Application of mesoporous magnetic nanosorbent developed from macadamia nut shell residues for the removal of recalcitrant melanoidin and its fractions

A novel mesoporous magnetic nanosorbent developed from macadamia nut shell residues was applied as an adsorbent for the removal of dissolved organic carbon (DOC) associated with melanoidin and its fractions in a batch system. The most favored molecular fraction of the melanoidin for adsorption onto the nanosorbent was 1-5 kDa with adsorption capacity of 10.26 mg DOC g(-1) achieving 68.4% removal efficiency. The sorption behaviors were all well fitted to a pseudo-second-order kinetic model and Langmuir isotherm. Optimum operating conditions needed for the maximum uptake of 14.7 mg DOC g(-1) were found to be pH of 6.3, temperature of 41.7 degrees C at the dosage of the magnetic nanosorbent of 877.7 ppm.