The aim of the present study is to improve the adsorption of tetracycline (TC) onto biochar of microalgae modified by nanocomposite of MnMoO4 (MM40BC60). The synthesized nanocomposite was characterized by Scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area, Fourier transforms infrared (FTIR) spectroscopy to investigate the morphology, surface area, pores and the functional groups of MM40BC60, respectively. The effect of various parameters including initial pH, TC concentration, and temperature on the adsorption performance of TC to the adsorbent was evaluated with considering kinetics, isotherms, and thermodynamics models. The adsorption of TC on MM40BC60 shows good agreement with the pseudo-second-order kinetic and the Langmuir isotherm models. Results of the thermodynamic study showed that the adsorption process was a spontaneous and endothermic reaction in nature.

Automated summary

A novel biocomposite for efficient removal of tetracycline from wastewater was synthesized and characterized. The study demonstrated the high potential of the biocomposite for TC adsorption and provided insights into its adsorption mechanism and thermodynamic properties.