What types of gases need to be tested and solutions for underground closed operations

Firstly, domestic sewage is water that has been used by humans in their daily lives and polluted by household waste. Its water quality and quantity vary with the seasons, with relatively more water used in summer and lower concentrations; In winter, the corresponding amount is low and the concentration is high. Domestic sewage generally does not contain toxic substances, but it has conditions suitable for microbial reproduction and contains a large number of pathogens, which poses certain hazards from a hygiene perspective.

Industrial wastewater is the wastewater generated during industrial and mining production activities. Industrial wastewater can be divided into production wastewater and production wastewater. Production wastewater refers to the water formed during the production process and contaminated by raw materials such as raw materials, semi-finished products, or finished products, as well as thermal pollution (referring to water with a temperature exceeding 60 ℃ generated during the production process); Production wastewater refers to water that is formed during the production process, but does not directly participate in the production process, is not contaminated by raw materials such as raw materials, semi-finished products, or finished products, or only has little temperature rise. Production wastewater requires purification treatment; Production wastewater does not require purification treatment or only requires simple treatment such as cooling treatment. The mixed sewage of domestic sewage and production sewage is called urban sewage.

Among the water pollution caused by human production activities, industrial pollution is the most serious. Industrial wastewater, which contains many pollutants and complex components, is not only difficult to purify in water, but also difficult to treat.

Industrial wastewater is the most important cause of water pollution caused by industrial pollution. It accounts for the majority of industrial emissions of pollutants. The pollutants contained in industrial wastewater vary greatly depending on the type of factory, and even for similar factories with different production processes, the quality and quantity of pollutants contained are also different. In addition to direct discharge of wastewater into water bodies causing pollution, solid waste and exhaust gases also pollute water bodies. Agricultural pollution is primarily caused by tillage or land reclamation leading to loose soil surfaces. When the soil and terrain are not yet stable, rainfall causes a large amount of sediment to flow into the water, increasing suspended solids in the water.

Another important reason is that in recent years, the use of pesticides and fertilizers has been increasing. However, only a small amount of pesticides and fertilizers are attached or absorbed, while the vast majority of the remaining residues remain in the soil and float in the atmosphere. Through rainfall and surface runoff, they enter and infiltrate surface water, causing pollution.

Urban pollution sources are caused by the concentration of urban population, water pollution caused by urban domestic sewage, garbage, and exhaust gas. The main source of urban pollution to water bodies is domestic sewage, which is a mixture of various types of sewage generated in people's daily lives, including sewage discharged from kitchens, washing rooms, bathrooms, and toilets.

Only urban areas in the world discharge up to 500 cubic kilometers of industrial and domestic wastewater in a year, and each drop of sewage pollutes several times or even dozens of times more water bodies.

What types of gases and solutions are required for underground closed operations? Generally, there are flammable and explosive gases as well as toxic and harmful gases such as carbon monoxide and hydrogen sulfide present underground in sewage treatment plants. Of course, the oxygen content underground also needs to be tested to determine whether personnel are safe to go down. In addition, if the environment is relatively special, toxic and harmful gases other than the above four gases may also appear, which need to be determined according to the specific situation of each site.