Every day, pharmaceutical companies around the world produce tons of products that people use to enhance their quality of life. This realm of products has been lumped into a category called “Pharmaceuticals & Personal Care Products,” (PPCPs). These products and drugs do not disappear, but are found increasingly in the water being discharged from wastewater treatment plants. The impact that this cocktail of chemicals has on the animals and people dependent on this water is not fully understood, but the evidence is clear that it is not good.
Ozone is a powerful oxidant capable of breaking troublesome molecules. What impact does ozone have on PPCPs? A recent laboratory study published in the engineering journal of the International Ozone Association (IOA) exposed water containing thirty seven different PPCPs to investigate the degradability of these chemicals.
Eight of the thirty five were very quickly degraded to or below their limit of detection with a dissolved ozone dose of 1ppm within 5 minutes. Five more were degraded with a dissolved ozone dose of 2ppm within 5 minutes. Five more required at least 10 minutes of retention time at 2 ppm.
The other half of the thirty five required more time and a higher dose of ozone. Three of them, (DEET, Ketoprophen, and Primidone) did not degrade below their limit of detection even when exposed to 9ppm of dissolved ozone for 15 minutes.
Ozone clearly has a significant role to play with PPCP cleanup. Further study is sure to discover ways to optimize the process and make it more effective. Oxidation Technologies specializes in integrating ozone into the specific process of diverse customers. We continue to pursue a better understanding of ozone use in a variety of applications.
N. Evelin Paucar, Ilho Kim, Hiroaki Tanaka & Chikashi Sato (2019) Ozonetreatment process for the removal of pharmaceuticals and personal care products in wastewater, Ozone: Science & Engineering, 41:1, 3-16, DOI: 10.1080/01919512.2018.1482456
Legionnaires’ disease is a bacterial pneumonia caused by breathing mist from water containing the bacteria. The bacteria thrive in the warm water found in whirlpool spas, cooling towers, fountains, humidifiers, produce misters, etc. Symptoms of Legionnaires’ disease include high fever, a cough, and sometimes muscle aches and headaches.
The rate of reported cases has increased over 5 fold since 2000, and deadly outbreaks continue today unabated. The reason or reasons behind this increase are unclear at this point, but ozone has proven to be effective at controlling the bacteria in water. Whether the bacteria are flourishing within a 100 gallon fountain or a 1000 ton cooling tower, the engineers at Oxidation Technologies will maintain will provide the precise dose of ozone needed for safe water.
Ozone that is safely dissolved into water has a tremendous disinfectant power and simply turns back into oxygen after expending its energy. As little as 0.01 ppm (1 part ozone to 100 million parts water) prevents the growth of these bacteria. We provide cost effective equipment and long term service to ensure safe and effective use of ozone for bacteria control.
The equipment needed to dissolve low levels of ozone into water can be very cost effective and sustainable for many water systems. A home well-water system uses one of the smallest ozone generators we sell to dissolve enough ozone when the well pump runs to disinfect all the water needed in a typical home. As a general rule of thumb for industrial cooling towers, five grams of ozone per hour is needed for every 100 tons of tower cooling capacity.
The 50 g/h ozone generator needed to supply a 1000 ton cooling tower will also require an oxygen concentrator, venturi, ORP controller, and sometimes a booster pump. The oxygen concentrator and controller comes in a complete package with our OXG systems. The following study conducted by Mazzei reports a one year payback for ozone use due to lower chemical and cleaning costs.
We also provide the convenience of a quarterly preventative maintenance plan to make sure the system continues to perform at peak efficiency and avoid costly repairs due to neglected maintenance. We often work with an independent water company that provides routine testing for the customer to make sure water quality remains good and inform us of any problems.
An oxygen concentrator is a wonderful machine … when it works. Attempts to diagnose and repair a your concentrator when it fails can be very frustrating. But understanding just a few principles of operation may turn frustration to success.
Principle #1 Remember your sand box.
If you have ever played with a sieve in a sandbox, you already understand the science behind an oxygen concentrator. The air we breathe contains about 78% Nitrogen and 21% Oxygen. The other 1% is composed of a few other gasses. An oxygen concentrator is a sieve that lets Oxygen molecules through and holds back the Nitrogen molecules.
So you need to picture some poor quality sand with about 80% pea gravel mixed in. It’s nice and dry, so when you scoop some up in your sieve and shake it a bit over a bucket, you end up with some nice, beach quality sand and a sieve that’s still got a lot of pea gravel in it. Dump out the gravel into another bucket and do the same thing over again. Slowly but surely you fill your sand bucket with some nice sand. This is like the tank of oxygen you accumulate with an oxygen concentrator. The pea gravel dump pile is the Nitrogen that hisses out of the concentrator muffler. Take the muffler off, and you can get a better feel of the process.
Principle #2 – Respect the destructive power of moisture
Now, you might recall that when you get some wet sand in your sieve, the process doesn’t work so well anymore. You might need to shake it more and everything starts to clog up. Moisture causes lots of problems for an oxygen concentrator as well. Once it starts to condense in the sieve material, the sieve begins to break down. It would be like your sandbox sieve falling apart or getting rusty so that either everything just goes straight through or it gets completely plugged and nothing goes through. The sieve material in an oxygen concentrator is in the form of little clay pellets that are treated with zeolite. This material does a great job sorting out the Nitrogen from the Oxygen, but is very vulnerable to moisture.
If the sieve material has been exposed to moisture and has begun to break down, you will begin to see signs of this process with dust that starts blowing out of the exhaust mufflers. It is best to take care of the problem as soon as possible, because the dusting will only lead to more problems. It will begin to disrupt the valve operation and may even totally clog up the mufflers to the point where the Nitrogen can’t exhaust anymore. Chances are, by this time the sieve material is ruined and is not filtering out the Nitrogen anymore.
What to do. Unfortunately, if your sieve material is breaking down, your concentrator sieve beds will need to be rebuilt. The sieve bed needs to be opened up, old material dumped, and new sieve material put in. Sieve beds are typically in the form of two aluminum tubes with some screens and a spring to hold the sieve material in place. These need to be carefully cleaned, inspected for damage, and carefully put back together so that it is sealed up tight. If you’re not up for the challenge of rebuilding the sieve bed, you can send the beds in to us for a re-build.
Principle #3 Valves need to operate flawlessly.
Rebuilt sieve beds may not be the whole solution. There is a good chance that the dust from degraded sieve material has found its way to the valve set. The valves are your arms working the sieve in the sandbox: dig up some sand, hold it over the sand bucket, dump out the gravel into the gravel pile, do it all over again and again and again. If you’re sloppy, you’re going to get gravel in your sand.
In an oxygen concentrator, two sieves are at work together. When one is sifting, it is also at the same time helping to clean out all the Nitrogen being exhausted by the other sieve bed. The valves direct a certain quantity of air for a certain time into the sieve. Too much air, and it is like the sieve overflows and Nitrogen spills into your oxygen, diluting it. If the Nitrogen isn’t dumped properly, the next cycle is ineffective and disrupts the rhythm.
The valves need to open to let compressed air into the sieve for a certain time. Oxygen flows out the other side through an orifice and a check valve. As the air valve closes, it opens a second port to release the Nitrogen trapped in the sieve back into the surrounding air. A second valve lets compressed air into the second sieve. As it fills, some of the oxygen leaving the other end helps force the remaining Nitrogen out of the first sieve.
The valves are typically a spindle that slides back and forth to direct the gas flow. A solenoid pushes the spindle back and forth. When electricity flows through the coil of wire in the solenoid, the magnetic field generated pushes a plunger to move the spindle. The spindle needs to move freely. Dust or contaminants can interfere with its movement so that the air is not precisely measured or timed properly. A careful cleaning of the valve often will fix a sticky valve, but sometimes even when it seems to be operating smoothly, only a new set brings the precision needed for proper operation.
Principle #4 Check valves and orifices may seem insignificant, but they’re not.
What looks like little connectors for oxygen tubing are actually precision parts that work together with the air valves to direct the Oxygen and Nitrogen flow. Orifices are precisely sized holes that limit the flow of Oxygen. In a concentrator, they are often used to allow a limited amount of Oxygen to push out any remaining Nitrogen left after exhausting from the de-pressurized sieve. If it gets plugged, Nitrogen stays in the sieve and ends up contaminating your oxygen supply. The check valves prevent any excess oxygen from flowing back into the sieve. Make sure the oxygen hoses are clear of debris, you can blow air through the orifices, and the check valves work. You should be able to blow through one way, but not the other. They need to be oriented so that the oxygen flows to the oxygen tank and not back.
Principle #5 More O2 flow is not better
A simple thing to overlook when trying to figure out when the O2 purity isn’t what it should be is excessive oxygen flow. Bring back to mind the sieve in the sandbox. The sieve is only so big. It will only hold so much sand and pea gravel. If you exceed the capacity, extra material is going to fall over the sides and not go through the sieve. Try operating your concentrator at a flow rate that is lower than the maximum rating. If you get good oxygen purity at a low flow rate, but it starts to fall off as you approach its rating, you might have some oxygen leaks. An oxygen leak won’t be measured by your flowmeter. Use some soaping water to look for leaks and fix them.
We sell and service most brands of industrial oxygen concentrators, stock parts, and do all we can to keep oxygen concentrators healthy. We also sell and rent oxygen meters to determine the oxygen purity of a system. A diet of clean, dry air is proven to greatly extend their life. They are designed to handle a limited amount of moisture, but it is risky. Continuous use, just like regular exercise, will also extend life. Startup on a humid day will be hard on them. Hot humid air from the compressor is liable to condense in a cooler sieve and begin the cycle of damage. If the suggested remedies do not solve your concentrator problems, feel free to give us a call.
The delicate balance of natural systems of the oceans provides an abundance of food for the world. The current rate of harvest, however, is degrading this rich resource. Inland farming of ocean fish is becoming an attractive alternative. Precise ozone control is a key component for replicating an ocean environment for inland farming of ocean fish.
Ozone provides excellent disinfection, enhances the filtration process, and increases the overall efficiency of recirculating aquaculture systems (RAS). Ozone is one of the most powerful disinfectants available. It accelerates the natural processes of breaking down toxins and filtration. It is made of oxygen, and decomposes back to oxygen or oxides when its work is finished.
“Foam Fractionation and Ozone in Modern Aquaculture Systems: Valuable Tools for Clear Water Production and Farm Management
Abstract Recirculating aquaculture systems (RAS) for farming finfish is a technology that offers the necessary biosecurity and water quality control, as well as waste management. Modern closed recirculating systems can operate far away from the natural water source and a water consumption of less than 1% of the system volume per day. High-tech systems such as the oceanloop technology (neomar.de) allow the land-based production of fish species of high commercial interest and value, close to the consumer. This technology  represents the cutting edge of science and technology. The discharge of nutrients and organic matter can be well controlled. The technology is environmentally sound and supports the sustainability of aquatic food production. Key words: Aquaculture, Foam Fractionation, Ozone
Conclusions The re-use of water is inevitable in modern aquaculture production systems. The use of biological water treatments, combined with a foam fractionation process, enhanced with ozone are crucial. Farm managers can profit from clear water production in terms of increasing both, mean stocking density without affecting fish welfare, and survival rate due to an optimization of water quality.”