Oxytetracycline Hydrochloride Adsorption by Biochar From Loofah Sponge Using Response Surface Method

ABSTRACT A potential biochar (KLS F ‐BC) was prepared by pyrolysis of loofah sponge (LS) at 600°C using KOH as an activator to adsorb oxytetracycline hydrochloride (OTCH). The response surface method (RSM) was applied to obtain the best preparation parameters (the first pyrolysis temperature of 573°C and pyrolysis time of 138 min, LS F ‐BC/KOH, 1:3, m/m) and adsorption conditions (OTCH concentration: 100 mg L −1 , adsorbent dosage: 0.84 g L −1 , adsorption time: 28 min, initial solution pH: 5.1), under which the adsorption capacity of KLS F ‐BC for OTCH was 662.96 mg g −1 . The adsorption data of OTCH on KLS F ‐BC conformed to the pseudo‐second‐order model and Freundlich model. The removal mechanisms of OTCH involved hydrogen bonding, π–π EDA interaction, pore filling, and electrostatic interactions. The study confirmed the great potential and significant application prospects of KLS F ‐BC for removing OTCH from wastewater, providing a valuable reference for biomass resource utilization and antibiotics treatment.