Influence of sulfide concentration and macronutrients on the characteristics of metal precipitates relevant to metal recovery in bioreactors

► Sulfide and wastewater composition govern kinetics and mechanisms of metal removal in bioreactors. ► Biosorption and precipitation with macronutrients are alternative mechanisms. ► XAS is a useful technique for the identification of poorly crystallized metal sulfides. ► Agglomeration of metal sulfides is important for particle growth and settling.