A new magnetic nanocomposite for selective detection and removal of trace copper ions from water

Abstract

A core–shell structured, magnetic nanocomposite (SDMA) modified by a new organic fluorescent probe and selective chelating groups was prepared for simultaneous detection and removal of low Cu²⁺ concentrations. A series of experiments was designed to detect and adsorb copper ions in aqueous solution via SDMA. Results showed that SDMA could detect Cu²⁺ from copper ion solution qualitatively and quantifiably with a certain degree of selectivity, and remove Cu²⁺ with a respectable removal efficiency of about 80%. In comparative adsorption experiments, the adsorption capacity of SDMA was significantly higher than that of another two common magnetic nanoadsorbents (Fe₃O₄@mSiO₂–SH and Fe₃O₄@mSiO₂–NH₂). The adsorption behavior of SDMA was studied through equilibrium and kinetic experiments. The adsorption isotherm was perfectly fitted via the Freundlich model and the pseudo-second-order model could fit the kinetic adsorption. Moreover, the SDMA could reach the adsorption equilibrium in only 20 min, which showed a fast kinetic adsorption to Cu²⁺. Prepared SDMA can be an effective and potential nanoadsorbent for detecting and removing copper ions from wastewater.