DELOACH BLOG

Converting Ferrous (Fe+2) (soluble) iron to Ferric (Fe+3) (Particulate/Solid form).

The iron must first be exposed to air or an oxidizing agent. Aeration System is the most cost-effective method to oxidize ferrous iron for its removal from water. In many areas around the globe, municipal and industrial operations need to remove naturally occurring iron (Fe) from the water to prevent damage to other equipment and improve water quality. Removing iron from the water must first be oxidized using the most widely accepted and cost-effective method called aeration. The aeration process changes the iron from its Ferrous (Fe+2) state (soluble) to ferric (Fe+3) colloidal participation. Did you know that Iron occurs naturally and is found in the earth’s crust? It occurs in both groundwater as well as surface waters and is not known to cause any harmful effects on humans or animals.

Iron does cause problems, though, for municipal facilities and their customers by impacting laundry operations and causing stains on buildings and on plumbing fixtures. Iron also promotes and facilitates the growth of iron bacteria in water, creating a problem for distribution lines and piping systems. Once the lines become blocked, this impacts the ability to distribute water to the customer. Iron bacteria also become detectible even at low concentrations and impact the taste of the water. The U.S. Public Health Service Drinking Water Standard set a recommended maximum level of 0.3 mg/L in public water supplies.

In industrial applications, iron can cause server damage in boiler systems.

Cation and Anion systems, piping and nozzles, and other equipment. In addition, for other industries such as food and beverage, brewery, semiconductor, or the production of chemical products, iron can interfere with the manufacturing or brewing and canning process, lowering the quality of the final product. In groundwater and anaerobic surface water, iron is normally present in its soluble form called “Ferrous” iron Fe+2 when the pH is in a certain range. When the same water is in contact with air, that allows the air to diffuse into the water, or when any form of an oxidizing chemical is added to the water, the iron is converted into its oxidized form called “Ferric” Fe+3, becoming a solid. The ferric iron becomes visible and impacts the turbidity of the water and is typically not accepted by customers because the ferric iron within the water when in contact with surfaces, will create colloidal precipitates causing discoloring to all that it encounters over time.

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 gained 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 blowdown process to eliminate solids. There are several different types of odor control and chemical wet scrubbers, industrial air scrubbers on the market today and each provides 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 concentrations in the ppm (parts per million) level then a Biological Scrubber will have difficulties balancing and acclimating fast enough to prevent a breakthrough.  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.

The need to remove harmful water elements, such as Hydrogen Sulfide H2s and Carbon Dioxide CO2, from water in the pisciculture and aquaculture market is extremely important.

To achieve maximum results, the industry utilizes a treatment technology called “Degasification” and controls the pH precisely to maximize results. When utilizing equipment such as the DeLoach Industries degasification systems, the hydrogen sulfide, and carbon dioxide levels can be removed to 99.999% ug/l.

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 including; 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.

Optimizing Water Quality and Enhancing Efficiency.

To enhance and balance the water quality in aquaculture and pisciculture operations, the industry is recognizing the benefits of utilizing a type of water treatment called “Forced Draft Degasification” to remove CO2 (Carbon Dioxide) and H2S (Hydrogen Sulfide) gases and oxidize other elements such as Iron or Magnesium.

Removing these elements from the water process improves the quality of the water and aids in the balancing of the pH without the need for additional chemicals. This also reduces the risk of unnecessary and preventable loss of life to your aqua farming project. Keeping the ph at the proper level will enable a good healthy environment and will prevent further problems that may occur due to the ph is not kept in a stable state.

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, H2S gas exposure, and H2S gas poisoning, H2S presence and reduce odor complaints. H2S gas is produced during 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 gas at higher concentrations, and it is not distinguishable as “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.

The process of Decarbonation requires the use of a Vertically Designed Degasification Tower.

A Decarbonation tower is specifically designed to remove Carbon Dioxide (CO2) from a water treatment process. When the water is being treated for “potable” use for direct or indirect consumption then all of the components used in the process must comply with NSF/ANSI 61 standards to assure that the components that have direct contact with the water are safe and will not introduce any foreign substance during the treatment process. Decarbonation towers have direct exposure and contact with the water during the removal of CO2 and therefore must be manufactured from a material such as Fiberglass (FRP) that complies with and meets the NSF/ANSI 61 standard.

Fiberglass FRP tanks and towers complying with NSF/ANSI 61 standards require the use of certified FRP resins and protocols during the fabrication process of the Decarbonation Tower.

It is normal protocol at DeLoach Industries Inc. to install a veil lining inside of a Decarbonator or Degasification tower that complies with NSF/ANSI 61 standards to safeguard all potable water projects. Decarbonators are utilized in the food and beverage industry, municipal industry, pisciculture, semiconductor industry, and other industrial markets. In addition to the Decarbonator complying with the NSF/ANSI 61 standard, it is equally important that the fiberglass (FRP) tanks also comply with the same standard and follow the same protocols during the manufacturing process. The NSF/ANSI 61 standard was developed to safeguard the public and provide assurances that water is free from impurities.

Basics of water decarbonation for dissolved organic carbon.

The water treatment industry continues to develop and evolve. Over the past two decades, there have been many new developments in technology and even more refinement in existing technologies such as "Degasification". The evolution and advancement of water treatment have been driven by the constantly increasing demand from an increase in population that demand cost-effective solutions and recognition to improve safety with the implementation of NSF 61 standards.

All human cultures on our planet share a single commonality: the dependency on water to survive.

Many existing technologies, such as "Degasification," have evolved with higher efficiency to meet the demand changes and provide safety to consumers and the systems. Degasification refers to the removal of dissolved gases from liquids, and the science to degasify water is based upon a chemistry equation known as "Henry's Law". The "proportionality factor" is called Henry's law constant" and was developed by William Henry in the early 19th century. Henry's Law states that "the amount of dissolved gas is proportional to its partial pressure in the gas." The most "cost" effective method to perform degasification is with the packed vertical tower called a "Degasifier” or “Decarbonator.”

The key words in this previous sentence for owners, operators, and engineers to focus on is "the most cost-effective" as there is no other process more cost-effective at removing dissolved gases at the lowest cost than using a Degasifier or decarbonator. The process of degasification is simple enough to understand. Water is pumped to the top of a vertically constructed tower, where it first enters the tower through some type of distribution system at the same time, there is a cross-current air flowing up from the bottom by a blower located at the bottom of the tower, and the air encounters the water and is exhausted at the top of the tower through an exhaust port. There are various types of distribution systems, and we will explore these in later discussions. Once the water enters the top of the tower and passes through the distribution system, it then travels by gravity downward. The next thing the water encounters is some type of media packing. There are various forms of media packing offered in the degasification industry, and each type can offer higher performance or have the ability to deter fouling. The selection of the type, size, and volume is where the “experience, engineering, and understanding of each application” comes into play.

In the production and purification of water for industry

there are many types of different processes available to remove harmful minerals and gases from the water stream but the most effective process and most cost-effective from both a capital investment and operational cost is a “Forced Draft Degasification System” (Degasifier).

Degasification is used in a wide range of water processes for industrial and municipal applications which extend from the production of chemicals to the production of semiconductors and in all applications the need to remove contaminants from the water and dissolved gases is key to achieving the end results needed in the industrial water process. Water from the ground often contains elements such as calcium carbonate, manganese, iron, salts, hydrogen sulfide, and sulfur just to name a few of the basic contaminants and these naturally occurring elements can cause serious damage and consequences to process equipment such as boiler systems, piping, membranes, and cation and anion exchange resins used in the demineralization process.

Calcium carbonate can dissolve in water under certain pH ranges forming carbonic acid and releasing carbon dioxide (CO2) gases. These gases are not only very corrosive to equipment like boiler feed systems and boiler tubes but also attack the actual resin beds found in cation and anion softening and demineralization system causing an increase in regeneration and chemical consumption and resin bed replacement.

By incorporating a Force Draft Degasification system you can remove dissolved gasses

like CO2 and hydrogen sulfide (H2S) to as low as 99.999% and improve the cation and anion system performance, extend the resin bed life, and lower the operating cost of the water treatment process.

Quite often Forced Draft Degasification is utilized “post” treatment to also remove newly formed dissolved gases prior to entering the boiler feed system to prevent corrosion damage within the tubes and feed system and pumps. These gases are easily removed with the forced draft degasifier at a much lower cost than chemical additives or liquid cell degasification that requires higher capital cost and much higher operating cost.

To enhance and control the production and quality of seafood grown and harvested.

The industry increasingly focuses on constructing in-house aquaculture fish farms, commonly called aqua farming. The most popular species of aqua farming continue to be salmon, tilapia, catfish, and carp. Increased interest in the United States has developed aqua farming facilities in southern Florida with favorable climate and water conditions.

When considering several types of fish species to grow for harvest, it is important to remember the need to control the water quality. If the aqua farm is intended to utilize man-made tanks, they will depend upon a constant flow of incoming water. If the aqua farm focuses on salmon, the water quality and temperature play a major role in the operation's mortality rates and production yields.

Having water with too high of hydrogen sulfide, carbon dioxide, total Organic carbons, and even turbidity can increase mortality rates among the younger fish species and is especially critical to salmon.

Having high levels of metals

Such as Iron that is identified as either “ferric” (Fe-) or “ferrous” (FE+2) and is naturally occurring within the Florida waters and other parts of the US will cause significant damage to young salmon species because the metal accumulates within the gills of the fish causing suffocation. Other metals are also detrimental to fish, including copper, aluminum, arsenic, cadmium, chromium, Lead, manganese, and mercury, to name a few, and the water quality must be evaluated and tested in the early stages of design to anticipate the required types of process systems needed.