First, pay special attention

Keep in mind the three main properties of hydrogen sulfide: the colorless smell of rotten eggs, a density slightly heavier than air, and flammable materials.

The first feature: colorless rotten egg smell, when you smell the smell of rotten eggs, the first reaction is to enter the place with hydrogen sulfide gas, keep away from it, pay attention to safety;

The second major feature: density is slightly heavier than air, so the high concentration is low, the low concentration is high, try to go higher.

The third feature: flammable items, then reach the explosive concentration will explode, so avoid fire.

Remember the above three characteristics, the subconscious first reaction is safety.

Second, hydrogen sulfide in detail

1. The molecular formula of hydrogen sulfide is H2S, the relative density is 1.19, slightly heavier than air, and it is a colorless gas.

2. When its content in the air is 0.012-0.03mg/m3, it can smell its special rotten egg smell.

3. When the content in the air reaches 0.01%, people will lose their sense of smell after 2-5 minutes of contact;

4. When the content is 0.07%-0.1%, it can cause acute poisoning and paralyze the respiratory center;

5. When the content exceeds 0.2%, it can cause people to suffocate and die within a few minutes.

6. It is theoretically believed that the human body's 60min safe exposure concentration of hydrogen sulfide in the air is 0.02%-0.03%, and the 8-hour safe exposure concentration is 0.001%.

7. Hydrogen sulfide is flammable, reacts strongly with oxidants, is easy to fire or explosion, and the explosion limit in the air is 4.3%-46%. Open flame is strictly prohibited in places with hydrogen sulfide, including sparks, smoking, etc., and the electrical equipment used should have explosion-proof performance.

Third, security measures

Many injuries and deaths in wastewater treatment plants are related to hydrogen sulfide, for example: hydrogen sulfide can accumulate in various sewers, Wells, sumps, pumping stations and structures, causing poisoning and even death of workers. Both urban sewage treatment plants and industrial wastewater treatment stations must have a series of safety measures to prevent hydrogen sulfide poisoning.

1. Master the composition and nature of sewage;

Identify the source of hydrogen sulfide contaminants. The sulfide concentration of each drainage pipeline and its change law to be aware of, acidic sewage and sulfur-containing sewage is the direct cause of the corrosion of sewers, valve Wells, metering Wells, sump basins, pumping stations and structures and the sulfur concentration of the sulfur, so it is necessary to strictly control and timely detection of PH value of acidic sewage and sulfide concentration of sulfur-containing sewage.

2. Test requirements

Often test the concentration of hydrogen sulfide in the catchment tank, pumping station, structure and other sewage treatment operators during inspection, entering all Wells, pools or structures of the sewage treatment plant work, must continuously test the concentration of hydrogen sulfide in the pool and well.

3. Ventilation facilities

Pumping stations, especially underground pumping stations, must be installed ventilation facilities, hydrogen sulfide is heavier than air, so the exhaust fan must be installed in the low part of the pumping station, and the air intake is set at the height of the pumping room.

4. Work space detection

When entering a well, pool or structure that contains hydrogen sulfide gas is detected, ventilation should be used first to reduce its concentration, and gas masks that filter hydrogen sulfide or use compressed air to supply oxygen should be worn when entering.

5. System management

Strictly implement the operation ticket system for sinking Wells and entering pools. To enter the sewage collection Wells, sumps, sewage pipes and inspection Wells to clean the silt is a dangerous operation, must fill in a variety of operation tickets in accordance with the relevant regulations, and can be countersigned by the relevant management personnel. The implementation of this management system can effectively control the number of Wells and pools, and avoid the randomness of Wells and pools; And can urge the well, into the pool personnel to pay attention to safety, to avoid accidents.

6. Personnel training

Relevant personnel must be trained on the necessary knowledge of air protection. It is necessary to make the relevant personnel understand the nature, characteristics, prevention of common sense and rescue measures after poisoning, etc., try to prevent in advance, once the problem occurs, but also do not panic, timely rescue, and eliminate the occurrence of even death and injury accidents.

7. Inspection management

In the sewage treatment plant where there may be hydrogen sulfide, the operator inspection or laboratory personnel sampling, can not go alone, must be supervised.