Microbial fuel cell enables phosphate recovery from digested sewage sludge as struvite.

Orthophosphate was mobilized from iron phosphate (FePO(4)) contained in digested sewage sludge by microbial fuel cell power. FePO(4) was reduced through electrons and protons obtained from metabolic activity of Escherichia coli. The process yielded up to 82% or 600 mg/l.