Possible applications of gas-liquid contacting system, such as degassing, are as follows:
- Drinking water with the smell of “rotten eggs” due to the presence of naturally dissolved hydrogen sulfide, are often encountered in shallow, poorly constructed wells or wells located close to sewer lines or septic systems. Often wells drilled in shale or sandstone or near coal or oil fields often will have hydrogen sulfide present in the water. Although typical concentrations in household water are not a health risk, high concentrations do affect the taste of water, at concentrations as low as 0.1 mg of hydrogen sulfide per liter of water (mg/L). Hydrogen sulfide can also corrode plumbing metals (iron, steel, copper, brass), resulting in black stains in laundry and bathroom fixtures, darken silverware and discolor copper and brass utensils. In addition, presence of dissolved sulfides increases the cost of chlorination, since chlorine is chemically consumed by dissolved sulfide.
- In treating water using an ion-exchange resin, the presence of dissolved carbon dioxide in the water can substantially increase the chemical costs for resin regeneration. When the dissolved carbon dioxide is removed from the water, the frequency of regeneration of the resin bed can be reduced, hereby saving thousands of dollars in sodium hydroxide costs.
- Removal of trihalomethanes (THMs) from drinking water is a major issue, especially since these halogenated compounds are carcinogenic. THMs often result from the use of chloroanilines by municipal water treating plants. The presence of these compounds can adversely affect downstream processes that require high purity water.