Abstract:
This research studied the effects of removal of tetracyanonickelate and hexacyanocobaltate in synthetic wastewater by ferrate oxidation. The experiment were done on synthetic wastewater (tetracyanonickelate, tetracyanonickelate and hexa- cyanocobaltate). It is to study the effect of pH and the increased mole fractions of ferrate per cyanide to both of by products and cyanide complex removal efficiency. From the first part, at the mole fraction of 1:1 ferrate per cyanide, total cyanide removal efficiency was 80-95% at pH 9, 10 and 11. The results indicated that tetracyanonickelate had no effect on cyanide removal efficiency and any mole fractions of ferrate per cyanide, but it retarded the chemical reaction rate. The ferrate molar consumption per oxidized cyanide was 0.99:1. From the second part, at the mole fraction of 1:1 ferrate per cyanide, the mole fraction of 2:1 tetracyanonickelate per hexacyanocobaltate, total cyanide removal efficiency was 55-60% at pH 9, 10 and 11. It was found that hexacyanocobaltate decreased the cyanide removal efficiency and slowed the chemical reaction rate for all pH, but had no effect on the reaction by-product, which was cyanate.