Jul 22, 2020

Important Considerations for Odor Control in Wastewater

What to think about when addressing odor control

wastewater control

Controlling odor in wastewater treatment plants, landfills and other sites is an important task. Even on a cold day with no wind, odor is present in each of these areas, causing potential issues for both workers and the surrounding communities.

In today’s culture of social media, it is easier than ever for people to go online and express their complaints. This can often lead to unwanted attention and even penalties and regulatory fines. Now more than ever, an odor control solution is an essential element of a wastewater treatment plant. If a facility does not have a sound odor control solution in place, now is the time to get started. 

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Identify the Sources

It is important to understand where odors are emanating from at a wastewater facility in order to effectively treat them. It is likely there are multiple sources of odor, which could require more than one system to control.  There also is the possibility that odor could be controlled with a singular system around the perimeter of the wastewater treatment plant. 

Common Sources of Wastewater Odor 

Most areas of a wastewater treatment facility typically dispel odor. In addition to primary treatment and sludge handling areas, odor may also be experienced in the below areas, which can emit hydrogen sulfide, ammonia, sulfur dioxide, skatoles, mercaptans, amines and indoles.

Determine the Odor Causes & Factor in the Elements

Odor production contains many characteristics, including its concentration or molecular weight, that can deem whether it is detectable or not. We sense odors when the structural characteristics of their molecules stimulate the body’s olfactory sensory cells that are responsible for processing smells. From the chemical side, once the cause of the odor is determined, we’re able to identify the solution that will effectively remove the odor. 

It is important to note that geography and weather conditions are significant factors in how odor emanates at wastewater facilities. Temperature, humidity, wind and precipitation are elements to consider when determining the appropriate odor control delivery method. 

For example, presume a facility is located in a hot and humid area (such as Florida). Odor issues will likely be significantly greater than a wastewater treatment facility in Washington state. Hot and humid weather creates the optimal environment for a facility to produce hydrogen sulfide, ammonia and mercaptans odors. To make matters worse, volatile organic compounds in your facility start coming off, creating even more odor. 

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Choose an Odor Control Partner

With all of these factors to consider, working with an odor control partner is the best option to determine the best odor control solution for a specific wastewater treatment facility. Companies who specialize in odor control will know how to access a facility, can determine the exact sources of odor, factor in weather and environmental conditions and recommend an appropriate course of action. 

How each odor control company does this will differ slightly. At OMI Ind., a team of engineers will start by coming on site to see the wastewater treatment facility in person. This is the best way to appropriately identify each factor contributing to odor at the site. In addition, being on-site helps identify the correct plant-based solution for it and what type of equipment is needed for specific applications.   

Not only will an odor control partner help identify the solution to combat odors now, that partner will be a go-to resource in the future for any additional needs as well. 

Select the Optimal Odor Control Solution

OMI Ind. uses natural, plant-based formulations to neutralize the odor molecules themselves rather than masking the smell. Through a mode of action, multiple delivery methods and rigorous safety qualifications, these methods are resulting in safe and complete control of odor emissions in wastewater treatment. 

When dispersed into the air, the molecules of these plant-based solutions immediately bond with present odor molecules. Once bonded, the plant-based molecules absorb odor molecules, similar to water droplets being drawn into a sponge. Odor neutralization is accomplished when the odor molecules are fully enveloped in these plant-based molecules through a combination of water solubility principles and natural plant oil reactions. 

Flexible delivery methods are another key benefit to plant-based solutions. This is important because there is no “one size fits all” odor control solution, and what works for one facility may not work for another. While the most common methods are atomization, vaporization and spray gel, some customers require up to 12 different systems to fight odor at their facility. 

Below are a few examples of how odor control solutions may differ at various locations at your wastewater facility: 

Headworks & Primary Treatment

Hydrogen sulfide odor is a serious issue in wastewater treatment plants. Vapor or fan systems can solve this issue by being installed at the bar screens and digesters. In some cases, the product can be diluted with plant water to form a more cost-effective solution.

Activated Biosolids Basins

Basins for activated biosolids are often large and uncovered. This means smells are free to drift into nearby areas. Custom biochemical delivery systems can be developed to neutralize these previously uninhibited orders naturally. With both low- or high-pressure atomization systems, plant-based solutions can be dispersed over these
large areas. 

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Wastewater Septage Dumping

Raw septage from haulers can present odor problems for plants that otherwise would have their industrial emissions under control. Fan or nozzle atomization systems posted near the unloading point and vented or opened downstream locations provide effective removal of these odors. 

Case Study

Ecosorb, a natural, plant-based odor control solution created by OMI Ind., is providing facilities safe, natural and effective odor control programs. It has established a proven track record in a variety of industries, including wastewater treatment.

The city of Crystal Lake is located about 45 miles northwest of Chicago with a population of nearly 45,000 people. Like many wastewater treatment plants, urban sprawl and suburban development puts the Crystal Lake Wastewater Treatment Plant near many commercial and residential neighbors, including a high school immediately west of the plant.

Plant managers were forward thinking and wanted to remain good neighbors to those occupying the surrounding area. They wanted to take steps to reduce — and hopefully eliminate completely — any odor issues from the plant.

Crystal Lake Wastewater Treatment Plant contacted the Ecosorb chemistry team to learn more about these plant-based products could be used at the plant. After working with an engineer, two high-pressure atomization systems were installed. Each has 20 nozzles for distributing Ecosorb liquid product. One system was installed in the plant influent flume area, and another was placed in the aerated grit removal area. Performance was pleasing enough at the plant that the waterless 130 CFM Vapor Phase units became available, one was installed in the influent flume area, replacing the original high-pressure system.

A newer 450 CFM Vapor Phase unit was installed around the aerated grit removal area, with more than 900 feet of 6-inch vapor line covering grit removal as well as the primary clarifiers. A second 450 CFM Vapor Phase system was installed outside the sludge storage building. It is insulated, heated and heat traced to withstand fluctuations in Midwest weather. Vapor ducts feed from the machine into the side of the building and create a continuous loop surrounding the building. The equipment runs 24 hours a day, seven days a week.

With these products and customized equipment, the plant was able to continue dredging throughout the summer with no further complaints.

About the author

Dr. Laura Haupert, Ph.D., is director of research and development for OMI Ind. Haupert can be reached at [email protected].

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