Preparation of phosphorus based hyper cross-linked polymers and adsorption of salicylic acid from aqueous solution

Phosphorous modified cross-linked resins TPPBN-X were synthesized by 1, 4dichloromethylnaphthalene (BN) reacted with triphenylphosphine (TPP), and the structure was characterized by FT-IR, XPS, SEM and BET. The XPS analysis shown that the phosphorus atom was mainly in state of quaternary phosphonium as well as phosphine oxide. The adsorption performance of obtained TPPBN-X to salicylic acid (SA) was evaluated. The effect of initial SA concentration, contact time, temperature, initial pH and recirculation of the adsorbent (TPPBN-3) were investigated. Kinetic data were fitted well by the pseudo-second-order kinetic model, and isotherm data were fitted by the Langmuir as well as Tempkin model. The adsorption of SA by the TPPBN-3 dominated by a chemical process. At an optimal pH of 3.67 and a SA concentration of 1033.17 mg/L, the equilibrium adsorption capacity reached a maximum of 449.67 mg/g. The uptake efficiency of the reused TPPBN-3 was still 94.3% after the fourth adsorption-desorption cycle. The DH and DS of adsorption process are -18.25 kJ/mol and -57.92 J/(mol. K), respectively. The prepared phosphorus modified cross-linked resins TPPBN-3 demonstrates good reusability for SA adsorption from aqueous media. (C) 2020 Elsevier B.V. All rights reserved.