Potential low-cost carbon-based adsorbent from gold mine tailings for anionic dye removal

In this study, a mesoporous carbon (CMK-3) was successfully synthesized using mesoporous silica (SBA-15) prepared from gold mine tailings (sample C-GMT) for removal of anionic dye from aqueous solution. For comparison, CMK-3 was prepared by the same method from pure silica (sample C-T), and the other CMK-3 sample was prepared by a one-pot route mixing with Pluronic P123 (sample C-P). The effect of the carbonization time on the synthesis of all CMK-3 samples was investigated, and the samples were characterized by X-ray diffraction and N-2 adsorption-desorption. The sample with the highest surface area was chosen as an adsorbent, for each CMK-3 obtained from different methods. Batch adsorption experiments were studied to determine the influence of pH, contact time, and initial dye concentration. The adsorption kinetics obeyed the pseudo-second-order model. All carbon-based adsorbents were observed to be quite effective for the removal of dye with adsorption percentage in the order of C-P > C-T > C-GMT. The maximum adsorption capacities were 188.99 and 204.57 mg center dot g(-1) for C-T and C-GMT, respectively. The comparative results of all carbon-based adsorbents show that C-GMT can be applied as a low-cost alternative to C-T for dye removal.

Automated summary

In this study, mesoporous carbon (CMK-3) was synthesized from mesoporous silica prepared from gold mine tailings for removal of anionic dye from aqueous solution. The effect of carbonization time, pH, contact time, and initial dye concentration on the adsorption process was investigated. Results showed that CMK-3 from gold mine tailings could be a cost-effective alternative to pure silica for dye removal.