Research Of Treatment Techniques To Alkali Decrement Waste Water

The process of alkali decrement to terylene is an important means to improve the touching feeling and pendency, etc. of terylene. But in the process, a great deal of waste water will be produced. In our country, the yield of terylene is huge, the output in 2004 is 14,300,000t. If all the terylene is decreased by alkali, there will be 715,000~2,860,000t waste materials in the remained liquid to come into the sewage system. These waste materials will make it very difficult to deal with the sewage. It will badly pollute our environment if it can not be treated properly.The primary controlling is introduced in this paper. The waste water produced in the alkali decrement to terylene is treated by itself. Then the treated water of low concentration comes into the treating system of dyeing waste water to be treated again. By this way, we get distinct effect that the letting indexes of waste water accord with the first national standard.Following is the means: the waste water of high concentration is trimmed by adding H2SO4 so that the vs-benzene-twain-armouracid-natrium in the waste water turns into vs-benzene-twain-armouracid which is deposition. And it will greatly decrease the COD_Cr in the water to get rid of the deposition. Then this part of water may come into the treating system of dyeing waste water to be treated by normal treatment of biochemistry and mixing coagulating, etc.. And the effluent water met with the first grade in GB4287-92 at last.