Operational trials of different propriety lamella and BAF systems

Halcrow Scotland were appointed by Grampian Regional Council (now North of Scotland Water Authority) in April 1993 to carry out the Aberdeen Wastewater Treatment Feasibility Study. The study started with a verification of the flows and polluting loads generated within the catchment followed by a review of the treatment technologies available. The purpose of examining the available technologies was to ascertain the land areas required. Different technologies had different land requirements, and it was important to evaluate this for the site selection stage. Inevitably, conventional activated sludge treatment processes required the greater land take, but it was the only proven technology as far as the client was concerned. Other treatment processes, loosely termed "small footprint", could be accommodated within a much smaller area. The most promising of these processes was Biological Aerated Flooded Filters (BAFF), but at that time there were very few plants operating in the UK and none in Scotland. Halcrow recommended that the client establish pilot plant trials of the BAFF process. For minimal land take lamella plate separators would be required in the primary treatment stage and it was decided to include this compact settlement process (with or without chemical assistance) in the pilot plant trials.