Moving bed biofilm reactor technology in municipal wastewater treatment: A review

The review encompasses the development of municipal wastewater treatment process using MBBR from early stages, established application, and recent advancements. An overview of main drivers leading to the MBBR technology development over its early stage is discussed. Biocarriers types and features together with biofilm development and role of extracellular polymeric substances (EPS) are presented, ultimately, addressing the challenge in decreasing startup time required for full operation. Furthermore, the review investigates the state of the art of MBBR technology for nutrient removal (i.e., COD and BOD, nitrogen and phosphorus) through process functionality and configuration of established (e.g., IFAS) and under development (e.g. PN/A) applications. Reactor operational characteristics such as filling fractions, mixing properties, dissolved oxygen requirements, and loading rates are presented and related to full scale examples. Current literature discussing the most recent studies on MBBR capability in reduction and removal of chemicals of emerging concern (CEC) released is presented. Ultimately, high rate carbon and nitrogen removal through A/B stage process are examined in its main operational parameters and its application towards energy neutrality suggesting novel MBBR application to further reduce energy requirements and plant footprint.