| 摘要 |
PURPOSE:To extremely reduce the amt. of the effluent to be discharged to the outside of a system by adopting a simple method of neutralizing a waste liquid contg. sulfuric acid and org. matter by a basic calcium compd. and/or basic barium compd. to treat said waste liquid. CONSTITUTION:For example, the waste liquid generated by the reaction to synthesize a diaryl compd. by condensing an arom. compd. and aldehydes in the presence of sulfuric acid; i.e., the waste liquid contg. >=15wt% sulfuric acid and >=0.5wt% water insoluble or hardly water soluble org. matter is treated by the respective following stages: (a) The above-mentioned waste liquid is diluted by the recovered liquid obtd. in the under-mentioned stage (b) to cause a phase separation by which the org. layer is removed and the water layer contg. the sulfuric acid is recovered. (b) The basic calcium compd. (e.g., calcium hydroxide) and/or basic barium compd. (e.g., calcium hydroxide) and/or basic barium compd. (e.g., barium hydroxide) is added to the water layer obtd. in the stage (a) to partially neutralize the water layer and the formed solid content is removed, by which the recovered liquid is obtd. As a result, the amt. of the effluent is decreased. |
