Health & Environmental Research Online (HERO)


Print Feedback Export to File
6021172 
Journal Article 
Method for Clarifying Aqueous Waste Liquids Containing Acid Dyes 
Kuwabara, K; Nakajima, M 
1978 
A method is provided for clarifying aqueous waste liquids containing acid dyes. The optimum amount of the dicyandiamide-formaldehyde resin and at least about 300 ppm, preferably at least about 350 ppm, of aluminum sulfate, both based on 100 ppm of the dye in the waste liquid, are added sequentially. There is no limitation in the order of adding them , but either can be added first. For example, the above resin is added to the waste liquid whose pH has been adjusted to a desired value, preferably an acidic region of not more than 7, in the course of conducting the waste liquid to a sedimentation apparatus or filtration apparatus, and the mixture is stirred so as not to cause non-uniformity in concentration. This results in the formation of a flocculated matter. Then, aluminum sulfate is added, and the mixture is stirred somewhat slowly. The flocculated dye can be sedimented or collected by filtration. Conversely, aluminum sulfate can be added first and then the resin. (Sinha-OEIS) 
Water Resources Abstracts; Patents; Waste water treatment; Industrial wastes; Water purification; Separation techniques; Chemical precipitation; Flocculation; Filtration