Study on Treatment of Direct Violet Dyeing Wastewater by Ozonation Process

Direct violet dyeing wastwater was treated by ozonation process.Effects of reaction time,dosage of ozone,and original pH on COD and color removal rate were investigated.The results indicated that during the ozonation process,COD removal rate increased with the increasing of ozone dosage,and increased firstly and then reduced with the increasing of reaction time and original pH;color removal rate increased with the increasing of ozone dosage and reaction time,increased firstly and then declined slightly with the increase of original pH.When initial pH was 10,dosage of ozone at 35 μg/L and ozonation reaction time for 7 min,the removal rate of COD and color was 92.8% and 98.3%,respectively.