The invention discloses a separation treatment method for waste water in a
coal tar machining process. The separation treatment method mainly comprises the following steps of: at first, pre-treating the waste water in the
coal tar machining process to remove free oil and
emulsified oil, and then entering a waste mixing groove; secondly, further removing oil matter by filtering and entering a subside for removing depositions through
settling, so as to obtain oil-removed waste water; removing
hydrogen sulfide and amine after the oil-removed waste water enters a
sewage steam stripping
tower, and extracting after acid-removed and amine-removed waste water enters an extraction
tower; recovering crude carbolic acid and an extracting agent after an extract phase enters a
phenol tower; separating the extracting agent from water after a residual extract phase enters a water tower; and
processing after the water enters a follow-up biochemical
system. The separation treatment method provided by the invention firstly removes acid and
anime of the waste water, provides a good acid-alkali condition for follow-up
solvent extraction and dephenolization, and has no need of adding a great amount of the acid and alkali in a treatment process. Meanwhile, byproducts, such as the crude carbolic acid, the
anime, the
hydrogen sulfide and the like, can be recovered. The
water quality of the treated waste water can meet the water inlet requirements of the normal biochemical treatment.