Abstract: A method and apparatus for the oxidation of liquid or solid contaminants in the exhaust gas from diesel engines is provided. The process is conducted by passing the contaminated diesel engine exhaust gas through a turbulent gas flow, particulate separator, wherein this separator contains a plurality of separate and serially-arranged vertical plates arranged so that there is no net gas flow in the space between two adjacent vertical plates. The plates contain a catalytically active surface of (i) a mixture of metal salts and/or metals oxides, such as a mixture of the oxides of vanadium, molybdenum and alkali metals, which may be in a molten state at the operating temperature of the separator and (ii) one or more catalytically active metal or metal compounds to promote the oxidation of soot, such as metals or metal compounds of iron, platinum and palladium.