Sewage treatment plants are important facilities for treating urban sewage. Its core function is to remove suspended matter, organic matter, nitrogen and phosphorus and other pollutants in sewage through a series of physical, chemical and biological treatment processes to meet the discharge standard or reuse standard. However, due to the complex structure of sewage treatment plants and the complicated and diverse sewage treatment processes, a large amount of dangerous gases will be produced. According to the different ways of harm, they can be divided into two categories: toxic gases (asphyxiating gases) and flammable and explosive gases.
Hydrogen sulfide is an inorganic compound with the chemical formula H₂S. Under normal circumstances, it is a colorless, flammable, acidic gas that is highly toxic. Stirring sludge and sewage in a small space can make the local hydrogen sulfide concentration too high. When the workers do not pay attention to personal protection, acute hydrogen sulfide poisoning or even death may occur.
Since sewage contains a large number of microorganisms, sewage treatment plants will produce biogas. The main component of biogas is methane, which is not only explosive, but also can cause oxygen concentration to decrease and suffocate people. Moreover, if it leaks out from the digester, it may also cause an explosion.
Among them, poisoning incidents caused by hydrogen sulfide and explosions and suffocation incidents caused by biogas are the main accidents in sewage treatment plants; they are also the key and difficulty of changing the safety and living conditions of sewage treatment plants. Therefore, it is an urgent problem to do a good job in monitoring toxic and harmful gases in sewage treatment plants.
Toxic and harmful gas solutions for sewage treatment plants
In summary, the gases generally detected in sewage treatment plants are combustible gases and hydrogen sulfide. Installing fixed hydrogen sulfide gas monitoring alarms, combustible gas monitoring alarms, gas alarm controllers, fans, etc. in accident-prone locations such as inspection wells, sewage pools, pipe networks, trenches, etc. can form a gas monitoring system with real-time monitoring and timely warning.
The staff can use the computer terminal to check the instrument status and gas leakage in the plant area in real time. When the concentration of toxic and harmful gas leakage reaches the preset value of the instrument, the alarm will immediately send out an audible and visual alarm signal, and the alarm information can also be transmitted to the computer terminal, so that the staff can perceive it in time and handle it remotely to prevent accidents.
When entering the sewage well, the staff needs to use portable and fixed gas detection equipment in combination. Gas storage areas, ozone generators, rooms where gas pipelines pass, and water treatment workshops should always be equipped with fixed detectors to detect specific gases (or gas mixtures).
In addition, when operators need to enter closed spaces where harmful gases exist, even if fixed detectors have been installed in these places, they should carry portable detectors with them as additional safety precautions. For example, a portable composite gas detector can monitor the concentration of hydrogen sulfide, combustible gas and oxygen underground in real time. In the context of the country’s increasing attention and support for the environmental protection industry, sewage treatment plants should firmly establish the concept of safe development, fulfill the main responsibility for safe production in accordance with the law, install toxic and harmful gas monitoring alarms, and comprehensively investigate safety accident hazards. At the same time, staff should also use normalized and nationwide prevention and control to deal with hidden and sudden risks, and build a strong dam for safe production in sewage treatment plants.
