Life in changing environments: The intriguing cycles of Polyphosphate Accumulating Organisms

Cells are complex systems continuously exposed to changing, dynamic environments. Understanding how cells respond and adapt is of great interest not only from a fundamental viewpoint but also for the development of solutions for current challenges in medical, industrial and environmental research fields.<br/><br/>In this thesis, the bacterial...

Aerobic Granular Sludge in Seawater

Increase in sea level will lead to an increase in salinity in domestic wastewater systems. In order to anticipate its effects on biological wastewater treatment, the impact has to be assessed with lab-scale experiments. Aerobic granular sludge (AGS) is a successful technology for simultaneous removal of organic carbon (COD), nitrogen, and...

Micro-pollutant removal from wastewater treatment plant effluent by activated carbon

In the recent years, the removal of micro-pollutants from treated wastewater has been highly advocated throughout Europe and the rest of the world. The relevant regulations and the suitable techniques have been proposed accordingly, which promoted the innovation of the conventional wastewater treatment plants (WWTPs). Activated carbon adsorption...

Application of dynamic membranes in anaerobic membranes in anaerobic membrane bioreactor systems

Anaerobic membrane bioreactors (AnMBRs) physically ensure biomass retention by the application of a membrane filtration process. With growing application experiences from aerobic membrane bioreactors (MBRs), the combination of membrane and anaerobic processes has received much attention and become more attractive and feasible, due to advantages...

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...

Emissions of methane and nitrous oxide from full-scale municipal wastewater treatment plants

Since 1750, the year that commonly marks the start of the Industrial Revolution, the atmospheric concentrations of carbon dioxide, methane and nitrous oxide have risen about 40 %, 150 % and 20 %, respectively, above the pre-industrial levels due to human activity (IPCC (2013) Climate Change 2013: The Physical Science Basis. Working Group I...

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...

Optimization of Urban Wastewater Systems using Model Based Design and Control

In this research a considerable amount of scientific evidence had been collected which leads to the conclusion that the urban wastewater components should be designed as one integrated system, if the protection of the receiving waters is to be achieved cost-effectively. Even more, there is a need to optimize the design and operation of the...

Monitoring as a tool for the assessment of wastewater quality dynamics

The wastewater system in the Netherlands comprises approximately 100,000 km of sewer pipes and more than 350 wastewater treatment plants (wwtp). The system collects and treats the majority of domestic and industrial wastewater. A small amount of untreated wastewater, however, is occasionally discharged to rivers and lakes, often resulting in a...

Dynamics of Nitric Oxide and Nitrous Oxide Emission during Nitrogen Conversion Processes

Nitric oxide (NO) and nitrous oxide (N2O) emissions can be a serious threat to the environment. Rising levels of N2O in the atmosphere contribute to global warming and destruction of the ozone layer. This thesis describes an investigation on the emission of NO and N2O during nitrogen conversion processes. Emissions were measured at wastewater...

Growth and metabolism of Anammox Bacteria

The anoxic ammonium oxidation (anammox) process is the conversion of nitrite and ammonium under anoxic conditions- to form dinitrogen gas. The process is performed by deep-branching Planctomycetes. The startup of the first full-scale anammox reactor in the world is described in Chapter 2. The described full scale reactor was a granular sludge...

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...

Filtration characteristics in dead-end ultrafiltration of wwtp-effluent

With a growing need for water for many purposes on one side and an increasing degree of wastewater treatment producing water with an improved quality on the other side, the necessity of water reuse will grow, especially in highly industrialised countries with restricted natural water sources. Improvement of advanced treatment schemes for...

Scenario Studies into Advanced Particle Removal in the Physical-Chemical Pre-treatment of Wastewater

The research dealt with in this dissertation had the objective identifying the specific roles of particulate matter in wastewater influent and its inherent characteristics. In addition, advanced particle removal techniques for the development of more sustainable treatment scenarios based on physical-chemical pre-treatment of wastewater were...