Nitrogen and phosphorus recovery from a piggery wastewater treatment facility

Abstract

The study demonstrated that the aeration of piggery wastewater enhanced the degree of phosphorus and ammonia precipitation (struvite) from the liquid phase. A bench scale reactor was used to evaluate the applicability of the struvite crystallization process to the effluent. The aeration of piggery wastewater leads to decreased phosphorous, ammonia, electrical conductivity and alkalinity due to the precipitation of Ca and Mg phosphate compounds. The degassing process also leads to the volatilization of ammonia and an increase in pH. Therefore, the feasibility of phosphate and ammonia recovery by struvite crystallization in a fluidized bed reactor from the effluent of a piggery waste water treatment facility was discussed. The phosphorous removal efficiency was measured in experiments with varying ammonia concentrations and NH/sub 4/-N/PO/sub 4/-P ratios. At an initial phosphorus concentration range under 40 mg/1 and NH/sub 4/-N/PO/sub 4/-P under 7, the removal efficiency reached about 80% and fine particles were decreased in the effluent.