UV Water Treatment: Provides Clean, Pure and Chemical-Free Water

Pure, pristine water constitutes a fundamental necessity in our lives. Often, we assume that the moment we twist the tap, crystal-clear water will effortlessly flow. Numerous sectors, including food and beverage production, aquatic activities, aquaculture, pharmaceuticals, and horticulture, heavily rely on a consistent supply of fresh, uncontaminated water to maintain the utmost quality of their products. The question then arises: What measures can be taken to attain such a lofty standard of pure water?

UV water treatment systems generate purified water that is free from contaminants. UV is effective against all known microorganisms, including chlorine-resistant Giardia and Cryptosporidium, which are inactivated by UV treatment. UV water treatment is both cost-effective and efficient, as it does not involve chemicals, preserves the water’s taste, and eliminates corrosion-related issues.

In UV water treatment systems, water flows through a chamber housing one or more UV lamps. As the water passes through this reactor, the UV energy emitted by the lamp(s) penetrates the outer cell membrane of any pathogens present, traverses through their cell bodies, disrupts their genetic core (DNA), and incapacitates their ability to reproduce. UV water treatment is a straightforward, efficient, and environmentally friendly method. UV systems are engineered to obliterate a minimum of 99.99% of harmful microorganisms, all without the need for additional chemicals, resulting in no alterations to taste or odor. Importantly, Uv water treatment does not induce any chemical changes in the water; it only introduces energy, making it suitable for various applications and industries.

 

The Use of Ultra-Pure Water in Pharmaceutical

Due to its capacity to disinfect ultra-pure water devoid of any byproducts or chemicals, UV water treatment stands as an excellent choice for the pharmaceutical and cosmetic manufacturing sectors, as well as medical facilities necessitating sterile water. It can be employed either independently or in conjunction with other purification techniques like reverse osmosis (RO) and electro deionization (EDI) to eliminate chlorine and ozone contaminants.

UV Water Treatment for Treating Wastewater

UV water treatment systems find widespread application in wastewater treatment facilities due to their effectiveness in deactivating harmful microorganisms like E. coli, Salmonella, Vibrio, Cryptosporidium, Giardia, enterovirus, hepatitis, and Shigella. These bacteria pose significant health risks and can lead to severe illnesses. Operators of municipal wastewater treatment plants are obligated to meet stringent disinfection standards, ensuring that specified microorganism thresholds are met prior to either reusing the treated water or discharging it into surface waters.

UV water treatment delivers highly efficient water disinfection against a comprehensive spectrum of microorganisms, encompassing spores, mold, yeast, and protozoa. Importantly, there is no risk of overdosing since UV systems operate without the use of chemicals. These UV water treatment systems neutralize microorganisms precisely at the point of contact, allowing for their application throughout treatment facilities to safeguard other treatment processes from potential microbiological contamination.

UV Water Treatment for Aquatic Applications

UV water treatment is equally effective in neutralizing bacteria, viruses, and molds in swimming pool water. Moreover, it reacts to disintegrate chloramines, commonly referred to as combined chlorine, which form when free chlorine interacts with human perspiration and urine within the pool. These chloramines are responsible for the unpleasant odors in swimming pools and can lead to eye irritation among swimmers. The implementation of UV water treatment reduces the need for excessive chlorine, enhancing the overall swimming experience and reducing the frequency of filter backwashing. This, in turn, leads to decreased water consumption while enabling swimming pool owners to comply with stringent regulatory standards.

Case Study 1 – Control Legionella with UV

Legionnaires’ disease is a severe and potentially life-threatening illness brought about by the Legionella bacteria, which flourish in warm and damp settings. Individuals with weakened immune systems face a greater susceptibility to this disease, which can be transmitted through hot and tepid water systems, commonly encountered in facilities like nursing homes and hospitals.

This ailment manifests with flu-like symptoms and can have fatal consequences. Typically, recorded outbreaks of Legionella bacteria have been linked to either improperly commissioned or inadequately maintained large air conditioning units or hot water distribution systems.

Legionella bacteria are often present in drinking water supplies at low levels. Yet, when warm water infrastructure lacks proper disinfection measures, these bacteria can rapidly multiply. Thermostatic mixing valves, frequently utilized in healthcare and hospitality settings to regulate water temperature, do not offer microbial control and can, in fact, facilitate the proliferation of Legionella and other microorganisms. An established and cost-effective method for Legionella control involves the installation of a UV disinfection system on either the warm water outlet or the return line of the water heater, or both.

A manufacturer specializing in UV disinfection equipment recently implemented a system at an elderly care facility in Sydney, Australia, catering to a capacity of up to 78 individuals. The primary purpose of this system was to ensure the provision of safe, warm water for showers, hand basins, and baths. Given that warm water systems operate as closed circulatory systems, any Legionella bacteria that infiltrate the system will remain within it until they are either eliminated or effectively controlled.

In this specific scenario, the chosen UV system was positioned on the plumbing infrastructure that connects to the outlet of the warm water tank. This location was strategically selected as it represented the closest point where the warm water would be accessed by the facility’s occupants, eliminating the need to install multiple UV units at every individual point of use.

The manufacturer’s engineers had to guarantee that the selected UV system was well-suited for its intended role and capable of effectively deactivating and eliminating bacteria by delivering the precise UV dose. (UV dose is determined by multiplying the UV intensity emitted by the lamp by the contact time within the UV reactor.) To accomplish this, they had to establish three critical parameters:

• The condition of the water to be treated, its UV transmittance (percent UVT) – This factor reflects the UV light’s ability to penetrate a specific water source (in this instance, warm water) in comparison to distilled water, which possesses a UVT value of 100. The UVT value directly affects UV intensity. The manufacturer’s laboratory conducted a test on a sample of the warm water from the facility, resulting in UVT values ranging from 75 to 80%. Therefore, the system’s design was based on the most conservative estimate, which is a UVT value of 75%.
• Peak flow through the warm water system – This particular data element plays a crucial role in determining the contact time. The manufacturer’s engineers collaborated with the nursing home’s personnel to conduct a comprehensive water audit, evaluating all connections associated with the warm water system to estimate peak flow. The combination of warm water usage patterns and fitting details was instrumental in establishing this parameter.
• UV dose requirement — The greater the UV dose, the more effectively it deactivates and eliminates Legionella bacteria. Existing data regarding the UV dose necessary to achieve a 4-log reduction (equivalent to a 99.99% reduction in bacteria) indicates that a UV dose of 5 millijoules per square centimeter (mJ/cm2) is required. The engineers are meticulous in specifying UV systems, erring on the side of caution. Overdosing a water source with UV does not pose any harm, but if the UV dose is insufficient, the system will fail to provide the required level of protection. Therefore, this manufacturer’s UV disinfection system for warm water are designed to attain a minimum UV dose of 40 mJ/cm2 by the end of the lamp’s lifespan. This deliberate specification of UV systems at this UV dose level enhances the system’s resilience in case of deteriorating water quality, increased peak flow, or fouling of the quartz tube, which houses the UV lamp within the reactor.

The installed system was equipped with UV intensity monitoring to consistently verify the attainment of the intended UV dose. Should there be any risk of not reaching the designated UV dose, the UV intensity monitor would promptly transmit a signal to the controller. Subsequently, the nursing home’s building management system would be alerted, enabling the staff to promptly address the system and identify the root cause of the issue.

Additionally, suggestions were put forward to conduct routine water sampling and Legionella testing at several critical junctures within the warm water system. This additional measure served to enhance the assurance of a bacteria-free warm water supply.

Case Study 2 – UV Water Treatment for Horticulture

Engall’s Nursery, a dedicated nursery with a history of cultivating fruit and citrus trees since 1976, employs a UV water treatment system for disinfecting irrigation water in its expansive four-hectare citrus cultivation zone in Dural, New South Wales. In pursuit of certification from the Nursery and Garden Industry Association (NGIA), Engall’s Nursery thoroughly evaluated various options and ultimately opted for UV water treatment. Central to this choice was the UV system’s capability to deliver in-line treatment, a clear advantage over alternative chemical solutions that necessitated the use of sizable storage tanks.

The engineering team collaborated closely with the nursery owner and the NGIA to develop a solution that integrated the precise treatment level needed. They conducted laboratory tests on the UVT of the irrigation water to ascertain the appropriate dosage. The specific species of concern for the crop at this location were Phytophthora and Pythium.

The team selected a UV system that surpassed the criteria established by both the NGIA and the nursery owner. This system would attain a UV dose of 100 mJ/cm2 at the conclusion of the lamp’s lifespan, accommodating a peak flow rate of 27 cubic meters per hour in cases where the UVT was 55%.

The skid-mounted system comprises four 450-watt, low-pressure UV lamps. An integral component of the design is a quartz auto-wiping system, triggered by UV intensity measurements taken by a UV intensity sensor and monitor. Whenever the UV intensity falls below a predetermined threshold, the wiping system activates to clean the quartz, ensuring the maintenance of the intended UV dose.

The system is managed through the nursery’s existing irrigation controller. This approach ensures that the system operates exclusively when necessary, a practice that is advisable for extending the lifespan of the UV lamps and minimizing power usage.

Cooperate with Puritor

Puritor designs and manufactures UV water treatment equipment for use in a variety of environments with its products including UV Water Purifier for Home, Industrial UV Water Purifier and Municipal Open Channel UV Water Treatment System. Puritor has been providing versatile UV water treatment solutions to customers from various industries for the past 17 years. If you want to learn more, feel free to Contact Puritor or visit Puritor.com.