ABSTRACT
Decentralized wastewater treatment through constructed wetlands (CWs) in urban settlements is a cost-effective, eco-friendly and sustainable wastewater treatment alternative. Integration of CWs as a wastewater treatment facility into urban development and for water reuse in agriculture is an excellent opportunity to generate a circular economy and numerous environmental benefits. The reuse of treated municipal wastewater for the irrigation of crops further lessens the dependency on additional fertilizer requirements and available water resources. However, the integration process concerning health and economy demands strict collaboration of various professionals. The application of CWs together with urban wastewater management is to improve water quality and reduce the impacts of urban heat islands, etc. Recently, the applications have been further extended to provide several ecological services and the development of new wildlife territories, add aesthetic value, groundwater recharge, carbon sequestration, aquaculture and flood control, and attenuate the emission of greenhouse gases to enhance the resilience of the urban environment. Several harmful impacts are also associated with treated wastewater irrigation, such as the existence of infectious pathogens and serious ecological contamination such as groundwater pollution, soil salinization, heavy metal accumulation, alteration of soil structure, and adverse effects on microbial diversity and activity. The change in soil quality and structure can also impact the growth of plants, their productivity and fruit quality.
