In situ characterizations for EPS-involved microprocesses in biological wastewater treatment systems

Microbial extracellular polymeric substances (EPS) determine the bacterial attachment and structural integration of microbial aggregates, and govern the binding, migration and transformation processes of substrate in extracellular microenvironment. The development of in situ characterization techniques is an interesting research topic to reveal the EPS functions. This review introduces the EPS-involved chemical and biochemical microprocesses in wastewater treatment, and describes the principles, applications, merits and drawbacks of the available in situ characterization techniques in the categories of biosorption and biodegradation of substrates by EPS, attachment kinetics of EPS on surfaces, response of microorganisms to environmental stress, and extracellular mass and electron transfer processes.