P18461: Solar Powered UV Water Purification
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Subsystem Build & Test

Table of Contents

Team Vision for Subsystem Level Build & Test Phase

Summarize:

Updated Gantt Chart Schedule

Updated BOM

Updates

Water Filter Housings

Standardized Filter Housing Front View

Standardized Filter Housing Front View

Standardized Filter Housing Top View (With 3/8'' Brass Fitting) Specifications: 3/8

Standardized Filter Housing Top View (With 3/8'' Brass Fitting) Specifications: 3/8" #10 Slim Line Black/Blue w/o PR 11.75" x 4.38" (298 mm x 111 mm) 2 psi @ 5 gpm (0.14 bar @ 19 Lpm)

Pump System

Hand Pump System With Filter Housing & 3/8'' Brass Fitting

Hand Pump System With Filter Housing & 3/8'' Brass Fitting

UV Batch Treatment Model

After further review of standards, and microbiological testing protocol, it was found that the desired treatment dosage --- for acceptable log reduction of marker biologic contaminants (MS2 Coliphage) --- is ~90 mj/cm2. Therefore we have updated our UV Batch Treatment Model to not only include this new desired dosage, but we have also included the dimensions of the solenoid valves at the inlet and outlet of the model.

The updated UV Model MATLAB code can be found: Here

The updated UV Model Documentation can be found: Here

Dosage Vs. Time MPSS LSI approximation for different normal distances from the bulb, calculated at furthest radial position from center of the bulb. Red and Green dashed lines show the 60 mJ/cm2 and 90 mJ/cm2 reference lines. If our dosage falls between these lines then we should experience about log 3-4 reduction in Enteric Viruses (contaminants most associated with outbreaks of gastroenteritis)

Dosage Vs. Time MPSS LSI approximation for different normal distances from the bulb, calculated at furthest radial position from center of the bulb. Red and Green dashed lines show the 60 mJ/cm2 and 90 mJ/cm2 reference lines. If our dosage falls between these lines then we should experience about log 3-4 reduction in Enteric Viruses (contaminants most associated with outbreaks of gastroenteritis)

The time required for stagnant water at the edge of the reactor, for different reactor diameters (different normal distances from UV bulb), and at the furthest radial distance from the center of the bulb to attain 90 mJ/cm2

The time required for stagnant water at the edge of the reactor, for different reactor diameters (different normal distances from UV bulb), and at the furthest radial distance from the center of the bulb to attain 90 mJ/cm2

Using gravity to remove water from our reactor, we can approximate the pulsatile flow of our system at different inlet flow rates (flow coming from the filters upstream of the UV Batch Treamtment) given the outlet size (dimensions of solenoid valve) and the time required for treatment. Our customer requirement is 0.5 gpm, therefore we must attain at least ~1.5 gpm inlet flow rate. For more information refer to the UV Batch Treatment Model Documentation.

Using gravity to remove water from our reactor, we can approximate the pulsatile flow of our system at different inlet flow rates (flow coming from the filters upstream of the UV Batch Treamtment) given the outlet size (dimensions of solenoid valve) and the time required for treatment. Our customer requirement is 0.5 gpm, therefore we must attain at least ~1.5 gpm inlet flow rate. For more information refer to the UV Batch Treatment Model Documentation.

Final UV Chamber Design by Phil Sammon & Graham Ardner

Final UV Chamber Design by Phil Sammon & Graham Ardner

Microbiological Testing

Originally we were planning on performing a modification of USEPA's Method 1602, which tests the microbiological efficacy of UV treatment using MS2 coliphage as an indicator of log reduction for enteric viruses. Since we do not have cultures of MS2 on campus; we would be required to purchase MS2 elsewhere. In a non-propagated form, MS2 can be purchased for about $60 from ATCC. MS2 in a freeze-dried state can be difficult to propagate. In a pre-propagated and set concentration MS2 can be relatively expensive, ~ $300 from GAP EnviroMicrobial Services Ltd. Therefore we are considering a new direction with microbiological testing that may better fit the reach of our MSD project.

After discussion with a professor in the Microbiological Department it was advised that we consider using E. Coli. as our indicator of microbiological efficacy. E. Coli. is easier to work with, and we have many ongoing cultures here at RIT that we could take advantage of. This would allow for more flexibility, and repetition in testing, and would likely require no investment from our budget. By removing colonies from plated E. Coli. and suspending them in solution, we can spike with E. Coli. and run the water through our UV Batch Treatment system. Then we can re-plate the suspension on EMB plates, and after 24 hours we can resuspend the E. Coli. and perform serial dilutions to enumerate the E. Coli. Comparing enumerations on test and control colonies we should be able to calculate the log reduction of E. Coli. post treatment.

The downfall of using E. Coli. is that it only requires ~10 mJ/cm2 to attain ~log 4 reduction, whereas MS2 requires ~83 mJ/cm2 to attain ~log 4 reduction. We will need to seek advice from other subject matter experts to brainstorm on the topic.

Test Results Summary

Problem Tracking

Problem Tracking Tool can be found:Here

Plans for next phase

Phil's Three Week Plan

Ryan's Three Week Plan

Alex's Three Week Plan

Erik's Three Week Plan

Aaron's Three Week Plan

Graham's Three Week Plan

Justin's Three Week Plan


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