| 摘要 |
PURPOSE:To make cyanides harmless by adding a polysulfide to cyanide-containing waste water followed by a biological treatment. CONSTITUTION:In the first place, cyanides are converted lnto thiocyanates of low toxicity by the addition of a polysulfide to cyanide-containing waste water in the first process, and then the thiocyanates formed are treated biologically in the addition of organic nutriments to the thiocyanates-containing liquid in order to make them harmless completely in the second process. The preferred amount of polysulfide to be added in the first process is equivalent or more of cyanogen ion (CN<->) present in the waste water and the kinds of the organic nutriments used in the second process include acetic acid and 4 or less carbon alcohols, ketone, or alkylamines. Also, the preferred pH range of biological treatment is 5.5-7. |
