In this study, calcium carbide-derived carbon materials (CMs) were prepared by reacting CaC2 with chlorinated polymers via mechanochemical (CMs-M) and thermochemical (CMs-T) reaction in a planetary ball mill and tubular reactor, respectively. Their composition, structure, and adsorptive properties for dibenzothiophene (DBT) in oil and Hg2+ in water were studied, and the reaction mechanism was analyzed. In comparison with CMs-T, CMs-M possess higher specific area (600 +/- 30 m(2).g(-1)) and rich acetylenic and O-containing functional groups, and accordingly higher adsorptivity. Its saturated adsorbance is as high as 291.2 mg-Hg2+.g(-1), and the adsorption isotherm can be well represented by Langmuir model, which manifests the chemisorption arising from the unique interaction between Hg2+ and the functional groups. CMs-M is one of the best carbonaceous sorbents for Hg2+ removal considering its high adsorption rate and capacity, high partition coefficient (21.8 mg.g(-1).mu M-1 at equilibrium concentration of 0.18 ppm), high selectivity w.r.t other heavy metal ions, and excellent recyclability. The mechanochemical method is more suitable for massive production of CMs in view of its mild operation condition and controllable reaction process. This study also sheds a light on the resource utilization of abundant highly chlorinated polymers, like polyvinylchloride (PVC) and chlorinated PVC (CPVC), for the manufacture of CMs-M.