Enhanced Biological Wastewater Treatment to Produce Effluents Suitable for Reuse

Abstract

Enhanced performance of biological processes for xenobiotic removal in municipal and industrial wastewater treatment plants can be achieved by adopting the following general strategies based on different principles of operation: increase of the biomass concentration (i.e., using biofilm, immobilized cell, and granular sludge reactors); dynamic operating conditions able to modify the biocenosis composition and to induce alternative metabolic pathways required by xenobiotic biodegradation; two-phase systems, which optimize the substrate delivery to the microorganisms on the basis of their metabolic demand; and combined treatment processes utilizing synergistic physical/chemical methods. In this chapter, the three following strategies for enhancing the biological process are presented and discussed: • Addition of adsorption or absorption media • Advanced oxidation processes: UV and UV/H2O2 • Bioreactors operated with attached and granular biomass The proposed alternatives have been chosen as representative examples of promising technological solutions still under investigation. For each alternative a short presentation including the principle of operation, the realized applications and potentialities, as well as a case study is reported.