More than 600 guests attended the first sewage sludge symposium in Berching
Outside exhibition: the extensive Huber program for sludge treatment
Scientists, representatives of the Bavarian State Government and operators of sewage treatment plants spoke under the chairmanship of the university professor Dr. Martin Faulstich who is the director of the chair for technology of biogenous raw materials at Straubing. From 1994 until 2000, when he took over his post as the managing director of the development centre for process engineering (ATZ-EVUS) in Sulzbach-Rosenberg, he had been at the Technical University of Munich in Garching as a professor for waste treatment and residue recycling.
New legal restraints demand for modification of sewage sludge disposal strategies. According to the German "TA Siedlungsabfall" (Technical Instructions for residential waste) landfilling of sewage sludge will be prohibited from 2005 on. Disposal to agricultural land and reuse for landscaping will be restricted by tougher legislature anticipated in the future. It is also anticipated that agricultural reuse of sewage sludge will further be limited due to a decreasing acceptance of such agricultural products. Besides, there is the permanently relevant hygienic risk that rose again recently with the BSE problem.
Against this background sewage sludge treatment is gaining increasing importance. Sewage sludge drying for example effects a significant weight and volume reduction and produces a manageable product with a high thermal value virtually corresponding to that of brown coal. Additionally, in view of the economical aspect and the requirement to minimize transport costs as those will increase in the future due to the upcoming implementation of the toll for trucks in Germany, sewage sludge treatment will become necessary also for smaller wastewater treatment plants, whether this will simply be thickening or dewatering in bigger plants with subsequent drying of the pre-treated sludge in a central plant.
The representative of the Bavarian State Government, Senior Legal Secretary (MR) Michael Spitznagel, resumed that abandoning of disposal to agricultural land must be a voluntary decision and cannot be prohibited. Continued implementation of the amendment of the German sewage sludge regulation will therefore be of special importance. MR Spitznagel also gave a summary of the situation in the neighbouring countries: Whereas Austria has partly abandoned disposal to agricultural land and even prohibited it in one state in 1999, Sweden is still discussing about prohibition. In the Netherlands legal standards have become so high that disposal to agricultural land does de facto no longer take place. Switzerland began last May to gradually implement a prohibition.
The Hans Huber AG responded to this development early enough, establishing a special business unit for sludge treatment. The 600 symposium attendees had the opportunity to inform themselves about the extensive Huber program for sludge treatment on the outside exhibition are where Huber presented for example the new ROTAMAT® Centrifuge, a high-performance centrifuge for industrial and municipal sludge dewatering. This completely new Huber development is selling very successfully. Also exhibited was a new Huber Bogenpress, which is a belt filter press that was integrated in the Huber product family after takeover of KLEIN and is now, after further development, offered with up to 12 rollers.
Other exhibited models were the KULT® Low Temperature Dryer and Solar Active Dryer. Of particular interest was obviously the Solar Active Dryer which is in combination with the use of regenerative energy especially interesting for smaller sewage treatment plants up to 10,000 PE, representing an alternative for external disposal via a disposal company.
A visitor from Switzerland who came with 25 guests from our Swiss subsidiary expressed his surprise about the intensive discussion in Germany, and some wondered in retrospect that and why there had hardly be any discussion in Switzerland before they decided to prohibit disposal to agricultural land from 2006 on. But this may be easier in a country that is twelve times as small as Germany.