Sunshine and a pinch of tropical soils: A natural, low-cost photo-Fenton variation for safer water, assisted by H2O2 or percabonate

•Solar water disinfection (SODIS) of E. coli was greatly enhanced by adding ferruginous soils.•Low [H2O2] or [percarbonate] drove a cheap and effective photo-Fenton (pF) process.•Iron storage conditions (acidity, ligands) highly improved the pF process at neutral pH.•pF with percarbonate with soils was not severed in natural (alkaline) water disinfection.•This natural-driven heterogeneous pF reduces the need for Fe2+ salts in challenging contexts.