• Vol 9, No 5 (2018)
  • Chemical Engineering

The Simultaneous Removal of Cyanide and Cadmium Ions from Electroplating Wastewater using UV/TiO2 Photocatalysis

Tedi Hudaya, Hans Kristianto, Christine Meliana

Cite this article as:
Hudaya, T., Kristianto, H., Meliana, C., 2018. The Simultaneous Removal of Cyanide and Cadmium Ions from Electroplating Wastewater using UV/TiO2 Photocatalysis. International Journal of Technology. Volume 9(5), pp. 964-971
Tedi Hudaya Chemical Engineering Department Parahyangan Catholic University
Hans Kristianto Chemical Engineering Department Parahyangan Catholic University
Christine Meliana PT United Tractors Tbk
Email to Corresponding Author


The simultaneous oxidation of cyanide and reduction of cadmium from electroplating wastewater using UV/TiO2 photocatalysis was investigated in this study. The investigation was performed using a batch-wise 3 L bubble-column photoreactor equipped with a 64-Watt low-pressure ultraviolet (UV) amalgam lamp (20 W at 254 nm). Preliminary experiments were conducted to identify the optimum aeration rate for ensuring the mixing of the catalyst and the wastewater. More specifically, this study focused on the two main factors that influence the effectiveness of oxidative and reductive processes, namely the TiO2 concentration (0.5–2 g/L) and the solution’s pH (11–13), at cyanide and cadmium ion concentrations of 50 and 100 ppm, respectively. A sample was taken every 30 minutes for 3 hours, and the cyanide and cadmium ion concentrations were determined using an ion-selective electrode and atomic absorption spectroscopy (AAS), respectively. It was determined that 3 L/min aeration was optimum, resulting in the removal of approximately 80% of the pollutants. A further increase in the aeration rate resulted in a decrease in the %removal rate due to competition between the oxygen and cadmium ions in terms of reacting with the electrons produced by the photocatalyst. An increase in the pH resulted in an increase in both the removal rate and the kinetics due to the high availability of the hydroxide ions needed to form the radical hydroxide that effectively oxidized the cyanide ions. It was observed that an increase in the TiO2 concentration increased both the removal rate and the kinetics until the optimum point, after which the performance of the photocatalyst decreased due to the shielding effect of the UV resulting from the excessive level of TiO2 present in the mixture. Within the experimental range, the best (most effective) condition was chosen based on the pseudo first-order rate constants. The best condition for cyanide oxidation was identified at pH 13 and 1 g/L TiO2 with kCN- 0.033 min-1, while the reduction of cadmium was found to be optimum at pH 13 and 2 g/L TiO2 with kCd2+ 0.039 min-1.

Cadmium; Cyanide; Electroplating wastewater; Photocatalysis; UV/TiO2


Cadmium-cyanide wastewater treatment using UV/TiO2 photocatalysis with an intensity of approximately 20 Watt/L could remove more than 95% of pollutants when at its optimum condition. The aeration rate, initial pH, and initial TiO2 concentration were the major factors found to affect the reaction rate. For cadmium plating wastewater, it could be concluded that the optimum condition involves an initial pH of 13 and a TiO2 concentration of around 1–2 g/L.  


This research was funded by the Indonesian Ministry of Education (Higher Education Commission) under grant No. 0241/K4/KL/2012. The authors are immensely grateful for the financial and technical support provided by the Ministry.


Acheampong, M.A., Meulepas, R.J.W., Lens, P.N.L., 2010. Removal of Heavy Metals and Cyanide from Gold Mine Wastewater. Journal of Chemical Technology and Biotechnology, Volume 85, pp. 590–613

Barakat, M., 2004. Removal of Toxic Cyanide and Cu(II) Ions from Water by Illuminated TiO2 Catalyst. Applied Catalysis B: Environmental, Volume 53(1), pp. 13–20

Chen, D., Ray, A.K., 2001. Removal of Toxic Metal Ions from Wastewater by Semiconductor Photocatalysis. Chemical Engineering Science, Volume 56(4), pp. 1561–1570

Chiang, K., Amal, R., Tran, T., 2003. Photocatalytic Oxidation of Cyanide: Kinetic and Mechanistic Studies. Journal of Molecular Catalysis, Volume 193, pp. 285–297

Gao, Y., Wahi, R., Kan, T., Falkner, J.C., Colvin, V.L., Tomson, M.B., 2004. Adsorption of Cadmium on Anatase Nanoparticles - Effect of Crystal Size and pH. Langmuir, Volume 20(22), pp. 9585–9593

Hu, C., You, L., Liu, H., Qu, J., 2015. Effective Treatment of Cadmium–Cyanide Complex by a Reagent with Combined Function of Oxidation and Coagulation. Chemical Engineering Journal, Volume 262, pp. 96–100

Litter, M.I., 1999. Heterogeneous Photocatalysis: Transition Metal Ions in Photocatalytic Systems. Applied Catalysis B: Environmental, Volume 23(2-3), pp. 89–114

Marugan, J., van Grieken, R., Cassano, A., Alfano, O., 2008. Intrinsic Kinetic Modeling with Explicit Radiation Absorption Effects of the Photocatalytic Oxidation of Cyanide with TiO2 and Silica-Supported TiO2 Suspensions. Applied Catalysis B: Environmental, Volume 85(1-2), pp. 48–60

Miltzarek, G.L., Sampaio, C.H., Cortina, J.L., 2002. Cyanide Recovery in Hydrometallurgical Plants: Use of Synthetic Solutions Constituted by Metallic Cyanide Complexes. Mineral Engineering, Volume 15(1-2), pp. 75–82

Munoz, M.J.L., Aguado, J., van Grieken, R., Marugan, J., 2009. Simultaneous Photocatalytic Reduction of Silver and Oxidation of Cyanide from Dicyanoargentate Solutions. Applied Catalysis B: Environmental, Volume 86(1-2), pp. 53–62

Nakata, K., Fujishima, A., 2012. TiO2 Photocatalysis: Design and Applications. Journal of Photochemistry and Photobiology C: Photochemistry Reviews, Volume 13(3), pp. 169–189

Nasir, S., Faizal, S., 2016. Ceramic Filters and Their Application for Cadmium Removal from Pulp Industry Effluent. International Journal of Technology, Volume 7(5), pp. 786–794

Nguyen, V.N.H., Amal, R., Beydoun, D., 2003. Effect of Formate and Methanol on Photoreduction/Removal of Toxic Cadmium Ions using TiO2 Semiconductor as Photocatalyst. Chemical Engineering Science, Volume 58(19), pp. 4429–4439

Ozcan, E., Gok, Z., Yel, E., 2012. Photo/Photochemical Oxidation of Cyanide and Metal–Cyanide Complexes: Ultraviolet a Versus Ultraviolet C. Environmental Technology, Volume 33(16), pp. 1913–1925

Papadam, T., Xekoukoulotakis, N.P., Poulios, I., Mantzavinos, D., 2007. Photocatalytic transformation of acid orange 20 and Cr(VI) in aqueous TiO2 suspensions, Journal of Photochemistry and Photobiology A: Chemistry, Volume 186, pp. 308–315

van Grieken, R., Aguado, J., Munoz, M.J.L., Marugan, J., 2005. Photocatalytic Degradation of Iron Cyanocomplexes by TiO2 Based Catalysts. Applied Catalysis B: Environmental, Volume 55, pp. 201–211