Tratamiento terciario de agua residual post-vermifiltración mediante humedal artificial y análisis del vermicompost del lecho del vermifiltro

Abstract

Freshwater, constituting only 2% of the total available, is affected by the inadequate management of wastewater, necessitating the development of effective and sustainable treatments. Non- conventional systems, such as vermifilters and artificial wetlands, stand out for their low cost, reduced demand for specialized labor, and sustainability. This study aims to employ an artificial wetland as a tertiary treatment for wastewater following vermifiltration, focusing on the removal of coliforms and amoebas. Weekly sampling was conducted over six weeks at two points: the outlet of the vermifilter and the outlet of the wetland. Total coliforms, fecal coliforms, and amoebas were analyzed using culture techniques and microscopic observation. Additionally, the quality of the vermicompost was evaluated based on eight parameters, comparing them with the Chilean Standard NCh 2880. The results indicated that the wetland achieved a 100% removal of amoebas but did not eliminate total and fecal coliforms. The vermicompost met seven out of the eight quality parameters analyzed, although the presence of fecal coliforms limits its use in agriculture. Therefore, the use of lime or increased temperature is recommended to improve the quality of the vermicompost. Furthermore, it is suggested to investigate the optimal hydraulic retention time to maximize coliform removal in both systems and ensure more efficient treatments.