WHY UV LED DISINFECTION OFFERS A COMPELLING ALTERNATIVE TO TRADITIONAL METHODS TODAY?

CONTEXT

Over the last 20+ years, UV Disinfection has become a mainstay treatment process in municipal drinking water, Wastewater and, more recently, Water Reuse applications.

UV disinfection has many advantages over competing technologies in that it is:

• Chemical-free,
• Does not affect the water chemistry
• Is particularly effective at inactivating such harmful pathogens as Cryptosporidium and Giardia.

CURRENT METHODS

By far the most common method of generating UVC radiation at present is the use of Mercury UV Lamps with the number varying from a single lamp to hundreds in a single system with every lamp containing between 20mg and 700mg of mercury.

WHAT ARE THE DRAWBACKS WITH THIS APPROACH?

A primary concern is that mercury lamps are vulnerable to breakage during operation, risking the release of harmful mercury into the water to be used for human consumption, or environmentally sensitive receiving waters.

Indeed in most countries around the world, the disposal of mercury lamps must be regulated to prevent the leaching of mercury into the environment.

The Minamata Convention is a global treaty intended to protect human health and the environment from the adverse effects of mercury with one of the rulings being the banning of the use of mercury and other heavy metals in the manufacture of electrical and electronic components.

Today UV Mercury Lamps have a 5-year dispensation from this ruling because there hasn’t been seen to be a viable alternative technology.

This means that today, thousands of water and wastewater treatment plants around the world use Mercury UV Lamps, with new systems installed every day.

WHAT IS UV LED WATER TREATMENT?

The last 10 years has seen a growing interest in the use of UVC-LED for water treatment, fuelled by a desire for the same energy efficiency advantages that visible light LEDs give us in our everyday lives and by the potential for a Mercury Free disinfection solution.

LED solid-state technology is fundamentally different to Mercury lamps and starts to challenge many of the traditional UV System design principles with benefits such as Instant ON/OFF, Dynamic LED Switching, Long Life and Low Maintenance.

Yet the challenge in recent years has been how to apply a small, low power, LED to a system suitable for 24/7, high flow rate applications as would be required for water utilities around the world?

ARE WATER COMPANIES READY FOR UV LED?

Haitz Law is an observation and forecast of the gradual improvement of LEDs over a protracted timescale and suggests that the cost per lumen will fall by a factor of 10, and the amount of light generated per LED will increase by a factor of 20 approximately every 10 years.

Typhon started its journey to develop a UV LED System suitable for municipal applications in 2014 when LED UVC output was little more than 1mW.

In 6 years that output has increased by more than 100x.

But even with that progression, UVC-LEDs are still in their infancy.

A Typhon UV LED system installed today has the potential to reduce infrastructure costs, simplify operation and reduce the resources required to manage an operational UV system.

Yet current UVC-LED efficiency is still relatively low compared to where the industry expects it to peak. A key aspect of the Typhon design is to allow future generations of LEDs to be retrofitted to a Reactor installed today, which means running costs will reduce through the system's operating life. But also, as LED power increases, the capacity of the installed system will increase - future-proofing the asset for population expansion.

Today municipal UV Systems are specified based largely on reactor cost and worst-case Power Consumption.

To commit to install a UV LED System today requires a commitment to long term, rather than short term savings and to have faith in the continued progress of Haitz Law.

That is why conservative water companies stay with the tried and trusted mercury lamp systems and why one of those water companies will be the last to buy a mercury lamp system as the Minamata Convention dispensation ends.

SUMMARY

Typhon has developed the world’s first USEPA validated UV LED Reactor and installed the world’s first full-scale municipal UV disinfection system treating almost 30,000m³/day. This high efficiency UV LED reactor can incorporate future generations of UVC-LEDs and so offer customers a system which can both increase in capacity and decrease in operating costs with each LED change-out through the system's operating life.

The time to start installing UV LED Systems is today. To understand the operational benefits, to take advantage of the UVC-LED evolution and to remove the use of mercury from water treatment forever.