Adsorption removal of cyclolinopeptide E from linseed oil using sodium chloride-induced walnut shell biochar: Kinetic and mechanism.

To produce linseed oil with mild bitterness, walnut shell biochar (WBSC) was synthesized via NaCl immersion, anaerobic calcination, and template removal for adsorbing bitter cyclolinopeptide E. Subsequently, a series of adsorption experiments were carried out to investigate the influence of various parameters on adsorption capacity and explain adsorption performance of the biochar. WBSC-30, prepared at 30 °C, exhibited the highest adsorption efficiency (93.66 %) due to its optimal specific surface area, pore size (12.04 nm), and abundant oxygen-containing functional groups, enabling simultaneous pore and surface adsorption. The adsorption behavior of WBSC-30 was confirmed to be spontaneous and endothermal, and was in accordance with pseudo-second-order kinetic and Langmuir isotherms model. Furthermore, compared with crude oil, WSBC-30-treated oil maintained original fatty acid profiles (p > 0.05) and > 82 % minor components retention. Overall, WBSC-30 appeared to be preferable for the efficient production of linseed oil with mild bitterness.