Phosphorus Recovery from Manure By Thermochemical-Biological Process

Phosphorus is an essential nutrient and fertilizer component to support the plant growth, but excess concentration of phosphorus in the animal manure can cause phosphorus accumulation in the soil and water eutrophication. This study investigated the phosphorus recovery from manure via several processes with different combinations of multiple conversion steps, including a thermochemical pretreatment, an anaerobic digestion and a fungal cultivation for phosphorus accumulation. In the first step, animal manure was thermochemical pretreated or partial anaerobic digested to release orthophosphate and sugars. The effects of pretreatment temperature, time, catalyst type and loading on orthophosphate and sugars release were studied. Then, a fungal strain (Mucor circinelloides) with high phosphorus accumulation capability was cultured in the pretreated manure or digested manure to form biological phosphorus fertilizer and the factors that affect phosphorus removal and storage by fungi were studied.