The National Research Council Canada (NRC) has recently completed a project to assist the City of Montreal in determining the condition of its water and sewer system. NRC staff members reviewed available and developing diagnostic techniques for both systems, conducted experiments on non-destructive evaluation methods and provided general scientific advice during the course of the project. This ...

The nature of trace element carriers contained in sewage and combined sewer overflow (CSO) was investigated by TEM-EDX-Electron diffraction and SEM-EDX. During dry weather, chalcophile elements were found to accumulate in sewer sediments as early diagenetic sulfide phases. The sulfurization of some metal alloys was also evidenced. Other heavy metal carriers detected in sewage include metal allo...

Asset management is an increasing concern for wastewater utilities and companies. Indicators are developed for supporting the definition of investigation and rehabilitation programs. These indicators are mostly based on visual inspections, which provide major information. However, difficulty remains in the translation of a visual inspection survey into dysfunction indicators. Condition grade of...

We simultaneously determined the phylogenetic identification and substrate uptake patterns of sulfate-reducing bacteria (SRB) inhabiting a sewer biofilm with oxygen, nitrate, or sulfate as an electron acceptor by combining microautoradiography and fluorescent in situ hybridization (MAR-FISH) with family- and genus-specific 16S rRNA probes. The MAR-FISH analysis revealed that Desulfobulbus hybri...

Most biological systems employ visually acquired information for their locomotion. In the course of evolutionary history, the visual system of organisms has evolved to he adapted to the environment. As a consequence of this adaptation, biological systems often display highly efficient visual skills. This reasoning has motivated the development of a specific visual system, which serves the purpo...

The city of Toulouse with its separate sewer system is ideal for studying stormwater. However, during dry weather, the storm sewer also discharges water into the environment, and it is the impact of these discharges on annual pollution from storm sewer that is the object of this study. Samples have been taken from the outlets of two storm drains located in heavily and moderately urbanized areas...

This study describes the temporal and spatial variability of bacterial communities within a combined sewer system in England. Sampling was conducted over 9 months in a sewer system with intensive monitoring of hydraulic conditions. The bacterial communities were characterized by 16S rRNA gene-targeted terminal restriction fragment length polymorphism analysis. These data were related to the hyd...

Adaptation has become an important aspect of robot design. The work here describes the perception and motion control of MAKRO an autonomous robot for sewer inspection from the point of view of MAKRO’s adaptation to specific features of the sewer environment. Two features are crucial for MAKRO’s adaptation. First, narrow sewer pipes connected into a unified system via junctions, compose a graph-...

Effective decision support and model predictive control of real-time environmental systems require that evolutionary algorithms operate more efficiently. A suite of model predictive control (MPC) genetic algorithms are developed and tested offline to explore their value for reducing combined sewer overflow (CSO) volumes during real-time use in a deep-tunnel sewer system. MPC approaches include ...

Reinforced concrete pipe (RCP) has been one of the most common pipes for medium to large diameter utility systems including sanitary sewer, and storm drainage systems. RCP typically has superior structural properties combining high compressive strength from concrete and tensile strength from reinforced steel. RCP tends to deteriorate over time due to hydrogen sulfide (H2S) gas in sewage and man...