Monitoring of TiO2-catalytic UV-LED photo-oxidation of cyanide contained in mine wastewater and leachate

Kim, Seong Hee; Lee, Sang Woo; Lee, Gye Min; Lee, Byung Tae; Yun, Seong Taek; Kim, Soon Oh

doi:10.1016/j.chemosphere.2015.07.006

Cited by 69 publications

(27 citation statements)

References 42 publications

(62 reference statements)

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“…The kinetic curves indicate a small decrease in CNdegradation when OH * radicals are inhibited by t-BuOH, due to the fact that oxidation occurs primarily by direct electron transfer. Several researchers have associated the photocatalytic oxidation of CNon TiO 2 with a direct charge transfer process [39][40][41][42][43] . Nonetheless, it has also been reported that such photocatalytic oxidation could also take place through indirect mechanisms at the semiconductor/electrolyte interface.…”

Section: Photoelectrocatalytic Oxidation Of Cyanidementioning

confidence: 99%

N and F Codoped TiO2 Thin Films on Stainless Steel for Photoelectrocatalytic Removal of Cyanide Ions in Aqueous Solutions

et al. 2017

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N-F codoped TiO 2 films were immobilized on stainless steel sheets through a combined approach involving a dip-coating technique and a hydrothermal treatment, followed by calcination at 400°C in the presence of air. Photocatalyst characterization was conducted using XRD, Raman and UV-VIS spectroscopy as well as SEM. The films were tested in a three-electrode cell for the photoelectrocatalytic degradation of CN-containing compounds. The results showed that the increase in the degradation rate of CN-containing compounds is both influenced by a synergistic effect of the doping agents and strongly dependent on the concentration of CN-containing compounds in the solution. Nitrogen contributed to the enhanced photoactivity under visible light due to the generation of localized states within the band gap of TiO 2 , whereas the presence of fluoride improved the superficial properties of the film, which resulted in higher amounts of CN-containing compounds that were degraded by direct charge transfer through the photogenerated holes.

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Section: Photoelectrocatalytic Oxidation Of Cyanidementioning

confidence: 99%

N and F Codoped TiO2 Thin Films on Stainless Steel for Photoelectrocatalytic Removal of Cyanide Ions in Aqueous Solutions

et al. 2017

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“…. Several studies have also compared the efficiency of LEDs with germicidal and blacklight lamps in photocatalytic applications . However, the comparison has usually been made between irradiation sources of different electrical power or at reactor geometries optimised for U shaped lamps, without considering the optical characteristics of LEDs.…”

Section: Introductionmentioning

confidence: 99%

“…[21][22][23][24][25] Several studies have also compared the efficiency of LEDs with germicidal and blacklight lamps in photocatalytic applications. [25][26][27][28] However, the comparison has usually been made between irradiation sources of different electrical power or at reactor geometries optimised for U shaped lamps, without considering the optical characteristics of LEDs. The directivity of LEDs affects dramatically the irradiation uniformity 24 and when integrated within the reactor at a close distance from the catalyst the non-uniform irradiation of the latter results in lower oxidation rates compared with blacklight lamps, as has previously been reported by Levine et al 28 Therefore, a study evaluating a UV-LED relative to a UV-BL at a set-up providing uniform irradiation, at the same spectral irradiance, electrical power and reactor geometry, in terms of organic removal, energy consumption and under a variety of photocatalytic conditions is still missing from the literature.…”

Section: Introductionmentioning

confidence: 99%

Photocatalytic degradation of saccharin under UV‐LED and blacklight irradiation

Davididou

McRitchie

Αντωνοπούλου

et al. 2017

J of Chemical Tech & Biotech

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“…Additionally, degradation products, such as NH 3 /NH 4 + , NO 2 -, NO 3 -, CNO -, sulfates, and carbonates are formed by the slow rupture of cyano-metallic complexes. Thus, the resulting wastewater (concentrated by these complexes) is not suitable for being poured into surface bodies of water [13,21].…”

Section: Production and Characterization Of Cyanide Wastewatermentioning

confidence: 99%

Recent Developments in the Photocatalytic Treatment of Cyanide Wastewater: An Approach to Remediation and Recovery of Metals

et al. 2019

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For gold extraction, the most used extraction technique is the Merrill-Crow process, which uses lixiviants as sodium or potassium cyanide for gold leaching at alkaline conditions. The cyanide ion has an affinity not only for gold and silver, but for other metals in the ores, such as Al, Fe, Cu, Ni, Zn, and other toxic metals like Hg, As, Cr, Co, Pb, Sn, and Mn. After the extraction stage, the resulting wastewater is concentrated at alkaline conditions with concentrations up to 1000 ppm of metals. Photocatalysis is an advanced oxidation process (AOP) able to generate a photoreaction in the solid surface of a semiconductor activated by light. Although it is well known that photocatalytic processes can remove metals in solution, there are no compilations about the researches on photocatalytic removal of metals in wastewater with cyanide. Hence, this review comprises the existing applications of photocatalytic processes to remove metal and in some cases recover cyanide from recalcitrant wastewater from gold extraction. The use of this process, in general, requires the addition of several scavengers in order to force the mechanism to a pathway where the electrons can be transferred to the metal-cyanide matrices, or elsewhere the entire metallic cyanocomplex can be degraded by an oxidative pathway.

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Monitoring of TiO2-catalytic UV-LED photo-oxidation of cyanide contained in mine wastewater and leachate

Cited by 69 publications

References 42 publications

N and F Codoped TiO2 Thin Films on Stainless Steel for Photoelectrocatalytic Removal of Cyanide Ions in Aqueous Solutions

N and F Codoped TiO2 Thin Films on Stainless Steel for Photoelectrocatalytic Removal of Cyanide Ions in Aqueous Solutions

Photocatalytic degradation of saccharin under UV‐LED and blacklight irradiation

Recent Developments in the Photocatalytic Treatment of Cyanide Wastewater: An Approach to Remediation and Recovery of Metals

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