In recent years, particularly following the COVID-19 pandemic, wastewater-based epidemiology (WBE) has emerged as an effective tool for the early detection of disease outbreaks. This manuscript presents a novel perspective on WBE by highlighting sewage as a predictive instrument, capable of providing near-real-time, community-level pathogen surveillance and anticipating and mitigating future pandemics even before the first clinical symptoms are detected. This approach enables cost-effective, non-invasive, and population-wide monitoring of infectious diseases’ emergence, evolution, and decline. By identifying pathogens in human waste (e.g., viruses and bacteria), WBE delivers real-time insights into infection trends, encompassing data from asymptomatic and pre-symptomatic populations, enabling timely interventions from public health authorities. Among the key advantages are its capacity to encompass large populations, pinpoint transmission hotspots, and facilitate resource allocation for containment efforts. The efficacy of sewage surveillance in predicting infection has already been validated during the COVID-19 pandemic, highlighting its potential as a critical component of pandemic response preparedness. However, this approach also presents challenges such as sample variability, environmental factors, and infrastructure limitations. Through a comprehensive review of the state-of-art available on this topic, including almost 300 published papers, the present manuscript emphasizes the expected impact of integrating sewage monitoring into global health surveillance frameworks and discusses its future applications in mitigating emerging infectious diseases, aiming to provide a multidimensional overview of WBE and its integration with other environmental surveillance tools.

The climate crisis, unrestrained use of water resources, and rising population demands have amplified the urgency for sustainable and eco-friendly wastewater treatment solutions. Conventional methods often fail to degrade emerging and persistent pollutants produced by industries, driving the need for alternative technologies. In this context, photocatalysis has emerged as a promising and effective method, offering superior degradation of contaminants and cost-effective application, especially with its advancements in recent years. As an advanced oxidation process (AOP), photocatalysis is particularly well-suited to address the limitations of traditional treatments. This review paper explores the types of photocatalysts and their operational mechanisms, examines the key parameters affecting degradation efficiency, such as operating conditions and photoreactor design, and analyzes recent developments in wastewater effluents containing emerging contaminants over the past five years. Lastly, this review proposes the integration of photocatalysis with other treatment technologies and presents potential future directions for research.