This paper presents an assessment of quantity and quality performance of a trunk main cleaning using ice slurry pigging intervention. Hydraulic calibration showed a 7x roughness height reduction after ice slurry pigging, although turbidity response due to carefully imposed shear stress increase remained significant, indicating loose materials had not been fully removed from the pipe wall. Due to ongoing material accumulation, one-off intervention may not be sufficient to manage the quality risk.

TOC (total organics carbon) analysis, as a laboratory and online technology, offers new perspectives to organic measurements in waters and waste water, supplementing regulatory oxygen demand tests. TOC monitoring, implemented as a tool to make informative and rapid treatment decisions, becomes a useful process control parameter. This paper discusses the various technologies available and details how three municipal plants gained insights into their processes and saved on their spending with TOC.

Flow intake based on predictive control using dry-weather flow and rainfall predictions offers reduced peak discharges on the waste water treatment plants. This results in a better performance of the waste water treatment plant and particularly the utilisation of the post-treatment phase. Results at waste water treatment plant Bennekom show that about 50 % of bypass volume of the post-treatment phase can be prevented with operational predictive control. This improves the surface water quality.

This paper aims at a better understanding of water consumption usage.

Water temperature in the drinking water distribution system (DWDS) and at the customers' taps approaches the surrounding soil temperature at 1 m in depth. In the Netherlands drinking water is distributed without additional residual disinfectant and drinking water temperature at the customers' tap should not exceed 25 ºC. Some urban infrastructures are heat sources and generate hot-spots. This article describes a method to find anthropogenic heat sources that influence temperature in the DWDS.

The article introduces a stable formulation of the model for water distribution systems that guarantees the existence of a unique solution. This is done regarding two modeling paradigms. First for models with customer demand as a fixed boundary condition and second for models that add a boundary condition on the minimum network pressure. The following discussion concludes that pressure-driven models are superior in modeling deficient networks, but still have to be improved.

The build-up and subsequent remobilization of microscopic particles can cause discoloration of drinking water during distribution. We theoretically investigated the relevant transport processes and dependencies on flow conditions and particle properties. The presented theoretical framework is intended as a starting point for a numerical tool to help water utilities determine regions of high discoloration risk and reduce these risks, e.g., by designing more efficient pipe cleaning programs.

With photocatalytic activity of commercially available photocatalysts, viz. ZnO, TiO₂ and SnO₂, a set of photocatalytic experiments was performed under similar conditions using crystal violet, basic blue and methyl red dyes in water. The comparison of photocatalytic activity of ZnO with the benchmark Degussa P-25 (TiO₂) catalyst as well as with AR grade TiO₂ and SnO₂ showed that despite low specific surface areas and larger grain sizes, ZnO displayed higher activity in the degradation of dyes.

Low-income countries lack the capacity to remove chemical contaminants like nitrates. Hence, an economical water filtration technology was explored, which is bio-sand filtration. In order to enhance the removal of nitrates through denitrification, a modified bio-sand filter with ethanol as an external carbon source at C / N ratios of 1.1 and 1.8 was investigated. The results of the research showed a removal rate of 53 % at a C / N ratio of 1.8.