There are provided methods for treating a gas having an undesirable odor. The methods comprise contacting the gas with an acidic aqueous oxidizing composition having a pH of about 2.0 to about 3.0 and comprising at least one cation of a metal a sequestering agent and H2O2 and submitting the gas and the composition to UV radiation when the gas and the composition are contacting each other, wherein the treatment permits to reduce by at least 60% intensity of the undesirable odor.
