Sulfonated modification of cotton linter and its application as adsorbent for high-efficiency removal of lead(II) in effluent

Sulfonated modification of cotton linter and its novel application as adsorbent for Pb2+ in effluent were investigated. Results show that sulfonated cotton linter (SCL) has strong adsorbability for Pb2+, more than 85% of Pb2+ can be removed at lower Pb2+ concentration (<20 mg/L). Its adsorbability for Pb2+ is related to effluent pH, temperature, and initial Pb2+ concentration. The adsorption process can reach equilibrium within 8 min, which can be described through the pseudo-second-order kinetic model. The adsorption isotherm is closely fitted with the Temkin isotherm model, which suggests that the adsorption of Pb2+ on SCL can be regarded as chemical adsorption. The adsorption process of Pb2+ on SCL is non-spontaneous and endothermic, based on the value of Gibbs free energy and enthalpy. Compared with commercial activated carbon, SCL is simple to prepare and does not require any special technology. (c) 2013 Elsevier Ltd. All rights reserved.