The principal sources of odor in wastewater operations are septic wastewater containing hydrogen sulfide (H2S) and other odorous compounds in the plant's pipelines; industrial wastes discharged to the sewage collection system; unwashed grit; scum on primary settling tanks; organically overloaded biological treatment processes; solids thickening tanks; waste-gas burning operations in which lower than optimum temperatures are used; chemical mixing operations; solids incinerators; and digested solids in drying beds or solids holding basins.
 
Odors from these sources vary in degree and intensity depending on the amount of anaerobic decomposition present. Hydrogen sulfide, the most prevalent source of all odors, often is accompanied by mercaptans, indole, skatole, amines, fatty acids and other volatile organic compounds (VOCs). Odor-control systems typically focus on H2S because of its low odor threshold (<0.5 ppb), predominance as an odorous agent, and ease of analytical detection.
 
Controlling odorous emissions has always been difficult for sewage treatment facilities, particularly for those near residential areas. But as nearby populations increase and pump stations transfer more wastewater solids to the plants, odor control is becoming a bigger challenge. Traditionally treatment facilities had used activated carbon adsorbers to clean the air. Advancements in media technology offered more options with the development of caustic-impregnated carbons and "catalytic" carbons that offered higher H2S removal capacities. Now there are even higher capacity engineered media products in use that provide overall better odor control. However, all of these systems have a one thing in common - at some point the media's H2S capacity is reached and it must be replaced, reactivated, or regenerated. Which option provides the most effective and economical solution? Now THAT is the question!

Click here to read the full article!