Bright field versus phase contrast microscopy in activated sludge image acquisition methodologies

Abstract

Monitoring activated sludge processes by microscopic observations and image analysis methodologies is a well established technique with the utmost importance for microbial community characterization. Furthermore, image processing and analysis is currently considered a powerful tool to identify and quantify biomass morphological and physiological changes. In the present work, image processing and analysis methodologies were used to determine aggregates and protruding filaments contents and morphology using both bright field and phase contrast microscopy. The obtained results showed that the simpler and less expensive bright field microscopy also provided the best overall results.