In this study, the usability potential of composite as a novel, cost-effective, and dual-function adsorbent, prepared by easy ball milling method, using carbonized forms of industrial wastes such as hawthorn waste pulp and marble waste powder was investigated to remove Remazol Brillant Blue R and mercury from aqueous environments. Response surface methodology was applied to define the effect of variables on adsorption and to optimize process conditions. In optimum conditions, removal efficiencies were obtained over 95% for both adsorption processes. Langmuir model was the most appropriate for both adsorption equilibria indicated that the adsorption processes occurred in single-layer homogeneous surfaces. Thermodynamic evaluations indicated that both adsorption processes were endothermic and spontaneous and had an increasing entropy. Moreover, the rate-limiting step of processes was identified with pseudo-second-order kinetic model. The composite showed a well-developed porosity and high surface area in addition to functional structures and active surfaces capable of adsorbing.