Results of pilot-scale dewatering trials performed in Braunschweig Assessment of various operational factors on centrifugation performances (Project Decamax, Work Package 2)
Sludge treatment and disposal is one of the key positions of operating costs in large wastewater treatment plants (WWTPs). On large WWTPs, dewatering of digested sludge is mainly performed with centrifuges. The performance of the centrifuge and thus, the (cost-)efficiency of the whole sludge dewatering process, strongly depends on the operating parameters of the centrifuge and the properties/preparation and dosage of the polymer used as flocculation aid. The research project “Decamax” therefore mainly focuses on these aspects and their impact on the dewatering result, i.e. mainly the dry solid content of the sludge cake and the quality of the sludge liquor. Moreover, the impact of sludge pre-heating on sludge dewatering is assessed, because it is known that the dewatering temperature has a high influence on the process as well. Besides a technical study (Work Package 3) and full-scale trials at a WWTP in Berlin (WP 1), the project included trials with a 0.4 m³/h pilot-scale centrifugation unit in Braunschweig (Work Package 2). The results of this work package (performed by the Institute of Sanitary and Environmental Engineering, Technische Universität Braunschweig (ISWW)) are summarised in this report. Besides the ISWW, the pilot-scale trials were supported and evaluated by the Stadtentwässerung Braunschweig (SE|BS), the KompetenzZentrum Wasser Berlin (KWB) – also responsible for the overall project management and control – and Kläranlagenberatung Kopp (KBK). Moreover, the Decamax project team and technical committee include the Berliner Wasserbetriebe (BWB) and Veolia Wasser. The project is financially supported by Veolia Water and BWB.