Treatment of cyanide effluents by oxidation and adsorption in batch and column studies

• Published in: Journal of hazardous materials Vol. 166; no. 2; pp. 1362 - 1366
• Main Authors: Yazıcı, E.Y., Deveci, H., Alp, İ.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 30.07.2009; Elsevier
• Subjects: Activated carbon; Adsorption; Agriculture, rearing and food industries wastes; Air; Air oxidation; Applied sciences; Catalysis; Catalytic reactions; Charcoal - chemistry; Chemical engineering; Chemistry; Cyanide removal; Cyanides - isolation & purification; Environment; Exact sciences and technology; General and physical chemistry; Hydrogen-Ion Concentration; Industrial Waste - prevention & control; Kinetics; Metals - chemistry; Oryza sativa; Oxidation-Reduction; Oxygen - chemistry; Pollution; Reactors; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Wastes; Water Pollutants, Chemical - isolation & purification; Cyanide removal; Environment; Air oxidation; Adsorption; Activated carbon; Carbon dioxide; Adsorption capacity; Rice by product; Sulfates; Vegetal waste; Aeration; Impregnation; Batchwise; pH; Oxidation; Agricultural waste; Aqueous solution; Catalyst
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2008.12.050

In this study the removal of free cyanide from aqueous solutions by air oxidation and adsorption was investigated. Effects of air and pure oxygen, and catalyst on the rate and extent of the removal of cyanide were studied. It was found that the oxidative removal of cyanide by air/oxygen was very limited although it tended to improve in the presence of pure oxygen and catalyst such as activated carbon (AC) and copper sulphate. In the presence of continuous aeration, the non-oxidative removal of cyanide was correlated with a decrease in pH effected apparently by the transfer of carbon dioxide from air phase into the medium. The removal of cyanide by adsorption on activated carbon, nut shell (NS) and rice husk (RH) was also examined. Adsorption capacity of activated carbon was shown to be significantly enhanced via impregnation of activated carbons with metals such as copper (AC–Cu) and silver (AC–Ag). In the column tests, the breakthrough capacity of adsorbents was found to be in an increasing order of RH < AC < AC–Cu << AC–Ag.