Abstract
Rapid urbanization, industrialization, and population growth have significantly increased wastewater generation across the globe. In many developing countries, untreated or partially treated wastewater continues to pollute rivers, wetlands, and groundwater systems, creating serious environmental and public health concerns. Conventional wastewater treatment systems mainly focus on pollutant removal and disposal, often neglecting the valuable resources embedded within wastewater streams, such as nutrients, organic matter, reusable water, and energy. In recent years, the concept of resource recovery from wastewater has gained global attention under the framework of the circular economy and sustainable development. Wastewater is increasingly being recognized not as waste, but as a valuable resource that can contribute to renewable energy production, nutrient recycling, water reuse, and climate change mitigation. Among the emerging sustainable technologies, algae-based wastewater treatment systems have shown remarkable potential due to their ability to simultaneously remove nutrients, capture carbon dioxide, and produce biomass that can be converted into biofuels, biofertilizers, bioplastics, animal feed supplements, and other value-added products. Despite increasing global research and technological advancements, the adoption of resource recovery technologies in developing countries remains limited due to technological, financial, institutional, and policy-related challenges. There is a growing need to create platforms for knowledge exchange, interdisciplinary collaboration, and awareness among researchers, students, policymakers, engineers, industries, and environmental practitioners.