Global water scarcity has intensified competition among different water-use sectors. Collection, treatment, and fit-for-purpose use of wastewater generated by non-agricultural activities offers an opportunity in augmenting water supplies, recovering nutrients and energy, and mitigating pollution. Disparities across countries persist with high-income nations treating 91.5% of wastewater, whereas low-income countries managing to treat only a small fraction (5.8%). Major challenges include limited investments, lack of pertinent policies and application of regulations, and fragmented institutional support amid aging infrastructure, emerging contaminants, and limited resource recovery, particularly in developing regions. Implementation of advanced treatment technologies, regulatory frameworks, and integrated resource management are fundamental to address such challenges. Investments in wastewater monitoring, governance, and capacity-building are essential to achieving safely managed wastewater systems. Such efforts can transform wastewater into a sustainable water resource, support public health and environmental protection, and provide economic benefits. Learning from successful policies, such as the EU’s Urban Wastewater Treatment Directive and the US Clean Water Act, can guide global efforts in line with the global sustainability agenda.
M. Qadir (Tue,) studied this question.