There is a hydrogen sulfide issue in the sewage treatment tank
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I’ve been hearing a lot about that company recently; it caused hydrogen sulfide poisoning incidents while cleaning sewage treatment tanks. What kind of sewage treatment tanks are prone to the accumulation of hydrogen sulfide? Is it related to the components present in the water being treated? How to solve the problem of hydrogen sulfide accumulation
The presence of dissolved sulfides and hydrogen ions makes it very easy to generate hydrogen sulfide under conditions of vigorous stirring； The handling method involves detecting the gas composition before cleaning, ventilating to replace the air, and taking proper protective measures. If the quantity is large, it can be drawn out and treated with concentrated alkali solution
The molecular weight of hydrogen sulfide is 34, while the average molecular weight of air is 29; therefore, hydrogen sulfide at the bottom of the pool does not spread easily. Hydrogen sulfide is adsorbed in the sludge; it comes out when the sludge is stirred. The gas in the analysis cell should be tested before the operation. Isolated air respirators or long hoses should still be worn during the task.
I wonder if Ca2+ can be added? If possible, CaS precipitation can be formed.
Is hydrogen sulfide generated on the bottom of the tank by itself, or does it appear as a result of impurities in the water quality?
Cleaning the pool constitutes work in a confined space; first, it is necessary to check for toxic and harmful gases inside the pool, and use a multi-functional gas detector. Personnel entering the pool must wear safety belts as well as safety ropes to ensure timely evacuation. There are two possible scenarios regarding hydrogen sulfide: one is in the gas form, and when its concentration exceeds the allowed level, forced ventilation is required; the other scenario involves it being present in the sludge, and during cleaning, hydrogen sulfide detectors emit alarms, prompting the addition of alkaline solutions for absorption. However, it’s not possible to absorb 100% of it, so cleaning is carried out only once the concentration is back within acceptable limits