Investigation of mercury cyanide adsorption from synthetic wastewater aqueous solution on granular activated carbon

Author(s)

Aliprandini, Paula ^[1] ; Veiga, Marcello M. ^[2] ; Marshall, Bruce G. ^[2] ; Scarazzato, Tatiana ^[3] ; Espinosa, Denise C. R. ^[1]

Affiliation

^[1] Univ Sao Paulo, Chem Engn, Sao Paulo, SP - Brazil

^[2] Univ British Columbia, Norman B Keevil Inst Min Engn, Vancouver, BC - Canada

^[3] Univ Fed Rio Grande do Sul, PPGE3M, Porto Alegre, RS - Brazil

• Document type: Journal article
• Source: JOURNAL OF WATER PROCESS ENGINEERING; v. 34, APR 2020.
• Web of Science Citations: 0

Abstract

Mercury (Hg) is one of the most harmful metals to human health. Combined with cyanide (CN-), Hg forms a stable complex (Hg(CN)(2)) that is difficult to remove from solution. Artisanal gold mining effluents containing mercury cyanide complexes are discharged into rivers and streams, which can be potentially bioavailable to aquatic organisms. In this study, activated carbon adsorption was evaluated for its capacity to remove mercury cyanide from solution. A solution with Hg(CN)(2) and free cyanide was prepared at pH 12, corresponding to 1 mg/L Hg2+ and 0.5 mg/L CN. Analysis in batch mode showed that 180 min were required to achieve adsorption equilibrium. The adsorbent dosage was fixed at 0.1 g of activated carbon, which represented an adsorption capacity of 0.14 mg/g, equivalent to adsorption of 81 % Hg(CN)(2). The free cyanide concentration did not affect the adsorption of mercury cyanide. Experimental data indicated that the adsorption follows pseudo-second order kinetics and equilibrium results corresponded to the Freundlich adsorption isotherm. (AU)

• FAPESP's process: 12/51871-9 - Study Center for Technology in Waste Solid Treatment and Recycling - SCTWSTR
• Grantee: Jorge Alberto Soares Tenório
• Support Opportunities: Research Projects - Thematic Grants