Biological contact oxidation is an efficient treatment process for purifying organic wastewater, primarily using biofilm attached to a carrier (commonly known as filler). Currently, it has been widely applied in the treatment of textile printing and dyeing, wool spinning and knitting, beer and food, petrochemical and fertilizer wastewater, medical and domestic sewage, etc., achieving significant environmental, social, and economic benefits. In recent years, with the increase in water demand and the fact that surface water such as rivers and lakes has been polluted by organic matter to varying degrees, the contact oxidation process has been adopted for treatment. For many years, this process has been widely adopted by design departments and favored by users due to its unique advantages such as high efficiency, energy saving, small footprint, impact load resistance, and convenient operation and management.