D301 resin for the nanoconfinement of Fe3O4 crystal: enhanced adsorption performance, mechanism and solid-phase extraction of 2,4-dichlorophenol from agricultural ditch water

2,4-Dichlorophenol (2,4-DCP) is a persistent organic pollutant that has been found in various water bodies. D301 anion exchange resin was anchored for the nanoconfinement of Fe 3 O 4 crystal (D301-Fe 3 O 4 ) to design 2,4-DCP adsorbent. In-situ grown Fe₃O₄ in D301-Fe 3 O 4 exhibited uniform distribution, nano crystal and strong superparamagnetism. The excellent thermal and chemical stability of D301-Fe 3 O 4 enabled its large-scale practical applications over a broad pH range (3−13), high salinity and alkalinity. The adsorption capacities of 2,4-DCP on D301-Fe 3 O 4 were superior to those of H103, XAD-4, D301, D201-Fe 3 O 4 and D201. D301-Fe 3 O 4 exhibited greater adsorption rate than D301. In the presence of interfering electrolytes and heavy metal Cd 2+ , D301-Fe 3 O 4 showed prominent anti-interference ability than D301. The synergistic adsorption mechanism of 2,4-DCP on D301-Fe 3 O 4 involved hydrophobic interaction, hydrogen bonding, π-π interaction and coordinate bonding. Ten adsorption-desorption cycles demonstrated that D301-Fe 3 O 4 could be effectively refreshed with 80% C 2 H 5 OH-1.5% NaCl and stably reused. 10 mL (1BV) of D301-Fe 3 O 4 could continuously purify 1584.4 BV of agricultural ditch water containing 0.05 mg/mL 2,4-DCP without the leakage of 2,4-DCP. Only 14.9 BV of 80% C 2 H 5 OH-1.5% NaCl as regenerant, the recovery rate of 2,4-DCP reached 95.87%. D301-Fe 3 O 4 holds great potential for 2,4-DCP wastewater treatment.