Wednesday, February 13, 2019
Lamp TechnologiesRoom: Colombo A
Assessment of Measurement Methods for Polychromatic UV Sources
Paul Ropic, Hanovia Ltd Assessment of Measurement Methods for Polychromatic UV SourcesPaul Ropic, Hanovia Ltd Low-Pressure (LP) and High-Pressure (HP) mercury lamps are the primary sources used of UV disinfection or advanced oxidation processes. The two different lamp technologies have distinctly different output characteristics. Accurate lamp measurement is required for system; design, validation and component replacement and is critical for ensuring performance continuity over the life of a UV system. Currently within the UV community a standardised method for LP lamps is employed calculating total lamp efficiency from a single measurement taken in air. Given a stable air temperature and electrical supply results have been shown to be consistent across test laboratories, which is primarily due to the characteristics of positive column of the low-pressure discharge. Practically such a discharge can be considered to have a ubiquitous generation of radiation throughout the plasma primarily at the 253.7nm resonance line. Therefore, for measurement purposes it is simplified to a monochromatic discharge with a uniform output. This is not the case with higher internal pressures as a wider range of energy transition levels develop that subsequently produce a broad spectrum of radiation. In addition, the plasma constricts, and photon emission is limited to this area only which may not be central to the lamp body. Consequently, the produced polychromatic sources with a potential non-uniform discharge is far more challenging to measure and to date a standardised approach has not been produced.
A continuation of previous work is presented where a comparison of differing HP sources with varying spectral characteristics are assessed. Alternative methods of measurement are used including a similar simplified approach to that of the LP measurement method described in addition to a more complex approach using a customised goniometer. The outputs are presented and recommendations to progress towards a standardised method for high pressure UV lamps.
Shedding Light on High Power Mercury Free Sources for Ultraviolet Disinfection
Paul Ropic, Hanovia Ltd Shedding Light on High Power Mercury Free Sources for Ultraviolet DisinfectionPaul Ropic, Hanovia Ltd Chemical free disinfection has been enabled using Ultraviolet (UV) radiation and has been utilised in water and wastewater applications since the mid-20th century. Its application rapidly expanded in part due to; the identification a wide range of chlorinated by-products, exceptional disinfection efficacy of chlorine resistant pathogens as well as technological improvements increasing practical reliability. The principle sources of UV for disinfection are mercury-based plasma lamps. Such lamps are broadly characterised as either low-pressure (LP) or high-pressure (HP) lamps. LP lamps have a high spectral efficiency producing a wall plug efficiency (WPE) of approximately 30-35%, yet a lower power output (max 1kW). HP lamps for the same lamp length could run in the region of 30kW, however they have a much broader spectral output and for disinfection purposes are less efficient approximately 10-15% WPE. Increasing environmental awareness and societal drivers for change such as the Minamata convention are increasing restrictions on the use of mercury and further restrictions are inevitable. Without practical alternatives to mercury the most disinfection applications are currently exempt from such restrictions. An emerging alternative is UVC Light Emitting Diodes (LED’s) which are increasing in power, life and spectral range. However, even the best performing diode arrays output in the upper UVC region, have a low efficiency and low power (mW range). As an emerging technology relative costs are high as well as lacking life performance data as seen from established technology. Novel mercury free UVC approaches are presented that operate in the kW range. One potential UVC source has many similarities with conventional lamp technology providing the option of system retrofitting and utilisation of existing certified electronic drivers. The developed high-power mercury free UVC source utilising robust and established electronics is a potential paradigm shift for global disinfection markets desiring a transition away from mercury-based applications. | AOP-4Room: Colombo B
An external standard calibration method to measure the hydroxyl radical scavenging capacity of water samples
Chengjin Wang, University of Toronto An external standard calibration method to measure the hydroxyl radical scavenging capacity of water samplesChengjin Wang, University of Toronto The hydroxyl radical (·OH) scavenging capacity is an important parameter for the design and operation of an advanced oxidation process (AOP) in water treatment. The scavenging capacity may change with time, and it would be useful to be able to continuously measure this change to be able to adjust and optimize AOP doses. In this study, we developed an external calibration method to allow relatively straightforward online measurement of the ·OH scavenging capacity. The method used low-pressure UV/H2O2 as the ·OH generation system, methylene blue (MB) as the probe compound, and isopropyl alcohol (IPA) as the standard. By monitoring, offline, the decay of MB in a series of IPA solutions with different scavenging capacity, a calibration curve was established between the MB decay rate and the scavenging capacity. The measured MB decay in an online process can then be used with this external calibration to estimate the scavenging capacity of the actual water sample. The accuracy in preliminary experiments was within 5%. Work was undertaken to ensure that the process would be robust under a wide range of water quality conditions, with considerations such as the MB and H2O2 doses, and optical path length, optimized to reduce errors. Parallel tests on the same samples using this method versus using other methods, including the conventional method using para-chlorobenzoic acid (p-CBA) as the probe, were conducted, and the preliminary results showed that this method was robust, accurate, and fast. An online scavenging capacity monitor prototype based on this new method was proposed.
A control of the taste and odor substance in drinking water by the pilot scale UV/H2O2 and UV/Chlorine advanced oxidation process
Chinyoung Park, Water Quality Institute of Incheon City A control of the taste and odor substance in drinking water by the pilot scale UV/H2O2 and UV/Chlorine advanced oxidation processChinyoung Park, Water Quality Institute of Incheon City As the results of comparing the pilot scale UV/H2O2 and UV/Chlorine process performance installed in a conventional drinking water treatment plant to remove 2-MIB which is a tasty and odorous substance, the average consumption rate of H2O2 in the UV reactor was 10% while that of chlorine was 26% with the deviation of the maximum value and the minimum being a bit large. In the UV/H2O2 process, the removal rate of 2-MIB was proportional to the increase of H2O2 injection concentration and the EED value. Finally, 2-MIB could be removed 90% or more by manipulating the H2O2 injection amount and the EED.
In the UV/Chlorine process, the pH of water being not artificially adjusted was increased as the concentration of chlorine was getting higher, thus the removal rate of 2-MIB was decreased with the average removal rate being as low as 20%. From this result, it was found that the UV/Chlorine process should be operated after adjusting the pH value to remove 2-MIB efficiently.
The EEO value which was a factor to evaluate the economic efficiency of the treatment process was getting lower as the H2O2 injection concentration increased in the UV/H2O2 process.
The EEO value measured at each H2O2 injection concentration point could be utilized as an index for the economical operation through taking into account the chemical cost and the electric power consumption.
Removal of micro pollutants from wastewater treatment plant effluent with low pressure UV-C and hydrogen peroxide.
Jos Driever, Van Remmen UV Techniek Removal of micro pollutants from wastewater treatment plant effluent with low pressure UV-C and hydrogen peroxide.Jos Driever, Van Remmen UV Techniek Introduction. Levels of micro pollutants are rising in our surface water. Awareness on removing these is rising in Europe. The implementation of Dutch laws for mandatory and standardised removal of pesticides from greenhouse wastewater and the European Water Framework Directive are clear indicators our perceptions of this challenge are changing. Nationally apparent ‘hotspots’ like hospitals and nursing homes are in focus for decentralised treatment. However we feel this is insufficient and sewage water treatment plants are a much better location since the treatment already in place gives a much more treatable water quality and a lot more sources are combined here while discharging directly on surface water with a high risk for the formation and transfer of antibiotic resistance
Technical status and alternative.
Currently Ozone is hailed as the technology to remove these micro pollutants from our water stream. Despite being easy and affordable Ozone also has distinct drawbacks often overlooked; metabolites, bromate and selectivity. We would like to challenge current views of Ozone and show how the combination of low pressure UV-C and hydrogen peroxide can challenge Ozone both economically as in applicability and effectivity.
Results
We have done extensive testing with two full-scale reactors on wastewater treatment plant effluent with two laboratories and two Waterboards. With this we can show how the combination of low pressure UV-C lamps and hydrogen peroxide performs on the removal of medicine residues with the following variations:
Hybrid of UV Irradiation and Sodium Persulfate Inactivation on Microorganism in Drinking Water
Yongji Zhang, TONGJI UNIVERSITY Hybrid of UV Irradiation and Sodium Persulfate Inactivation on Microorganism in Drinking WaterYongji Zhang, TONGJI UNIVERSITY Bacillus subtilis spores are considered to be good surrogates for parasitic protozoans like Cryptosporidium and Giardia who prove to be very sensitive to UV irradiation. Moreover, B. subtilis spores are often used for UV reactor validation in Europe. Therefor B. subtilis spores was selected to investigate inactivation effect of UV irradiation and sodium persulfate disinfection individually and synergistic disinfection. The study first use E. coli to observe if UV/PS has inactivation effect. 7.24 log reduction can be achieved after 10min exposure to 113.0 μW/cm2 and 0.5mM Na2S2O8. While the results showed that sodium persulfate alone caused hardly any inactivation of B. subtilis spores. Only 0. 98 log inactivation was achieved by sodium persulfate with concentration of 0.5 mM after 10 min contact time．UV irradiation was able to inactivate B. subtilis spores to a certain extent — The inactivation reached 3.50 log at a UV intensity of 113.0 μW/cm2 after 10 min contract time. The combination of UV and Na2S2O8 could significantly improve the inactivation effect. Simultaneous UV and sodium persulfate synergistic disinfection was proved to be the optimal treatment methods which can achieve 4.30 log. Ultrastructural changes caused by UV/ Na2S2O8 process were observed by transmission electron microscopy which showed that the cell wall got blurred and the inner cytoplasm was indistinguishable, followed by a complete leakage of the cytoplasmic content. |
Validation-3Room: Colombo A
The journey towards the first NSF 55 certified UV LED Water Purifier
Ashkan Babaie, Acuva Technologies The journey towards the first NSF 55 certified UV LED Water PurifierAshkan Babaie, Acuva Technologies Acuva’s Eco 1.5 recently became the first UV-LED water purifier to be certified against NSF 55-Class B by The International Association of Plumbing and Mechanical Officials (IAPMO). As the primary standard for ultraviolet microbiological water treatment systems, NSF 55 verifies claims regarding disinfection capability of water treatment devices. In addition, the scope of this standard includes material safety and structural integrity of the water purifier. As part of the certification process, the production facility is audited to evaluate the quality control process within the production facility. The NSF 55 certification process is indeed a very valuable and demanding exercise to assure the effectiveness and safety of the water treatment system for microbial disinfection, with respect to the fact that currently no other standard is available specific to UV-LED water treatment devices; however, considering NSF 55 has primarily been developed based on the utilization of UV mercury lamps in water disinfection systems, there are challenges involved in following the standard protocols for UV-LED based water purification systems.
In this presentation, the certification process of Acuva’s Eco 1.5 against NSF 55 with IAPMO will be explained, including the detail of the bioassay, material extraction and pressure tests along with the official test results. In addition, the overall NSF 55- Class B standard will be evaluated in respect to UV-LED based water treatment systems. We will share our learnings within the certification process and offer an insight on improving the current protocols or establishing an alternative approach for global validation of UV-LED water disinfection systems for different industries and markets.
Validation of a UV reactor containing UV-LEDs for the disinfection of municipal drinking water
Olivier Autin / Jim Bolton, Typhon Treatment Systems / Bolton Photosciences Validation of a UV reactor containing UV-LEDs for the disinfection of municipal drinking waterOlivier Autin / Jim Bolton, Typhon Treatment Systems / Bolton Photosciences Ultraviolet Light-emitting diodes (UV-LEDs) have been seen, for a decade now, as the future of UV-based water treatment. In this study, we present the results of a full-scale validation testing of Typhon Treatment Systems’ BIO-310 UV-C LEDs disinfection unit conducted in July 2018 in the United Kingdom. The technology has been validated as a 2 to 4-log Cryptosporidium and Giardia barrier and can treat up to 250 m3/h (6 MLD) of water for UVTs in the range 90 to 98%. The validation followed the Ultraviolet Disinfection Guidance Manual (UVDGM) with some adaptations according to the draft ‘Innovative Approaches for Validation of Ultraviolet Disinfection Reactors for Drinking Water Systems’ guidelines from the US-EPA using MS2 as challenge microorganism.
This work represents what we believe to be the first large scale UV reactor containing UV-LEDs to be validated for municipal drinking water disinfection purposes using the combined variable approach. The presentation will describe the technology, the design of the validation test plan, how the biodosimetry testing enabled the development of a fitted equation, how the combined variable approach has been used and how this approach enables real-time monitoring and real time UV dose adjustment for energy optimised drinking water disinfection.
Non - Contact UV validation NWRI 2012 and the challenges
Arne Diering, Enaqua Non - Contact UV validation NWRI 2012 and the challengesArne Diering, Enaqua For Waste Water UV Disinfection there are different systems available. these are mainly sealed submerged UV lamps direct in the effluent water. Horizontal, vertical or inclined alignment of the lamps. Another opportunity is the non - contact UV system were the water runs through UVC transmitting fluoropolymer tubes. Non - contact UV disinfection is known since many decades and is as well published in the EPA handbook 1986.As all the submerged technologies of lamps covered by a quartz tube developed a validation protocol. There are many suppliers which follow this protocol and have achieved T22.These are open channel and as well closed vessel systems. This was never done for the non - contact UV system. In 2015 Enaqua A Grundfos Company started this process by designing with Corollo a test and validation protocol to achieve Title 22. According to the NWRI guidelines 2012 for reuse. This was successfully executed and DDW acknowledged the T22 for the non - contact UV system of Enaqua. The whole process started in August 2015 setting up the test reactor, getting onsite and starting the process. The sampling was done within 2 months and the test results were put together and handed over to DDW in January 2016. The acknowledgement, verification was achieved in October 2017.
The presentation will talk about the way to T22 for non - contact UV systems.
Impact of Inorganics on the Performance of UV Water Treatment systems
Babak Adeli, Acuva Technologies Inc. Impact of Inorganics on the Performance of UV Water Treatment systemsBabak Adeli, Acuva Technologies Inc. Inorganic minerals in water are classified into ‘healthy’ and ‘unhealthy’ compounds. Primary water treatment technologies, such as membranes and advanced filtration, has placed an emphasis on the elimination of unhealthy minerals such as lead, arsenic, and antimony; while preserving those benefit human health, such as calcium, magnesium and potassium. In particular, calcium and magnesium are the most common minerals in water supply, and their concentration is recognized as the water hardness indicator. Despite their health benefits, minerals tend to deposit inside disinfection systems, particularly, in the vicinity of conventional UV lamps, owing to their temperature dependent solubility in water. In addition, hard water exhibits lower UV transmittance (UVT), compared to water with less than 120 ppm minerals content, the so called ‘moderately hard’ water. Therefore, the disinfection performance of UV water treatment system is a strong factor of water hardness level, and the application of UV-based water disinfection systems is limited in the regions with high mineral content in water supply.
Here, we will discuss the effect of water hardness level on the performance and reliability of UV disinfection products. UV-LED and UV-lamp disinfection systems were operated with ‘hard’ and ‘extremely hard’ water, and their optical characteristics were evaluated. Furthermore, the effect of mineral content on water UVT, and subsequently the microbial disinfection performance of UV systems was correlated and guidelines for operation of UV systems for regions with high mineral content water will be presented. It is shown that UV-LED disinfection systems exhibit consistent microbial disinfection, owing to uniform temperature gradient across the reactor. The outcome of this study provides an insight on reliable operation of UV disinfection systems in regions with various water qualities.
| Technology Trends-3Room: Colombo B
Powering UV sources in the most efficient way
Tonnie Telgenhof Oude Koehorst, Nedap Powering UV sources in the most efficient wayTonnie Telgenhof Oude Koehorst, Nedap Ultra Violet low- and medium pressure lamps and LED’s are well known and widely accepted UV sources for disinfection applications for water and other fluids, air and surface. Improving efficiency of UV lamps has reached physical limits and UV LEDs still have a long way to go. Unfortunately the overall efficiency of the energy supply systems for the UV sources are in most cases not getting the right amount of attention and short term costs for initial investment are prevailing over the total cost of ownership. Most ballasts/lamp drivers act as non-linear loads on power grids, drawing a distorted waveform that contains harmonics and results in electromagnetic compatibility (EMC) problems, including Power Quality issues. When electronic lamp drivers consume power in a pulsed manner, it leads to a lower Power Factor (PF). Remind that our ‘conventional’ power grid was designed for linear loads.
Repeating peak currents at the mains input will contain harmonics and the summation of all harmonics is known as total harmonic distortion (THD) of the current and mains voltage, depending on the power line impedance.
The impacts of lower Power Factor and harmonic current and voltage distortion are increased losses in transformers, power lines and overheating and degradation of conductors and insulating material. Last but not least, it could reduce lifetime of components.
Another Power Quality problem to UV systems can be mains surges, transient peak voltages (several kilovolts) at the input of the ballast/lamp driver. With insufficient surge suppression in the ballast, these transients can lead to damage of the driver and will reach the lamp, possibly leading to premature lamp failures.
In this presentation we show the impact of Power Factor and THD in UV systems and compare several driver technologies with regard to overall efficiency, reliability, EMC, Power Quality, costs and CO2 footprint impact.
Synthesis and Application of UV-LED Activated ‘Metal-Oxide + Metal-Naonparticle’ Gas Sensors
Fariborz Taghipour, University of British Columbia Synthesis and Application of UV-LED Activated ‘Metal-Oxide + Metal-Naonparticle’ Gas SensorsFariborz Taghipour, University of British Columbia Ultraviolet light-emitting diode (UV-LED) is a new technological field that has recently seen rapid improvements and novel possible applications. These include the development of UV-LED based gas sensors. UV-activated sensors have a variety of advantages, compared to the traditional chemi-resistive metal oxide semiconductor (MOS) sensors, such as higher stability, lower preparation time, and the ability to safely detect flammable gases. The advances in ultra-violet light emitting diode (UV-LED) technology and its utilization in the gas sensing industry may offer a breakthrough in UV-based sensors, providing several important progresses such as broader application, smaller size, and higher efficiency of the developed sensors. Among the various metal oxides that have been studied for gas sensing applications, ZnO nano-materials have shown promise because of high electron conductivity features. ZnO has strong luminescent properties, broad UV absorption, and high stability. The photo-activity of ZnO can be improved by synthesizing one-dimensional (1D) nanostructures and by functionalizing with catalytic metal nanoparticles. This combination lowers the required activation energy and reduces the recombination rate of photo-generated charge carriers. We will discuss the fabrication of a sensitive 1D nanostructure ZnO gas sensor decorated with Ag and Pt nanoparticles to detect low concentrations of toxic gases at room temperature under UV-LED irradiation. The sensor was characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) analyses. The results indicated a significant increase in sensor response toward NO2 as a model gas, compared to pristine ZnO samples due to charge carrier enhancement. The effect of UV irradiance was found to play an important role with respect to the sensor response and detection speed. We will present the results and discuss how UV-LED has the potential to significantly impact sensor development and portable gas monitoring systems by enabling novel sensor design concepts.
Commercializing of synthetic quartz sleeve for UV water treatment
Klaus Zoltner, Heraeus Quarzglas GmbH & Co KG Commercializing of synthetic quartz sleeve for UV water treatmentKlaus Zoltner, Heraeus Quarzglas GmbH & Co KG The use of UV light is useful for both air and water treatment. These processes involving UV light have been proven to have multiple advantages for many of these applications. As with any investment the total cost of ownership (capex and opex) is the main points considered in the decision. It is these key point that will be my focus for my presentation even if it is primarily about the most suitable material selection. In previous presentations it was shown that for lamps (ozone-generating for 185nm low pressure lamps) but especially for sleeves (protecting the UV lamps from the direct contact to the media) high purity synthetic quartz glass has significant advantages (for the total cost of ownership). Synthetic quartz glass is considered a niche solution by many users or system manufacturers. There are various reasons for this such availability and the image synthetic material as a ‘luxury solution’ and therefore not required.
With this presentation I show that commercialization of synthetic quartz glass is possible with all the necessary superior properties of premium synthetic properties, e.g.
Measuring nitrogen oxides for emission monitoring using a UV oxidizer in combination with a UV LED analyzer
Camiel Heffels, Siemens AG Measuring nitrogen oxides for emission monitoring using a UV oxidizer in combination with a UV LED analyzerCamiel Heffels, Siemens AG Environmental regulations require the measurement of hazardous gas components emitted into the atmosphere by industries and local polluters in urban areas to monitor legislative limiting values of gas components continuously. Especially nitrogen oxides have a harmful effect on human beings leading to respiratory and cardiovascular diseases. During the 2018 IUVA congress a UV LED analyzer was presented to measure the concentration of nitrogen dioxide with a UV-A LED source based on a direct absorption measurement. However, in a typical exhaust of a fuel burner most of the nitrogen oxides consist of nitrogen monoxide, which cannot be monitored by direct absorption of LED light from commercial available devices because of very short wavelength around 226nm. In this contribution a new measurement principle is introduced to measure the sum of nitrogen oxides by converting all NO into NO2 by using an oxidizer. The oxidizer is based on an excimer UV lamp generating ozone from rest oxygen contained in the measurement gas. The analyzer consists of a double-beam photometer with an absorption path and a reference path for monitoring the LED intensity using a beam splitter, which additionally allows the use of two alternating LED. One LED measures rest ozone the other nitrogen dioxide. The ratio of the absorption and reference signal is used to calculate the concentration of both gas components according to Lambert-Beer’s law. The ozone level generated by the excimer lamp is controlled in such a way that minimal excess ozone is produced leading to a complete oxidation of nitrogen monoxide without the risk of producing larger nitrogen oxide molecules like NO3, N2O5 that would falsify the NOx measurement. The method can compete with the reference chemiluminescence method for determining NO concentrations and has the advantage that the NO2 concentration contained in the measurement gas is additionally measured while chemiluminescence requires the use of a consumable NO2 to NO converter making it more expensive than the system introduced in this work.
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