“UV Tube” Water Disinfection P07402 Sponsored by Dr. Andres Carrano and Dr. Brian Thorn of the KGCOE ISE Department Final Project Review • 18 May 2007

P07402: UV Water Disinfection Project Anna Murray Project Management (ME) Miguel Bazan Design for Manufacture (ISE) Micah Brewer Material Selection, CAD (ME) Manaal Eisa Life Cycle Assessment (ISE) Gregory Hupp Product Testing, CAD (ME) Robert Norquest Fluids Analysis (ME) Brendan Richard Electrical Design (EE) KGCOE Multidisciplinary Sr. Design

KGCOE Multidisciplinary Sr. Design Outline Project Background Needs assessment & specifications Concept Generation and Selection Final Design Testing Results Summary of Design Improvements Next Phase Considerations KGCOE Multidisciplinary Sr. Design

KGCOE Multidisciplinary Sr. Design Project Motivation 1 in 6 people in the world lack access to “improved” drinking water source Water borne illness claims the lives of 1.7 million people annually (World Health Organization) Photos courtesy of Sarah Brownell KGCOE Multidisciplinary Sr. Design

KGCOE Multidisciplinary Sr. Design UV Disinfection Function of light Intensity and tube residence time KGCOE Multidisciplinary Sr. Design

KGCOE Multidisciplinary Sr. Design Project Description Point-of use device used to disinfect water using exposure to UV radiation Target user: residents rural areas of developing countries (Venezuela) Building upon a current design KGCOE Multidisciplinary Sr. Design Photo courtesy of Sarah Brownell

Issues of Current Design Accessibility of bulb for repair Difficult to manufacture Rolling/drilling stainless steel Leakage Water turbidity No safety design KGCOE Multidisciplinary Sr. Design

KGCOE Multidisciplinary Sr. Design Customer Needs Tier I Tier II Tier III Easy to build, install and use. User should know when the device is on. Easy to take apart, clean, and repair. Safe from electric shock and UV exposure. Effective at sterilization and child proof. Inexpensive to build and maintain. Utilizes power grid, alternative power source available. Adaptable fluid input. Reliable. Doesn’t leak or clog. Lasts and is sturdy. Build & repair with local materials. Environmentally benign. Power efficient, works quickly. Small and lightweight. Looks good. Water output is clear, odor-free, good taste. Multilingual operations and maintenance manual provided with universal symbols. KGCOE Multidisciplinary Sr. Design

KGCOE Multidisciplinary Sr. Design Specifications Metric Units Marginal Value Ideal Value Number of installation steps Number 50 30 Usability test-Ease of use % 90% 95% Number of total parts 20 Water flow rate L/Min 3 6 Filter output Size Microns 10 5 Filter turbidity output FTU Usability test- construction Time to disassemble Minutes 1 Cost of materials USD 100 40 Power consumed per year KWhr 50   5 Cost to operate per year 20  2  UV dose J/m2 400 800 Weight Kg 7 Volume m3 0.1 0.075 Max footprint m2 0.3 User is not exposed to UV radiation Binary Yes Enclosure of core components (ballast, bulb) Device indicates On/Off Table 2: Target Specifications KGCOE Multidisciplinary Sr. Design

Functional Diagram Grid (AC) Power UV Bulb Energy Alternative Disinfect water Disinfected Water Water input sources Water flow through cavity Materials Filter water infected water sediment Sediment, Dirt KGCOE Multidisciplinary Sr. Design

Selected Design Concept Sand pre-filter Stainless steel channel with removable wooden lid Bag filter in reservoir DC Generator to 12 volt battery KGCOE Multidisciplinary Sr. Design

Design Concept: Tube Detail KGCOE Multidisciplinary Sr. Design

KGCOE Multidisciplinary Sr. Design Final Design KGCOE Multidisciplinary Sr. Design

KGCOE Multidisciplinary Sr. Design Final Design Canvas filter Electrical system Bag filter Safety switch Outlet and Drain Tube UV bulb KGCOE Multidisciplinary Sr. Design

Prototype Construction KGCOE Multidisciplinary Sr. Design

KGCOE Multidisciplinary Sr. Design Solar System 300 mA, 4.5 Watt panel 8 Amp-hour, 12 V Battery KGCOE Multidisciplinary Sr. Design

KGCOE Multidisciplinary Sr. Design Product Testing Filter Testing Flow Testing Aluminum/UV Interaction Testing Biological Testing Solar System Testing Usability Ease of construction Ease of use KGCOE Multidisciplinary Sr. Design

Filter, Flow and Aluminum Testing Results Filter Testing Reduction from 300 to 2 FTU using 4 layers of canvas. Chosen for lightweight, relative consistency and ease of use Flow Testing Range (based on fluence model): 3-6 L/min Test: 2.9 – 4.1 L/min Aluminum/UV Interaction EPA Recommended limit: 0.05 mg/L Test results: 3.18 mg/L KGCOE Multidisciplinary Sr. Design

Minimum Theoretical Fluence Average Experiemtnal Fluence Biological Testing MS2 Bacteriophage 2 samples Log reductions of 5.45 and 5.15 Corresponding UV dose of 1335 and 1265 J/m2 Minimum Theoretical Fluence Average Experiemtnal Fluence KGCOE Multidisciplinary Sr. Design http://rael.berkeley.edu/old-site/uvtube/uvtubeproject.htm

KGCOE Multidisciplinary Sr. Design Electrical Testing Standard Power Testing (120V AC) Total Yearly Power Consumption: 6 KWh Alternative Power Testing (Solar) 300 minutes to charge battery to 75% Can run for 3 consecutive days without recharging. KGCOE Multidisciplinary Sr. Design

Usability Testing: construction Average Assembly Time: 1.6 hours for experienced 1.9 hours for inexperienced Perceived Difficulty to Assemble: 85% thought it was of “medium” difficulty or easier Ease of Use: 100% thought it was “easy” to “very easy” to use KGCOE Multidisciplinary Sr. Design

Summary of Design Improvements Solar Option Ease of repair, maintenance, construction Top-down construction, easy access to bulb. Use of locally available materials Standard sizes of wood, hose, etc. Elimination of some PVC Safety features Switch interference Sealing of light by wooden enclosure Improved tube drainage between uses Filtration system: Turbidity reduction Cost Materials: $103.25 (retail) Maintenance: ~$11 KGCOE Multidisciplinary Sr. Design

KGCOE Multidisciplinary Sr. Design Future Work Eliminate all PVC (new end cap material) Better water and light sealing Allow tube to drain fully Research use of LEDs New tube material testing: cheaper, safe w/UVC Easier removal of top Water input adaptability for use with pressurized systems More affordable alternative power Long-term field or use testing Design for mass production: expands material, design options and will reduce number of components, dependence on fasteners and cost, as well as allowing easier assembly operations. KGCOE Multidisciplinary Sr. Design

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