Document Type : Original Research Paper


Department of Mining Engineering, Lorestan University, Lorestan, Iran



The present work is aimed to examine the elimination of cyanide ions from the wastewater derived from the Agh-Darreh gold mine using the Caro’s acid method. The response surface modeling is utilized to evaluate and optimize the influential parameters such as the sulfuric acid/hydrogen peroxide ratio, pH, Caro’s acid concentration, and contact time on the elimination process. The results obtained indicate that the increase in the Caro’s acid concentration and contact time has a positive impact on the elimination of the free cyanide ions, while the increment in the weight ratio of sulfuric acid/hydrogen peroxide and pH higher than 9.5 demonstrate a negative impact. Also it is found that the quadratic effect of pH has the highest influence on the removal of cyanide ion, and the linear effect of the ratio of sulfuric acid/hydrogen peroxide has the lowest degree of importance. Additionally, the optimization process is carried out, and about 96.4% of the cyanide ions is eliminated from the wastewater under the optimal conditions including 2 g/L Caro’s acid concentration, 9.3 pH, 8 min contact time, and sulfuric acid to hydrogen peroxide (weight) ratio of 2.


[1]. Mudliar, R., Umare, S.S., Ramteke, D.S., and Wate, SR. (2009). Energy efficient-Advanced oxidation process for treatment of cyanide containing automobile industry wastewater. Journal Hazard Mater 164,1474–1479.
[2]. Mudder, TI. and Botz, MM. (2001). The Cyanide Monograph (Eds.). Mining Journal Books Limited, London, UK.
[3]. Akcil, A. (2002). First application of cyanidation process in Turkish gold mining and its environmental impacts. Mineral Engineering. 15 (9): 695–699.
[4]. Mudder, T. and Botz, M. (2004). Cyanide and society: a critical review. The European Journal of Mineral Processing and Environmental Protection 4, 62–74.
[5]. Akcil, A. (2006). Managing cyanide: health, safety and risk management practices at Turkey’s Ovacik gold–silver mine. Journal of Cleaner Production. 14(8): 727–735.
[6]. Akcil, A. (2010). A New global approach of cyanide management: international cyanide management code for the manufacture, transport, and use of cyanide in the production of gold. Mineral Processing Extractive Metallurgy Review. 31 (3): 135–149.
[7]. Mondal, M., Mukherjee, R., Sinha, A., Sarkar, S., and De, S. (2019). Removal of cyanide from steel plant effluent using coke breeze, a waste product of steel industry. Journal Water Process Engineering. 28: 135–143.
[8]. Environmental Protection Agency, U.S. (1985). Drinking water criteria document for cyanide, Environment Criteria and Assessment office, Cincinnati, EPA/600/X-84-192-1.
[9]. Dash, RR., Majumder, CB., and Kumar, A. (2008). Treatment of metal cyanide bearing wastewater by simultaneous adsorption biodegradation (SAB). Journal Hazard Mater. 152,387–396.
[10]. Dash, RR. and Balomajumdar, C. (2014.) Treatment of cyanide bearing effluents by adsorption, biodegradation and combined processes: effect of process parameters. Desalination and Water Treatment. 52, 3355–3366.
[11]. Sinbuathong, N., Kongseri, B., Plungklang, P. and Khun-anake, R. (2000). Cyanide removal from laboratory wastewater using sodium hypochlorite and calcium hypochlorite. Witthayasan Kasetsat. 34 (1): 74-78.
[12]. Barter, J., Lane, G., Mitchell, D., Kelson, R., Dunne, R., Trang,C. and Dreisinger, DB. (2001). In Cyanide: Social, Industrial and Economic Aspects, Ed. Young C, Tidwell L, Anderson C, The Minerals, Metals and Materials Society Annual Meeting, 549-562.
[13]. Parga, J., Shukla, S. and Carrillo-Pedroza, F. (2003). Destruction of cyanide waste solutions using chlorine dioxide, ozone and titania sol. Waste Management journal. 23,183–191.
[14]. Dash, RR., Gaur, A., and Balomajumder, C. (2009). Cyanide in industrial wastewaters and its removal: A review on biotreatment. Journal  of Hazardous Material. 163 (1): 1–11.
[15]. Yazıcı, EY., Deveci, H. and Alp, İ. (2009). Treatment of cyanide effluents by oxidation and adsorption in batch and column studies. Journal of Hazardous Material. 166: 1362–1366.
[16]. Yeddou, AR., Nadjemi, B., Halet, F., Ould-Dris, A., and Capart, R. (2010). Removal of cyanide in aqueous solution by oxidation with hydrogen peroxide in presence of activated carbon prepared from olive stones. Mineral Engineering. 23,32–39.
[17]. Moussavi, G., Majidi, F. and Farzadkia, M. (2011). The influence of operational parameters on elimination of cyanide from wastewater using the electrocoagulation process. Desalination journal. 280,127–133.
[18]. Hijosa-Valsero, M., Molina, R., Schikora, H., Müller, M. and Bayona, JM. (2013). Removal of cyanide from water by means of plasma discharge technology. Water Resistant journal. 47 (4): 1701-1707.
[19]. Dwivedi, N., Balomajumder, C. and Mondal, P. (2016), Comparative investigation on the removal of cyanide from aqueous solution using two different bio-adsorbents. Water Resources India. 15: 28–40.
[20]. Alizadeh Ganji, S.M.S. and Hayati, M. (2018). Selecting an appropriate method to remove cyanide from the wastewater of Moteh gold mine using a mathematical approach. Environmental Science and Pollution Research. 25 (23): 23357–23369.
[21]. Bahrami, A., Kazemi, F., Alighardashi, A., Ghorbani, Y., Abdollahi, M. and Parvizian, A. (2020). Isolation and removal of cyanide from tailing dams in gold processing plant using natural bitumen. Journal of Environmental Management. 262:110286.
[22]. Mamelkina, MA., Herraiz-Carboné, M., Cotillas, S., Lacasa, E., Sáez, C., Tuunila, R., Sillanpää, M., Häkkinen, A. and Rodrigo, MA. (2020). Treatment of mining wastewater polluted with cyanide by coagulation processes: A mechanistic study. Separation and Purification Technology. 237,116345.
[23]. Eskandari, P., Farhadian, M., Solaimany, AR.and Goshadrou, A. (2020). Cyanide adsorption on activated carbon impregnated with ZnO, Fe2O3, TiO2 nanometal oxides: a comparative study. nternational Journal of Environmental Science and Technology .
[24]. Montalvo Andiaa, JP. and Ticona Cayteb, A E. (2021). Combined treatment based on synergism between hydrodynamic cavitation and H2O2 for degradation of cyanide in effluents. Minerals Engineering. 171: 107119.
[25].Liu, Q., Zhang, M.,  Peng, B.  and Barvor, J  B. (2021). Zinc cyanide removal by precipitation with quaternary ammonium salts. Separation and Purification Technology. 274, 119057.
[26]. Teixeira, LAC., Andia, JPM., Yokoyama, L., Araújo, FVF. and Sarmiento, CM. (2013). Oxidation of cyanide in effluents by Caro’s Acid. Mineral Engineering. 45: 81–87.
[27]. Ghanbari, F. and Moradi, M. (2017). Application of peroxymonosulfate and its activation methods for degradation of environmental organic pollutants: Review. Chemical Engineering Journal. 310: 41-62.
[28]. Loveitt, E. (1981). The preparation of Caro’s Acid from hydrogen peroxide and sulphuric acid or oleum. Solvay Interox Research Report, UK.
[29]. Smith, RH. and Wilson, IR. (1966). The mechanism of the oxidation of thiocyanate ion by peroxomonosulphate in aqueous solution. I. Stoichiometry of the reaction. Australian Journal of Chemistry. 19 (8): 1357–1363.
[30]. Kuyucak, N. and Akcil, A. (2013). Cyanide and removal options from effluents in gold mining and metallurgical processes. Mineral Engineering. 50–51,13–29.
[31]. Jauto, AH., Memon, SA., Channa, A. and Khoja, AH. (2019). Efficient removal of cyanide from industrial effluent using acid treated modified surface activated carbon. Energy Sources . 41 (22): 2715-2724.