Coal-containing wastewater treatment system and process

The invention provides a coal-containing wastewater treatment system and process. The system comprises a pre-sedimentation tank, a wastewater adjusting tank and a membrane filter which are connected in sequence, the wastewater adjusting tank is provided with a dosing device; and the membrane filter is provided with a cleaning device. The treatment system disclosed by the invention is wide in filtering range, solids in filtered liquid can be effectively removed from 20 ppm to 10000 ppm, and the filtrate is clear; the membrane filter performs low-pressure filtration under the operation pressure of 0.07-0.1 MPa, so that the filtration resistance is small, and the operation energy consumption is low; the automation degree of the treatment process is high, the membrane filter has the characteristics of automatic backwashing and continuous filtration, the automatic backwashing process is controlled by a computer program, the filter membrane can be automatically backwashing in a short time (several seconds), and the