Sequenced Bioleaching and Bioaccumulation of Phosphorus from Sludge Combustion – A New Way of Resource Reclaiming
The recovery of phosphorus from sewage sludge incineration ash as well as the separation of heavy metals from ash was investigated by using the biotechnological process of bioleaching and bioaccumulation of released phosphorus by newly developed population of bioleaching bacteria, Acidithiobacillus sp. strains, and polyphosphate (poly-P) accumulating bacteria, the AEDS-population (Acidithiobacillus sp. enriched digested sludge). The biologically performed solubilization of phosphorus from sewage sludge incineration ash is accompanied by the release of toxic metals. Therefore a combined process to separate phosphorus from heavy metals by achieving a plant available phosphorus-enriched product and a metal depleted ash was designed. Leaching experiments were conducted in laboratory scaled leaching reactor containing a bacterial stock culture of Acidithiobacillus sp.. Next step was the enhancement of P-recovery in combining bioleaching with simultaneous bio-P-accumulation by AEDS-population. The uptake of phosphorus in biomass reaches up to 66 % of the mobilized phosphorus by bioleaching. The combined biologically performed technology of phosphorus leaching and separation from toxic metals by simultaneous bioaccumulation developed in this study is a promising process for economical and ecological recovery of phosphorus from waste solids.
Edgardo R. Donati, Marisa R. Viera, Eduardo L. Tavani, María A. Giaveno, Teresa L. Lavalle, Patricia A. Chiacchiarini
J. Zimmermann and W. Dott, "Sequenced Bioleaching and Bioaccumulation of Phosphorus from Sludge Combustion – A New Way of Resource Reclaiming", Advanced Materials Research, Vols. 71-73, pp. 625-628, 2009