The invention relates to a device for optimized control over 
carbon source feeding in a 
denitrification biofilter process. The device is provided with a 
denitrification biofilter, a 
carbon source box, a frequency-conversion 
carbon source pump, a carbon source flowmeter, a 
backwashing air pump and a 
backwashing air 
inlet valve; the 
denitrification biofilter is internally provided with an online-water-inlet 
nitrate sensor, an online-water-inlet dissolved 
oxygen sensor, an online-water-outlet 
nitrate sensor, a 
nitrate determinator, a dissolved 
oxygen determinator, a process controller, and an industrial 
personal computer; and a water inlet pipeline is provided with a water inlet pump, a water 
inlet valve and an online-water inlet flowmeter. A method for optimized control cover the carbon source feeding is characterized by comprising the following steps of: (1) introducing water; (2) 
processing and judging parameters; (3) 
processing frequency ft by a frequency converter; (4) preventing excessive feeding of a carbon source; (5) stably running; (6) diagnosing faults; and (7) performing 
backwashing. The device and the method disclosed by the invention can be widely applied to 
sewage advanced treatment and nitrogenous 
industrial wastewater treatment, is particularly suitable for producing high-quality recycled water, have the advantages of complete structure, precision for control, good effect and high efficiency.