Nanoscale Zerovalent Iron Immobilized on Functionalized Nonwoven Cotton Fabric for As(V) Adsorption

Abstract

A functionalized nonwoven cotton fabric-Fe(0) (denoted as FNCF-ZVI) as a novel adsorbent material was synthesized in two main steps for water treatment of arsenate ions. Firstly, the Fe(III)-immobilized chelating fabric with iminodiacetic acid (IDA) functional groups was synthesized through an epoxy group–containing glycidyl methacrylate (GMA) grafted to the nonwoven cotton fabric (NCF) via plasma-initiated emulsion graft polymerization. Subsequently, the obtained Fe(III)-immobilized FCNF was followed by a reduction of Fe(III) into Fe(0) to obtain stabilized nanoscale zerovalent iron (ZVI) on the surface of FNCF. FNCF-ZVI was applied for arsenic(V) removal in batch experiments at different pH values (2.00–9.00) and concentrations ranging between 1 and 500 mg/L As(V). The FNCF-ZVI had a positive impact on the absorption of As(V) species under acidic conditions, and the highest adsorption was seen at a pH value of 3.00. The adsorption equilibrium of adsorbent was reached in 420 min with initial solution concentrations at 1 mg/L, 10 mg/L, and 50 mg/L, and the process better fitted to the nonlinear pseudo-second-order model than to the nonlinear pseudo-first-order model. The resulting FNCF-ZVI showed a high maximum adsorption capacity of 158.73 mg/g at 35 °C for As(V) adsorption, and the adsorption data fitted the Freundlich isotherm model. Regeneration studies displayed that after 3 times usage, the adsorption capacity can remain up to 86%. It has been observed that ZVI nanoparticles have superior adsorption capacity compared to Fe(III) under their optimum conditions.