Research pertaining to end-use water analysis plays a pivotal role in enabling local communities to enhance their management of pipelines, water resources, and associated policies. Nowadays, various end-use models have been developed based on diverse databases and measurements. Nonetheless, a predominant drawback prevalent in most of these models is their limited spatial scope and sluggish computational speed. This thesis endeavors to address these challenges through the proposition of a generative adversarial network (GAN) based stochastic end-use demand model. The SIMDEUM model, a stochastic end-use model, was first published in 2010. Since its inception, it has garnered substantial recognition and validation from numerous researchers. Within this thesis, the GAN model utilizes SIMDEUM as the training set and undergoes validation utilizing a comprehensive measurement dataset, encompassing over 1000 households from the Netherlands and the United States. Remarkably, the GAN model attains an error rate of 12% for end uses, coupled with an R2 value exceeding 0.8 for the overall model. In contrast to SIMDEUM, the GAN model significantly enhances computational speed by more than 500%. Furthermore, the GAN model can be tailored to specific requirements and seamlessly processes raw data.It is concluded that the GAN-based stochastic water use model presented in this thesis adeptly simulates end-use water demand.

Inherently related to the quadrupling of global population and the 20-fold increase of global economic output in the last century, is the increase of inputs of raw materials and energy into society and its corresponding outflows. In order to lower the volume of outflows and effectively control pollution, a reduction of raw material use throughout the economy is required. A shift from a linear to a circular economy plays an important role in achieving global climate goals. In a circular economy materials are kept in use for as long as possible so that the need for virgin materials is as little as possible. From a perspective of a circular economy material stocks in urban areas can be considered as ‘natural resources’. These in-use stocks can be described as the urban mine, a concept that is defined as the systematic reuse of anthropogenic materials from urban areas such as buildings and infrastructure for example. Although using the urban mine is desirable, knowledge about stocks and flows of the potential urban mines is limited. One of the infrastructure stocks that has not been assessed yet is the infrastructure of the urban water cycle in the Netherlands. The Dutch urban water cycle as assessed in this study consists of the drinking water production sites and supply network as managed by the 10 drinking water companies, the sewage network, gully pots and a large part of the sewage pumping stations as managed by the municipalities, and some of the sewage pumping stations, transportation pipelines and wastewater treatment plants as managed by the 21 water boards in the Netherlands. In order to analyse the urban mine of the Dutch urban water cycle infrastructure, stock data was gathered about the current size and historic development of the different components of the urban water cycle infrastructure. Per component, the material composition and share is determined to calculate the total material stocks of the urban water cycle between 1950 and 2020…

Drinking water temperature is an essential parameter for water quality related to the physical, chemical and biological processes in water. However, in many countries, the drinking water temperature has not been taken seriously and was excluded from water quality standards. For example, in the Netherlands, the temperature of drinking water should not exceed 25℃ at customers’ taps, which is an advanced guide for ensuring water safety. Moreover, with the tendency of global warming, the drinking water temperature in the distribution system will become higher and higher without sufficient attention and practical solutions. Therefore, understanding the mechanism and cause of water temperature fluctuation is instrumental in finding appropriate measures to cope with it and improve the drinking water quality.

This thesis provides relatively comprehensive and overall ideas to research drinking water temperature. The objective of this thesis consists of three parts: i) Determining impact factors on water temperature; ii) Simulating water temperature in the distribution system; iii) Choosing measures to control water temperature. Firstly, data measurement and analytical methods were applied to determine impact factors on water temperature, and the influence level of each impact factor had been identified. Subsequently, implementing these impact factors to calibrate the water temperature simulation model to verify the model’s feasibility. Finally, the performance on reducing water temperature of three measures, porous asphalt, pervious interlocking concrete pavement, and grass cover, were compared to determine the most effective measure from the standpoint of pipe cover. The results show as following: i) Four impact factors are summarized as surface cover material, district heating pipe, shade effect and groundwater level based on the collected data; ii) It is feasible to simulate the water temperature in the water distribution system. For the model of city Almere, around 88% of simulation values had a difference smaller than 1℃ compared with measurement data; iii) Grass cover has a better performance than the porous asphalt and pervious interlocking cement pavement. Additionally, this thesis discusses limitations during the measurement and simulation process and more relative interventions to reduce water temperature.

In summary, this thesis further summarizes the various impact factors that affect the drinking water temperature and the measure to control drinking water temperature has launched from the point of pipe cover compared with previous references. These results provide guiding advice on the engineering projects of constructing and renovating drinking water distribution systems considering water temperature.

Wastewater discharged from the domestic household has proven to be a potential source for resource recovery. Apart from wastewater, kitchen organic waste contains an enormous amount of energy in terms of organic content and nutrients such as TKN and TPH. Now that the disposal of waste into landfills is prohibited in most parts of Europe, one of the options is to divert the organic waste to wastewater treatment plants using kitchen waste grinders (KWG). Since KWG is a water-consuming appliance, the installation of KWG with water conservation technologies may be a viable option in the future. This can aid efficient recovery of resources and reduce the drinking water demand. The evolution towards sustainable urban sanitation will lead to several positive and negative effects. Some of the positive effects, apart from resource recovery, are the possibility to postpone the enlargement of existing sewer systems, to construct new sewers of smaller pipe diameter and to lower energy consumption for sewage pumping. While the negative effects are blockage of sewer due to reduced flow rates, increased sedimentation and release of malodour in the contemporary sewerage system and increased treatment costs due to increase in COD oxidation and nitrogen or phosphorus removal. Eventually the low flow-high load wastewater needs to be transported through sewers and treated locally (decentralised treatment). In this study, an attempt was made to investigate the effect of coupling the effluent from KWG at various penetration rates such as 100%, 75%, 50% and 25% with water conservation scenarios on hydraulic and quality parameters in the sewerage system. Water conservation scenarios were onsite greywater and rainwater reuse and application of ultra-low water demand appliances. SIMDEUM was upgraded with the addition of an extra appliance in the form of KWG to generate stochastic discharge patterns with appliance specific wastewater flows and quality. The data generated was incorporated into the sewer network model, InfoWorks ICM to analyze the impact of the addition of KWG with water conservation strategies on the contemporary sewer network. The results obtained showed that there is an increase in the mass load of COD, TKN and TPH of 118%, 84% and 90% respectively and reduction in flow, velocity and shear stress of up to 54%, 49% and 74% respectively for the application of water conservation strategies with KWG. This substantiated the fact that the contemporary sewer system is not efficient in transporting the wastewater generated due to the addition of KWG along with water conservation strategies at the household level. A new sewer design with smaller diameters and steep slopes was used to study if the low flow-high load wastewater can be safely transported, in terms of adequate self-cleansing velocity and shear stress. The results from the investigation of new sewer design showed that 100% and 75% implementation of KWG with water conservation technologies will achieve self-cleansing capacity which will help prevent clogging and sedimentation for a piping network of 110mm diameter at a slope of 1:160. KWG market penetration rates of lower than 50% along with water conservation strategies might face issues of sedimentation and clogging. In conclusion, the up-gradation of SIMDUEM with KWG was successful to generate stochastic discharge patterns. This research has demonstrated that the application of KWG along with water conservation strategies may aid in resource recovery and reducing freshwater demand in the urban water cycle. The accomplishment of implementation of KWG with water conservation strategies is not realistic in the contemporary sanitary system however, this transition can be adopted in new urban developments with efficient design of wastewater transport and decentralized treatment system. Further research is required into the feasibility of a decentralised resource recovery system for the implementation of KWG with water conservation strategies.