AN EFFECTIVE ODOR CONTROL SYSTEM RELIES ON MORE THAN SELECTING THE RIGHT TECHNOLOGY

The key to addressing nuisance odors may not be as straightforward as expected. We recognize that technologies are available to treat and reduce nuisance odors at municipal and industrial wastewater treatment plants. The challenge comes in understanding the nature and source of the nuisance odors so that the appropriate odor control technology can be selected, designed and installed. When properly implemented, the appropriate technology will produce exhaust emissions that will not be perceived as offensive by the local communities off-site. But, unless we capture and contain the odors at the point of release, and then convey them to the odor control device, the money spent on an effective odor control technology will have been wasted.

A critical element of odor control systems that is often overlooked is the design of containment structures and ventilation air flows that can eliminate the release of fugitive odors. We will examine the design options and constraints that the engineer is faced with when developing an effective odor containment system, focusing on the two basic areas of interest:



cover system

ventilation system

Selecting a cover system can be a complicated procedure, considering that the options range from the style of cover (flat, arch, dome, penthouse, complete building, etc.) to the materials of construction (concrete, stainless steel, fiberglass reinforced plastic (FRP), aluminum, wood, plastic, canvas, etc.). Before selecting a cover, the ventilation requirements and constraints need to be evaluated. Historically, ventilation systems have been designed in accordance with principles consistent with heating and cooling occupied spaces, instead of with odor control in mind.

Some of the key odor capture and containment design criteria that will be evaluated include:



minimize the volume of odorous air to be treated

satisfy worker safety air exchange requirements

cost

satisfy plant staff access/visibility requirements

provide fresh make-up air in worker space areas

maintain negative pressure within the enclosed area and duct conveyance network

satisfy client aesthetic requirements

environment factors

The importance of each of these criteria will be discussed and related to multiple projects where these issues were addressed.