An evaluation of biological air treatment in combination with physical adsorption as polishing

Although new advanced biotreatment sytems for odor treatment at wastewater treatment facilities have been in operation for many years as proven technology, some extra security is requested at extreme odor sensitive locations or when specific high VOCs removal (e.g. benzene) is required. An evaluation of a biological treatment system combined with adsorption as polishing is tested at two different locations and is used to illustrate the importance of a good design of the biological treatment system when combined with an activated carbon adsorption as polishing. When small molecules like hydrogen sulfide and mercaptans are removed prior to the carbon adsorption, impregnated or catalytic activated carbons are not necessary and virgin (unmodified) activated carbon can be used. Virgin activated carbon gives the advantages that (1) the capacity of organic compounds (VOCs and VOSCs) is undiminished, that (2) it contains no risk for smoldering which is associated with impregnated activated carbons and that (3) its costs per pound is much lower compared to impregnated orpatented catalytic activated carbons.