Understanding Degasification and Decarbonation

In industrial and municipal water treatment systems, controlling dissolved gas levels is crucial for maintaining optimal performance, ensuring safety, and ensuring compliance. The term “Degasification” (or “Decarbonation”) refers to the process of removing unwanted gases such as hydrogen sulfide (H₂S), carbon dioxide (CO₂), and oxygen (O₂) from water.

While both processes share the same purpose of gas removal, the terminology changes based on the type of gas being targeted:

Decarbonation is typically used when removing carbon dioxide (CO₂).

- Degasification most often refers to the removal of hydrogen sulfide (H₂S) or other dissolved gases.

These processes are a critical step in water treatment, especially when preparing water for reverse osmosis (RO), boiler feed systems, or industrial reuse applications.

How Degasification Works

Degasification operates on the principle of transferring gases from water into the air. By forcing air through the water stream inside a degasification or decarbonation tower, the system promotes mass transfer, allowing the unwanted gases to escape.

Key factors influencing degasification efficiency

- Inlet Water Flow Rate: Higher flow rates require larger towers or more efficient packing media.

- Water Temperature: Warmer water releases gases more readily.

- Ambient Air Temperature: Impacts air density and transfer rate.

- Gas Concentration: Measured in ppm, ppb, or mg/L, this determines the tower’s design and airflow volume.

- Desired Effluent Levels: Defines the level of purity required for downstream applications.

Understanding these variables enables engineers to design a customized degasification system that meets stringent quality standards. For example, systems treating well water high in hydrogen sulfide must maintain consistent airflow and contact time to ensure complete removal of the gas.

To learn more about custom-engineered degasification systems, visit DeLoach Industries.

Applications: Reverse Osmosis and Membrane Filtration

Degasification is often integrated after Reverse Osmosis (RO) or membrane filtration to remove residual gases that pass through the membrane, such as H₂S and CO₂.

1. Reducing Chlorine Demand

By eliminating these gases before chlorination, operators can significantly reduce chlorine consumption, improving disinfection efficiency and minimizing chemical costs.

2. Improving Total Suspended Solids (TSS) Levels

Removing dissolved gases also enhances TSS performance, resulting in clearer, higher-quality permeate.

3. Adjusting pH Without Chemicals

When CO₂ is removed, the pH naturally rises, helping stabilize the water without the need for caustic chemicals or lime, making degasification an eco-friendly solution for optimizing water treatment.

For a deeper dive into membrane treatment post-processes, explore DeLoach Industries’ water treatment solutions.

Managing Off-Gas and Odor Control

In some cases, the air discharged from a degasification or decarbonation tower can contain elevated H₂S levels, creating odor nuisances or even health and safety hazards for nearby personnel.

1. Why Off-Gas Treatment Is Essential

Hydrogen sulfide, when combined with moisture, forms sulfuric acid, which corrodes nearby equipment and building materials. This makes off-gas treatment essential in steam processes, boiler feed systems, and industrial wastewater applications.

2. Odor Control and Scrubber Systems

To mitigate emissions, facilities often install air scrubbers or odor control systems directly onto the off-gas line. These scrubbers use chemical or biological media to neutralize odors and capture harmful gases before release.

DeLoach Industries offers custom-engineered odor control and degasification solutions that integrate seamlessly with your existing treatment systems. Learn more about industrial water treatment technologies at www.deloachindustries.com.

The Economic and Environmental Benefits of Degasification

Degasification systems are not only effective, they’re also highly economical compared to chemical treatment methods.

Some key advantages include:

- Reduced chemical usage and maintenance costs

- Extended equipment life by preventing corrosion

- Improved water quality consistency

- Compliance with EPA and OSHA air quality standards

In municipal systems, this can translate into lower operational costs and enhanced environmental performance, especially when paired with other sustainable technologies, such as odor-control scrubbers and biotrickling filters.

Partner with DeLoach Industries for Advanced Water Treatment Solutions

For over 65 years, DeLoach Industries has been a trusted leader in designing and manufacturing custom degasification, decarbonation, and odor control systems for industrial and municipal clients worldwide.

Whether you need to remove hydrogen sulfide, naturally raise pH levels, or enhance the performance of your reverse osmosis system, our team can design a customized solution that meets your exact specifications.

Contact DeLoach Industries today at (941) 371-4995 to request a quote or speak with a water treatment expert.

Understanding the Challenges of Hydrogen Sulfide (H₂S) in Water

Understanding Hydrogen Sulfide Hazards and Solutions

The Science and Risks of Hydrogen Sulfide

Hydrogen sulfide (H₂S) is a colorless gas notorious for its distinctive "rotten egg" smell, detectable even at very low concentrations. This malodorous compound occurs naturally during the decomposition of organic matter and is also a byproduct of several industrial processes such as petroleum refining, sewage treatment, and paper manufacturing. With its chemical formula comprising two hydrogen atoms bonded to a sulfur atom, H₂S poses significant threats due to its toxic and corrosive characteristics.

The Science Behind Hydrogen Sulfide and Its Hazards

Hydrogen sulfide (H2S) is a colorless gas known for its pungent "rotten egg" smell, even at low concentrations. With the chemical formula H2S, it consists of two hydrogen atoms bonded to a single sulfur atom. This compound is naturally produced during the decay of organic matter and can also be a byproduct of various industrial processes, such as petroleum refining, sewage treatment, and paper manufacturing. Despite its natural occurrence, hydrogen sulfide poses significant risks due to its toxic and corrosive nature.

Water purification is critical in industrial operations, especially when it comes to removing dissolved gases that can cause corrosion and compromise the efficiency of equipment. Various methods exist to address these issues, with Forced Draft Degasification (FDD) systems often cited as one of the best options. However, while FDD systems have clear advantages, they may not always be the ideal solution depending on specific needs. In this article, we'll explore the ins and outs of Forced Draft Degasification, weigh its benefits and drawbacks, and compare it to alternative methods to help you determine if it's truly the best choice for your water purification needs.

Understanding Forced Draft Degasification Systems

Forced Draft Degasification systems are designed to remove dissolved gases, such as carbon dioxide (CO2) and hydrogen sulfide (H2S), from water, which can cause significant problems in industrial equipment. The principle behind FDD is simple but effective: water flows through a vertically structured tower, typically packed with media that maximizes the surface area. As water travels downward, a cross-current of air is forced through the system, helping to strip out unwanted gases.

This interaction between air and water allows for the efficient removal of these gases, which otherwise would contribute to the deterioration of industrial equipment through corrosion. Corrosive environments not only shorten the lifespan of machinery but also increase maintenance costs, leading to inefficiencies that can disrupt entire operations. The goal of FDD systems is to mitigate these risks, making water safe for industrial use and protecting expensive equipment investments.

These systems are widely used in industries such as power generation, chemical processing, and oil refining, where the presence of dissolved gases can lead to substantial equipment failure or process inefficiencies. The vertical design of the FDD system enables it to handle large volumes of water efficiently, making it ideal for high-capacity industrial needs. The simplicity of the FDD system, combined with its ability to consistently remove dissolved gases, makes it a preferred choice for many industrial operations that prioritize reliability and cost-effectiveness in their water treatment systems.

Degasification and decarbonation are essential processes in water treatment that play a crucial role in improving water quality.

Requires an application commonly referred to as either “Degasification” or "Decarbonation" and it requires the use of a piece of water treatment equipment called either a “degasifier” or a “decarbonator”.

The Basics of Water Decarbonation

and the removal of carbon dioxide (CO2). The need to remove (CO2) is essential in most Aquaculture, Municipal, Industrial, and Food & Beverage Processes To understand you must familiarize yourself with Henry’s Law.

Henry's Law defines the method and proportional relationship between the amount of a gas in a solution in relation to the gas's partial pressure in the atmosphere. Often you will see and hear various terms like degasification, decarbonation, aeration, and even air stripping when discussing the removal of dissolved gases and other convertible elements from water. Understanding the impacts that Carbon Dioxide (CO2) can have on both equipment and aquatic life provides the basic reasons why the need to decarbonate water, exists. Carbon Dioxide (CO2) can exist naturally in the raw water supply or be the result of ph control and balance. In either case, the process called Decarbonation or Degasification provides the most cost-effective and efficient manner to reduce or tally remove (CO2) from the water. In addition to Carbon Dioxide (CO2), water can contain a variety of other contaminants that may impact the removal efficiency of the Carbon Dioxide. A variety of elements as well as dissolved gases such as oxygen, nitrogen, and carbon dioxide (CO2). A full analytical review of the water chemistry is required to properly design and size the “Water Treatment” process.

Breaking the bonds in water releases a dissolved gas

such as carbon dioxide (CO2) you must change the conditions of the vapor pressure surrounding the gas and allow the gas to be removed.  There are many variables to consider when designing or calculating the “means and methods” of the removal of carbon dioxide (CO2). When I refer to the means and methods. I am referring to the design of a decarbonator and its components. The means equals the size and type (Hydraulic load) of the decarbonator and the “method” equals the additional variables such as the cubic foot of airflow (CFM) and “Ratio” of the air to water to accomplish the proportional condition needed to remove the carbon dioxide (CO2).

Odor control in a manufacturing facility is essential.

It prevents potential health risks and discomfort caused by the spread of chemicals, vapors, and fumes. Additionally, excessive vapors can hinder the efficiency of exhaust and natural ventilation systems.

One effective solution for addressing odor issues is the installation of an Odor Control Scrubber Tower. These towers are part of the ventilation system in manufacturing plants and chemical processing facilities.

Odor control scrubbers help to remove noxious fumes and odors from exhaust and air streams. This is an effective way to improve air quality. This process involves utilizing an activated carbon filter and an ionic air filter

Key Considerations for Installing an Odor Control Scrubber Tower:

Health and Safety of Workers:

Industrial environments pose risks of exposure to hazardous fumes and gases for workers. Unhealthy odors emitted in high concentrations can jeopardize their well-being and safety. In some cases, these gases may even be combustible, adding an extra level of danger.

Odor control scrubber towers remove gases from the contaminated air, ensuring a safe working environment. These towers reduce the risk of health issues such as nausea, headaches, allergy symptoms, eye irritation, and loss of consciousness. This helps maintain worker productivity and prevents sickness caused by toxic fumes and gases.

Water demineralization is also called deionization and is a process known as “Ion Exchange.”

In simple terms, water demineralization is “Water Purification.” The process involves removing dissolved ionic mineral solids from a feed-water process, typically for “Industrial” water applications. Still, it can also be utilized to remove dissolved solids from a water process for “Aquaculture,” “Food and Beverage,” and the “Municipal” markets.

Why is demineralization utilized? It can remove dissolved solids to near distilled water quality at a much lower capital and operational cost than other treatment processes such as membrane softening (Reverse Osmosis). Demineralization applies the science known as “Ion Exchange,” which attracts negative and positive charged ions and allows either to attach themselves to a negative ion depending on their respective current negative or positive charge during what is known as a resin cycle. In other technical articles, we will explore and go into more specific details on the science of the ion exchange process. Water that has dissolved salts and minerals has ions, either negatively charged ions known as “Anions” or positively charged ions known as “Cations.” To treat the water and remove these contaminants, the ions in the water are attracted to counter-ions, which have a negative charge. In a demineralization treatment process, there are pressure vessels that hold resin beads which are typically made of plastic. The beads are made from a plastic material with an ionic functional group that allows them to hold and maintain an electrostatic electrical charge. Some of these resin groups are negatively charged, referred to as “Anion” resins, while others hold a positive charge and are called “Cations” resins.

There are different applications to apply Ion exchange technologies, which is why you will often hear different terminology interchanged like deionization and demineralization. The raw water quality and the specific application will dictate the type of ion exchange process needed. For example, if the water contains a high level of hardness, the water will most likely contain Ca2+ or Mg2+ dissolved solids possessing a positive charge. To replace these hard ions, it is typical to utilize a resin bed with a salt ion like Na+. As the water passes over the resin bead material within the pressure vessel. The hard ions are replaced with the salt ion; therefore, all the hardness within the water is removed. However, the water will now contain a higher concentration of sodium ions, and this must be considered during the evaluation and selection process of the type of resin material to utilize for the specific application. If the water application requires high purity and the removal of as many solids as possible, then the term or process selected is referred to as demineralization.