Growing environmental concerns have resulted in the construction and upgrading of waste water treatment plants throughout North America.
By their very design, processes involved in sewage treatment produce and use a number of highly toxic and explosive gases, requiring waste water monitoring to ensure the safety of both employees and the environment.
There are three main gases to be aware of when designing monitoring systems for waste water treatment facilities.
Hydrogen Sulfide: A highly toxic gas (TLV 10 PPM) produced wherever large holding tanks or settling basins are located. Because few of these areas conform to normal square footage guidelines, sensors are located as required near probable H2S sources.
Methane: Also known as natural gas, methane is an explosive gas (L.E.L 5% volume) produced primarily in the initial stages of decomposition. Because of its low density, methane will accumulate in pockets near the ceiling of enclosed areas such as holding tanks and settling basins.
Oxygen: Because of the high number of chemical and organic processes occurring in any wastewater treatment plant, adequate levels of oxygen must be maintained to ensure worker safety. Oxygen sensors should be located in enclosed areas, wherever oxygen levels may be in question.
Purifying Chemicals: Chemicals such as ammonia, ozone and chlorine are all used in the decontamination of water, both in waste water and water purification plants.