5. Environmental Impacts and Necessity of Removal of Emerging Contaminants to Facilitate Safe Reuse of Treated Municipal Wastewaters

Contaminants of emerging concern or more precisely, emerging contaminants (ECs) are set of bio-refractory compounds that originate in the water cycle from the technosphere. A more direct pathway is via reuse of treated wastewater that might have residual concentration of ECs that are not easily degraded in the current wastewater treatment practices. In this context, it is pragmatic to firstly understand the pathways of EC release, as well as the physiochemical interactions and transformation of theses ECs in the environment. This understanding of potential impacts can be translated into discharge guidelines for target ECs. This is important, as often variation in discharge standards can dictate the type and degree of treatment required. To understand this stated fact more clearly, this chapter discusses the necessity to undertake removal of the ECs in light of spread and extent of environmental contamination caused by ECs. The advanced oxidation processes that are capable of removal of these pollutants are also being discussed. Thus, attempt has been made to summarize appearance of ECs in aquatic environment, their ecological impacts, and removal methods to produce reusable quality treated water safe for reuse.