So what is a biological scrubber?
A Biological Scrubber is a type of wet odor control scrubber that treats and removes contaminants from an air stream that only utilizes caustic typically to control the pH of the re-circulation solution. There are several types of odor control and chemical fume scrubbers on the market today and each of them play a role in the treatment of noxious or corrosive gases in the industry. Biological scrubbers are commonly utilized in municipal applications for the treatment of hydrogen sulfide (H2S) gases that are removed from a water or waste water treatment process. In water treatment equipment such as a “degasification” or “decarbonation” tower strips the hydrogen sulfide gas from the water and exhaust the gas from an exhaust port. These gases are captured and sent via an air duct system to the biological scrubber. Hydrogen gases captured at a wastewater treatment process which may include the treatment plant, lift station or head-works facility are also sent using a PVC or FRP duct system to the biological scrubber.
So how does a Biological Scrubber work?
Interesting enough a biological scrubber utilizes tiny microorganisms (bacteria) to breakdown and digest contaminants and the bacteria feed on the contaminants and utilize this as a feed source to live and grow. When utilizing a biological scrubber for hydrogen sulfide (H2S) treatment the by-product waste is acid from the digested H2S. This lowers the pH and requires the use of caustic to buffer the water and nutrient solution that is
recirculated within the scrubber to maintain a neutral pH. The captured gas containing contaminants enters into the bottom of a vertical biological scrubber much like the gas enters any other type of chemical scrubber or other type of single or dual pass odor control scrubber.