Process for deeply treating printing and dyeing wastewater by using chlorine dioxide and a coagulating sedimentation technology

The invention discloses a process for deeply treating printing and dyeing wastewater by using chlorine dioxide and a coagulating sedimentation technology. The process comprises the following steps of: biochemically treating printing and dyeing wastewater, firstly oxidizing secondary water by using chlorine dioxide, then carrying out coagulating sedimentation on the secondary water by using a coagulant, and finally adding a flocculating agent and standing for 30min for realizing mud and water separation. According to the invention, pre-oxidization is carried out by using the chlorine dioxide, a microenvironment of partial colloids in raw water can be changed, the destabilization probability is increased, and the treatment effect of coagulating sedimentation is improved. Aiming at the characteristic of difficulty in degradation and discoloring of the printing and dyeing wastewater, the printing and dyeing wastewater is treated by applying a strong oxidant and the coagulant, so that the purpose of deeply treatin