Study of removing hydrogen sulfide from ventilation
and sewage gas-air emissions by absorption cleaning

Summary

The results of studying the removal of hydrogen sulfide from ventilation and sewage gas-air emissions by absorption cleaning on a packing irrigated with sodium hypochlorite are presented. The studies were carried out in a laboratory setup. The subject of research was artificially prepared gas mixture of air and hydrogen sulfide obtained by dosing hydrogen sulfide solution into acidic solution (gas generator). Variation of the hydrogen sulfide concentration in the air was achieved by changing the feed from a hydrogen sulfide-containing solution dispenser. The laboratory setup included an absorber with a volumetric packing made on the model of Raschig rings. Chlorine-containing 0.3% sodium chloride solution was used as the absorption solution. The regeneration of active chlorine (reduced by hydrogen sulfide to chlorides) in the absorbent was carried out by direct electrolysis in a flow-through electrolyzer installed in the line supplying the absorbent to the absorber. The actual dose of active chlorine for the oxidation of hydrogen sulfide absorbed by the absorbent was determined. The main dependences describing the chemisorption of hydrogen sulfide and the electrochemical regeneration of sodium hypochlorite in the absorbent are presented. A method for calculating the absorber of the laboratory setup is presented. Specific electricity consumption for removing hydrogen sulfide from air was determined. In the follow-up studies the obtained results will provide for calculating the costs of air purification, estimating the operating costs and conducting an engineering and economical comparison of the proposed and competing methods of removing malodorous substances from ventilation emissions from sewer facilities. The presented method can be recommended in the schemes for cleaning ventilation emissions at the wastewater treatment facilities.

Key words

sodium hypochlorite , reeking substances , hydrogen sulfide , absorption , cleaning of ventilation emissions