Anaerobic zone Functionality, Design and Configurations for a Sustainable EBPR process: A Critical Review

Stringent discharge phosphorus limits and rising urge to reach very low effluent total phosphorus concentrations have challenged the available technologies to further remove phosphorus. The significance of Enhanced Biological Phosphorus Removal (EBPR) process may have been overshadowed by the design and operation limitations. These scarcities mainly root back to the lack of knowledge and understanding of fundamental mechanisms, design standards, and operational guidance. Anaerobic biomass fraction design and operation as a primary driving force for biological phosphorus removal process is commonly outweighed by aerobic and total plant sludge retention operation and design criteria. This paper tends to critically review the different perspectives of mainstream and side-stream EBPR processes and to particularly target contrasting views on hydrolysis and fermentation rates as well as anaerobic condition implementation and magnitude. Subsequently, from distinct point of views, knowledge gaps are comprehensively discussed to eventually recognize the advances and drawbacks aimed to reach a sustainable EBPR process. [Display omitted] •Conventional EBPR design hold doubtful concepts to be addressed to enhance efficiency.•Promoting anaerobic hydrolysis and fermentation boost EBPR performance and stability.•Diverse approach to hydrolysis is for insight gap in metabolism, design, and operation.•Side-stream EBPR is an alternative method to promote hydrolysis and fermentation.•Adequate anaerobic design may promote hydrolysis without any mediation plan needed.