To improve the understanding of the nature of sewage changes upon aging during transport or storage, simulation experiments were conducted using batch reactors under a number of well defined conditions, i.e. anaerobic, aerobic and micro-aerophilic at 10°C, 20°C and 30°C. Important characteristics of the studied sewage were the visual appearance, various chemical properties and odour. The effect of temperature on the degradation processes and reaction kinetics of different polluting fractions of the sewage is studied under mainly micro-aerophilic and anaerobic conditions.

The results of non-inoculated batch simulating experiments reveal that micro-aerophilic conditions are suitable for both pre- and post-treatment of sewage, while anaerobic conditions will suffice for pre-treatment. At low temperatures, anaerobic conditions mainly serve for pre-acidification. On the basis of the results obtained, we recommend putting emphasis on further research dealing with on-site and on-line treatment systems, combined with a central wastewater treatment plant. Such processes look attractive in improving the organic removal efficiency and in reduction of operating cost and capital outlay of wastewater treatment systems.