The present invention relates to the technical field of printing and
dyeing wastewater treatment, and specifically discloses a method for treating
vat dye wastewater, comprising the following steps: subjecting the
vat dye wastewater to an electroflocculation treatment, sequentially adding an adsorbent and a hydroxy
silicone oil emulsion to the treated wastewater for
flocculation and
precipitation treatment in stages; wherein the adsorbent is diatomaceous earth or diatomaceous earth modified with an aminosilane
coupling agent. The method for treating
vat dye wastewater provided by the present invention utilizes a diatomaceous earth adsorbent in conjunction with a hydroxy
silicone oil emulsion to promote the adsorption,
coupling, and re-
flocculation of flocs generated by the electroflocculation reaction, effectively enhancing the structure of the flocs, increasing the
specific gravity of the flocs, increasing the
flocculation speed, and shortening the
sedimentation time, thereby significantly improving the
treatment effect and efficiency. The national emission standards can be met through simple
filtration, and the process is simple, does not require special equipment, is low in cost, has high applicability, does not cause secondary
pollution, and has high practicality.