The present invention discloses a three-stage biological comprehensive treatment method for
printed circuit board (PCB) waste water. The method comprises a three-stage biological treatment process, and is characterized in that: the method is performed by the following steps that: (1) PCB mixing waste water is poured into a reaction tank 1, the pH value is adjusted to 2.7-3.2 with
sulfuric acid,
ferrous sulfate is added, the waste water is transferred to a
flocculation tank 1, the pH value is adjusted to more than 7 by an alkali solution, a flocculating agent is added to carry out
precipitation, and the waste water and the resulting
precipitation are transferred into a
precipitation tank; (2) the waste water is poured into a
neutralization tank, a
nitrogen source is added, the pH value is adjusted to 6.8-7.2, the resulting waste water enters an
aeration tank to carry out
biodegradation, and flows through a precipitation tank 2; (3) the waste water is poured into a reaction tank 2, the pH value is adjusted to 8.8-9.2, the flocculating agent is added, the waste water is introduced to a precipitation tank 3, and then is discharged. With the present invention, the
grinding plate waste water, the
printing ink waste water, the
copper-containing waste water and the
electroplating waste water can be simultaneously treated, the treatment efficiency of the
organic compound with high complex
copper is high, and the cost is low.