Method for measuring biodegradation rate of contaminants in urban river

The invention discloses a method for measuring the biodegradation rate of contaminants in an urban river. The method specifically comprises the following steps of selecting the urban river which is 100-200 m long and does not have tributary afflux as a test river section, and measuring the length L, average flow velocity v, flow rate Q, depth d, wet perimeter w and conductivity value of the riversection; simultaneously measuring background values of concentrations of the target contaminants and non-biodegradable tracing ions in the river; adding the target contaminants and substances containing the tracing ions into a container to be dissolved, and then putting a mixture into the river from the upstream portion; measuring the conductivity of river water at the downstream portion of the river section, and conducting sampling once very 30-150 s; when the conductivity returns to the background value of the conductivity, ending the test; calculating the biodegradation rate E of the targetcontaminants by the urban