Ultraviolet Disinfection Collimated Beam Apparatus

Ultraviolet Disinfection
Collimated Beam Apparatus

Carollo’s collimated beam apparatus provides the following benefits:
• Offers portability, which allows on-site investigations.
• Allows for small sample volumes, which provide the flexibility to conduct long-term performance verification studies.
• Allows cost-effective assessment of UV disinfection compared to pilot studies.

Carollo Engineers’ collimated beam apparatus is designed to provide a rapid and accurate determination of ultraviolet (UV) dose-response for both drinking water and wastewater UV disinfection system sizing.

The collimated beam apparatus is equipped with either a low- (i.e., 254 nm) or medium-pressure (i.e., 200 to 300 nm) mercury lamp. Small sample volumes (between 25 and 100 mL) are placed under the collimating tube and exposed to UV light for a controlled period of time. The UV intensity incident on the samples is accurately measured using an International Light radiometer with a National Institute of Standards and Technologies (NIST) traceable calibration. UV transmittance of the sample is measured either at 254 nm using a P254 Photometer or at 200 to 300 nm using a spectro-photometer. The UV dose delivered to the sample is calculated using the measured intensity, exposure time, and UV transmittance. The UV dose-response curves are obtained by irradiating several samples at different UV doses and plotting the inactivation of the microbe or the formation of a disinfection by-product as a function of dose.

Applications
The UV dose-response of indicator microbes in wastewater samples is used to size UV disinfection Ultraviolet Disinfection Collimated Beam Apparatus "Dedicated to creative, responsive, quality solutions for those we serve." Bench-Scale Testing Technical Specifications Weight 50 lbs Dimensions (L x W x H) 30 in x 30 in x 48 in Electrical Requirements Single-phase, 60-hz, 120-volt.  Carollo’s approach is to design the collimated beam studies to identify the impact of waste-water quality, such as total suspended solids (TSS) and iron concentration, on UV dose-response. Our analysis of the data provides optimal sizing of wastewater UV systems. Collimated beam studies are also used to troubleshoot installed UV systems that are experiencing difficulties achieving compliance with disinfection requirements.

In drinking water treatment, the collimated beam apparatus can also be used for UV reactor validation. In these studies, the UV dose of the reactor is determined by measuring the inactivation of indigenous or seeded microbes by the UV system. This inactivation is related to the corresponding dose using the dose-response relationship developed with the collimated beam apparatus. UV reactor validation can be performed either on-site or at a test center, and performance of the reactor can be assessed as a function of flow rate, UV transmittance of the water, and lamp aging or fouling.

Nitrite and formaldehyde formation has also been identified as a concern of UV disinfection of drinking water with medium-pressure lamps. Collimated beam studies are used to assess the potential for forming these disinfection by-products for a given water, and determining operating conditions that minimize their formation.







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