Nutrient Recovery from Slaughterhouse Wastewater

Poultry slaughterhouse wastewater commonly contains high concentration of NH⁴⁺ and PO^43-. These nutrients can cause eutrophication and unpleasant odor problem if untreated properly. By adding some minerals, the nutrients can be recovered in the form of immiscible powder called struvite. Struvite precipitation process for nutrients recovery from waste sources is beneficial not only providing slow-releasing and high-quality fertilizer but also reducing soil and water pollution from rich-nutrients wastewater. Three parameters in struvite precipitation will be observed in this study which are pH, temperature, and PO^43-/Mg²⁺ molar ratio. The optimum conditions obtained based on the highest removal efficiency of phosphate (99.3%) and ammonium (98.1%) are PO^43-/Mg²⁺ ratio of 1:3; pH of 9.0; and temperature at 30°C. Meanwhile for kinetic study, the temperature increase will reduce the rate constant (k) value, while increasing pH tend to increase k values. The obtained powder of struvite has been confirmed by X-Ray diffraction (XRD) with expected impurity of MgCl₂ due to the excess usage during struvite precipitation process. This study is applicable for wastewater treatment plant which not only treating wastewater but also producing eco-friendly fertilizers.