The application provides a
system and method for treating
wastewater by using
flue gas CO2 and electrochemical dehardening and sterilization, wherein the
system comprises an electrochemical treatment device, an ultrasonic descaling device, a conical
sedimentation tank and a
flue gas treatment device. The electrochemical treatment device is internally provided with a
cathode and an
anode; the ultrasonic descaling device is installed in the electrochemical treatment device; the conical
sedimentation tank is located below the electrochemical treatment device, and is internally provided with an inclined tube
clarifier and is provided with a residue
discharge port at the bottom; and the
flue gas treatment device comprises a
flue gas pipe and a fan, the
flue gas pipe is connected to the fan and extends into the lower part of the electrochemical treatment device, and a plurality of
aeration holes are formed in the
wastewater contact section of the
flue gas pipe. The
system can quickly and efficiently supplement CO3 2‑ in the
wastewater on the one hand, and can maintain the
water quality of the electrochemical
treatment system in weak acidity, so that a
high concentration of HClO is generated in the water, thereby having a significant sterilization effect. 2+ The system can improve the Ca 2+ and Mg
precipitation removal effect of the wastewater, and can maintain the
water quality of the electrochemical
treatment system in weak acidity, so that a
high concentration of HClO is generated in the water, thereby having a significant sterilization effect.