Cyanide removal with a copper/active carbon fiber Cathode via a combined oxidation of a Fenton-like reaction and in situ generated copper oxides at anode

Electrocatalytic oxidation of cyanide on copper-doped cobalt oxide electrodes

“…This enhancement was assigned to an electrocatalytic effect caused by copper oxide films in-situ deposited on the anode [23][24][25][26][27][28]31,32]. This catalytic activity is in agreement with the reported promotion of cyanide decomposition by copper species when using other elimination methods [38,39]. Nevertheless, the electrodeposited copper oxide films showed variable low stability and adherence [11,24,31,32], hindering their practical application for electrochemical cyanide destruction.…”

Cyanide oxidation by singlet oxygen generated via reaction between H 2 O 2 from cathodic reduction and OCl − from anodic oxidation

“…Like hydroxyl radicals, 1 O 2 is a kind of excited species with a very high affinity for electrons captured from compounds in aqueous solutions. Hydroxyl radicals generated in the reaction between copper cyanides complexs and H 2 O 2 were responsible for the cyanide removal [34]. When the 1 O 2 was generated, the cyanide oxidation reaction proceeded according to the main reaction (7) and the cyanate was the final production.…”

Cyanide Degradation from Mining Effluent Using Two Reagents: Sodium Metabisulphite and the Metabisulphite Mixture with Hydrogen Peroxide

“…It was found that the CNL degradation is favored with the increase in the percentage of the excess of the reagent [17][18][19][20][21][22], which is the variable most relevant to the study (figure 4). According to Figure 2, when using a 400% excess of Na2S2O5 reagent, CNL is degraded up to a mean value of 10,1 mg/L, compared to the mixture Na2S2O5 + H2O2, with which it was degraded to 20.93 mg/L.…”

“…Usually, the research to degrade the CNion is focused on the use of cyanide synthetic solutions to experience its destruction [4] [17]. In [7] when using vacuum ultraviolet and ultraviolet/persulfate UVC/(S2O8)2there was a complete destruction of 50 mg/L of cyanide in 15 min and 50 min respectively at a pH of 11; [4] when using Caro´s acid reduces the initial free cyanide concentration from 400 mg/L to 1 mg/L, after 10 min and at pH of 9 to 11 at 25°C; [9] when evaluating two non-thermal plasma reactors at atmospheric pressure, eliminates 99% of the CNL in both, from an initial concentration of 1 mg/L at a pH of 11, times of 15 and 3 minutes; [11] when reacting a molar ratio of (H2O2 + NaClO)/CN -= 2:1, oxidizes free cyanide by 98%, from an initial concentration of 100 mg/L, achieving a final concentration less than 0.2 mg/L in 20 minutes at a pH of 9°C and 25°C; [17] when increasing the molar ratio [H2O2]O/[CN -]O in the presence of activated carbon impregnated with copper, eliminates more than 90% of free cyanide in 20 minutes at a pH of 11. However, the present study focuses to degrade CNL from the tailings pulp solution, which comes from the treatment of a gold-bearing ore that has been leached using sodium cyanide (NaCN).…”