Access to clean water and adequate sanitation remains one of the most significant global environmental and public health challenges of the twenty-first century. Increasing urbanization, industrialization, agricultural activities, and population growth continue to place enormous pressure on freshwater resources worldwide. Wastewater treatment and water reclamation technologies have therefore become essential components of sustainable water management systems aimed at improving water quality, protecting ecosystems, and promoting human health. This technical review discusses the principles, sources, properties, uses, and quality parameters of water and wastewater, as well as major wastewater treatment operations employed in modern environmental management. The review highlights important physical, chemical, and biological characteristics of water, common contaminants found in wastewater, and treatment methods including sedimentation, filtration, oxidation, disinfection, brine treatment, and polishing processes. The environmental, economic, and public health significance of wastewater treatment is also examined alongside the advantages and limitations associated with water recycling and reclamation. Furthermore, the review emphasizes the relevance of sustainable wastewater treatment technologies in achieving the United Nations Sustainable Development Goal 6 (SDG 6): Clean Water and Sanitation. Effective water treatment systems contribute to environmental protection, disease prevention, improved sanitation, climate resilience, and sustainable resource management. The study concludes that integrated wastewater management, technological innovation, public awareness, and sustainable policy implementation are critical for ensuring global water security and environmental sustainability.
Akunna Francess Ujuagu (Sat,) studied this question.