Indiana Water Operator Training Manual

Introduction We have written 'Design Criteria for Sewers and Watermains' manual for City of Toronto staff and consulting engineers. The purpose of this manual is to ensure there is consistency in our operations. Clients—that’s you—want to be instructed in the same way each time you come to us, regardless of which office you may visit. This manual will help ensure that the information provided by staff is the same in all offices. This manual is written for City staff and consulting engineers working on capital improvement projects and for consulting engineers working for the development industry preparing engineering designs and drawings for private developments. It can also serve as a reference for third parties designing transit infrastructure, underground utilities, and any other works located within a city right-of-way, located in close proximity to City sewers and watermains. This manual takes you step by step through all the criteria you will need in the design of a sewer or watermain and the requirements for submission. If you are going to be preparing a servicing study or designing a sewer or watermain in the city of Toronto, this manual is for you. This manual is available in both print and online formats.

Introduction Since several years, conventional wastewater treatment has been dealing with low volumetric loading rates and a high energy consumption (Van Haandel & Van der Lubbe, 2007; Pronk et al., 2017). Especially with the increasing standard of living and an increasing amount of households connected to a sewage system constant improvements are needed (Vlaamse milieumaatschappij, 2019a). The question arises how these challenges can be met in an efficient way. Over the past 20 years, aerobic granular sludge is presented as a promising technology to meet these challenges. Conventional activated sludge flocs, i.e. suspended microorganisms forming bulky aggregates, are converted into compact aerobic granules. This results in 25-75% less land area, 20-50% less energy and up to 7-17% less costs compared to conventional activated sludge plants (Pronk et al, 2017). The conventional use of aerobic granular sludge is in batch systems, but continuous systems are under research as well (Jahn et al., 2019). The aim of this thesis is to gain further insight in continuous processes with aerobic granular sludge. Given that the current continuous systems are not depreciated, yet cannot meet the demand for higher treatment capacity, continuous aerobic granular sludge systems seem promising. Better settleability of granules could lead to higher biomass concentrations in the existing continuous systems, possibly resulting in a higher treatment capacity. Before researching how to get stable granules in a continuous flow reactor, it is needed to investigate the overall effect of granules on the performance of continuous reactors. In this thesis it is questioned if refurbishment of the current continuous activated sludge plants into continuous aerobic granular sludge plants would be advantageous in terms of treatment capacity and energy consumption, in order to meet the effluent criteria. This was investigated by developing the comparison between continuous systems with activated sludge and with aerobic granular sludge. The comparative study is obtained in different steps. In the literature review, a state-of-the-art on current wastewater treatment with activated sludge and aerobic granular sludge is given. Both the typical aerobic granular sludge implementation in batch systems and perspectives on aerobic granular sludge in continuous systems are discussed and compared based on literature findings. The chapter ‘Materials and methods’ describes the mathematical model based on the Benchmark Simulations Model No. 1 (BSM1) in Matlab-Simulink. A continuous activated sludge system serves as the reference model. Furthermore, this model is adapted to make it representable as a continuous design with aerobic granular sludge based on two characteristics: better settleability and diffusion limitation. In the chapter ‘Results and discussion’, the differences between both continuous systems are elucidated to answer the research question. Both the maximal treatment capacity and energy consumption in order to meet the effluent criteria were calculated and compared for both systems. Conclusions are summarized in the chapter ‘General conclusions’ and ‘Recommendations for further research’ are given.