The sludge after drying and pressure filtration is transported for landfill or mixed with coal for combustion. The clear water overflows from the lower regulating plate and enters the biochemical treatment module through the pipeline. The water treated by biochemical treatment meets the standard for discharge or recycling. The process adopts a simple and efficient activated sludge method and improves the removal rate of suspended solids by adding chemical precipitation. The activated sludge method has strong shock load resistance, high organic matter removal rate, and stable and reliable treatment effect. The aeration system adopts the push flow underwater aerator developed by our company, which has significantly better aeration effect, land occupation, noise, power consumption, and operation and maintenance than other aeration equipment. Overall, the mixed wastewater can be fully guaranteed to meet the discharge standards through the above treatment.