Investigation On Dye Wastewater Treatment With Improved Internal Iron Electrolysis Method

The printing and dyeing wastewater has characteristics of high concentration of organic substance, high alkalinity, high chroma, variation of water quality and weak biochemical treatability.It is a kind of wastewater which is hard to be treated.The traditional and the improved iron-carbon internal electrolysis methods have been used to treat the acid red GR simulant dyeing wastewater in this paper.The iron-carbon internal electrolysis method has been used to treat the acid red GR simulant dyeing wastewater.The influence of the factors such as the iron dosage, the iron/carbon quality ratio, the pH value and the reaction time has been investigated.The results show that the feasible condition is that the iron dosage is 0.8g/L, the iron/carbon quality ratio is 5:3, the pH value is 5, and the reaction time is 40min. The removal efficiency of chroma can reach 80%. And the static displace method shows the order of the factors to the removal efficiency is reaction time>iron dosage>pH value.One of the improved methods is the catalyzed iron internal electrolysis method. The main improved aspect was replacing carbon with copper. The method has been used to treat the dyeing wastewater. The influences of the factors such as the Fe dosage, the iron/copper quality ratio, the pH value and the reaction time have been investigated. The results show that the feasible condition is that the iron dosage is 0.8g/L, the iron/copper quality ratio is 5:1, the pH value is 6.5, and the reaction time is 20min. The removal efficiency of chroma can be above 90%. And the static displace method shows the order of the factors to the removal efficiency is iron dosage>reaction time>pH value.Another improved method is the salt-added iron-carbon internal electrolysis method, which is adding salt on the base of the iron-carbon internal electrolysis method.The aluminum sulfate,ferric sulfate,calcium chloride and ammonium chloride have been investigated. The result shows that adding ferric sulfate and calcium chloride to the iron-carbon system is feasible.