Wastewater Biorefineries: Integrating Water Treatment and Value Recovery BT - The Nexus: Energy, Environment and Climate Change

Abstract

The wastewater biorefinery (WWBR) bridges the gap between the concepts of the biorefinery (BR) and wastewater (WW) treatment. A WWBR aims to generate a product, or products, of sufficient value to make the process economically viable and enhance resource productivity, while simultaneously remediating wastewater to an acceptable quality. It is centred on the conversion of the organic carbon, nitrogen, phosphorous and associated trace nutrients in the wastewater stream to value added products, while concomitantly providing clean or ‘fit for use’ water as a product. The WWBR is increasingly recognised for its potential contribution to the bio-based economy, as well as its potential to augment the industrial sector. The concept of a WWBR contributes to valuing wastewater treatment as an integrated component of a wider system rather than a unit process for ‘end-of-pipe treatment’, as is generally the state of current operation, a significant paradigm shift which has the potential to increase plant profitability and reduce environmentally deleterious effluents. It provides a link between the users of water and those responsible for its management, leading to the recovery of resources in closed loop cycles and thus contributing to progressing towards the concept of a circular economy, where valuable nutrients and components are recovered and reused. This chapter examines the pedagogy around the design and implementation of WWBRs with a focus on the classification of wastewaters for WWBR design, selection of potential products, flow sheet development and the criteria for reactor selection.