Hisao Ohtake is a Guest Professor of Phosphorus Atlas Research Institute at Waseda University, Tokyo, Japan. He is also a Professor Emeritus of Osaka University, Osaka, Japan. He serves as the Chairman of Phosphorus Recycling Promotion Council of Japan, which is now being reorganized to the Phosphorus Industry Development Organization of Japan. His recent publication is Phosphorus Recovery and Recycling, Springer Nature, 2018.