Abstract: Hydrogen sulfide, mercaptans, corrosion and odor are treated through either a single phase gas treatment, a single phase liquid treatment or a multiphase (liquid and gas) treatment via an application of a gas infused liquid, oxidizing agents, and/or liquid bacterial formulations within a structure or within an external treatment chamber or pipe. An apparatus for treatment of an exhaust gas specifically to mitigate or eliminate H2S, mercaptans, corrosion, and odor includes means for introducing an oxidizing liquid, an oxidizing gas, or an oxidizing gas and liquid into an external treatment chamber or pipe whereby the introduced agent interacts with the exhaust gas to mitigate or eliminate its effect.