NINETEEN scholars who have been active in research in environmental science from 10 different countries have come to Hong Kong for an international training course on advances in waste-water treatment technology at the Chinese University of Hong Kong. The six-day course, jointly organised by the International Cell Research Organisation of UNESCO and the Chinese University started on August 22 and ends this Saturday. It is believed this course for the first time brings together local and overseas experts from a diversity of disciplines relating to the topic. Professor Kenneth Young, Pro Vice-Chancellor of the Chinese University said: ''I am sure there will be fruitful exchange of ideas, and the fostering of an inter-disciplinary approach to sewage treatment technologies.'' Acting Deputy Director of the Environmental Protection Department, Mike Stokoe, said: ''This course brings in experts in the environmental field from around the world and draws in the local experts from Hong Kong. The territory benefits from getting all their native thinking.'' The course aims to provide the participants with information of the principles and practices of new and current techniques and designs in waste-water treatment, according to Professor Chang Shu-ting, chairman of the local organising committee. ''Through the course, the participants will be updated with recent advances in the field and be able to explore the opportunity of future research collaboration of mutual interest,'' Professor Chang said. The highlight will be a seminar on Hong Kong Sewage Strategy on Saturday. Vic McNally of the Environmental Protection Department, Professor Masanori Fujita of Japan's Osaka University, Tsang Kam-lam of the Hong Kong Productivity Council's Environmental Protection Department and Richard Baker of Binnie Consultants Limited will participate in the panel discussion.