Treatment of cyanide wastewater dynamic cycle test by three-dimensional electrode system and the reaction process analysis

• Published in: Environmental technology Vol. 42; no. 11; pp. 1693 - 1702
• Main Authors: Yonghui, Song, Siming, Lei, Ning, Yin, Wenjin, He
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 12-05-2021; Taylor & Francis Ltd
• Subjects: Activated carbon; Anions; Anode effect; Cathodes; Charcoal; Chemical evolution; Chemisorption; Coal; Coal industry wastewaters; coal-based material; Coordination compounds; Copper; Cyanide process; cyanide wastewater; Cyanides; Dosage; dynamic cycle test; Electric fields; Electric potential; Electrodes; Flow rates; Flow velocity; Metal ions; Morphology; Oxidation; Oxidation-Reduction; Reaction mechanisms; Reaction time; Synergistic effect; Three dimensional analysis; Three-dimensional electrochemical process; Voltage; Waste Water; Wastewater treatment; Water Pollutants, Chemical; X ray photoelectron spectroscopy; Zinc; coal-based material; Three-dimensional electrochemical process; cyanide wastewater; dynamic cycle test
• ISSN: 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2019.1677783

Dynamic three-dimensional electrode system treatment of cyanide wastewater used coal-based electrodes as cathode and anode, activated carbon as particle electrodes, the effects of applied voltage, reaction time and flow rate on ion removal rate were studied. SEM-EDS and XPS were used to study the morphology of coal-based electrode and the composition and existing state of the load substances, and the reaction mechanism were analysed and discussed. The results show that the removal rates of CN
T
, Cu, Zn, CN
−
, SCN
−
in cyanide wastewater were 97.03%, 95.79%, 99.82%, 99.42% and 94.19%, respectively, when the applied voltage of 4 V, the electrode distance of 10 mm, the flow rate of 30 ml/min, the reaction time of 2.5 h and the dosage of activated carbon particles of 2 g. The applied voltage is the key factor affecting ion removal. When the voltage was 2 V, the ion removal is mainly due to the synergistic effect of chemisorption and electrosorption. The CN
−
, SCN
−
, and metal cyanide complex anions in wastewater migrate to the anode of coal-based anode and particle electrode rapidly under the combined action of electric field and magnetic stirring. On the surface of porous coal-based electrode, the removal of CN
−
, SCN
−
was mainly attributed to the oxidation of oxygen evolution from the anode reaction, while the removal of Cu, Zn and other metal ions was mainly by the electrodeposition process on the cathode surface.