title: Synergistic effect of the presence of suspended and dissolved matter on the removal of cyanide from coking wastewater by TiO2photocatalysis.
abstract: This study assesses the influence of the presence of suspended and dissolved matter on the efficiency of TiO2photocatalysis for the removal of cyanide from coking wastewater. Photocatalytic processes were carried out at basic pH (pH 9) with titanium dioxide (1 g/L), artificial radiation (290-800 nm) and during different time periods (20-100 min). The first assays applied in aqueous solutions achieved promising results in terms of removing cyanide. The maximum cyanide removal obtained in coking wastewater was 89% after 80 min of irradiation in the presence of suspended and dissolved matter. The presence of suspended matter composed of coal improves the efficiency of the photocatalytic process due to the synergistic effect between carbon and TiO2. The absence of dissolved matter also improves the process due to the minimization of the hydroxyl radical scavenging effect produced by carbonate and bicarbonate ions. On the other hand, the presence of certain species in the real matrix such as silicon increases the activity of the titanium dioxide catalyst. In consequence, the improvement achieved by the photocatalytic process for the removal of cyanide in the absence of dissolved matter is counteracted.
authors: a Department of Chemical Engineering and Environmental Technologies , University of Zaragoza , Zaragoza , Spain.
authors: Noelia
authors: N
authors: Pueyo
authors: a Department of Chemical Engineering and Environmental Technologies , University of Zaragoza , Zaragoza , Spain.
authors: Natividad
authors: N
authors: Miguel
authors: a Department of Chemical Engineering and Environmental Technologies , University of Zaragoza , Zaragoza , Spain.
authors: Rosa
authors: R
authors: Mosteo
authors: a Department of Chemical Engineering and Environmental Technologies , University of Zaragoza , Zaragoza , Spain.
authors: José L
authors: JL
authors: Ovelleiro
authors: a Department of Chemical Engineering and Environmental Technologies , University of Zaragoza , Zaragoza , Spain.
authors: María P
authors: MP
authors: Ormad
mesh_terms: D002384:Catalysis; D003077:Coke; D003486:Cyanides / Q000737:chemistry*; D006801:Humans; D007220:Industrial Waste; D010782:Photolysis; D014025:Titanium / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D003077:Coke; D003486:Cyanides; D007220:Industrial Waste; D014025:Titanium; D062065:Wastewater; D014874:Water Pollutants, Chemical; C009495:titanium dioxide
keywords: Activated carbon; coking effluent; cyanide; inorganic anions; photocatalysis; titanium dioxide