Life cycle assessment of nutrient removal and recovery processes

Conventional wastewater treatment plants can be upgraded to advanced systems to remove nutrients from wastewater. However, the benefit of nutrient removal may not be sufficient to compensate for the additional environmental burdens associated with increased energy and chemical consumption. Nutrient removal and recovery processes can be evaluated using life cycle assessment (LCA) to quantify both the environmental burdens of the applied processes and the environmental benefits resulting from reduced effluent emissions and nutrient recovery. This chapter examines both conventional and innovative nitrogen and phosphorus removal processes, including nitrification/denitrification, partial nitritation/anammox, enhanced biological phosphorus removal, and membrane-based processes in the context of LCA. In addition, various nutrient recovery processes, such as struvite recovery, ash treatment, and microalgae cultivation, which follow different pathways and aim to produce valuable end products, are analyzed in terms of their environmental burdens and benefits.