Odour and corrosion problems in pressure sewers

Sulphide generation in sewers and waste water facilities is a world wide problem and much research has been done concerning this issue to determinate its causes, effects, prevention and control. Due to the lack of systematic research in Austria several investigations were carried out in different pressure sewers from different waste water treatment plants (WWTP) in order to assess the efficiency of the available technologies to control sulphide generation. Within this project some of the most applied technologies like pipe “pigging” or mechanical cleaning to remove the biofilm from the pipe wall, pneumatic waste water transport to minimise retention times, air or oxygen supply or addition of nitrate salts to avoid anaerobic conditions were tested. Finally the addition of iron salts proposed to eliminate accumulated sulphide by precipitation was also evaluated.