7 - Technologies for nitrogen recovery from municipal wastewater

Abstract

Conventional nitrogen removal processes from municipal wastewater are energy and cost-intensive processes, which lead to the wastage of nitrogen. Nitrogen is an essential nutrient for agricultural crops, and conventionally nitrogenous fertilizers are produced by spending a large amount of energy. Hence, it is important to recover nitrogen from municipal wastewater, considering its multidimensional implications. The major constraint in the recovery of nitrogen from municipal wastewater is its low concentration (20–40mg/L NH4-N). Various technologies are available to recover nitrogen from municipal wastewater and from other waste streams having high nitrogen concentrations, such as urine, swine wastewater, etc. The major technologies that can be employed for the recovery of nitrogen are struvite precipitation, air stripping, bioelectrochemical systems, recovery using microalgae, adsorption, etc. This chapter aims to elucidate the important biological, physical, and chemical technologies that can be adopted for the recovery of nitrogen from municipal wastewater. It is important to make use of suitable technologies to recover the nitrogen present in the wastewater, which is a valuable resource that should not be wasted.