LI'AN HOU is an environmental engineering expert and a member of Chinese Academy of Engineering. He first proposed and developed water treatment and air purification technologies and series of equipment with independent intellectual property rights in term of drinking water safety guarantee, decentralized point source domestic sewage treatment and air purification in human settlements, and achieving multiple breakthroughs and creative achievements. He won 1 First Prize, 3 Second Prizes and 2 Third Prizes of National Scientific and Technological Progress Award, 26 Military, Provincial and Ministerial Scientific and Technological Progress Awards and Teaching Achievement Awards, and 47 national patents. He has published 8 monographs and over 300 academic papers. He was granted Ho Leung Ho Lee Science and Technology Progress Award and National Outstanding Scientific and Technological Worker, etc.