Application of Diatomaceous Earth for Fecal Coliform Reduction in Sediments and Its Agricultural Benefits

This study highlights the potential of diatomaceous earth to eliminate pathogenic microorganisms from canal sediments used in agricultural irrigation. The findings demonstrate both technical feasibility and economic benefits for agriculture, particularly in regions where such irrigation practices are common. The research incorporates three distinct projects. The first involved monitoring water and sediment quality in the Xochimilco canal zone in Mexico City. The other two were experimental studies aimed at assessing the efficacy of diatomaceous earth in reducing fecal coliforms in sediments. The first project evaluated the water and sediment quality. Subsequently, an experiment was conducted in the San Gregorio Atlapulco chinampa, where diatomaceous earth was applied to a coriander crop to measure its effectiveness in reducing fecal coliforms. A laboratory experiment at the Institute of Engineering, UNAM, tested the impact of diatomaceous earth on sediments from a Xochimilco canal, focusing on fecal coliform reduction. In all experiments, diatomaceous earth was utilized in its commercial form. The results of the first project identified wastewater discharges as the primary source of pathogenic contamination in the canals. The second demonstrated a significant reduction—over 70%—in fecal coliforms within a crop after the application of diatomaceous earth. Similarly, the third project achieved an average fecal coliform reduction of 70% in sediments during laboratory testing. The study underscores the affordability and accessibility of diatomaceous earth for local agricultural producers. Moreover, its application does not adversely affect soil quality or crop productivity, further supporting its viability as a sustainable solution for improving irrigation water quality.