1. What happens to the chemicals that are broken down?

Most chemicals are organic molecules –consisting of carbon, hydrogen, and oxygen – these just break down into water and trace levels of CO2. Heavy metals deposit on the catalyst. Other materials are mineralized, that is, they are broken down into their simplest and least reactive state, safe, simple molecules. For example, MTBE (C5H12O) would be decomposed to CO2 and water.

2. What about salt and minerals?

This is not a desalination technology, salt is already in its
mineralized state and won’t be removed. Other minerals which give water a pleasant taste are
also not removed.

3. What types of metals deposit on the photocatalyst and do they affect product performance
over time?

Heavy metals with known health risks such as arsenic, mercury, and chromium are
removed from the water through a photoadsorption process. Over time, the accumulation of
adsorbed metals will slow the performance of the catalyst and reduce the performance of the
Shield. The rate of this reduced performance will depend on the level of heavy metal content in
your water. A Pur-Blue test is a quick way to determine if your product is still functional or if it
needs to be replaced.

4. Are there any replaceable components?

Yes, there is a replaceable catalyst cartridge and a UVC bulb that needs annual replacement. The catalyst may need replacing on a more frequent basis dependent on the application and the level of heavy metals present in the source water.

5. Are there any contaminants that it does not address?

Yes, no system covers every contaminant, but we will degrade more than any other commercial technology. However, there are some minerals and inorganic chemicals which do not degrade in our system – some of the lighter metals, and some of the minerals like fluoride, many of these are considered desirable at low amounts.
Specific minerals could be removed by ion exchange or reverse osmosis, and our system can work
in conjunction with any other technology to address specific concerns.

6. Isn’t CO2 a bad thing?

Water has a certain amount of CO2 in it all the time, the amount added by photo-degradation is trivial. CO2 is generally regarded as a greenhouse gas, yes; but the production of it from advanced oxidation processes for water treatment is comparably trivial. For instance, a Shield operating non-stop would take 150 days to produce an amount of CO2 equivalent to using 1 gallon of gas in your car.

7. What are the key environmental benefits?

100% water recovery - no concentrated effluent or backflush stream. Absolutely chemical free processing. Low power consumption. Destruction of contaminants in water means no contaminants wind up in a landfill or other waste stream.

8. What are the primary technology advances?

Our patented technology uses LEDS to activate five photochemical processes. Three of the processes are activated when the light strikes the nanocoated surface of a fibrous mesh. The nanocoating is a photocatalyst, and the water flows through the mesh and the photocatalyst to be purified. The five processes work synergistically on the contaminants, often two or more are in operation on a single contaminant type.

9. Why LED’s?

LEDs are superior to alternative light sources such as lamps because of their long life time, high energy efficiency, and high power output. This allows for incredibly energy efficient lighting systems compared to conventional methods. LEDs are also a quickly growing market seeing vast improvements in product performance, meaning that as the LED industry improves,
so do Puralytics’ products.

10. Can you scale it up?

The current process volume for a Shield is up to 5678 Liters per day (3.94 L/min)- or 1500 Gallons per day (1.04 G/min); adequate for a variety of POU commercial and industrial applications, and POE for residential off-grid applications. All of the technology can be scaled to much higher volumes.

11. How much does it take out?  

The Shield was designed to achieve 99.9999% bacteria, 99.99% virus, 99.9% protozoa, and > 70% reduction in any specific organic or heavy metal at 3.94 lpm (specifically, the microbiological targets are zero units found in standard tests which start with the log values of the targeted removal). By adjusting the flow rate, the reduction rate can be increased or decreased for a specific contaminant type. Shield units can be operated in parallel to increase throughput or contaminant reduction. Higher performance systems are in development.

12. What about hard water or high TDS?

In hard water applications calcium and magnesium need to be controlled to prevent scale from forming. Typically this reduced by using Ion exchange.

13. What is the pressure drop across the Shield?

2-7 psi

14. Where would it be used?

The Shield fits many commercial/industrial POU applications, such as process water for industrial operations to eliminate problem contaminants, product water for food/beverage establishments, source water for manufacturing when water purity is important to the process, treating all of the health related contaminants for commercial or residential off-grid (well or surface) water, emerging needs for regulated waste water, and school, village or community level projects around the globe.

15. Does it address endocrine disruptors?

Yes, this is the most effective technology for all of the emerging organic contaminants such as pharmaceuticals, petrochemicals, herbicides, pesticides, and personal care products.

16. Do you have any proof?

Yes, independent third parties have verified the unit’s performance specifications, and this information is available on our website and by request.

17. Does the unit shut-off when water is not running?

Yes, there is a flow switch in the system which shuts off the LED’s when water is not flowing.

18. How long will the unit last (in days and in gallons)?

The Shield is designed to last 1 yr or 547,500 gallons (2,072,512 Liters) with continuous operation before cartridge replacement is recommended.

19. What components fail first?

The UVC bulb and the photocatalyst cartridge should be replaced once a year to ensure appropriate performance.

20. What happens if the unit gets wet?

The unit has been designed to be 100% water safe, all sensitive electronics are imbedded in water safe potting compound so no electrical failures can occur due to water. The unit is designed to be spill proof but is not designed to operate under water.

21. How often should I check the status of my Shield?

A routine monthly check of the units status status lights would be advisable, this is a simple visual inspection.

22. Can I monitor the system remotely?


23. What should I use to clean the reflective surfaces should they become fouled?

A 30-70% Isopropyl alcohol solution on a clean paper towel should be used to clean all internal metallic surfaces. If there is water spots that cannot be removed using this solution contact Puralytics for advice on appropriate cleaning agents to use inside the Shield. Note: If water is spilled inside the
unit during maintenances it should be wiped off with a clean rag, this will help prevent water
spots from depositing on the metallic surface over time.

24. How heavy is the Shield when it’s empty? When it’s full?

The Shield weighs approximately 55 lbs when shipped. When full of water the unit is closer to 70 lbs.

25. How often does the unit need to run to stay clean?

We do not recommend long periods of inactivity. Periods of 3 months or longer without any water flow can cause growth inside the system. This growth can be easily broken down but requires a system flush of 5 gallons of water. If the unit is not being used a 20 min cycling every month will keep the unit in pristine shape.

26. Can the unit be powered with DC or does it require AC?

The unit can only be powered using AC power sources 110-240V.

27. Max flow? Min flow?

0.5L/min - 3.94L/min 

28. What repairs can be done in the field?

All annually scheduled maintenance can be performed in
the field.

29. What kind of failures are catastrophic and will require the Shield to be returned to Puralytics for replacement or rework?

If for some reason the LED’s are not functioning, this will require a replacement unit to be sent out. If there is a catastrophic water leak that cannot be replaced with a new fitting, this too will require a replacement unit to be sent out.

30. Does it reduce turbidity?

The Shield is not designed to work on highly turbid sources. Pre-filtration will be required in applications with turbid water above 30ntu. 

31. Does it require pre-treatment?

Depending on the application a variety of pre-treatment methods can be implemented. 

32. What is the upper limit of ppm of contaminants the Shield is capable of handling effectively?

Depends on the application. Ideally, we would target applications with target organic contaminants below 10 ppm due to the limitation of dissolved oxygen in the water. For special cases where recirculation designs are possible, this number can extend.

33. How do you dispose of the used photocatalyst cartridge?

It is non-toxic and harmless and can be safely disposed in any designated waste facility. Based on the application, additional testing may be necessary to ensure that the removed compounds meet TCLP requirements. Some states such as CA have more stringent disposal regulations that would need to be followed.

34. How long does it take to replace the photocatalyst?

It takes approximately 10 minutes to change out the photocatalyst cartridge.

35. How many hours of annual service is required?

Approximately 1 hour.

36. Why does the Shield a UV lamp? Doesn't it do the same work the photocatalytic process does?

The UVC lamp is placed immediately before the exit of the Shield to ensure that all biological contaminants are killed prior to consumption. This is especially important when re-starting a Shield that has been sitting idle for extended periods of time.

37. How many Shields can be installed in parallel or series?

There is no physical limit on the number of shields that can go in parallel (provided there is adequate flow provided to each system.

38. What indicator is there that purification process is working?

Each Shield is thoroughly tested by Puralytics this ensures the system is purifying water effectively prior to shipment. After installation water samples can be taken and analyzed by local labs at any time to ensure the water is pure, otherwise no indicator is given.

39. Could a water leak cause unit to fail permanently?

No. The unit is designed to get wet should a leak occur. If the leak is significant, the unit needs repair to fix the leak.

40. If the Shield loses power will water flow automatically stop?

No, but the lights will turn off, indicating the unit is no longer purifying water.