Water is essential for life, influencing human health, agriculture, and ecosystem stability. As global demand and pollution rise, effective water treatment becomes increasingly crucial. Traditional methods like chlorination and sedimentation have been vital for providing safe water but often require high energy and chemical inputs and may not fully address the spectrum of emerging contaminants. This chapter delves into advanced water decontamination technologies, including Advanced Oxidation Processes, nanofiltration membranes, electrochemical treatments, bioremediation, nanotechnology, and solar photocatalysis. It offers a comprehensive evaluation of these technologies, focusing on their efficiency, cost-effectiveness, scalability, and sustainability. This chapter analyzes comparative advantages and limits to offer insights for optimizing water treatment systems and directing future research and development, thus improving global water quality management and ensuring a safe and clean water provision for all.