Wastewater Treatment Plant Stripper Tank / Filter Tank Confined-Space Multi-Gas Monitor Installation

This is a case of installing gas monitors in the confined space of a wastewater treatment facility's stripper liquid tank and filter tank. When entering or working in a confined space at a wastewater treatment plant, checking the H₂S (hydrogen sulfide) concentration is just as important as measuring oxygen concentration. Even if the oxygen concentration is stable at 20.9%, the H₂S concentration must always be double-checked to prevent safety accidents.

Gas monitor installed in the confined space of the stripper liquid tank

Before installing the gas monitoring equipment in the confined space, the indoor air condition was checked. From the moment of entry, a portable gas sensor confirmed that hydrogen sulfide gas was being generated.

Measuring the indoor air condition before installing the gas monitor at the wastewater treatment plant

Even after opening the door and ventilating, the oxygen concentration did not change, but the H₂S concentration did not drop and was continuously measured at around 5 to 15 ppm.

Gas monitor installed in the confined space

For the safety of workers, a gas monitoring status board was installed above the entrance. Gas monitor: FIX800 installation-type multi-gas monitor. Measurement items: O₂ (oxygen), H₂S (hydrogen sulfide), CO (carbon monoxide), CO₂ (carbon dioxide). Gas alarm: a warning light activates when a reading goes above or below the set threshold. Additional option: equipped with "Entry Permitted" and "No Entry" indicators.

Gas concentration status board

When gas is detected, a "No Entry" message appears at the bottom of the gas display board. Through this intuitive display, an alarm can warn workers not to enter the confined space when a hazard is present.

Gas monitoring installation in the confined space of the stripper liquid tank

Although there was a ventilation fan inside the confined space, the H₂S concentration was so high that, even after the door was closed, it was confirmed to rise above 20 ppm. At other sites as well, the oxygen concentration was often stable while the H₂S concentration rose to high levels. For wastewater treatment plants, we strongly recommend always measuring H₂S together with oxygen.

Installation-type multi-gas monitor

The cost of installing gas monitoring equipment is incomparably smaller than the cost of dealing with an asphyxiation accident. For vulnerable confined-space areas, it is advisable to always keep a portable gas monitor on hand or to build a gas monitoring system.

Gas monitor installed in an asphyxiation-risk area

If you have any questions about installing gas monitors or selecting the right specifications, please feel free to reach out. Always work safely!