Biological clogging of geotextiles under discontinuous fermentation scenario

This article presents the effect of biological clogging on the hydraulic performance of geotextiles used for the construction of filter and drainage in landfills. Clogging tests were performed on specimens of woven and non-woven geotextiles in a discontinuous fermentation scenario using natural leachate and a nutrient solution. The consequences of biological clogging were assessed through experimental measurements of changes in the cross-plane hydraulic conductivity and the impregnation ratio of different geotextiles specimens at different immersion times. Porosity reduction was then back-calculated from the hydraulic conductivity results using the Kozeny-Carman equation. Additionally, the impact of an antibiotic and antifungal solution on biofilm development was evaluated. It was demonstrated that the cross-plane hydraulic conductivity of geotextile specimens decreases as biomass accumulation per unit area increases with immersion time. The application of an antibiotic and antifungal solution resulted in a porosity recovery of over 90% and a hydraulic conductivity recovery ranging from 78 to 83% for both woven and non-woven geotextiles. These results demonstrate that the clogging was primarily due to biological activity. Despite certain limitations in measurement and definition, the impregnation ratio proved to be a reliable parameter for the evaluation of biological clogging.