The presence of toxic Cr(VI) in the aquatic environment and their harmful effects on living organisms has emerged as one of the most serious environmental concerns in Thailand, located in the Southeast Asian region. The research, undertaken at the Sirindhorn International Institute of Technology of Thammasat University (2001-2003), directly addressed the need of our society for clean water. This book reports the technical applicability of coconut shell waste, a low cost material from local agricultural waste for treatment of Cr(VI)-contaminated water, and can be a useful resource for environmental scientists, engineers, researchers, policy and decision makers, and engineering students world-wide.