Hunter, Gary

Mr. Hunter is a Principal Process Specialist with Black & Veatch Corporation for the past 38 years. In that role he is responsible for a number of focus areas ranging from industrial preatment to wastewater disinfection. Gary holds BSCE and MSCE from Brigham Young Universtiy. He holds a PE from the State of Kansas. Gary is a board certified environmental engigeer and is ENVSP. He has served as the Chair of the Disinfection and Public Heath committee and Disinfection and public health symposia.

Titles from this speaker

A New Light UVC-LED for Wastewater Disinfection

Abstract

The growth of UltravioletC Light Emitting Diode (UVC-LED) systems in the water and wastewater market has been occurring at a geometric. Based on a recent survey (Cosman 2019) the number of vendors providing UVC-LED system has increased from 3 in 2017 to over 18 in 2019. While not all the companies provide systems for water and wastewater applications, the interest and growth of the UVC-LED vendors is occurring at a very rapid pace. The Electric Power Research Institute (EPRI) (2019) estimated the UVC-LED systems would reduce the capital cost of UV systems by 75 percent and the power use by 50 percent in the wastewater industry. Aqua-Aerobic Systems Inc. (Aqua-Aerobic) installed the METWATER UVC-LED unit at its Rockford, Ill test facility. Validation test runs were completed using filtered effluent as well as secondary treated effluent to determine the effectiveness of the unit in treating wastewater. A combination of various test runs were completed to determine the conditions under which the unit could be used to treat wastewater. Based on these results, computational fluid dynamic (CFD) and light intensity modeling was recommended to develop a plan to increase the treatment capacity of the test unit. The procedures for the models have been completed, however the actual runs have not been completed due to issues related to COVID-19. It is anticipated that the results of the model will show that a change to inlet conditions as well as baffling may need to be incorporated into the design of the existing unit to improve its overall effectiveness.

SpeakerHunter, Gary

Presentation time

08:30:00

08:50:00

Session time

08:30:00

09:50:00

SessionDisinfection on The Edge

Session number313

TopicDisinfection and Public Health, Research and Innovation, Water Reuse and Reclamation

Author(s)

G. HunterW. DeckerG. SmithR. SimonsO. Lawal

Author(s)G. Hunter1; W. Decker2; G. Smith2; R. Simons3; O. Lawal3;

Author affiliation(s)Black & Veatch, SC1; Aqua-Aerobic Systems, Inc2; AquiSense Technologies3;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2020

DOI10.2175/193864718825157849

Volume / Issue

Content sourceWEFTEC

Word count8

Improved Operating Practices for Emerging UV Systems

Abstract

UV systems are emerging as a cost-effective, reliable approach to disinfect treated wastewater effluent. As these new UV systems are brought to the market, effective operation and maintenance approaches must be developed and validated to ensure that facilities using these emerging UV alternatives can maintain compliance at sustainable and reliable operating costs. Over the past several years, two emerging UV systems that have shown promise for implementation at water resource recovery facilities are HOD UV and the UVC-LED systems. With these new UV systems entering the market, there is a need to understand the operating procedures required by these new systems and to determine how to improve existing operating practices. A comparison of operational and maintenance activities of Hydro Optic Disinfection Ultraviolet light (HOD UV) and Ultraviolet Light C - light emitting diodes (UVC-LED) was made to practices employed by WRRF staff. Proper operation and maintenance activities may result in longer life, resulting in lower operating costs.

Operational and maintenance activities are for critical for the optimized performance ultraviolet (UV) system. Two emerging UV systems UVC- light emitting diode (LED) and hydro optic disinfection (HOD) -UV. UVC-LED systems are projected to provide a 30 percent reduction in capital cost and 50 percent reduction in operating cost over traditional UV systems. HOD UV systems appear to be more efficient in the deployment of the UV dose which allows for less equipment to be used resulting in the reduction of operating and maintenance costs. This presentation provides a comparison of traditional UV operating and maintenance practices to those used by emerging UV systems

SpeakerHunter, Gary

Presentation time

8:30:00

08:45:00

Session time

08:30:00

10:00:00

SessionRiding the UV Wave: Tracking the Evolution of UV Technology (UV-LED) and New Applications

Session number402

TopicDisinfection and Public Health, Energy Production, Conservation, and Management, Facility Operations and Maintenance

Author(s)

Gary Hunter

Author(s)G.L. HunterNo Number Attached; L. Casson6; B. Drouhard2;K. Fredrickson1;D. Bitter3;B. Decker4;O. Lawal5;

Author affiliation(s)Black & Veatch Corporation, Greenville, SC1Black & Veatch Corporation, Atlanta, GA2Atlantium Technology, Lakewood Ranch, FL3Aqua-Aerobic Systems, Inc, Loves Park, IL4AquiSense Technologies, Erlanger, KY5

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct, 2021

DOI10.2175/193864718825158099

Volume / Issue

Content sourceWEFTEC

Word count8

Resilience, Sustainability, and Risk of Intermittent UV LP And LED Systems

Abstract

UV LP and LED systems were compared in their engineering viability for an intermittent flow, 1 MGD average flow UV wastewater system at 65% UVT regarding resilience, sustainability, and risk. Resiliency to system cycling, sustainability via a life-cycle cost comparison, and risk of maintaining system performance guarantees were evaluated for LP, current LED, and future LED systems. Overall, this assessment demonstrated the feasibility and future optimization of these systems in wastewater disinfection. As UV LEDs continue to develop and enter the wastewater market, full-scale UV LED systems could help wastewater treatment systems reduce energy cost, labor requirements, and monetary risk. Advancement of UV LP and LED systems in treating intermittent flows with minimal energy requirements will help the wastewater industry meet climate change and sustainability initiatives.

UV LP and LED systems were compared in their engineering viability for an intermittent flow, 1 MGD UV wastewater system at 65% UVT regarding resilience, sustainability, and risk. Resiliency to system cycling, sustainability in a life-cycle cost comparison, and risk of maintaining system performance guarantees were evaluated for LP, current LED, and future LED systems. Overall, this assessment will demonstrate the feasibility and future optimization of these systems in wastewater disinfection.

SpeakerPimentel, Anthony

Presentation time

09:00:00

09:30:00

Session time

08:30:00

10:00:00

SessionUV Disinfection: Where are we? Where are we going?

Session locationRoom S404c - Level 4

TopicDisinfection and Public Health, Intermediate Level, Municipal Wastewater Treatment Design, Research and Innovation

Author(s)

Pimentel, Anthony

Author(s)A. Pimentel 1; G. Hunter 2 ; A. Pimentel 1; H. Mettlan 3; R. Osborne 4; J. Garrison 6; S DeBoses 6;

Author affiliation(s)Black & Veatch 1; Black & Veatch 2 ; Black & Veatch, Los Angeles, CA 1; Black & Veatch 3; Black & Veatch 4; Clemson Wastewater Treatment Facility 6; Clemson Wastewater Treatment Facility 6;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159162

Volume / Issue

Content sourceWEFTEC

Word count12

UVC-LED the Wave of the Future

Abstract

INTRODUCTION
In the wastewater industry, energy and operation costs are major factors in selection of a disinfection technology. Ultraviolet Light Emitting Diode (UV-C LED) systems based on a solid-state technology, generally tends to operate with low electrical consumption and less relative space to conventional technology. A comparison of LED UV to UV systems applied to wastewater indicating that there was large (over 50 percent) cost savings for this technology when applied to wastewater systems. UVC LED Technology currently is on a rapid development scale. UVC LED units were produced 2 years ago have changed dramatically the output and decreasing the production costs. Testing of three different UV-C LED water disinfection pilot-scale units at the U.S. Environmental Protection Agency (EPA) Test and Evaluation Facility in Cincinnati, OH. The pilot-scale testing included collimated beam testing and flow-through testing for both drinking water and municipal wastewater. During the first two studies the test runs targeted MS-2 bacteriophage and other organisms. The focus of the third test was on Legionella inactivation.
BACKGROUND
In much the same way that visible light emitting diodes (LEDs) have revolutionized the general lighting industry, UV-C LEDs are now viewed as the 'next generation' in UV-C disinfection and are expected to rapidly replace conventional mercury arc lamps in water disinfection applications. LEDs are made from crystalline compound semiconductors that emit light when energized. UV-C LED system integrators purchase many single-packaged UV-C LEDs and combine them into a larger UV-C LED reactor which is then equipped with electronics, thermal management system, optics, and housing to create a finished UV-C LED system or module. Point-of-use (POU) UV-C LED systems for the treatment of potable water are already commercially available and market competitive, but larger-capacity UV-C LED systems for municipal water and wastewater disinfection are still under development.
RESULTS<b/>
The primary objectives of this project were to evaluate the disinfection performance, reliability, and energy use requirements of three small-scale UV-C LED water disinfection units (e.g., one at 10 gallons per minute (gpm) and two at 20 gpm rated sizes) for a variety of test conditions. Test conditions included treating water to achieve public supply drinking water, municipal treated secondary wastewater, combined sewer, and reuse water requirements. Both Collimated beam and flow through testing was conducted to validate the removal of MS-2 and Legionella. MS-2 Testing Results of MS-2 Testing can be divided into two group. Collimated beam testing was Collimated Beam Results MS-2 bacteriophage was added to the dechlorinated water to conduct this test. The Ultraviolet Transmittance (UVT) was 98.7% at 280 nm. Collimated beam tests were performed at 280 nm with results shown in Fig. 1. Reuslts of testing indicate a 0.5 log removal of MS-2 per 5 mJ/cm2 increase in dose. These results match with data presented and used for development of NWRI response curves. Extrapolating the data, a 5 long inactivation would indicate that a 5 log removal of MS-2 could be achieved at a dose of 50 mJ/cm2 if the removal remained linear. Typically the inactivation curve is more geometric, therefore the predicted dose would probably be more closely to 100 mJ/cm2. Flow-Through Results Due to the piping configuration at the EPA T&E Facility, the flow rate to the unit was limited to 22.7 liters per minute (6 gpm). Flow-through testing was only conducted with MS-2 bacteriophage.. The test water was inoculated with MS-2. The MS-2 was fed at a rate of 93 mL/min. The water flowed through the unit for 3 minutes and then inlet and outlet samples were collected at 8-minute intervals. The results for both pilot unit 1 and 2 are shown in Figure 2. At 22.7 liters per minute (6 gpm), the pilot unit 1 could provide a 3-log removal at a dose of 85 mJ/cm2. Pilot unit 2 achieved a 4-log removal at 85 mJ/cm2 and with a flow rate of 15.14 liters per minute (4 gpm). Based on these flow rates, the power input would be in the range of 200-250 kilowatt-hours per million gallons (kWh/MG).
LEGIONELLA TESTING
Legionella Testing was conducted by USEPA to validate the dose response that could be achieved four different SerioGroups at three wave lengths. UVC-LED disinfection efficacy were evaluated for four Lp strains representing three clinically significant serogroups (sg1, 4, and 6) in drinking water utilizing both a collimated beam (at 255, 265, and 280 nm) and a point-of-entry (POE) treatment set-up (280nm). Understanding the inactivation differences between Lp serogroups in drinking water, especially for UVC-LED POE applications, will help determine the most effective remediation strategies needed to target specific isolates during contamination events. The focus of the testing was to examine the inactivation of legionella at 280 nm a that was the wavelength of the unit shown in Figure 3. However, for the POE tests, only sg6 displayed the highest reduction (mean Â± standard deviation) of 5.0 Â± 0.5 log10 CFU/mL compared to 3.5 Â± 0.5, 3.3 Â± 0.2, and 3.6 Â± 0.1 log10 CFU/mL for sg1, sg1 DW, and sg4, respectively.
DISCUSSION<b/>
Using the flow-through pilot test results, the project team developed scale-up factors to project energy use values for UV-C LED water disinfection. Because of the flowrate limitations, the energy use projections for the UV-C LED system are preliminary, and we provide the energy use values in relatively wide ranges. We project the energy use for UV-C LED disinfection of drinking water is in the 65-250 kWh/MG range. The projection is for a UV-C LED system treating drinking water with 90% transmittance at a UV dose of 40 mJ/cm2. The energy use projections for UV-C LED disinfection systems are comparable to conventional UV mercury vapor lamp systems. The energy use requirements for disinfecting drinking water are approximately 60-120 kWh/MG for medium-pressure mercury vapor lamp systems and 50-200 kWh/MG for low-pressure mercury-vapor lamp systems.
CONCLUSION
A summary will be provided of the advances of LED UV, focusing on its ability to reduce microbial transfer across several applications. There are often limits in place that prevent fully utilizing newer technology. When capital and operating costs come down, availability of products, new possibilities open up to apply technology. UV LED technology can be seen to following the same path. Test results collected by USEPA on the use of UVC-LED on MS-2 as well as Legionella have been shown to be able to achieve similar results to that in low pressure UV applications. System can be applied to point of use applications cost effectively and improvements in design will allow for deployment in larger flow systems.

UV-C LED Technology currently is on a rapid development scale. UV-C LED units were produced 2 years ago have changed dramatically the output of the systems. With the rapid changes that are occurring, the question exists: Where LED UV will be in 2 years (short- term as well as in 10 and 20 years)? Test results are presented from a number of bench scale (collimated beam) and demonstration scale tests. While a variety of test organism were examined, only test results on MS

SpeakerHunter, Gary

Presentation time

09:30:00

09:55:00

Session time

08:30:00

10:00:00

TopicFundamental Level, Disinfection and Public Health

Author(s)

Hunter, Gary

Author(s)Gary Hunter1; Bill Decker2; Oliver Lawal3

Author affiliation(s)Black & Veatch Corporation, Greenville, SC1; Aqua-Aerobic, Systems, Inc., Loves Park, IL2; AquiSense Technologies, Erlanger, KY3