Enhancement of the biodegradability of wastewater containing recalcitrant or inhibitory chemical compounds by photocatalytic pre-oxidation

Industrial wastewater often contains chemical compounds that are either recalcitrant or inhibitory to microorganisms found in conventional biological treatments. mDinitrobenzene, diphenylamine and resorcinol are among such organics. These compounds are regulated in Ontario, Canada, and two of them, diphenylamine and resorcinol, are also regulated under the Resource Conservation and Recovery Act of the USA. To meet North American regulations, these compounds may have to be degraded. Consequently, chemical treatments such as photocatalysis, ozonation, UV-peroxide or Fenton’s reagent could be utilised to degrade these regulated organics to enhance the biodegradability of water in which they are found [1–5].