Inactivation of biofilm-bound bacterial cells using irradiation across UVC wavelengths

•UV disinfection of biofilm-bound bacteria was investigated.•5 UV sources were tested emitting at wavelengths from 222 to 282 nm.•UV transmittance and absorbance across the biofilm structure was documented.•UV LEDs emitting at 270 nm provided the best disinfection performance.•Inactivation of biofilm-bound cells was much lower than planktonic cells.