Editorial for the Special Issue "Wastewater and Waste Treatment: Overview, Challenges and Current Trends".

This document is an editorial for a special issue of the journal "Processes" focused on wastewater and waste treatment. The editorial highlights the urgent need for innovative and sustainable solutions in waste and wastewater management due to escalating pollution levels, climate change, and diminishing natural resources. The special issue includes a diverse array of research papers covering various topics, such as urban waste, industrial and agro-industrial wastes, physicochemical and biological treatment methods, and advanced oxidation processes. The editorial also mentions specific research papers that present innovative treatment technologies, optimization of existing processes, and the recovery of valuable materials and energy from waste streams. The document concludes by emphasizing the challenges faced by the field and the importance of interdisciplinary collaborations to develop holistic and adaptable solutions for a cleaner and more sustainable future. [Extracted from the article]