The Langmuir sorption capacity, q ^sub max^, for Cd(II) was improved by 18 times by thiolation of chitosan. However, the q ^sub max^ for Cu(II) by ETB was seven times lower than that of pristine chitosan beads, possibly due to exhaustion of amine groups (-NH2). The batch sorption data was generally fitted well by a linearised Freundlich isotherm model and a Ho's pseudo-second-order kinetic model, indicating metal interaction with the heterogeneous surface of ETB and chemical adsorption as the possible rate-limiting step, respectively. The metal uptake has resulted in the oxidation of -SH to -SO3 ^sup -^ group in ETB, thereby decreasing the stability of metal-sulfide bonds as well as their metal uptake.