Managing Dewaterability, Pathogen and Heavy Metal Content in Sewage Sludge Using Fenton's Reagent

Fenton's Reagent generates reactive and oxidising hydroxyl radicals that have a major impact on the properties of sewage sludge. Legislation in many areas is becoming tighter as regards heavy metal concentrations and pathogen content, which may have a considerable impact on our ability to recycle biosolids to agricultural land in the future. Improving sludge dewaterability is increasingly important to reduce transport costs, a problem exacerbated recently due to the increased production of secondary sludge. Fenton's Reagent was shown to improve dewaterability, reduce pathogen levels and significantly reduce levels of certain metals (Cu, Zn, Cd, Ni) in raw primary and activated sewage sludge. The presence of iron was shown to be crucial in the Fenton's treatment process with sludge containing low iron levels responding poorly compared to those with high iron levels, unless additional iron was supplemented to the system