Visualization of Polyhydroxyalkanoate Accumulated in Waste Activated Sludge

Polyhydroxyalkanoates (PHAs) can be produced with municipal waste activated sludge from biological wastewater treatment processes. Methods of selective fluorescent staining with confocal laser scanning microscopy (CLSM) were developed and optimized to evaluate the distribution of PHA storage activity in this mixed culture activated sludge...

Biotrickling Filtration for the Reduction of N₂O Emitted during Wastewater Treatment: Results from a Long-Term In Situ Pilot-Scale Testing

Wastewater treatment plants (WWTPs) are a major source of N₂O, a potent greenhouse gas with 300 times higher global warming potential than CO₂. Several approaches have been proposed for mitigation of N₂O emissions from WWTPs and have shown promising yet only site-specific results. Here, self-sustaining...

Exploring the Limits of Polyhydroxyalkanoate Production by Municipal Activated Sludge

Municipal activated sludge can be used for polyhydroxyalkanoate (PHA) production, when supplied with volatile fatty acids. In this work, standardized PHA accumulation assays were performed with different activated sludge to determine (1) the maximum biomass PHA content, (2) the degree of enrichment (or volume-to-volume ratio of PHA...

Sulphate reducing bacteria in wastewater treatment

The depletion of fresh water sources forces to design innovative integral solutions for the urban water cycle. Usual practice in most cities is to use drinking water to transport waste outside the city via sewer system. For toilet flushing the water quality is less important and seawater could be used as alternative to use of drinking water. Due...

Filtration Characterization Method as Tool to Assess Membrane Bioreactor Sludge Filterability—The Delft Experience

Prevention and removal of fouling is often the most energy intensive process in Membrane Bioreactors (MBRs), responsible for 40% to 50% of the total specific energy consumed in submerged MBRs. In the past decade, methods were developed to quantify and qualify fouling, aiming to support optimization in MBR operation. Therefore, there is a need...

Prospects for flux enhancement in anaerobic membrane bioreactors treating saline wastewater

Activated sludge filterability and full-scale membrane bioreactor operation

Despite continuous developments in the field of MBR technology, membrane fouling together with the associated energy demand and related costs issues remain major challenges. The efficiency of the filtration process in an MBR is governed by the activated sludge filterability, which is still limitedly understood and is determined by the...

Aerobic granular sludge: Scaling up a new technology

Most conventional wastewater treatment plants need a large surface area for the treatment of their sewage. This is due to the open structure of the biomass used to convert the polluting components in wastewater. Because of the flocculated growth, sludge concentrations in reaction tanks are low and settling times need to be long in order to keep...

Filtration characteristics in membrane bioreactors

Causes of and remedies for membrane fouling in Membrane Bioreactors for wastewater treatment are only poorly understood and described in scientific literature. A Filtration Characterisation Installation and a measurement protocol were developed with the aim of a) unequivocally determination and quantification of the filterability of an activated...

Theoretical and practical aspects of modelling activated sludge processes

This thesis describes the full-scale validation and calibration of a integrated metabolic activated sludge model for biological phosphorus removal. In chapters 1 and 2 the metabolic model is described, in chapters 3 to 6 the model is tested and in chapters 7 and 8 the model is put into practice. Chapter 1 is a general introduction to this...

Bulking sludge control. Kinetics, substrate storage, and process design aspects

The activated sludge process is the preferred technology for biological wastewater treatment. Despite decades of progress and operation serious operating problems still occur with this process. One major problem is the regular occurrence of excessive growth of filamentous bacteria, phenomena known as filamentous bulking sludge. Poor solid-liquid...

Het onderzoek naar de gekombineerde behandeling van met hexacyanoferraat verontreinigd grondwater en stedelijk afvalwater