Waste Phosphorus Recovery and Re-Use

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The fundamental studies of crystallization engineering and biomineralization processes inspire new approaches to creating sustainable strategies to reduce waste and create useful products. This proposal addresses the large problem of waste phosphorus, and aspires to address it with bio-inspired engineering processes. Our agricultural productivity is reliant on mineral fertilizer. Phosphorus (P) is one of the important mineral fertilizers. There is currently one source for the majority of P-fertilizer production. This source is phosphate rock, which is produced over millennia by the action of certain marine bacteria, and ancient skeletal beds. After use as a fertilizer, P can become a pollutant, causing eutrophication when P-runoff from agricultural fields and manure from livestock farms accelerates algal growth. This proposal seeks to capture P effluents in agricultural run-off and wastewater, and to create sustainable, useful P-fertilizer Most municipalities avoid contaminating local waters with P from sewer wastewater by fixing P in municipal wastewater treatment plants. This is accomplished by adding soluble iron chloride, which makes insoluble iron phosphate. This insoluble iron phosphate is a component of the biosolids produced by wastewater treatment plants that are either landfilled or carefully applied to some agricultural fields. Unfortunately the insoluble P is not taken up by plants, which means that we have a one-pass use of P, from mined phosphate, to fertilizer, to a pollutant. The goal of this work is to recover P from waste produced by municipal wastewater treatment plants, dairy cattle complexes, breweries, and dairy producers, and use our understanding of biomineralization processes to produce a useful P-material that is similar to the biomineral that we mine to produce P-fertilizer. The inspiration for the underlying chemistry for this work arose from studying the genesis of skeletal mineral formation. The complex skeletal biomineralization problem is still unsolved; continued investigation of how biology creates useful phosphate minerals may generate new engineering strategies for waste phosphate capture and re-use.