Reasearch On Treatment Of Cyanide-containing Washing Wastewater Of Blast Furnace Gas

In the paper,the main current methods for the treatment of cyanide-containing wastewater were introduced and several perspectives about these methods were suggested.Some treatment methods for the cyanide-containing washing wastewater of blast furnace gas,such as peroxide oxidation,activated carbon adsorption,calcium hypochlorite oxidation and some united methods as peroxide oxidation- activated carbon adsorption and ferrous sulphate deposition-calcium hypochlorite oxidation were researched in the paper.The technological conditions for treatment of these methods were obtained by single factor experiment. The test results would be applied to the dynamic processing.After the dynamic processing,the CN- concentration was lower than 0.5 mg/L.Peroxide oxidation has a good result on cyanide-containing wastewater treatment.Trough the single factor experiment,the result shows the best optimum conditions were that when peroxide of 30% concentration dosage was 22mL/L, initial pH was 10 and the reaction time was 15 minutes, the wastewater of the total cyanide was 201mg/L was treated.After treatment,the total cyanide concentration was 5.70mg/L.The single-step removal rate of total cyanide were 97.29%.After was treated by this method,the treated wastewater can't meet the discharge standard,but the remains were just the easily liberated cyanide, and the ferricyanide meet the discharge standard.Activated carbon adsorption can be better to remove the simple cyanide ,and has a good reslut on the low concentration of cyanide-wasterwater treatment. Trough the single factor experiment,the result shows the best optimum conditions were that when the amount of carbon added was 1g/L,reaction pH was 8,and the reaction time was 9h, the wastewater of the total cyanide was 5.70mg/L was treated by activated carbon.After adsorption,the total cyanide concentration was 0.41mg/L,and the removal rate was 92.5%.Ferrous sulphate deposition has a good result on cyanide-containing wastewater treatment. Trough the single factor experiment,the result shows the best optimum conditions were that when ferrous sulfate dosage was 2.5 times as the theoretical, the initial pH was 6 and the reaction time was 30 minutes, the wastewater of the total cyanide was 201mg/L was treated.After treatment,the total cyanide concentration was 8.15mg/L.The single-step removal rate of total cyanide were 95.52%. After was treated by this method,the treated wastewater can't meet the discharge standard,but the remains were just the easily liberated cyanide, and the ferricyanide meet the discharge standard.oxidation can be better to remove the simple cyanide ,and has a good effect on the low concentration of cyanide-wasterwater treatment. Trough the single factor experiment,the result shows the best optimum conditions were that when calcium hypochlorite dosage was 3 times as the theoretical, pH was 10 and reaction time was 30 minutes, the wastewater of the total cyanide 8.15mg/L was treated by calcium hypochlorite.After treatment ,the total cyanide concentration was 0.38mg/L,and the removal rate was 95.34%.The high concentration cyanide-containing washing wastewater of blast furnace gas Peroxide can be cost-effective and dynamic continuous treated by oxidation-activated carbon adsorption and ferrous sulphate deposition- calcium hypochlorite oxidation method.The test results of static experiment would be applied to the dynamic processing.After the dynamic processing,the CN- concentration was lower than 0.5mg/L.After was treated by this method,the treated wastewater meet the discharge standard.