Results are presented from investigations of multispark electric discharge in water excited along multielectrode metal-dielectric systems with gas supply into the interelectrode gaps. The intensity distribution of discharge radiation in the region covering the biologically active soft UV (190⩽λ⩽430 nm) has been determined and the absolute number of quanta in this wavelength interval has been measured. The potentiality of the slipping surface discharge in water for its disinfection is analysed. The energy expenditure for water cleansing is estimated to be as low as ~10-4 kWh l-1.

The UV-spectrum of a high-current slipping surface discharge radiation has been investigated experimentally by means of a liquid chemical actinometry technique. The photon fluxes emitted in the hard UV ( <190 nm) and soft UV (190 nm< <430 nm) regions were determined by the H2 O2 yield in irradiated distilled water and by the Fe II yield in an irradiated solution of K3 Fe(C2 O4 )3 , respectively. The results obtained lead to the conclusion that the spectrum differs from the Planckian one by the presence of an `enriched' short-wavelength ( <190 nm) component.