Recuperación de nutrientes en forma de estruvita a partir del agua residual generada en campus universitarios: caso de estudio Universidad Autónoma de Occidente

Abstract

Wastewater has a high potential for use, because it derives highly utilizable resources such as water, nutrients, sludge and energy. Thus, in this degree work, the potential for the recovery of nitrogen and phosphorus in the form of struvite was evaluated, based on the chemical treatment of wastewater. The project had an experimental stage on a laboratory scale in which conditions necessary to promote struvite precipitation, such as the dose of precipitating reagent (MgCl2) and the reaction pH were evaluated and analyzed, from the treatment of two types of wastewater samples, which corresponded to raw wastewater (ARC) and treated wastewater (ART) from the wastewater treatment plant of the Universidad Autónoma de Occidente. The analysis of the struvite recovery potential showed that from the treatment of 1.0 m3 of ARC it is possible to obtain 62.36 ± 23.21 g of struvite and from the ART 22.57 ± 5.72 g, considering the available phosphorus in wastewater as limiting reagent reaction. From the operational conditions evaluated, it was found that for the tests with pH adjustment of reaction and without external source of magnesium, those that presented a better response in terms of reduction of particulate material, dissolved material, and nutrients, were for a pH of reaction of 11,48 and 11,39 units for the ARC and the ART respectively. For the tests with external source of magnesium and pH adjustment of reaction, it was found that the operational conditions with a better response in terms of reduction of particulate material, dissolved material and nutrients, were for the ARC with a magnesium chloride dose of 131,7 ppm and reaction pH of 9,32 units, and for the ART a dose of 15,9 ppm magnesium chloride and reaction pH of 9,33 units