PASG Technical background Introduction
      During 1982 and 1984, Professor Yang Jingxia was sent to Imperial College as a sponsored researcher by the government for scientific research, when she was touched by the beautiful scenery of Hyde Park, which told her a truth that the naturally bad environment can be improved by efforts of human being. Since then Professor Yang aspired to engage in the environmental protection career once she returns to China and contribute her wisdom and talents to beautify the environment of her motherland.
      In 1986, under the guidance of the Principal of Sichuan University, Professor Wang Jianhua and Vice Principal, Professor He Jinqiu, Professor Yang Jingxia, with Professor Zhang Shisen and Professor Zhu Lianxi together planned and founded Environment Science and Engineering Department in Chengdu University of Science and Technology (hereafter abbreviated as CUST), and then took charge of the first Environmental Science and Engineering Research Institute of CUST( which was later renamed as Environmental Protection Science and Technology Institute of CUST).
      As a famous environmental protection expert, Professor Young has visited American, Germany, Japan and Canada etc for several times, and has also invited and received the visiting experts and professors from multi-country for many times. It has been more than 20 years for her to take up the international communication activities in the domain of environmental protection technology up till now.
      For Professor Yang Jingxia and Mr Ding Shutao, the birth of PASG Technology is a natural result. Since they have accumulated dozens of years teaching and research experience in governing wastewater, and they also undertook several times of technical inspection, investigation and communication with the foreign experts, among which they were especially inspired by the ideas discovered in the domestic wastewater processing engineering projects organized by some American companies while they were participating in the design and implementation procedures. The PASG Technology has therefore gradually come into being by combining the foreign advanced theories with the realistic situation of our country. in 1998 Prof. Young proposed an innovative thought apart from the present traditional techniques both abroad and in China--“establishing a sewage plant, returning a beneficial lively garden.”Her team later explored and improved the technology, and named it simply as PASG Processing Technology 【P（Package）for a complete set of techniques, A（Anaerobic）for its main body, S（in-Site）for in-site processing, G（Gardening） for its garden-like style)】, which has applied for patent protection from State Patent Office and obtained approval.
       Since 1988 the team has started their case studies by applying the core technology of PASG into practical engineering for further research and improvement, which was completed in 2000. They have finished a dozen of engineering cases of domestic sewage treatment during 2000 and 2008, which was also a process of updating the technology. Therefore, in 2008, PASG team again applied for patent protection (Landfilled Domestic Sewage Treatment Technology with a High Efficiency and a Low Operational Fee, simply referred to as PASG Technology) from State Patent Office and had been approved. PASG Technology also led to the invention of various implementation techniques and means concerning with application, which applied for a dozen of Inventions and Patents of Utility Model with four Inventions and ten Patents of Utility Model approved.
       In this course, PASG Technology also obtained the scientific research supports from Department of Environmental Protection in Sichuan Province, which has rather promoted its technology advance. For example, PASG was listed as one of the merit products and equipment in the domain of Environmental Technology in 2012 of Sichuan Province and one of the influential models of technological engineering in preventing and governing the pollution. Furthermore, it won the third prize of technology advancement issued by Environmental Scientific Society of Sichuan Province and was identified as Scientific and Technological Achievements of Sichuan Province in 2012 by Science and Technology Department of Sichuan Province as well.