Black Soldier Fly-based bioconversion of biosolids creates high-value products with low heavy metal concentrations

•Black Soldier Fly larvae convert biosolids into protein- and fat-rich biomass.•Efficient reduction of biosolids substrates of < 40% within 20 days.•Heavy metals from biosolids get partitioned into residues but not mature larvae.•Heavy metals in larvae that fed on biosolids blends is below limits for animal fodder.•Substrate bioconversion is affected by volatile solids content, Mg, Mn, pH, and Ca.