At the Lucas County Water Resource Recovery Facility (WRRF) in Ohio, primary effluent flows by gravity to the aeration basins where ferrous chloride is added to aid in phosphorus removal. The primary effluent then receives secondary treatment via the activated sludge process in the aeration basins. The mixed liquor from the aeration basins then flows to final clarifiers for solids separation from the secondary effluent.
The clarified effluent is then measured via a Parshall flume and flows through TrojanUV4000Plus™ disinfection systems prior to discharge into the Maumee River. The UV installation includes two TrojanUV4000Plus systems. There are a total of four banks, with 48 UV lamps per, for a total of 192. It was designed specifically for the Lucas County Water WRRF based on several different factors, including flow rate, water quality and permit requirements.
The facility was experiencing disinfection inefficiencies and, even after repeated inspection and analysis, staff couldn’t figure out why. They started to question if the issues were stemming from the use of non-genuine UV lamps, quartz sleeves, and lamp drivers.
Jason Collins, the facility’s manager, decided to call Trojan’s Technical Assistance Center (TAC) for help.
It Was Time For a System Inspection
Trojan offers comprehensive service packages tailored to meet the specific requirements of individual drinking water and wastewater treatment plants. These packages, in combination with proper maintenance as per the system’s O & M manual, help to ensure effective and efficient operation over a longer period of time.
A Trojan Certified Service Technician was sent to the Lucas County WRRF to conduct a comprehensive inspection and also provide refresher training, which included educating plant staff about the science behind UV disinfection as well as the benefits of using genuine Trojan parts.
TrojanUV systems are engineered, tested and certified as a complete disinfection unit. The type and number of UV lamps installed are carefully selected to ensure the UV dose required to meet permit gets delivered throughout the lamp’s entire lifespan.
The non-genuine parts being used was identified as a possible root cause of the disinfection inefficiencies being seen at the facility. There are many unknown variables involved when using such parts, which makes troubleshooting issues like those occurring at the Lucas County WRRF difficult.
|Potential Issues Associated With The Use Of Non-Genuine Parts At The Lucas County WRRF||How Genuine TrojanUV Parts Differ|
|Inability to measure UV output of the non- genuine lamps and exactly how the output declines over time||Genuine lamps are validated and UV output at end of lamp life (EOLL) is known and documented
PLC-controller monitors lamp age and water quality, and adjusts UV output accordingly
|Non-genuine quartz sleeve design and material||With genuine quartz sleeves, it is known exactly how much UV light is transmitted, and how it will scatter, absorb and deflect|
|Plastic cap on non-genuine quartz sleeve – if breakers did not trip as they should, there is potential for electrical hazard||Genuine quartz sleeves have ground faults between the module and GFCI|
The Switch to Genuine Parts
To demonstrate the effectiveness and benefits of using genuine replacement parts, genuine lamps, sleeves and lamp drivers were installed in the two lead UV banks while the non-genuine parts remained in the lag banks (these banks only come online if more UV output is needed to meet a required dose).
Improved Sleeve Cleaning
Sleeve cleaning was also drastically improved, thanks in part to the switch to genuine quartz sleeves as well as the system optimization work completed by Trojan.
Ferrous chloride is used in the pretreatment process to remove phosphorus (the phosphorus is formed by spent pickle liquor discharge from nearby steel plants). However, the ferrous chloride can cause an orange fouling on quartz sleeves. Now, with the proper quartz sleeves installed and the ActiClean™ sleeve cleaning system optimized and operating efficiently, the fouling is no longer an issue. The sleeves and intensity sensors are cleaned regularly, without disrupting disinfection.
Equipped, Educated, And Ready For The Future
Now armed with genuine replacement parts for their UV disinfection system and newfound knowledge of the science behind UV, the staff at the Lucas County WRRF are excited to focus on a multi-million dollar upgrade project – including upgrades to their anaerobic digesters – that will see them recover and create electricity and become 80 to 100% off the grid.
“We thank Trojan for helping us solve our disinfection inefficiencies and look forward to working with them in the future as we continue to refine our treatment processes,” says Collins.
System Design Parameters
|Average Design Flow||22.5 MGD|
|Peak Design Flow||70 MGD|
|Ultraviolet Transmittance (UVT)||65%|
|Disinfection Requirement||126/100mL monthly, Phosphorus 1.0 mg/l|