Wastewater Management in Circular Cities: Challenges of Toxic Emerging Compounds

Development of industry and increasing trend of population growth in urban areas has been resulted in global and local environmental concerns such as natural resource depletion because of increasing demand of wastewater management due to the entrance of Emerging Contaminants (ECs) into wastewater. Therefore, a new concept for the waste/wastewater management, which is called as circular city, is introduced by international organizations. According to the principles of circular city, wastewater management requires the reuse/recycle/recovery of water and materials instead of discharging them to the receiving environment which is the application of linear (conventional) cities. For example, after proper treatment, recovered wastewater can be used as tap water or irrigation water, and treated sewage sludge can be used as fertilizer in agricultural areas. However, one of the major concerns for wastewater recovery is the direct contact of human and environment with ECs present in recovered wastewater which potentially have toxic effects. ECs are a new class of pollutants, for which the toxic effects are not understood clearly, and they are not regulated even for the wastewater discharge in linear cities. Although the literature for the occurrence, fate and effects of ECs has been relatively advanced for the receiving environment, the literature for the recovered wastewater, which has direct contact with human and organisms, is quite limited. Therefore, this chapter aims to address the wastewater management in circular cities by comparing with linear cities in terms of ECs removal and the challenges for the presence of ECs in recovered wastewater.