Removal of copper ions from aqueous solutions using poly (Vinylbenzyl chloride)

Abstract

Nowadays, contamination of copper (Cu(II)) has become one of the worst environmental problems. Due to its environmental resistance and persistence, the treatment of Cu(II) is crucial. Poly(vinylbenzyl chloride) (PVBC) was synthesised through reversible addition-fragmentation chain transfer (RAFT) polymerisation technique utilising monomer vinylbenzyl chloride (VBC), 4-cyanopentanoic acid dithiobenzoate (CPADB) as RAFT agent and 4,4ʹ-Azobis (4-cyanopentanoic acid) (ACPA) as initiator. This study aims to synthesise PVBC and to test the ability of PVBC to remove Cu(II) ions from aqueous solution. In this study, PVBC was successfully synthesised when reacted for 24 h at 80 °C, and the ability of the PVBC to adsorb and remove Cu(II) ions was investigated. Important adsorption parameters such as adsorbate concentration, adsorption dosage, and contact time were studied. The maximum Cu(II) adsorption capacity (qmax) of PVBC was 263.15 mg/g with a copper removal rate of 95% under optimum initial concentration (160 mg/L), adsorbent dosage (14 mg), and contact time (180 min). The experimental results better fit into the Langmuir adsorption isotherm model than the Freundlich model, and the kinetics experiments were compared with the pseudo-second-order kinetic model. Polymer adsorption efficiency was above 90% after five cycles of adsorption and desorption, but the overall adsorption capability of PVBC for Cu(II) ions began to decrease after another five cycles from 80% to 54%. Given the outcomes acquired, it can be concluded that PVBC can be an efficient and potential adsorbent for the removal of Cu(II) ions from aqueous solution. The adsorption study showed that PVBC has an affinity to Cu(II) ions. The prepared PVBC is potentially useful for wastewater treatment applications.