三种混凝剂处理大红染料废水的脱色研究

用投加化学混凝剂的方法处理直接耐晒大红染料废水,讨论了不同种类的混凝剂、混凝剂的投加量和废水的pH值对色度去除率的影响。试验结果表明：在硫酸亚铁、氯化铝、氯化铁3种混凝剂中,硫酸亚铁的脱色效果最好,在最优化条件下（pH值为8,投加量为300 mg/L）,达到最高色度去除率94.0%。并且得出氯化铝、氯化铁的最佳pH值范围分别为：5～7、6～8,最佳投加量分别为25、250 mg/L,相应的脱色率分别是79.4%、88.0%。其中,氯化铝投加量极少,有利于节约成本。

Decolorization of direct fast scarlet dye wastewater by three kinds of coagulants

Using chemical coagulants to treat direct fast scarlet dye wastewater, the effects of coagulant type, coagulant dosage and pH value on the chroma removal were discussed. The results of the test showed that： among the three kinds of coagulants： FeSO4, A1C13 and FeC13, FeSO4 is the one who had the best decolorization performance. Under the optimal condition（pH value was 8, coagulant dosage was 300 mg/L）, the decolorization rate by FeSO4 reached the maximum： 94.0%. Besides, the optimal pH value for AlCl3 and FeCl3 treating direct fast scarlet dye wastewater were determined as 5 - 7 and 6 - 8 respectively, the optimal dosage of the two agents were 25 and 250 mg/L respectively, and the corresponding decolorization rates reached 79.4% and 88.0% respectively. It could be seen that, AlCl3 was helpful to the cost saving for its very low dosage.