A manufacturing facility cannot ignore the importance of odor control.

The smell of chemicals, vapors, and fumes can spread quickly in a small area. They cause discomfort to workers and pose health risks to them. In addition, excess vapors directly impact the efficiency of exhaust or natural ventilation systems. For example, an odor control scrubber tower is an additional layer in the ventilation system of a manufacturing plant or chemical processing facility with odor issues. These towers effectively remove noxious fumes and odors from ventilation exhaust streams using an activated carbon filter and an ionic air filter.

Reasons why you should consider installing an Odor Control Scrubber Tower :

Health & safety of workers.

Anyone working in an industrial environment, directly or indirectly, is at risk of exposure to hazardous fumes and gases. At times, high concentrations of these gases may be emitted into the atmosphere in the form of unhealthy odors, putting the health and safety of the workers at risk. These gases may even be combustible in some cases, posing a significant threat to workers. The purpose of an odor control scrubber tower is to remove these gases from the contaminated air stream and help the workers stay safe. In addition, it reduces the risk of health issues such as nausea, headaches, loss of consciousness, allergy symptoms, dizziness, and many more. It also prevents workers from missing their daily performance targets due to sickness caused by toxic fumes.

Pro-environment step.

Although it is vital to protect workers from exposure to harmful fumes, it is also essential to protect the environment. Odor control scrubbers are used in petrochemical refining, pharmaceutical, food & beverage, paper, mining, chemical, and pharmaceutical industries. Therefore, choosing the right scrubber type that suits your industry’s requirements is crucial. The right choice of equipment also protects the environment as it helps reduce operational costs and maintenance supervision. It also protects the environment because it produces minimal sludge and reduces the risk of corrosion.

If you’ve been following the news, you know a growing problem with PFAS (per and poly-fluoroalkyl substances).

These man-made chemicals are found in everything from clothing to food packaging. While they are inexpensive and stable in products, some tend to break down into other substances, such as PFAS-methyl tetrahydrofuran. PFASs have been discovered in drinking water nationwide, including in parts of the country with very high water tables. As a result, it’s essential to learn how to remove contaminants from your drinking water. What should you do if you suspect that there’s a problem with your water? Check the source of the water, test it, and treat it if necessary.

Follow these steps to remove contaminants from your drinking water.

Test Your Water

Although it’s essential to know how to remove contaminants in general, it’s even more important to know how to test your water for contamination. A water test kit can help you determine whether there are contaminants in your water and whether they are at a dangerous level. You can purchase water test kits at grocery stores, hardware stores, and online retailers. Generally, these kits come with the standard set of tests for a home water filtration system, but they also often include tests for specific contaminants. Use these tests to determine whether your water is safe to drink. If your water contains contaminants, you need to remove them from your water source. This can be done by digging a more bottomless well, installing a water filtration system, or getting a water purification system. If your water does not contain contaminants, you don’t need to do anything except continue drinking your water.

A BIOLOGICAL ODOR CONTROL SCRUBBER IS JUST ONE OF MANY DIFFERENT TYPES OF AVAILABLE TECHNOLOGIES

To treat air emissions that may contain harmful gases. This class of equipment commonly falls into a category referred to as “Odor Control Scrubbers” and they are utilized to remove dangerous or noxious odors from an air stream. The Biological Odor Control System has gain popularity among many end users such as municipal operators due to the reduced operating cost and more simplistic operating requirements. A typical chemical odor control scrubber often requires two or more chemical additives, and more instrumentation is required to maintain system performance. With the additional chemicals required and instrumentation comes the need for more hands-on maintenance, calibration, and safety requirements which increases the operating costs and workload of the operator.

A Biological Odor Control System relies on active bacteria cultures that recirculate within a water stream and flow across a random packed media bed that is beneficial to the bacteria culture. During the process of metabolizing harmful gases such as Hydrogen Sulfide (H₂S) the biological odor control system requires only the addition of Caustic to control and balance the pH and additional water makeup to replace what has been consumed through evaporation or during the blow down process to eliminate solids. There are several different types of odor control and chemical wet scrubbers on the market today and each provide a solution for the treatment of noxious or corrosive gases and odors in the industry.  And even though Biological scrubbers are commonly utilized in municipal applications for the treatment of hydrogen sulfide (H2S) gases that were produced by a water or wastewater treatment process there are times when a Biological Scrubber does not provide the best solution for treatment. When there are wide or rapidly changing concentration in the ppm (parts per million) level than a Biological Scrubber will have difficulties balancing and acclimating fast enough to prevent break through.  As an example, In water treatment there is a treatment process referred to as “degasification” which strips the hydrogen sulfide gas from the water and then the concentrated H2S gas is exhausted from the tower through an exhaust port.  When the concentration rises above 1 ppm for hydrogen sulfide gas then the levels become both noxious to the surroundings as well as corrosive. Many times, the levels range from 3-7 PPM in concentration with Hydrogen Sulfide and pose a serious health threat, noxious odor, and corrosive environment demanding capture and treatment. When utilizing an Odor Control Scrubber such as a Biological Scrubber the gases are pulled or pushed through an air duct system that is connected to the Biological Scrubber inlet or suction side of the blower. The same process is utilized when treating Hydrogen Sulfide (H₂S) gases that were captured at a wastewater treatment process. These gases may have been generated from a source such as the wastewater treatment plant, lift station or master head-works facility. When captured the gases are also conveyed in a similar manner to the Biological Odor Control Tower for treatment.

A Biological Odor Control Scrubber is in fact a eco system all to itself. The biological scrubber relies upon an initial seeding of tiny microorganisms (bacteria) which attach themselves to the internal media substrate or packing providing both a place to attach and to breed and multiply all the time coming in direct contact with the contaminated air. The bacteria are utilized to breakdown and digest contaminants, and it feeds on the contaminants as a food source which allows it to not only live but continue to grow and multiply.

When utilizing a Biological Odor Scrubber for hydrogen sulfide (H₂S) treatment and removal the by-product that is produced during the reaction is a waste in the form of Sulphuric Acid which is produced as the Sulphur is consumed as a food source. The Sulphuric acid waste lowers the pH of the recirculating water and can create an unhealthy 

The need for pH control with water degasification and decarbonation in water treatment includes almost every industry and includes;

The need for pH control with water degasification and decarbonation in water treatment includes almost every industry and includes; Aquaculture, food and beverage, industrial, municipal, and even pisciculture.  In some water treatment applications, harmful gases such as Hydrogen Sulfide (H2S) are removed, while in other applications, Carbon Dioxide (CO₂) or a combination of both. In addition, there's a host of other organic and inorganic elements found in water, both naturally occurring and manmade, that require removal during some part of the water treatment process.  

In almost every application of degasification or decarbonation, you will hear or see the term pH used either by need or by the result.  If, as an example, the water treatment application requires the removal of Hydrogen Sulfide (H₂S) to be removed either as “free” gas or requires the conversion of Sulfides into (H₂S) gas. You will often also see the need to adjust the pH of the water chemistry to maximize both the removal and the conversion to increase the efficiency of the equipment being utilized to remove the hydrogen sulfide, such as a degasification tower or commonly called a degasifier.

So, what is pH?

Water pH is a term used to describe whether or not the water is “acidic” or “basic.”  pH ranges in water can be from 0-14.  0 is the most acidic, and 14 is at the far end and is the most basic, leaving “7” as the neutral state.  A pH of 7 is neither acidic nor basic. So, what causes pH to be acidic?  In nature, the most common cause of a low acidic pH in water is Carbon Dioxide (CO₂) which occurs naturally when photosynthesis, decomposition, or respiration occurs in nature.  The increase in CO₂ causes an increase in ions, producing a lower pH in a simplified explanation.

How does pH play such a significant role in degasification and decarbonation? 

As mentioned above in the example of the removal of certain harmful elements such as sulfides, sulfates, and free H₂S hydrogen sulfide gases, to maximize the removal from water utilizing a degasification tower, it is essential to maintain as close to a pH of 5 as possible.  When the pH rises above 5, the ability to convert and strip the free H₂S gas from the water diminishes.  When a degasification tower operates within this specific range and if it has been designed with the higher efficient distribution systems such as the ones utilized by DeLoach Industries, removal efficiencies of 99.999%- 100% can be achieved.   If the pH rises to seven or above, the removal process becomes much more complex, and typically, you will have much lower results.  The pH adjustment during the water treatment process is typically accomplished by adding commercially available acid, such as “sulphuric acid,” one of the most common in the municipal and food and beverage industry.

Hydrogen Sulfide Chemical Formula and the Molar mass of H2S

H2S is a naturally occurring chemical compound created in nature with the decay of organic material. Hydrogen sulfide is a chemical compound with a molecular formula comprised of (2) hydrogen atoms and (1) one sulfur atom. The formula is displayed as H2S. The gas is a colorless hydride, often known as the “Rotten egg gas.” This gas is very dangerous as it is poisonous and toxic to all life forms. It is also very corrosive and flammable. The H2S molar mass is 34.1 g/mol, with a melting point of -76 F (-60 C) and a melting point of –115.6F or (-82C).

Hydrogen sulfide gas is also created more often from a byproduct of a manufacturing process or the removal of water or wastewater treatment systems. In wastewater, as organic material decays, H2S is released, captured, and treated to protect human lives, reduce corrosion, and reduce odor complaints. Hydrogen sulfide gas is produced during the manufacturing operations at refineries, pulp mills, and mining. These high levels of H2S are released during manufacturing. They must be captured and neutralized to protect human life from unwanted health effects such as pulmonary edemaand prevent excessive corrosion to your system. You cannot even smell the gas at higher concentrations, and it is not distinguishable as the “rotten egg gas,” which makes it even more dangerous and drives the need for hydrogen sulfide scrubbers equipment, fume scrubbers, or odor control scrubbers.

According to the “Agency for Toxic Substance & Disease Registry,” those who work within certain industries are exposed daily to higher levels of hydrogen sulfide gas than the normal public. Because the gas is also heavier than air, it will settle into lower places like manholes, tanks, and basements, and it will travel across the ground filling in low-level areas. To protect the public, OSHA (occupational safety and health administration) has set guidelines and rules known as “Permissible Exposure Limits” (PEL). A PEL is a legal limit a worker may be exposed to a chemical substance. The PEL limit for hydrogen sulfide is ten parts per million (10 ppm) over eight hours.

On behalf of DeLoach Industries Inc., I would like to thank you for entering our drawing for the first annual "Clean Water Professional Appreciation Award".  As you know we are celebrating our 60th year serving the water and wastewater Industry.

The Term Sour Gas

refers to any natural gas or other gas that contains high levels of hydrogen sulfide (H2S). The H2S is typically naturally occurring and found in deposits of natural gas and when there are concentrations above 5.7 milligrams per cubic meter or 4 milligrams per cubic meter when tested under standard temperature and pressure. At these levels the industry classifies the gas as “Sour.” Of course there are variations to this classification dependent upon agency an organization.

A Sour gas is not to be confused with an acidic gas 

although one could be both a sour gas is strictly defined by having large quantities of hydrogen sulfide and is usually accompanied by having mercaptans which adds to the foul smell and odor. The term is often used in the oil refinery business and when gases contain sour gas the process to remove the hydrogen sulfide and mercaptans is referred to as “Sweetening”. The most common method to “sweeten” and remove the sour gas is by processing the gas through an “amine process” which removes the harmful gas.

Caustic solution for Sodium hydroxide water treatment

There are many industries that require the use of a caustic scrubber which is considered a chemical scrubber and they range from the municipal industry, mining, semiconductor markets, pulp and paper and chemical refining.  There is a wide variety of industrial processes that generate noxious or corrosive off gases that require treatment and a comparison is made about biological Vs. chemical.  Often biological scrubbers have limitations due to concentrations, composition, or temperature of the contaminants and if the gas stream contains acid fumes then a biological scrubber is quickly ruled out.

The odor control selection is often fraught with choices of capital cost over operational cost and quite often comes down to familiarity from the designer or purchaser.  It is always a good idea to freshen up on the industrial odor control the do’s and don’t’s before selecting the final solution.  If the off gas source that needs to be treated is hydrogen sulfide (H2S) or some other type of gas stream produced by an acid or ammonia it will often require neutralization for human health reasons and to protect equipment or may be required to meet regulatory compliance. Caustic scrubbers may be either vertical or horizontal by design, but both utilize a packed media bed of either random packing or trays to allow the gas fumes to meet the recirculating caustic solution which then forces the reaction to occur.

What type of Odor Control Scrubber do I select?

It's a common question many customers and design professionals ask in the Odor Control Industry when selecting, engineering, and deciding on the best odor control process to utilize to treat gases and noxious odors. An odor control system is comparable to choosing a car in many ways because you have many different options. Each odor control scrubber comes in different types to address the different variations within the industry.  For example, odor control scrubbers are designed to treat “ammonia” and other ones to treat “acid” off-gases. Odor control scrubbers utilize “acid” or “caustic” as the scrubbing reagent to neutralize an off gas.

Odor control scrubbers also come with different purchase prices, each with different operating costs.  It is always important to analyze the operating cost of the odor control solution you select because several different types may perform equally. Each may have varying initial purchase costs, but you should ask and understand, “what will the continued operating cost” be for the type of odor control system selected?  And how long will the scrubber I selected last before additional costs are needed for any significant repairs to keep it running? When you are a design professional, if you choose an odor control system that is difficult or expensive to maintain, you can be assured you will have continued phone calls from customers looking for answers and solutions.  

The industry may soon change with the adaption of “artificial intelligence” as AI is slowly incorporated into the market.  Companies like DeLoach Industries are now incorporating the first variation of artificial intelligence into their odor control scrubber line of products to help owners and operators with real-time information and data communications.  Remember that many types of odor control systems work and remove odors, but selecting and designing a system that works efficiently and effectively without breaking the bank can be challenging.  A design professional should evaluate the cost of the reagents utilized in an odor control scrubber at any specific location because the cost of “caustic” in one location may vary from another.  Or the cost of “acid” may have different base costs or handling costs and considerations.  For a design professional and the supplier of the system, it is essential to consider what an owner and or their operators will be faced with to maintain the odor control system over the long term and what the anticipated operating cost will be both on a day to day basis and a long term service replacement basis.

A Biological Scrubber is a wet odor control scrubber that treats and removes contaminants from an air stream. It 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. Each plays a role in treating noxious or corrosive gases in the industry.