Assessment of diffuser pressure loss on WWTPs in Baden-Württemberg

摘要

Aeration of activated sludge is a critical treatment step for the operation of activated sludge plants.nTo achieve a cost effective treatment process, assessing and benchmarking of aeration systemnperformance are important measures. A simple means of gauging the relative condition of a finenbubble diffused aeration system is to evaluate the pressure loss of the diffusers as oxygen transferntests are rarely applied during the lifetime of an aeration system. This paper shows an assessmentnof fine bubble diffuser systems in Baden-Württemberg, Germany, based on the results of anquestionnaire sent to 941 WWTPs. Apart from the results with regards to the diffuser pressure loss,nthis paper also presents information on the current state of diffuser technology such as types andnmaterials as well as the diffuser cleaning methods used in Baden-Württemberg. The majority of thenWWTPs were equipped with tube diffusers (71%) with 50% of all plants having EPDM membranesninstalled. Regular mechanical cleaning is the most common cleaning method followed by regularnpressure release/air-bumping programs during operations. With regard to the diffuser pressure loss itnwas found that 50% of the evaluated plants had a diffuser pressure loss that was twice as high asnmeasured for new diffusers.