About This Webinar
Free Webinar presented by Photonics Media & OSA
Additional Questions and Answers from the Webinar below:
Wayne Lem
Market Manager
Trojan Technologies
From the water we drink to the processed water we use in our industries and in agriculture, water is a precious resource that touches every person on the planet in one way or another every single day. Since 1977, Trojan Technologies of Ontario, Canada, has led the change to municipal water disinfection systems that use environmentally responsible, cost-effective ultraviolet light in place of chemicals. In this one-hour webinar, Wayne Lem, municipal wastewater market manager for Trojan Technologies, will explain how Trojan became the leader in advanced UV water treatment technology and the inaugural winner of the Optical Society's Enabled by Optics contest. Topics he will address include the challenges to developing an innovative technology, the development of Trojan's technology, and its future applications.
Wayne Lem is a registered professional engineer and has been working in the field of UV disinfection for over 19 years. He has authored many technical papers and has spoken at various conferences to educate and promote knowledge on UV disinfection for municipal applications.
The webinar will be hosted by
Dr. Simin Cai, Founder, President & CEO, Go!Foton Group, a member of the OSA's Corporate Associates Committee, and an Enabled By Optics contest judge.
Additional Questions & Answers from the Webinar:.
Q: Does the company use the units on the side of swimming pools to disinfect pool's water? If not, why?
We actually do, this is part of the products manufactured by Aqua fine, a Trojan Technologies company. Please see www.aquafineuv.com.
A: The units are capable of disinfecting organisms found in swimming pool water, and also remove chloramines formed by the combination of pool chlorine and organic compounds.
Q: Have you considered using photocatalytic processes to supplement the injection of H2O2 For example, UV radition indocent on TiO2 will produce H2O2.
A: Yes, the challenge is finding a material that would promote chemical reactions at a fast enough rate to use in a commercial product. This is a topic of ongoing research in many labs.
Q: What was the placement of the lamps in reactor B? How far apart are they spaced?
A: The diagram was shown as a general illustration, no distance scale is provided. In general, the spacing will be determined by the lamp UV output and transmittance of water for UV light – the higher the lamp output and more transparent the water to UV is, then the wider the spacing can be. Optimum placement is determined by fluid dynamics simulations.
Q: Wayne what is the point of diminished return when it comes to the number of UV lights per unit volume?
A: In cross-section in a working channel, it would be the number of lamps per unit area. The optimum amount would depend on the range of water flow rates and water transparencies experienced at a site, as well as the power of the individual lamps. Typically, a product will have a set value to treat water for a specified range of conditions to meet customer’s needs. For typical secondary WW disinfection in the market today, UV systems utilizing amalgam lamps use anywhere from 4 to 12 UV lamps per MGD (million gallons treated).
Q: Is there any disavantage of this technology?
A: For UV disinfection, some organisms are more resistant than others so more UV dose is required. Fortunately in drinking water treatment, the most UV resistant viruses are easily treated by low concentrations of chlorine so a multi-barrier disinfection approach combines the advantages of UV and chlorine. For wastewater treatment, the elimination of chlorine is desirable to eliminate harmful chemical byproducts from forming. One disadvantage to UV would be the lack of a residual l(which is not the case for chlorination). Depending on regulations, a chlorine residual is typically required in drinking water whereas it is not in wastewater. Since UV does not provide a residual, a reliable, accurate and traceable UV sensor used to indicate/measure lamp output is an important part of the UV system.
Q: What happens to remnant of destroyed microorganism ?
A: Organisms treated by UV are actually not killed but are unable to reproduce, so they cannot multiply and infect a host.These organisms die naturally.
Q: How do you keep the optical surface interfacing with water clean for a longtime?
A: The surfaces of the quartz sleeves used to protect the lamps are periodically cleaned by wiping mechanisms (one illustrated for the Trojan UV3000+ module in the presentation). Trojan Technologies uses a chemical-mechanical cleaning process.