Treatment technologies for pointsource nitrogen pollution from wastewater

Over the last century, anthropogenic emissions have risen significantly, threatening ecosystems and human health. For example, excessive nitrogen loading to surface waters can accelerate the growth of microorganisms, resulting in eutrophication and hypoxia in ecosystems. Furthermore, nitrogen compounds such as nitrites and nitrates in drinking water can lead to adverse health effects. Among point sources of anthropogenic nitrogen emissions, the contribution of wastewater can be significant if not adequately managed. It should be noted that nitrogen is mostly discharged as organic and ammoniacal forms in wastewater. Consequently, many legislations and international guidelines include nitrogen compound emission limits for drinking water and wastewater. In this light, this chapter discusses wastewater treatment technologies designed to reduce nitrogen pollution originating from wastewater. Indeed, effective physicochemical and biological techniques have been implemented over the last few decades. Alongside established technologies, new ones have emerged and are being investigated