Water renewal and stratification modelling in small estuaries

Water renewal and flushing in small, intermittently open or closed estuaries is receiving increasing attention particularly in light of the climate change induced alterations in run-off, wave and sediment transport conditions along coasts. The challenges of predicting the stratification-circulation state and the balance between tidal or...

Integrated urban flood design in the United States and the Netherlands

Spatial design integrates social, cultural, economic, and political perspectives with natural site conditions and man-made construction to plan for sustainable urban development. The current flood-risk-related challenges induced by climate change place pressure on designing cities in which both natural and man-made conditions can be imbalanced....

Microbiological Health Risk Assessment ofWater Conservation Strategies: A Case Study in Amsterdam

The aim of this study was to assess the health risks that may arise from the implementation of greywater reuse and rainwater harvesting for household use, especially for toilet flushing. In addition, the risk of cross connections between these systems and the drinking water system was considered. Quantitative microbial risk assessment (QMRA) is...

Sediment transport prediction in sewer pipes during flushing operation

This paper presents a novel model for predicting the sediment transport rate during flushing operation in sewers. The model was developed using the Evolutionary Polynomial Regression Multi-Objective Genetic Algorithm (EPR-MOGA) methodology applied to new experimental data collected. Using the new model, a series of design charts were...

Fouling control in ceramic nanofiltration membranes during municipal sewage treatment

Using ceramic nanofiltration membranes for treatment of municipal sewage is upcoming. However, the knowledge on fouling control methods for this application are very limited. The most commonly used fouling control method, chemical cleaning, has disadvantages. Chemical cleaning negatively impacts (i) the glass seal layer of tubular ceramic...

Efficacy of flushing and chlorination in removing microorganisms from a pilot drinking water distribution system

To ensure delivery of microbiologically safe drinking water, the physical integrity of the distribution system is an important control measure. During repair works or an incident the drinking water pipe is open and microbiologically contaminated water or soil may enter. Before taking the pipe back into service it must be cleaned. The efficacy of...

A greedy algorithm for optimal sensor placement to estimate salinity in polder networks

We present a systematic approach for salinity sensor placement in a polder network, where the objective is to estimate the unmeasured salinity levels in the main polder channels. We formulate this problem as optimization of the estimated salinity levels using root mean square error (RMSE) as the "goodness of fit" measure. Starting from a...

Model Predictive Control of Salinity and Water Level in a Hypothetical Polder Ditch: Is it Possible to Use the Discretized Linearized Physical Equations for Optimization

Surface water salinization in deltaic areas due to saline groundwater exfiltration is an important issue. Fresh water diverted from the rivers is used for flushing the canals and the ditches in coastal areas to remove the low quality saline surface water mixed with saline groundwater. Worldwide, deltaic areas are under stress due to climate...

Rainwater harvesting in the Netherlands: useful or not?

Often rainwater harvesting is considered as an important contribution to a more sustainable society. Rainwater is assumed to be clean water, requiring only limited treatment, and it is thought that there is sufficient rainwater available to provide people with drinking water. In order to check these assumptions, we carried out a desk study into...

Impact of Distribution and Network Flushing on the Drinking Water Microbiome

We sampled the tap water of seven unique, full-scale drinking water distribution systems at different locations as well as the corresponding treatment plant effluents to evaluate the impact of distribution and the potential presence of a core drinking water microbiome. The water was also sampled during network flushing to examine its effect on...

Polder Flushing: Model Predictive Control of Flushing Operations to Effective and Real Time Control of Salinity in Polders

More than 35% of the world’s population live within 100 km of the coast. Groundwater resources in these areas are the main source for domestic, industrial and agricultural use. Worldwide, deltaic areas are under stress due to climate change, sea level increase and decrease in fresh water availability. In addition, in deltaic coastal areas around...

Sustainable Application of a Novel Water Cycle Using Seawater for Toilet Flushing

Global water security is a severe issue that threatens human health and well-being. Finding sustainable alternative water resources has become a matter of great urgency. For coastal urban areas, desalinated seawater could serve as a freshwater supply. However, since 20%–30% of the water supply is used for flushing waste from the city,...

Dynamic control of salt intrusion in the Mark-Vliet river system, The Netherlands

The Volkerak-Zoom Lake is an enclosed part of the estuarine delta in the southwest of the Netherlands and exists as such since 1987. The current freshwater lake experienced a deterioration in water and ecological quality. Especially cyanobacteria are a serious problem. To solve this problem it is proposed to reintroduce salt water and tidal...

Rinsing water analysis of helicopter jet engine compressors