In this work, we designed and prepared a novel magnetic thiolated/quaternized-chitosan composite as an adsorbent for removal of various heavy metal ions from solution, including cation and anion. Characterizations by Fourier transform infrared spectroscopy (FTIR), scanning electronic microscopy (SEM), vibrating sample magnetometer (VSM) and thermogravimetric analysis (TGA) confirmed the structure and composition of this adsorbent. Adsorption experiments indicated that the initial pH of the solution influenced the adsorption ability of the composite for heavy metal. The composite showed high removal efficiency for all the tested metal ions (As(V), As(III), Cu2+ Hg2+ Zn2+, Cd2+, Pb2+) under neutral condition within a short time, especially for Pb2+, with a high adsorption capacity of 235.63 mg/g. Adsorption kinetic and XPS analysis indicated that the major adsorption mechanism for heavy metal removal by the composite was chemisorption. Moreover, the composite showed good regeneration performance, and its removal efficiency for Pb2+ was still over 93% even after 5 recycles. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.