Preparation of magnetic biochar for nitrate removal from aqueous solutions

• Published in: Reaction kinetics, mechanisms and catalysis mechanisms and catalysis, 2022-10, Vol.135 (5), p.2629-2642
• Main Authors: Oprescu, Elena-Emilia, Enascuta, Emanuela Cristina, Vasilievici, Gabriel, Banu, Nicoleta Doriana, Banu, Ionut
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Chemistry and Materials Science; Industrial Chemistry/Chemical Engineering; Physical Chemistry
• ISSN: 1878-5190; 1878-5204
• DOI: 10.1007/s11144-022-02263-1

The present paper presents the evaluation of the adsorption efficiency and adsorption capacity for nitrate removal of magnetic biochar derived from corn stalk prepared by pyrolysis process. Characterization of magnetic biochar have been performed by TGA, XRD, FT-IR and BET methods. The results indicate that the adsorbent has a mesoporous structure graphed with O–H and COOH groups. The effect of various parameters such as pH, mass of Fe 3 O 4 -BC adsorbent, contact time, and nitrate concentration on the adsorption process of nitrate were studied. The ranges investigated were pH 4–10, concentration 50–300 ppm, the amount of activated carbon 0.15–0.35 g and contact time 30–120 min. The experimental data show that the prepared magnetic biochar has a nitrate removal efficiency of 98.91% at pH, 50 ppm nitrate concentration, 0.25 g adsorbent and 120 min. The adsorption capacity of the Fe 3 O 4 -BC adsorbent was studied by using Response Surface Methodology based on a Box-Behnken design (BBD). The optimum conditions for the equilibrium adsorption capacity (q e ) calculated at pH 7, 300 ppm nitrate concentration, 0.15 g adsorbent and 30 min was validated by experimental data and the results are in agreement with the experimental data.