Another example of how UV disinfection and chlorine can be good partners is for swimming pools. The Model Aquatic Health Code (MAHC) stresses the need for a secondary disinfection system, given the rise in Waterborne Illness outbreaks caused by disinfectant tolerant parasites.
What are the applications of UV water disinfection?
There is a wide range of applications for the water disinfection using the UV technology, BIO-UV Group offers solutions for both professionals and individuals. For instance, you can treat surface water, residual water, pool water, industrial process water, drinking water, etc…
What is the difference between chlorine and UV disinfection?
If a concrete channel is to be constructed, the cost to accomplish this is significantly smaller compared to chlorine since the footprint of a UV system is much smaller. UV disinfection occurs in seconds, whereas chlorination requires several minutes of retention time.
What does UV light do to chlorine in water?
Ultraviolet Light Oxidizes Free Chlorine in Water. In pharmaceutical processing, chlorine oxidizing agents can disrupt important chemical reactions and destroy products. High chlorine levels also accelerate corrosion on process vessels and piping, and are generally considered damaging to process equipment.
Can UV be used for municipal wastewater treatment?
For the past few decades, UV has been successfully used around the world for municipal wastewater treatment. Download the article to learn the differences between UV and chlorine wastewater treatment.
Why do some treatment plants use Ultraviolet light instead of chlorine?
Unlike chemical approaches to water disinfection, UV provides rapid, effective inactivation of microorganisms through a physical process. The retention time required to achieve disinfection ranges from a few seconds compared to several (>30) minutes for chlorine disinfection.
What is one benefit of using UV light instead of chlorination?
As UV water treatment is a chemical-free process there is no need to handle potentially dangerous chemicals, such as chlorine, and no chemical disinfection by-products. Also, as UV disinfection is almost immediate, there's no need for contact tanks which are needed in chlorine disinfection.
Is UV a primary or secondary disinfection?
UV and ozone have been served up as two logical choices to act as a secondary disinfectant to chlorine. The efficacy of a combined chlorine/UV or chlorine/ozone system addresses the primary causal agent, Cryptosporidium, responsible for the majority of RWIs.
Is UV light better than chlorine?
UV is very effective at inactivating both these dangerous microbes, whereas chlorine is not. As with any water treatment, there are choices for disinfection.
What is one disadvantage of disinfecting water with UV light rather than with chlorine?
One disadvantage of UV treatment is that the disinfection only works within the UV aggregate and – as such – doesn't protect against subsequent contamination in the distribution network. In chemical disinfection, the cell membranes of microorganisms are oxidized and destroyed, which kills the organisms.
What are the advantages of purifying water with UV rays?
Advantages of UV water purifiersCOST EFFECTIVENESS. UV water purifiers are pretty cost effective and the bulb makes use of about 60 watts of power only. ... USE NO CHEMICALS. ... SIMPLE MECHANISM. ... NO DAMAGE TO PIPES. ... NEED FOR ELECTRICITY TO WORK. ... DO NOT REMOVE ALL IMPURITIES. ... NO STORAGE TANK OPTION. ... NO UV LIGHT SHUTOFF.More items...•
Why is ultraviolet light used in water treatment?
As a water treatment technique, UV is known to be an effective disinfectant due to its strong germicidal (inactivating) ability. UV disinfects water containing bacteria and viruses and can be effective against protozoans like, Giardia lamblia cysts or Cryptosporidium oocysts.
Does UV light really purify water?
UV water purification systems purify water by using ultraviolet rays to kill microorganisms present in the water. UV rays completely kill water-borne microorganisms and prevent their reproduction by disrupting their DNA. Also, UV rays do not lead to chemical changes in the water.
Can you drink UV treated water?
UV-C treated water is considered to be incredibly effective. It is both safe and healthy because the UV-C technique eliminates up to 99.99% of microorganisms such as bacteria and viruses. This method of disinfection has the following benefits: You don't have to handle potentially dangerous chemicals.
Does UV destroy chlorine?
UV radiation is an effective method to remove chlorine and destroy chloramines by a process called photodegradation or photolysis. Both Low Pressure UV lamps and Medium Pressure (polychromatic) uv lamps have been shown to dechlorinate and reduce chloramines successfully.
Does UV water filter remove chlorine?
Medium Pressure UV provides high intensity, UV light at wavelengths from 200 to 400nm (ideal for the destruction of free chlorine). The applied UV dose is much higher than for standard disinfection, so as well as removing free chlorine, the system can disinfect microorganisms at the same time.
Can a UV light replace chlorine?
An increasingly popular dechlorination technology—with none of the above drawbacks—is ultraviolet (UV) treatment. High intensity, broad-spectrum UV systems (also known as medium-pressure UV) reduce both free chlorine and combined chlorine compounds (chloramines) into easily removed byproducts.
Is concrete channel cheaper than chlorine?
A concrete channel also needs to be constructed for this method, however this is cheaper as the overall size of the system is considerably smaller. Another aspect that makes this a cheaper alternative is that UV water disinfection can occur in a matter of seconds, whereas retention time for Chlorine is much higher.
Is chlorine a toxic substance?
Chlorine is inexpensive, however it is highly toxic and has to be handled with caution and stored in large tanks under pressure. One great benefit to using UV water disinfection is that it does not produce harmful by-products and is non-toxic to the environment.
Can you disinfect with UV water?
In short, both disinfection methods are reliable and can protect you and the public against pathogens which can include bacteria and viruses, however there are certain pathogens such as Cryptosporidium that are in fact Chlorine resistant – but can be disinfected by UV water treatment.
Is chlorine a disinfectant?
The main two to consider are UV water disinfection or Chlorine treatment. More recently, UV water treatment has been successfully used around the world as an effective alternative to chemical disinfection treatment like Chlorine. Chlorine is inexpensive, however it is highly toxic and has to be handled with caution and stored in large tanks ...
Is UV water disinfection safe?
Safety Of UV Disinfection. Although UV water disinfection is the safer alternative to Chlorine disinfection, UV disinfection equipment should also be treated with caution. The risks are low, but you should always ensure you have a safety plan in place that reduces the exposure to high levels of UV light and electrical hazards.
How long does UV disinfection take?
UV disinfection occurs in seconds, whereas chlorination requires several minutes of retention time. The annual cost of operating and maintaining a disinfection system can have a significant impact on the economic evaluation of each option.
Why is a chlorine contact tank required?
Because chlorination requires a lengthy retention time, a large chlorine contact tank or channel is required unless one already exists. This adds additional concrete, civil works, excavation and construction to the overall capital cost.
Why are there lockouts in UV power cabinets?
There are lock-outs in the power cabinets as well to ensure power is off, and lock-out/tag-out occurs when servicing a UV system. As with operating and working with any type of equipment, it is recommended that proper personal protective equipment be worn and safety procedures be followed.
Is sodium hypochlorite a disinfectant?
Sodium hypochlorite is a diluted liquid form of chlorine that is also commonly used. Today, UV disinfection is widely accepted for municipal wastewater disinfection around the world. UV is rapidly growing, given it’s a safe and cost-effective alternative over chemical disinfection. Also, it produces no disinfection byproducts or a chlorine ...
Does UV light affect water?
Also, it produces no disinfection byproducts or a chlorine residual, which is harmful to the environment. The UV disinfection process adds nothing to the water but UV light, and therefore, has no impact on the chemical composition of the water.
Is chlorine gas toxic?
Lem: Traditionally, the use of chlorine gas was the most common method of wastewater disinfection. Chlorine gas itself is relatively inexpensive but is a highly toxic chemical that must be transported and handled with extreme caution. It is stored under pressure in large tanks and is released into the wastewater as a gas.
Is UV disinfection toxic?
As a growing alternative and a direct replacement technology to chemical (chlorine) disinfection, UV does not produce harmful byproducts and is not toxic to the environment.
Why is UV light important for disinfection?
UV Dosage. UV dosage is the most critical function of UV disinfection, because the extent of inactivation is proportional to the dose applied to the water. As individual UV lamps emit a set amount of ultraviolet energy, it is important that a system be sized correctly.
How many coliforms are in a UV disinfectant?
There is also a limit to the number of bacteria that can be treated. An upper limit for UV disinfection is 1,000 total coliform/100 mL water or 100 fecal coliform/100 mL. Special Considerations. Prefiltration is required to remove color, turbidity, and particles that shield microorganisms from the UV source.
What are the three types of UV radiation?
UV Types Comparison. Principles of UV Disinfection . UV radiation has three wavelength zones: UV-A, UV-B, and UV-C, and it is this last region, the shortwave UV-C, that has germicidal properties for disinfection. A low-pressure mercury arc lamp resembling a fluorescent lamp produces the UV light in the range of 254 manometers (nm).
What is UV dose?
The effective UV dose, expressed in mJ/cm² (millijoules per square centimeter), refers to the necessary UV energy that the micro-organisms (bacteria, viruses, algae in suspension…) must absorb before being destroyed. When this UV dose is reached, the UV-C rays penetrate the micro-organisms’ DNA and eradicate 99,9% of them.#N#The UV dose is a result of an equation between:#N#• the flow rate#N#• the UV exposure time (depending on the device’s design)#N#• the UV-C power emitted by the lamp#N#Other parameters must to be taking into account while calculating the UV dose and notably, the UV transmittance measured as a percentage. It is the UV rays ease to go through water; the easier they are going through, the higher the percentage is.#N#Thanks to our expertise, we are able to offer optimum UV disinfection solutions even with low UV transmittance. (Learn more about BIO-UV Group’s expertise)
How does UV radiation affect microorganisms?
UV radiation affects microorganisms by altering the DNA in the cells and impeding reproduction. UV treatment does not remove organisms from the water, it merely inactivates them. The effectiveness of this process is related to exposure time and lamp intensity as well as general water quality parameters.
How much radiation does UV light produce?
There are UV lamps that produce radiation in the range of 185 nm that are effective on microorganisms and will also reduce the total organic carbon (TOC) content of the water. For typical UV system, approximately 95 percent of the radiation passes through a quartz glass sleeve and into the untreated water.
What is BIO-UV?
There is a wide range of applications for the water disinfection using the UV technology, BIO-UV Group offers solutions for both professionals and individuals. For instance, you can treat surface water, residual water, pool water, industrial process water, drinking water, etc….
Why is chlorine not tolerated?
However, many industrial and commercial processes cannot tolerate chlorine in the process because of chlorine's reactive nature. For example, chlorine affects the flavor or smell of drinks and liquids. In pharmaceutical processing, chlorine oxidizing agents can disrupt important chemical reactions and destroy products.
How long can a RO membrane be exposed to chlorine?
It says that an RO membrane can tolerate 1 ppm of free chlorine for 1,000 hours before "significant" damage has occurred. Therefore, based on our limit of 0.01 ppm free chlorine, the end users membranes won't reach the 1,000 ppm-hours limit until after 11.4 years of exposure, an acceptable timeframe.
Why do pools need chlorine?
This natural phenomena forces owners of outdoor pools to routinely add chlorine to their pools in order to maintain a disinfection residual. Municipal water districts using surface water sources must also compensate for the sun's effect when chlorinating. This phenomenon can be duplicated on a commercial level using a concentrated source ...
How does RO water work?
A large west coast semiconductor manufacturer recirculates 80 gpm of RO water through an air scrubber to wash isopropyl alcohol (IPA) out of the exhaust air coming from one of their manufacturing processes. After removing the IPA from the exhaust air, the water is run through RO to reject the alcohol.
Does bisulfite add to water?
Bisulfite only adds to the complex chemistry of the incoming water, and must be removed during the water purification process.
Does chlorine oxidize water?
Ultraviolet Light Oxidizes Free Chlorine in Water. Chlorine is the most frequently used chemical for water disinfection. However, many industrial and commercial processes cannot tolerate chlorine in the process because of chlorine's reactive nature. For example, chlorine affects the flavor or smell of drinks and liquids.
Is chlorine bad for piping?
High chlorine levels also accelerate corrosion on process vessels and piping, and are generally considered damaging to process equipment. For example, reverse osmosis (RO) membranes and deionization (DI) resin units can be damaged by continual exposure to chlorine.
Disinfection and its purpose
How can you remove all the residual harmful substances from the wastewater after the removal of the strongest contamination? The answer is disinfection. It is the last and one of the crucial steps of wastewater treatment.
Chlorine as the safest method
There are three methods of wastewater disinfection. The most frequently used method is chlorine that enters the water in liquid form.
Ultraviolet disinfection
The second method we will cover is the ultraviolet disinfection which is being increasingly used to treat municipal wastewater.
Ozone removes both viruses and turbidity
E. coli is a bacteria commonly found in the lower intestine. Some E. coli mutations are not vital since they are harmful. For instance, an undesirable E. coli strain causes diarrhea, pneumonia, or infection of the urinary tract.
What are the challenges of sodium hypochlorite?
Sodium hypochlorite poses three challenges your water treatment facility will need to overcome: UV rays, off-gassing, and oxidation. Poly Processing has established a set of best practices and containment solutions that overcome these challenges.
Is chlorine gas dangerous?
Chlorine gas is incredibly dangerous. If there’s a leak near residential or school zones, there could be a significant kill zone.
Is sodium hypochlorite an oxidizer?
Sodium hypochlorite is an incredibly aggressive oxidizing chemical. Using an antioxidant barrier can more than double the life of the chemical storage tank system and help ensure the safety of the tank. Traditional polyethylene tanks may fail when storing an oxidizer, but an XLPE tank with an inner-surface engineered polyethylene system helps protect your investment long term.