Dan Peter
Odor emissions from transfer stations and landfills continue to be a major issue for surrounding residents and businesses. The fermentation and degradation of waste, which is the source of odors, are accelerated at elevated temperatures, making the problem of odor emissions more acute during summer months.
While tarps, domes or other enclosures help contain repugnant odors, chemical treatments work at the source of the odors to help reduce the severity of odors or in some cases eliminate them completely. Though the idea behind odor control chemicals is the same, the methods and effectiveness of each solution is different.
Atomized Essential Oils
Atomized essential oils have been used for years to treat organic odor emissions. The mechanisms for odor treatment include adsorption (covering) and absorption (penetrating) of odor molecules on and in the surface of the oil droplet, respectively.
The perception of odors is based on the molecules being in a gaseous state, and once these odor molecules are adsorbed or absorbed into a liquid phase, they are no longer odorous. Water-soluble oils make the atomized less polar, increasing the solubility of odorous compounds in the water. Non-water-soluble oils form a thin film on each atomized droplet, creating a negative electrostatic charge on the droplet鈥檚 surface. This reaction forces the droplets to repel each other, preventing the accumulation of the droplets and suspending them in air for a longer period of time.
Though essential oils encapsulate or suspend odor molecules, they do not reduce or prevent these odors. Along with its characteristic scents, essential oils mask odors and can be less effective when wind patterns cause odor to travel quicker, reducing contact time between the atomized droplets and odor molecules. The accumulation of residue from essential oils can also interfere with equipment performance, as well as become an allergen to people in and around the facility.
Masking Agents
Similar to essential oils, masking agents do as their name suggests. Fragrances or heavy perfumes attempt to cover or mask malodors to make them less offensive to olfactory senses. Masking agents are usually effective in small, confined areas, but are largely ineffective in large, open areas since the masking agent and odorous molecules separate due to differences in gas-phase diffusion coefficients.
Enzyme/Protein Solutions
Enzyme/protein solutions interact with odor molecules similarly as essential oils, but do not mask odors. They are also dissolved in water and atomized to present a high surface area to the odorous gases. Odor molecules react with the enzymes and proteins changing their molecular structure inhibiting them from becoming odorous and undetectable by the olfactory senses.
Though constraining odor molecules forming by adding enzymes/proteins can be effective, it does not necessarily work in all environments or applications. There are more than 10,000 different enzymes identified by scientists and each one has a specific job or ability. On the other side, within any landfill or transfer station, there could be a wide array of odors present, each with a unique molecular structure. Since enzymes/proteins are usually specific to certain types of odorous molecules, the effectiveness of reducing or eliminating odors can vary significantly.
Non-Active Biocatalysts
Rather than masking/encapsulating odors or introducing an active enzyme/protein into a waste environment, vegetable-based non-active biocatalysts (NABCs) expedite the natural degradation process of existing bacteria through the introduction of micronutrients. It naturally eradicates odor-causing molecules by disallowing the formation of contaminants such as hydrogen sulfide, ammonia, mercaptans and skatole.
NABCs do not contain active bacteria, enzymes/proteins or harsh chemicals. Instead, these environmentally beneficial products contain nutrients vitamins and trace elements that provide 鈥済ood鈥� bacteria with the ability to expedite the digestion of odor-causing organics and converting it into water, carbon dioxide and various innocuous salts.
NABCs do this by enhancing the existing metabolic processes of the microorganisms present in all live matter, regardless of environment type. The naturally existing bacteria already produce enzymes that facilitate the absorption of organics through their cellular membranes. Since it can be used in any waste environment with odor issues, it does not have the limitations that enzymes/proteins have with targeting specific odor molecules or potentially having a negative effect on the current biological environment.
Application
Many other odor solutions try to control odors once it has been generated, misting continuously at entrances and exits of the transfer stations or around the perimeter of the landfills where air currents and wind can make these applications inefficient. Coverage and retention time is key for optimal results. NABCs should be applied in transfer stations and landfills by regularly spraying over new waste, which is the source of the odor. This multi-layered coverage allows the bacteria to constantly feed on organics to disallow the formation of malodors.
The use of NABCs at transfer stations and landfills also reduces, and in most cases eliminate, the need for leachate water treatment. NABCs have eradicated many of the odor-causing contaminants, including FOG, BOD and more, and no chemicals needed to be added allowing the leachate to be reused. The safety and green nature of NABCs is unparalleled. Containing all organic elements, NABCs are truly safe for humans, animals and the environment. It is non-allergenic, non-irritating
Nature鈥檚 biological cleaning crew
Keeping odors from becoming a nuisance to the surrounding community can not only be a public relations issue, but also a financial one. Treating those odors with ineffective or environmentally harmful methods can prove to be just as detrimental.
NABCs not only provide a cost-effective solution for transfer station and landfill odor issues, but they can also be used in sludge tanks, lagoons or other areas where odors are an issue. The environmentally beneficial foundation of NABCs provides effective and natural odor elimination without any environmental or safety concerns. Think of NABCs as nature鈥檚 biological cleaning crew.
Dan Peter is the Marketing Director for Apex Engineering Products (Aurora, IL), a manufacturer of safe and biodegradable specialty chemicals, including RYDALL OE Odor Eliminator. For more information on how RYDALL OE can help with odor and leachate issues at your landfill, transfer station or accompanying equipment, call (800) 451-6291 or (630) 820-8888 or visit www.apexengineeringproducts.com.
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Case Study
RYDALL OE Odor Eliminator Eradicates Odors, Recycles Leachate Back into Landfill
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A Florida landfill was experiencing significant odor issues from the open face of the landfill and its leachate holding tank. The odors were not only a nuisance for residents and businesses in the surrounding community, but also resulted in costly fines on a regular basis. Essential oils, fragrances and other masking agents were largely ineffective and proved not to be cost-effective.
After learning about the science behind RYDALL OE Odor Eliminator, as well as calculating the cost-savings, the landfill decided to use RYDALL OE in two phases. The first phase was to dilute 7 gallons of RYDALL OE into 3,500 gallons of water and apply it over the open face of the landfill on a daily basis.
After approximately one week, the repugnant odors emanating from the landfill significantly decreased, putting an end to the regularly issued fines. To achieve further odor eradication and cost-savings, the second phase targeting the leachate was implemented. Approximately 65,000 gallons of leachate is collected daily and stored in an 80,000-gallon tank until hauled off to the local WWTP (wastewater treatment plant), adding significant costs for haul-off and WWTP fees.
In this second phase, approximately 13 gallons of RYDALL OE was added to the 65,000 gallons of leachate and retained for 24 hours. After the treatment, rather than having the leachate hauled off, the effluent was able to be recycled back onto the landfill for further odor eradication without additional RYDALL OE dosing.
In addition to the elimination of fines and odor complaints, the landfill also saw substantial savings from reduced haul-off and WWTP fees for its leachate. The amount of RYDALL OE needed on a daily basis to maintain the optimal level of odor control was also decreased as this non-active biocatalyst continued to work on all layers and areas of the landfill.
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