DELOACH BLOG

Have you ever walked on a sidewalk or in a parking lot and passed by a lift station or manhole and noticed a smell so bad you thought you were going to pass out? 

Most people who encounter these types of odors do not live in the world of designing and building odor-control treatment systems.  For those of us who do we fully understand that when we encounter such a noxious smell it most likely needs an odor control system.  It does not matter if the odorous smell is coming from an industrial water treatment process, food and beverage plant, wastewater plant, or from the off-gas of a “degasification process”.  All of these types of industries and many more can generate odors and quite often these noxious odors must be addressed and treated because of either safety or public outcry. Many times odorous gases are generated as the result of processing and purifying drinking water.  When water contains contaminants like hydrogen sulfide (H₂S), carbon dioxide (CO₂), or ammonia (NH₃) there is a need to treat and remove these harmful elements from the water. 

Odors come from many sources

When processing and purifying drinking water which requires pH adjustment by adding acid to lower the pH and allow for the removal of hydrogen sulfide (H₂S) which will not convert at higher pH levels.  After the pH level is properly adjusted the hydrogen sulfide can be removed by degasification.  After the degasification process the pH will rise in the water from the removal of the carbon dioxide (CO₂) and if the pH remains slightly acidic then caustic is normally injected into the water stream to raise the pH back up to a neutral level of 7.  This entire required process to purify the water is what generates the odor and creates the requirement for an odor control scrubber.  Odor control scrubbers may utilize chemicals such as acid and caustic to treat the air gas noxious odor or it may be a biological Scrubber that consumes the contaminants within the noxious gas air stream including ammonia and hydrogen sulfide.  Noxious or corrosive odorous gases are not always from wastewater treatment plants or underground lift stations that are commonly referred to as “wet wells”.  Quite often odors are generated during manufacturing or food processing as well as from the efforts just mention in a municipal water treatment and purifying plan.  During the period of pH adjustment hydrogen sulfide (H2S) and other odorous substances can be released by means of Decarbonation or Degasification.  Some odors have a pungent smell and other odors are harmful corrosive gases that must be contained to protect the surroundings or even human life.  There are many types of odors and off gases that must be contained, captured, treated, or neutralized.  Understanding the; who, what, where, and why, first will normally put you on the road to selecting the right solution for odor control.

Water treatment towers and storage tanks are high places that require special precautions when entering. While the majority of people who enter these locations for work can be trusted, there are some hazards that make it more important than usual to follow safety procedures.

These locations can get very hot and humid, and can also be filled with harmful chemicals and microorganisms that can cause serious health issues if inhaled or absorbed through the skin. Therefore, the general standard for workplace safety is much higher when entering locations like these.

Make sure you have read and understood the following information about safety when entering a water treatment plant. It will help you understand how to stay safe and protect yourself from harm when entering a water treatment plant. normal installation, maintenance, or even emergency repairs, it is often required to enter into a water treatment tower (degasifier, air stripper, decarbonator, or clear well/ storage tank). When this occurs, full safety protocols should be followed at all times, in accordance with OSHA regulations.  A tower or tank B classification is a "Confined Space" location. For more information visit the OSHA confined space regulations page.

In addition, there are other safety risks that an operator or technician can be exposed to while inside these types of closed locations. The risk can come from fumes of hydrogen sulfide (H2S), chlorine from an injection line, or a lack of oxygen O2. A proper confined space permit should be prepared and only technicians with proper training and certifications should enter into these types of confined spaces.

When it comes to removing hydrogen sulfide (H2S) from water through the process of degasification.

It is crucial to ensure that the pH of the water is properly adjusted prior to treatment. This step becomes more complex if you are not already pre-treating water for membrane filtration or softening. The reason behind this is that when the pH of water rises above 5.5, it becomes increasingly challenging to convert H2S or sulfides into a gaseous phase, which is necessary for their removal through the degasification process utilizing a degasifier.

At a pH of 7, the conversion rate drops significantly, and a standard degasification tower can only remove about 80-85% of hydrogen sulfide (H2S), leaving behind worrisome levels of this compound in the water. However, by lowering the pH to 5.5 (or at least a pH of 6), the removal efficiency dramatically increases to 99% in most cases. In situations where high water quality is demanded, such as in breweries or canneries, removal rates as high as 99.99% can be achieved by carefully adjusting the pH.

Leaving excessive amounts of hydrogen sulfide (H2S) or sulfur in the water can lead to various additional problems with water quality, including unpleasant taste and odor. Moreover, it can cause fouling and corrosion of the primary equipment and even the facilities themselves. The negative consequences of inadequate hydrogen sulfide removal underline the importance of addressing this issue effectively.

If you would like to obtain more information or learn about the various solutions available, we recommend reaching out to the professionals at DeLoach Industries Inc. They have extensive expertise in the field and can provide you with valuable insights and guidance. Feel free to contact them at (941) 371-4995 to discuss your specific needs and find the most suitable approach for hydrogen sulfide removal from your water in your water treatment system.

By addressing the pH adjustment requirement and ensuring effective degasification, you can significantly improve the overall quality of your water supply. Investing in proper treatment measures not only enhances the taste and smell of the water but also safeguards the longevity and functionality of your equipment and infrastructure.

DeLoach Industries Inc. is renowned for its commitment to excellence and customer satisfaction. Their knowledgeable team is well-equipped to assist you in finding the most effective solutions for hydrogen sulfide removal, tailored to your unique circumstances. Don't hesitate to get in touch with them today to explore how they can help you achieve optimal water quality and mitigate the potential challenges associated with hydrogen sulfide contamination.

In conclusion, when dealing with the removal of hydrogen sulfide (H2S) from water through degasification, ensuring proper pH adjustment is essential for successful treatment. Adjusting the pH to an ideal level of 5.5 or at least 6 significantly improves the removal efficiency, offering rates as high as 99%. Neglecting this crucial step can result in compromised water quality, fouling, and corrosion of equipment and facilities. For expert guidance and solutions tailored to your needs, contact DeLoach Industries Inc. at (941) 371-4995, and take proactive steps toward ensuring clean and high-quality water.

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Related Blog: Degasification Tower Design: Square vs. Round?

A wide range of electric pumps, blowers, compressors, and material conveying equipment are used in water treatment facilities—whether municipal, industrial, aquaculture, or pisciculture. Despite their varied applications, they all share a common requirement: the need for an electric motor to deliver the torque and energy necessary to drive the equipment and fulfill its intended function.

One of the most common questions asked or considered during the design phase of the water treatment process is what type of motor enclosure should be selected.  There are 7 

types of motor enclosures that are available and defined by NEMA standards MG1-1.25 through MG 1.27.  The final decision should be driven by the all of demands that the application will have placed upon it.

The selection of the type of motor enclosure can be a difficult choice. 

If the application is for a process like Reverse Osmosis, Degasification, or Decarbonation, it is important to consider the efficiency of the motor and what the motor will be exposed to during its operating life cycle.    We will briefly review each of the 7 different types that NEMA defines for motor enclosure types. 

The ODP (open drip proof) is one of the most common types of enclosures. 

The enclosure is open and vented at the back end of the motor and allows air to circulate in and around the motor windings carrying off heat.  The ODP motor is designed to prevent liquid from entering the motor at a 15-degree angle based on the vertical alignment.  ODP motors are normally utilized at water treatment facilities or aquaculture facilities where they will not be exposed to corrosive conditions such as HVAC systems.

Often times a wastewater treatment plant clarifier will need repair and retrofitting, especially in and around the weir trough.

Most clarifiers are manufactured out of steel, and over time the corrosive conditions at a wastewater treatment plant corrode and the adjustable weirs often disintegrate, making proper operation impossible.  The most cost-effective method to rebuild and retrofit the clarifier weir is to utilize a fiberglass replacement. Depending on the extent of the damage, which could involve just replacing the weir plate or it could involve a more extensive process that requires replacing portions or all of the trough.  If you are lucky enough to still have the original submittals or plans for the clarifier you will be able to obtain critical measurements and information from them. If not, you will need to obtain measurements from some portion of the existing clarifier weir and trough so that a new fiberglass replacement can be ordered.Carefully measure and record all dimensions of the weir plate and trough. Be sure to obtain the length of each V-notch, its depth, and the spacing between each V-notch. Clarification weir plates are calculated for specific flow and water velocity, so a high level of care should be taken to properly duplicate the original design, to not compromise the performance.

When it comes to starting up a biological scrubber tower, ensuring proper acclimation is crucial to avoid costly shutdowns and ensure optimal performance.

This is especially important for projects involving the removal of acid gases, such as Hydrogen Sulfide (H2S). Acclimating the biological scrubber tower to specific conditions is essential to guarantee efficient gas removal.

A helpful analogy for understanding the acclimation process is to imagine taking care of a new aquarium. Just as introducing fish too quickly can cause shock or potential harm, improper conditions in a biological scrubber tower can lead to unfavorable results. Factors such as water temperature and pH balance play significant roles in the acclimation process.

One common challenge arises when the off-gas loading rate is inconsistent or rapidly fluctuates.

Such variations can create difficulties during the initial balancing and operation of the scrubber. To address this, it is important to bring the scrubber online and establish a steady state for all the essential parameters. The specific type of cultures being treated will determine the necessary conditions for successful acclimation. Given the right conditions and sufficient time, the microbes will adapt and acclimate to the media structure within the scrubber tower.