Tratamiento de lodos procedentes de la planta de tratamiento de aguas residuales de la parroquia de Pifo mediante la técnica de compostaje

Abstract

The aim of the current research was based on the treatment for the wastewater sludge generated by “Barrios Pifo” Wastewater Treatment Plant (WWTP), located in Pifo Parish, Quito - Ecuador; this was carried out through a composting process in order to establish an Initial Environmental Review (IER). For the IER, a description of the operational aspects of the facilities was carried out, as well as a characterization of wastewater and sludge. The analyses involved physical-chemical, chemical and biological parameters, obtaining highly-variable results during the sampling process, which reflected inconsistency over time for the removal of pollutants in most of the facilities. For the composting process, sludge from the "Barrios Pifo" WWTP was used, where 2.4 tons/month of waste is generated; in addition, barley residue was used as structural material. Two windrow piles were made, containing 35% sludge residue and 65% barley residue, 45% sludge residue and 55% barley residue, respectively. The compost obtained revealed a considerable decrease in organic matter, which caused an increase in pH and EC, as well as a significant reduction in the C/N ratio and phytotoxicity. Nutrients and heavy metals were within the limits established by European and American guidelines; in addition, a germination index > 50% was also obtained. Thus, concluding that the sludge-derived compost is a material with a high nutrient content, free of potentially toxic compounds that can be used in agricultural soils. It is recommended to implement projects involving the use of compost from sewage sludge from degraded soils in the area.