Efficient removal of arsenate from water using electrospun polyethylenimine/polyvinyl chloride nanofiber sheets

Abstract

Arsenic is a highly toxic pollutant affecting over 200 million people worldwide in >100 countries. Adsorption is an effective method for arsenic removal, and the development of efficient adsorbents for arsenic removal has received much attention. This study reports a regenerable electrospun polyethylenimine/polyvinyl chloride nanofiber sheet adsorbent with excellent adsorption performance for As(V). The adsorbent showed the highest As(V) uptake at pH 5. At the initial As(V) concentrations of 1, 10, and 100 mg/L, the adsorption equilibrium was reached in 10, 90, and 180 min, respectively. The maximal As(V) uptake on the adsorbent was 111.77, 115.79, 119.20, and 122.74 mg/g at the temperature of 15, 25, 35, and 45 °C, respectively, as calculated by the Langmuir model. The adsorption process was endothermic and spontaneous, as demonstrated by thermodynamic studies. Effects of competing anions on As(V) adsorption follow the order of SO42− > PO43− > CO32− ≈ NO3− ≈ F−. The main adsorption mechanisms were electrostatic attraction and coordination. The adsorbed As(V) can be eluted from the adsorbent with 0.2 M NaOH. The adsorption efficiency remained above 91% even after 5 reuse cycles. Overall, the sheets is a promising adsorbent for removing As(V) from water. © 2023 Elsevier B.V.