Asset management platform integrates real-time sulfide data

Background
Every year, hydrogen sulfide induced corrosion causes water utilities around the world to waste a significant part of their operating budgets on repairs and replacements of prematurely deteriorated wells, pipes, pumps and other assets. Without access to a full and dynamic overview of the cause and magnitude of their hydrogen sulfide challenges, utilities are often forced to make important asset management decisions on an uninformed basis, which might cause them to replace healthy assets prematurely or overlook severely damaged ones altogether.

The new asset management software data|APX by APX10 addresses this problem by enabling water utilities to make big decisions on an informed basis using the necessary data.

Sensor integration
Data|APX is a big data analytics platform comprising a default framework and a range of specialized modules. In the H₂S module, force mains are analyzed using dynamic modelling techniques to predict which end-of-pipe discharge wells and nearby urbanized areas are likely to be affected by the consequences of hydrogen sulfide degassing.

The screening tool highlights potentially problematic areas using color gradient overlays on maps embedded with GIS data of sewer lines, wells, pumping stations and other assets. Utilities are then able to assess and prioritize further inspections to understand the scope and cause of a problem in greater detail by integrating real-time sensor data from the SulfiLogger^TM H₂S sensor in the data|APX platform.

Using the data|APX platform, the Danish water utility Struer Forsyning identified a potentially problematic branched force main south of the city Struer. With a major highway located above a potentially affected gravitational line, it was of vital importance for the utility to initiate actions to prevent or minimize hydrogen sulfide degassing and maximize the lifespan of the line. Although Struer Forsyning already doses chemicals, the utility suspects the current dosing rate is insufficient.

To understand the situation in greater detail, Unisense installed two inline SulfiLogger^TM H₂S sensors at a pumping station sump and in the gravity line just after the force main’s end-of-pipe discharge. Using the online sensor signal from these two installations, Struer Forsyning adjusted the dosing rate to match actual H₂S peak levels resulting in a complete elimination of the hydrogen sulfide problem as visualized in the data|APX platform interface.

Visualization of the H2S module in data|APX before and after Struer Forsyning decided to increase the injection rate at the chemical dosing station in the beginning of the force main. The potential for hydrogen sulfide degassing is visualized using color gradient circles around the blue marker points, while a click on a marker expands this view with real-time sensor data in a pop-up window.

Perspectives
Although dynamic modelling and simulations provide an excellent screening tool for capturing daily variations in hydrogen sulfide formation under ideal conditions, they are still unable to capture the full effect in complex sewer networks with branched connections or unpredictable industrial sewage discharge.

To understand the dynamic effects of such networks, real-time sensor data is required, which in cooperation with state-of-the-art modelling solutions can improve our understanding of hydrogen sulfide formation in sewer networks for efficient mitigation actions.