Odour Control and Legislation in Hong Kong
Author: Kwan, Yiu-keung, John
The objectives of the work are to identify the odour problem caused by the large offensive smell facilities such as sewage treatment plants, refuse transfer stations, refuse collection points, abattoirs, composing plants and pumping stations; and to review the development of deodourization measures and legislation in the overseas countries. This is also to compare with the ones in Hong Kong.
The approach to the problem is by conducting a survey to collect the data. Questionnaires have been sent to 59 relevant organisations and authorities of overseas countries, and the relevant departments in Hong Kong to gather information on odour control and legislation by them. The main themes of the questionnaire were to:
- identify the odour problem and the seriousness in different facilities;
- find out what kind of measures are being used for odour control; and
- obtain information on the legislation related to the control of odour.
In summary of the study, it was learnt that there are various kind of air pollution control equipment (e.g. activated carbon, scrubber, biofilter, and ozone etc.) used for the treatment of odorous gases generated from the offensive smell facilities. The most commonly used equipment in Hong Kong are activated carbon and scrubbers. However, biofilter and ozone are increasingly accepted by many overseas countries. Although biofilter has many advantages such as the low running cost and high odour removal efficiency, more work is still required to reduce the large surface of the biofilter especially for accommodation in the plants of Hong Kong.
Odour control systems do not give overall success unless the entire facility is properly enclosed and maintained, especially for the densely populated area like Hong Kong. The air pollution control system includes capturing devices to direct the odorous emissions to the control systems. It also includes effective housekeeping and general cleanliness, proper material handling and storage, good spill protection and waste disposal procedures. In addition with the dispersion through the chimney, the odour could be reduced to the acceptable level.