Method and device for detecting COD (chemical oxygen demand) of water body through synergy of ozone and ultraviolet

The invention provides a method and a device for detecting the COD (chemical oxygen demand) of a water body through the synergy of ozone and ultraviolet. The method and the device have the advantages that the COD of the water body is detected by utilizing an ozone-ultraviolet-synergic advanced oxidation technique based on an oxygen consumption difference value theory, so that various organic matters in the water body can be rapidly and thoroughly oxidized and digested within a short time, and the oxidation efficiency is high; the whole measurement process can be automatically controlled by utilizing an automatic technique, and the method and the device are particularly suitable for the online detection of the chemical oxygen demand in environmental water quality online monitoring systems; no chemical reagent is added in the whole oxidative digestion process, so that the secondary pollution is avoided; the measurement method is simple, is easy to understand, is insensitive to the influence of chloride and is a