transportable water purification...

Transportable Water Purification System

GEAR Enterprise - Senior Capstone Design Project

Final Report - Fall 2016

Prepared By:

Matt Byrne

Megan Rady

Gabrielle Heinz

Neil Hawke

December 2016

GEAR Enterprise Senior Capstone Final Project Report - Fall 2016

Acknowledgements

Transportable Water Purification System 1


On behalf of GEAR Enterprise and the Transportable Water Purification

System Senior Design Team, we would like to thank the following people for supporting this project and for helping to provide the resources that have facilitated the project thus far.

Advisor:

Brett Hamlin

Michigan Tech Faculty Aid Stephen Techtmann

Donors :

Akilla Desai Thomas A. Coleman

Joel Wilson Joseph & Erin Thompson

Brett & Amy Hamlin Jeff Mazzoccoli

Paul & Beth Rady

Thank you



Table of Contents Abstract

1. Executive Summary

2. Introduction

3. Background

4. Objectives and Requirements

5. Project Schedule

6. Design Concepts

6.1 Initial Filter System Designs

6.2 Component Evaluations

6.2.1 Component Specifications

6.2.2 Component Comparison

6.3 Final Design Concept

6.3.1 UV Disinfection

6.3.2 Micro Filtration

6.3.3 UV Chamber Designs

6.4 Component Testing

6.4.1 Filter Flow Rate

6.4.2 UV Led Dosage

7. Final Design Summary

7.1 Filter System Overview

7.1.1 Filter Model Description

7.1.2 Model Components

7.2 Filter System Prototyping

7.2.1 Prototyping Procedure

8. Expenditures and Costs

9. Conclusion & Future Plans

Citations



Appendices



Abstract This technical report contains the design process, steps followed, and conclusions from the initial stages of development through prototyping for the Transportable Water Purification System developed thus far by GEAR Enterprise from 2015-2016 at Michigan Technological University. The purpose of this project is to investigate and develop a transportable water purification system which could support a group of people for an extended period of time in a base-camp type of environment. Through the development of concept designs and the use of comparative analysis tools, the team was able to narrow down the potential options to the ones that fit the design criterion with the best chances of meeting or surpassing expectations.

The prototype will utilize gravity to pull the water through a ceramic filter to remove sediments and decrease water turbidity. The water will then pass through a disinfection chamber where UV-C LEDs will be utilized to kill any potentially harmful bacteria that could be present in the water. After disinfection, the water flows down into a vessel where it is stored for consumption. Based on the necessary length of exposure to the UV-C light, the disinfection chamber and connecting tubes were designed to delay the flow of the water to keep it exposed to the light for the necessary amount of time. Through the design and testing process it was found that achieving the desired flow-rate was the most significant and complex factor in determining overall water quality. This issue was evaluated through individual component testing to ensure potable water will flow out of the filter system at a sustainable rate. Continuing the project into the spring 2017 semester, the team will focus on analyzing the flow rate and subsequently, the water quality of the existing prototype, which may lead to component redesign to improve these conditions.



1. Executive Summary GEAR Enterprise seeks to design, engineer, and produce an easily transportable water purification system for use in situations such as an expedition base camp or in areas where communities don’t have access to clean drinking water. When on extended backcountry trips, a water pump is often needed in order to filter water before drinking. Using a single hand pump requires a great deal of time and effort, especially if there is a large volume of water need, such as for numerous people. This proposed design would eliminate the need for hand pumping, while still producing a sufficient volume of water needed to sustain a group. The design of this project is expected to extend its use into areas where clean water is not available, such as small villages in underdeveloped areas.

This report has been compiled to document and inform interested people of the progress made on this project and also future work that will be performed. Included in this body of the report is all project research, design, and fabrication that has been done as well as testing results from the last three semesters. Information collected during this period was used to reach conclusions and evaluate the design so as to determine what the next steps would be in subsequent semesters.



2. Introduction The water purification system will be designed with two objectives in mind. The first focus is the water purification system’s capability to produce enough water to supply a base camp during extended stay trips in backcountry areas where there is no clean water available. In these situations, the people in the backcountry would have to spend a fair amount of time pumping water from a river or other water source, which can be a hassle. A secondary focus of this system is its use in communities around the world where there is no access to clean water and the means to purify it. With this system, communities could have access to clean, safe water for extended periods of time.

Figures 1 and 2: Human Interactions with Water Filtration Systems [1] [2]

The current design for the filter system will use gravity to create the required pressure to force water through the system. Unpurified water will flow through a filter and into a disinfecting chamber where it is exposed to UV light. This exposure will eliminate harmful microbes so the water can be consumed without harmful side effects. Through initial testing and designing, it was found that the flow rates through the ceramic filters chosen for this system are lower than the required rates to sustain the projected volume of water. These flow rates were increased so the design requirements was met for the prototype. Additionally, the proposed UV disinfection chamber was modified in order to accommodate the change in flow to ensure all the water is exposed to the UV light for the necessary time.

Going forward, the team will work to analyze the existing prototype and determine ways in which it can be redesigned to better fulfill the design requirements. This may involve modifying the size of components to control flow rate and adjusting overall UV light strength to purify



water more quickly or thoroughly. With this information, the final design can be drafted and verified as to meet the initial requirements of this project.

3. Background Currently, the EPA regulates standards for the treatment of drinking water. The concentration of contaminates in the water can cause illness or foul taste. These contaminates are in standardized concentrations of milligrams per liter. Some known harmful substances, such as the bacteria Giardia, are not allowed in any concentration in potable water as it is a cause of gastrointestinal illness [3]. Water purification systems are categorized and approved by what substances, and how much of these substances they can filter out or eliminate. NSF/ANSI test standards outline the types of certifications for testing purification systems. These certifications are performed using a seven point water treatment standard that evaluates the purification systems ability to remove contaminates. Different purification methods such as reverse osmosis, microfiltration, and ultraviolet exposure, are evaluated differently due to their purification processes, but are still held to the same standards [4].

Safe, drinkable water is free of bacteria and viruses that can pose short or long term health risks. There are international water regulations that seek to provide clean water to all, but this is a difficult task to enforce. Many countries have adopted more stringent regulations, but again, these are not always enforced in underdeveloped areas. There are several ways water can be purified and be classified as drinkable. Many physical substances and minerals are removed through a microfiltration process. This method removes the particles by blocking and trapping them in a porous material which is often made of carbon, ceramic, or tightly woven materials. However, there are limitations to the filtration process based on the pore size of the filter since some smaller particles can pass through the pores if the pores are too large. A pore size of .1 micron is effective in removing many contaminants including bacteria and protozoa. Filtration systems are poor in removing chemicals and viruses unless they are capable of having pore sizes on the nanofiltration scale [5].

Other methods of purification are much more effective in treating viruses and chemicals. In particular for viruses, boiling water or exposing it to ultraviolet radiation kills the virus which are then harmless to the consumer [5]. Both forms of purification are also simple to utilize and are often used in emergency situations such as running out of water on a camping trip [6]. UV disinfection can be achieved by using UV-C lights that are available commercially, but also by



exposing the water to the sun for long periods of time. However, the water must not be murky or this method is not as effective. Pre-filtration is still necessary to remove or treat chemicals and suspended particles in the murky water.

When using UV light, the exposure time of the water to the UV light is very important. Depending on the UV power output in the form of UV-C radiation, the amount of time the water needs to be exposed to the light can be calculated. By having more intense light bulbs or a larger quantity of bulbs concentrated on a small area, the exposure time will be reduced. Clearer water will also reduce the exposure time as the light will be able to penetrate all of the water more effectively.

Harmful minerals and chemicals in water sometimes have to be removed through distillation, reverse osmosis or other processes. Some of the dissolved solids are allowed to be present in small quantities in drinkable water, but others are not permitted at all due to health side effects [3]. A combination of treatment processes can be used depending on what each can remove from the water. For example, microfiltration can be used to collect large particles and bacteria, but then it must be boiled or distilled or exposed to UV light to further purify the water for consumption.

Two important aspects of the design are the materials used for transportation and containment of the water. For the transportation of the water, it is important to use a type of tubing that will not further contaminate the water and will ensure that the water flowing to the reservoir remains safe to drink. As for the reservoir, ideally it will be collapsible for ease of transportation and made out of a fairly robust plastic or fabric that will not be susceptible to puncture or tearing. The reservoir will need to be able to hold a substantial amount of water and should be fully enclosed to prevent contaminants from entering the already purified water. The materials used for the UV-disinfection chamber are extremely important due to the need for UV-C permeable materials so the UV-C light can penetrate them and effectively disinfect the water flowing through the materials.

4. Objectives and Requirements Main design specifications for the Water Purification System focus on the filters ability to purify enough water to sustain a group of people for extended periods of time without the need for large amounts of intervention. To facilitate the design and final progression of the filter system, Table 1 below depicts a description of the design requirements that are being implemented as the final specifications of the water filter are being performed. These objectives and requirements are



sought to be met through the final design and will be evaluated against the initial specifications upon completion. Any deviations from the initial design parameters will be described as to why the deviations were made. Below the table is a more detailed description of each objective or requirement.

Table 1: Objectives and Requirements Outline Summary

Requirement Description Method of Measurement

Value

Lightweight Design must be of reasonable weight for ease of transportation

Weigh final Prototype

< 5 lbs

Sustain 6-10 People Ability to filter water to provide 6-10

people for cooking, drinking and hygienic

use

Run tests to find normal operating

flow rates and compare to standards

102-170 L/Day

Run off Solar or External Battery

Filter capability to run of solar or battery

power

Confirm Filter operation when used with power method

Yes/No Indication

Cleanable Water Filters ability to be cleaned and

maintain full functionality

Filter dirty water until cleaning is

needed, clean, and evaluate use after

cleaning.

Yes/No Indication

Replaceable Parts Ability to replace parts and maintain full functionality

Replace parts and evaluate use after

replacement.

Yes/No Indication

Transportable Design is collapsible Test flexibility of Yes/No Indication



and can contort into many configurations

design and evaluate volumes in different

shapes

Durable Design can withstand bumps, abrasions, and abusive use

Check durability of individual

components and materials used

Yes/No Indication

To achieve the goals for this filter to be used on base camping trips, it will need to be lightweight as these trips often include great deals of travel. Excessive weight of the filter could deter potential users from using this product as the weight may cause fatigue over extended periods of time. To minimize this requirement, the design of the filter system will utilize components in an efficient manner. Each component will also be chosen and evaluated for its weight component in the design. A majority of the weight of the filter system will be due to the ceramic filter and UV chamber. It is predicted that the housing for these components, will be made of a material that will not add a great deal of weight to the product and will retain the appropriate durability. When full of water, the weight of the filter will be much greater than empty. It is assumed that the user will not be transporting the filter when full of water so the weight of the water, or volume capacity, will not be involved in this criterion. A value of less than 5lbs was targeted for the restraint and was chosen as a suitable weight for the filter system based on the weight of the components and a weight that is comfortable to carry for long periods of time.

An important design factor in the filter is that it is able to provide a group of people with clean water that can be used for drinking, cooking, and hygienic purposes. To provide water for 6 to 10 people, is was found through research that 102-170 liters per day would be recommended to satisfy the water needs. This value also has a great deal of flexibility, as people can also monitor water use and use it sparingly if needed. This concept could extend the range of people to several more, or less depending on the consumer. To make sure the filter is capable of providing this amount of water, the ceramic filter and UV chamber can be tested for its flow rate and ability to provide microbe free water. A simple test can be performed by monitoring the water volume over a specified time period.

To satisfy the intentions of using the filter system in areas where there is no formal electrical grid, the system will run off of solar or battery power. The design will be made so that either



source can be interchanged depending on the user's preference or availability of resource. To test this, the filter system can be run using only solar or only battery. If the system performs as designed, and has the ability to fully run the UV lights, the system will be deemed solar and battery compatible, and this objective will be met.

With use of dirty and turbid water, a buildup of sediments will occur. Periodically, it is expected that the user will have to manually remove silt and sediments that will settle inside the top of the filter system. To ease the manner in the removal, the filter system will be constructed so that this process is easy and quick to perform. To achieve this, tight angles will be minimized through the design of the system and as an entirety, the design will be made to come apart and have open areas that are accessible. An easily removable geotextile fabric will be at the top of the filter to catch sediments from the water and to aid in the cleaning of the filter. This will be confirmed through a physical cleaning and commenting on observations or frustrations that will occur in the cleaning process.

Somewhat similar to the filter systems ability to be cleaned, the replaceability of parts is also of concern. To achieve this, an open area and minimization of tight spaces will be utilized to provide the user with a large area to work with. Individual components of the filter system will be chosen and implemented in a manner that they are commercially available and interchangeable without the use of specialized tools or materials not provided with the filter system.

Transportability of the system is an important factor of the system use in camping environments. As stated earlier, typical use in a base camp may involve moving to various locations. To improve the ability of the design to move easily, the volume of the empty filter system will be minimized and the flexibility will be maximized through the choice of products used. Rigid components in the filter system, such as the ceramic filter and UV chamber, will limit the flexibility to an extent. To provide flexibility to other areas, it is proposed that the body of the filter system be made with a waterproof food grade fabric. The choice of fabric will allow a collapsible design that has the ability to fit into many shapes and is able to be compacted. This design criterion will be fulfilled by minimizing the volume of the filter system and evaluating its flexibility through packing it into different shapes and commenting on any bulkiness.

The durability of the design will be tested with its use in the type of environment that is projected. It is estimated that the system will be moved and transported on a regular basis and to possibly rough environments. To ensure the filter system will retain its performance through rugged use, durable materials and components will be chosen to improve the overall resistance to wear. Filters and UV lights that are susceptible to breaking upon dropping or bumping will not



be chosen. Additionally, components that are fragile will not be used, or will be contained in a manner that will isolate them from external forces that could cause damage. The body of the filter system will be constructed to be very strong and also made of abrasive resistant material. It is also important that the material is not prone to puncture easily, and that repairs can be made if this occurs. To test the durability, components can be visually inspected to evaluate their strength or toughness. If additional clarification is needed, the components can be exposed to forces and re-evaluated to search for signs of wear or fracture. The fabric material for the body of the filter system can be abrasion tested by rubbing the material on various surfaces and observing the effects. If these tests and observations are deemed to realistically represent the use of the filter system and do not show wear that would affect the performance, the objective will be met.

5. Project Schedule Goals for the Fall 2016 semester for the Water Filter System will be to move forward with the design process towards prototyping, and having a working prototype at the end of December 2016. Continuing on from the Spring 2016 semester, the UV LED’s were tested in a biology lab to verify and determine the dosage of UV light. This testing will help to determine how many of the UV LEDs are needed to sufficiently clean the water passing through the filter for consumption. Leading up to this testing, much preparation was needed. A procedure for the Team’s intentions during the lab was created to facilitate the progression of the testing and ensure a smooth execution. After securing a lab and finding Michigan Tech Faculty that were able to guide this lab, a safety training was needed along with physical preparation for the instrumentation that was used during the lab. Completion of this experiment paved the way for final design decisions to be made and the model for the Filter System was created.

The model for the filter system served as a proto typing guide and to also create part files for several components that were 3D printed for this project. The model verification and creation took several weeks to make sure the parts fit together in a logical and easy to use manner. After the model creation, an Engineering drawing was created along with a bill of materials for the project. Once the material list was available, supplies for the filter system were ordered online or resourced from other vendors. During this process, the wiring for the LED system was schematically depicted using multiSim software. This software helped to confirm the wiring would work properly and according to the needs of the Water Filter. The wiring was also hooked up to a breadboard and tested physically before being installed in the prototype components.



Prototyping for the Filter began with having several of the structural components 3D printed through an outside source. As these components were made available, the were assembled and put together to reflect the model that was previously created. Along this process, notes were taken to keep track of the progression of steps needed to create the prototype. Physical Testing of the Filter System will be postponed until Spring of 2017, however several goals from the testing have been put together to facilitate the progress once the semester begins. A full Gantt Chart of the Semester deadlines and tasks can be found in Appendix B.

6. Design Concepts This section of the report will explore the progression of design ideas from the initial concepts to the final concept that is projected to be built in the coming semesters. In short, the initial designs were deemed to be too large and rigid to meet the specifications for transportability and use in backcountry areas. The dependence of early designs on electricity to effectively clean the water was not sustainable for long term use. These realizations led to later configurations of the design and ultimately a gravity fed system that uses electricity only to power a UV light source. Through research and evaluations, several components and technologies were chosen to achieve the design objectives. In an effort to create a more innovative and compact product, the team considered a design that combined gravity, microfiltration, and UV disinfection to increase flow rates compared to other products that exclusively used filters. This combination of treatment techniques is relatively uncommon among water filters currently on the market for this volume of water. Research done on potential competing products led to a selection of a multitude of geotextile fabric filters, ceramic pre-filters and several sources of UV-C light. In keeping up with technology, the team decided to use UV-C LEDs, which are a relatively new technology that is still developing. A great challenge in designing this system is to balance the flow rate through the ceramic filter with the exposure time required to effectively disinfect the water.

6.1 Initial Filter System Designs

Using the requirements and specifications desired for the filtration system, several designs were generated featuring different layouts and functions. Each system accomplished the same task, treating water so it can be consumed, but all of the designs utilized various methods and hardware to accomplish the tasks. The different designs are detailed below and are then followed by descriptions and evaluations of the various hardware alternatives that could be used for the



filtration system. These designs are preliminary concept designs and will not be used in the final project. They are presented to establish the background and basis on which the current design is founded. Some of the ideas are used in the current design but are no longer considered as a complete design option.

Figure 4: Single Tank Filter System

Figure 4 features our first preliminary design which was a large tank vessel which stores the clean water. Before the clean water is stored it passes through the filtration process. This process begins with small tube that is placed at the water source. The water is pumped through the tube and through the filter(s) where contaminants are removed. To kill harmful microbes, the water is then exposed to a UV light, eliminating the chance for a consumer to become ill from consumption. The pump and UV light are both powered by a solar panel with the power capacity to operate each. After the water has been thoroughly cleansed, it is stored in the large tank for consumption. A spigot at the bottom of the tank controls outward flow.



Figure 5: Divided Tank Filter System

Figure 5 is very similar to the design in Figure 4, but has a divided tank for raw and clean water. The water is pumped through a tube placed at the source and held in the raw water storage compartment until it is passed through the filter system and into the clean water tank. This design also utilizes a UV killing microbe filter to remove harmful bacteria and viruses. Both the UV light and pump are powered by a solar panel.



Figure 6: Gravity Fed Filter System

Figure 6 is a gravity fed water filtration system that uses the force of gravity to pull the water through the filters rather than using a pressure gradient created by a pump. This system features two holding compartments for dirty and clean water. The dirty water is pumped into the system using a pump and a tube placed in the water source. The dirty water then slowly passes through a filter where contaminants are removed. After filtration, the now clean water is stored in a collapsible bag for consumption.

At the beginning of the spring semester, the gravity fed system from Figure 6 was re-evaluated and it was realized that the pump could be eliminated and a collapsible bag or bucket could be used to fill the upper reservoir which would reduce the power consumption greatly and improve its size and weight. From there we came up with the idea of using a geotextile fabric to remove large sediments from the water followed by a basic ceramic filter as a pre-filter and then a UV chamber to disinfect the water to make it drinkable. After developing a couple of very similar designs, the best aspects of each were combined to make our final concept design.

Several components that may be utilized in each of the above designs are described below, displaying the most important features of each. These parameters for the components are later evaluated using Pugh Analysis in the Design Evaluations section. Table 2 depicts different ceramic filter types and commercial filters available for purchase. Table 3 hosts solar panel options and wattage. Table 4 shows options for UV lights.



6.2 Component Evaluations

6.2.1 Component Specifications

Table 2: Different options for filters used in the final water purification system design

Ceramic Filter

Name Pore size Flow rate Ext. Life Span

JustWater Ceramic Filter 0.2-0.5 1gal/1.5h 1000gal or 1 year

Zenwater Micro Ceramic Filter 0.2 1 gph 1-2 years

Katadyn Vario 801535 Ceramic Pre-Filter 1 Unknown Unknown

Santevia Ceramic Pre-Filter 0.3 micron Unknown 1 year

Table 2 outlines the options for the filters that were looked at for use as the ceramic pre-filter. This table shows 4 very similar ceramic filters with slightly varying pore sizes, flow rates, and life span expectancies. Based on the performance needed, some of these filters were better than others which will be shown later through Pugh Analysis.

Table 3: Different options for solar panels to power the system

Solar Panel

Name Size Power Output Weight

Thunderbolt Solar 13' x 37' 15W -

Solar Land 22' X 14" 20W 6.17 lb

Renogy Solar 24' 25' 50W 9.9 lb

Table 3 outlines the different solar panels that were found for use in powering the UV lights. With the UV LEDs the system shouldn’t require more than 15W of power which gives a lot of potentially small and less expensive options for solar panels. Once the final power calculations



are determined after LED testing, the solar panel options will be much clearer depending on the total power necessary.

Table 4: Different options for UV lights used to clean the water

UV Bulbs

Name Voltage Wattage Length Price

GTL-3 10.5 3 2.48 in $6.56 ea

G6T5,4 6 8.29 in $3.38 ea

E265SL 6.6 0.12 3.45mm $43.72 ea

HGEN UV LED 5.5-8.5 0.06 2-5mm $1-20 ea

GTL-2 (Eiko) 02449 10 2 2.2 in $9.79 ea

Sun-Pure UV Lamp 5.5 - 6.6 0.5 mW 3.45 mm^2 $43.72 ea

Purely T5B PUVLLB504 4 6 in $16.95 ea

Anyray ASE3WE17 3 2.2 in $9.99 ea

SMD LED (Requested Info) .3W small Unknown

Table 4 outlines some UV lights that could be used in the system, ranging from UV-C LEDs to normal glass, gas filled bulbs. Most of the lights are very similar. The big differences between the bulbs are whether they are LED bulbs or non-LED bulbs as well as the amount of UV energy they put out compared to their input power. The more efficient the bulbs are, the less power they will require, and they will be able to clean water faster with the same power input. Another important variable to look at when deciding what bulbs to buy is the price per unit. Ultimately, the cheaper the better as to keep the project more reasonably priced. However, in order to get the LED bulbs, there will inevitably be more of a cost due to them being a relatively new technology.



6.2.2 Component Comparison Table 5: Evaluation of different filters through Pugh Analysis procedure

Filter Pugh Analysis

JustWater Ceramic

Filter

Zenwater Micro

Ceramic Filter

Katadyn Vario

801535 Ceramic Pre-Filter

Santevia Ceramic Pre-Filter

Criteria Item Weight

Pore size 4 0 -1 -1

Flow rate 5 0 1

Cleanable 4 0 1 -1 1

Ext. Life Span 3 0 1 0

Silver Impregnated 2 0 1 0 0

Active Carbon 3 0 1 0 0

Price 2 0 0 -1

Minus Total 0 0 2 2

Plus Total 0 5 0 1

0 Total 7 0 3 3

Total 0 5 -2 -1

Weighted

Total 0 17 -8 -2

From the Pugh analysis in Table 5, the Zenwater filter performed the best based on the chosen design criteria. The best looking option was the Zenwater micro ceramic filter. The JustWater ceramic filter was used as the baseline with zero ratings in every category. The Katadyn and Santevia filters both performed poorly in the analysis. The Zenwater and Katadyn filters were ordered for further testing of flowrates and cleaning performance. Ultimately the filter just needs to remove most of the sediment in order to improve the cleaning capability of the UV lights. The



Katadyn filter had a larger pore size and could have potentially had a higher flow rate while still removing enough sediment.

Table 6: Evaluation of different UV-C lights through Pugh analysis procedure

Bulbs Pugh Analysis

GTL-3 G6T5,4 E265S

L HCEN UV LED

GTL-2 (Eiko) 02449

Purely T5B

PUVLLB504

Anyray ASE3WE1

7 SMD LED

Criteria Item

Weight

Voltage 4 0 1 1 1

Wattage 5 0 -1 1 1 1 -1 0 1

Length 3 0 -1 1 1 1 -1 1 1

Price 3 0 1 -1 -1 -1 -1 -1

Base 2 0 0 0 0 0

Wavelength 2 0 0 0 0 0 0 0 0

Life Hours 4 0 1 -1 -1 1 1

Minus Total 0 2 2 1 2 3 1 0

Plus Total 0 2 3 3 3 1 2 2

0 Total 7 1 1 1 2 2 3 2

Total 0 0 0 1 0 -2 1 2

Weighted

Total 0 -1 5 9 5 -7 4 8

Table 6 shows the Pugh analysis procedure for the different UV light option which include a variety of different options from LEDs to standard bulbs. From the analysis, it can be seen that the two LEDs performed the best of any of the other bulbs due to their efficiency and power



ratings. Based on these results, it was decided that LEDs would be chosen for the final design. The only problem with the LEDs is that they are more expensive compared to the standard bulbs. The HCEN LEDs were purchased for testing and use in prototyping.

6.3 Final Design Concept After calculating the retention time (the length of time required to effectively disinfect the water), the team was able to estimate the range of flow rates through the ceramic filter. It is expected that the flow rate will be much greater through the filters than what was actually achieved. For this reason, a restrictive flow regime within the UV chamber is unnecessary. A simple chamber must be adequately sized to never allow flow to exceed the required exposure time to increase the efficiency of the system.

Figure 7: Final concept design sketch



Figure 7 is a sketch of the final concept design for the Basecamp Water Purification System. The system utilizes a funnel shaped fabric container with a ceramic filter at the base of the funnel and a geotextile material cover at the top. Large particles are removed via the geotextile material, and after flowing through the ceramic filter, the water passes through a chamber where it is exposed to UV light from UV LEDs for the necessary amount of time to disinfect it. The UV LEDs are powered by a 9-volt battery. Alternatively, future designs may offer the option to power the system using a solar panel. After flowing through the disinfection chamber, the water flows into a container where it is stored to be used when needed.

6.3.1 UV Disinfection The wavelength of ultraviolet light is shorter than the visible spectrum and is classified into UV-A, UV-B and UV-C according to their wavelength. All forms of UV rays are naturally produced by the sun. UV-A penetrates the skin and mutates the cells of the dermis, resulting in a tan. UV-B penetrates less deeply and is the main cause of sunburns. UV-C rays are blocked by the Earth’s atmosphere and never reach the surface. UV-C rays are considered germicidal as they damage the DNA of all of living organisms. UV-C light can be produced artificially by low-pressure mercury bulbs and the newly developed UV-C LEDs. The wavelength of UV-C light ranges from 100-280 nm. The wavelength that is commonly considered the most effective for water treatment applications in 254 nm. Recent research has found that the most destructive wavelength depends of the type of bacteria or virus. The destructiveness of a certain wavelength of UV-C light is recorded as log-removal value. For example, a 2-log removal would effectively kill 99.99% of bacteria and viruses present in untreated water. 4-log removal would kill 99.9999%. The National Science Foundation recommends a standard dose of 40 mJ/cm2 to kill 99.9999% of bacteria and viruses. This value is representative of UV intensity (mW/cm2) x exposure time (seconds) per 1 cm2. However, the calculation is also dependent on the reflectance at air-water interface, absorptivity of water, depth of water and distance from lamp to water surface. Figure 8 depicts some of these design parameters. We estimated that 3 HCEN-brand UV LEDs would require an exposure time of about 8 seconds. HCEN is a Chinese manufacturer of electronic components. Currently, the electrical efficiency of UV LEDs is quite low. However, this project has a greater focus on developing UV disinfection applications than on electrical efficiency.



Figure 8: Design Parameters

6.3.2 Micro Filtration The UV disinfection process is negatively impacted by turbidity of the water sample. Suspended solids and inorganic metals reduce the effectiveness of UV disinfection. The UV disinfection is coupled with a ceramic microfiltration system to remove the majority of particles affecting turbidity. These relatively inexpensive ceramic filters are commercially available in a wide range of sizes, flow rates and pore sizes. Ceramic filters are also easy to clean and durable for outdoor recreational purposes, but are not commonly used for gravity fed systems because there is a direction relationship between pore size and flow rate (ie. smaller the pore size translates to slower the flow rate). A large pore size would allow for faster flow rates, but would also allow larger particles to pass through unfiltered. After research, several ceramic filters that were suitable for gravity fed applications were chosen. The Katadyn ceramic pre-filter is a component designed for use with the Katadyn Vario water filter. This design combines a ceramic filter with a high performance glass fiber filter. This pressurized system allows the user to bypass the ceramic filter when water quality is relatively high. This allows for faster flow rates through the filter. The ZenWater ceramic filter is dome shaped with reduces the rate of fouling pore clogging. Both filters are reusable and cleanable with a scrub pad. To reduce the likelihood of large particles preventing flow by clogging microfilter pores, a geotextile pre-filter is employed in the final prototype design, filtering as water enters the vessel.



6.3.3 UV Chamber Designs Designs for the UV chamber were also evaluated and created. The design objectives of these configurations seek to maximize retention time of the dirty water so the UV exposure time is longer. The flowrate through the UV chamber must also be kept and much match that of, or be greater, than the flow rate through the ceramic filter. The following designs are currently being evaluated for these specifications. Crude models of each were created to test the concepts of each, which are described below.

The first design evaluated is shown below in Figure 9. This design is cylindrical in shape and features a UV light located in the center to purify the surrounding water. The chamber works by passing the untreated water through the top of the design and into capillary tubes. It is predicted that the small diameter of the capillary tubes will slow the water down so it does not flow completely free out of the chamber further increasing the retention time. As the water flows from the top to the bottom, the UV light will kill of the microbes until a sufficient dosage is reached. The now purified water will pass through a large pore size filter to further increase the retention time. After the clean water passes through this final filter, it can be used for consumption.

Figure 9: Capillary UV Chamber Design



The second design, Figure 10, features small stacked plates and mounted UV LED’s spread out inside the chamber. As the dirty water flows into the top of the chamber, it will reach the first plate, which contains small holes that the water can pass through. The water will then reach another plate with holes that are alternately positioned compared to the previous. Ideally, this stacking of plates and altering holes will increase the turbulence of the water and fully mix the water as to increase the exposure of the LED light to all of the microbes. Additionally, it is proposed that the mixing and turbulence of the water will greatly increase the retention time of the water, while maintaining a suitable flow rate. As stated, the UV LED’s will be positioned as to maximize the exposure area so the microbes will be killed in an appropriate amount of time. The clean water will flow out of the bottom of the chamber and is ready for use.

Figure 10: Plated UV Chamber Design

The third design for the UV chamber, shown in Figure 11, features a cylindrical shape and a UV light mounted in the center. Water flowing through this chamber will pass through a set of conical walls that will direct the flow in a constantly reversing vertical manner, increasing the retention time. This configuration also ensures that the water is properly exposed to the UV light by alternating the path of the water and increasing the turbulence due to those turns. Flow through this design will be maintained and will not interfere with the flow of water through the



ceramic filter. The UV bulb in the middle can be unscrewed from the base and is easily replaceable. Water flowing out of this chamber is ready for consumption. .

Figure 11: Walled UV Chamber Design

Each of the UV chamber designs above possess unique characteristics that are desired in the final design. Evaluation of these designs has partially been fulfilled though the construction of each using household materials. This aspect of the design has proven challenging as the retention time of the chamber must fulfil the requirements for the dosage of the UV lights. For the final design, a variant of the design in Figure 11 was chosen. The final chamber design, Shown in Figure 12 below, will utilize the volume capacity of the cylindrical chamber to increase the retention time. Un clean water will flow from the bottom of the chamber to the top. While the water travels, it is exposed to the UV light where the microbes will be killed off. The clean water at the top can then be stored or used for drinking. Further explanation of this chamber design is in Section 7 of this report.



Figure 12: Final UV Chamber Design

6.4 Component Testing Both the ceramic water filters and UV LEDs will need to undergo initial testing before they are verified for use in the final design. The filters will be tested for flow rate to ensure the design requirements for supplying water for 6 to 10 people can be achieved. The UV LED will be evaluated to ensure they can properly kill off microbes that can cause illness. This potency will also be affected by the flow rates of the filters, as the water flowing out will then pass through the UV chamber. Currently, testing for the flow rates has been performed and is discussed below. A UV LED testing procedure has been drafted and is also shown.



6.4.1 Filter Flow Rate It was assumed that items that are purchased online with limited data available rarely perform as expected. Two filters were tested (Katadyn pre-filter and Zen Water Dome) to determine the relationship between flow rate and head pressure acting upon the surface of the filter. The testing apparatus consisted of a 7 foot long section of PVC pipe with a flexible rubber coupling used to attach each of the filters. Height marks were inscribed into the pipe at ½ foot intervals along the length. Flow rate out of each filter was measured through the filter at ½ foot intervals of height, up to 7 feet. The volume of water collected for each test was 8 ounces (volume). The time taken to fill this volume fluctuated throughout the test runs. Since units of gallons per minute were needed, this time interval and water volume were multiplied by a factor of 16. For several height intervals, two flow rate measurements were collected to compare fluctuations and ensure accuracy. The resulting data was compiled and is displayed below in Figure 13.

Figure 13: Plot relating flow rate of the filters tested to the water column height

Based on observations in the above plot and from those made during the experiment, the Katadyn filter performance decreased greatly as the water pressure decreased. After testing and disassembling the pipe and filter, there was a large buildup of sediments on the surface of the filter. This is believed to greatly affect the performance. For the Zen Water filter, the flow rates were fairly constant over the range of water heights. It performed well and did not experience the buildup of sediments on the surface. To further examine the pressures at each height, the



pressure was calculated to find target values of pressure that could produce the flow rates that would sustain the water volume needed to meet the requirements. The results are shown in Table 7 below.

Table 7: Water Head Pressure and Column Height Column Height

[ft] Head Pressure [psi]

6.5 2.82

6 2.60

5.5 2.38

5 2.17

4.5 1.95

4 1.73

3.5 1.52

3 1.30

2.5 1.08

2 0.87

1 0.43 Naturally, the greater pressures were for the greater water heights. This idea will be heavily considered in the final design for the water reservoir. It was also noted after testing that a pre filter, a geotextile fabric, is desired to remove larger sediments from the water before passing through the ceramic filter to prevent the occurrence of reduced flow rates that was experienced by the Katadyn filter. Ceramic filters are susceptible to frequent fouling (physical obstruction of flow through the filter by built up debris). The degree and rate at which fouling occurs depends on the source water turbidity and several other factors. The testing procedure outlined above used Hancock city water, but evidence of fouling can be seen in the variability of the Katadyn flow rate data.



6.4.2 UV Led Dosage and Intensity

The UV treatment concept was tested early on in the Fall 2016 semester. The major outcome of the testing was that the treatment objective was not met. A 4-log removal is recommended by the National Drinking Water Standards, and was adopted for the purpose of this project. The actual result was between zero and 1-log removal (90% removal of microorganisms). Several factors were thought to impact the results of the experiment. The LED was radiating through a curved test tube of unknown material. The refraction both at the air-glass and glass-water interface reduced the effective UV intensity. Mixing is a critical factor in water treatment, however, mixing was neglected in the experiment due to the small scale. It was predicted no mixing significantly reduced the delivered UV dose. No mixing creates hotspots of overexposed water, and other areas where UV radiation was essentially zero. Since, the entire volume of water in the test tube was used to culture samples, this effect is exacerbated over time. The experiment led to one major design change. The number of LEDs was increased from 3 to 9. We struggled with setting up and maintaining the testing apparatus. The small size and fragility of the LED made them very difficult to work with. The testing apparatus was designed to be temporary, so no solder was used to keep the wires attached to the LEDs. The testing apparatus was redesigned to allow for the user to easily swap out LEDs, while keeping good electrical connection between components. The experiment also provided us with a better understanding of UV chamber design and effective UV intensity distances. The effective distance from the LED to the sample was maximized at about 2 cm. The UV chamber was redesigned with this in mind. Water is allowed to flow upward, toward the LED. This eliminates the risk that water will short circuit, or quickly flow into-out of the chamber without adequate treatment time, when the chamber is not flowing completely full.



7. Final Design Summary

7.1 Filter System Overview The final filter system design closely resembles that shown in Figure 7. Dimensions for the filter system were selected and the geometry and fit of all of the components were determined as to meet the specifications of this project and modeled using Solidworks. The same basic functionality of the final filter design model were based on the sketch shown in Figure 7. The upper portion of the filter basket houses the water, which then flows through the UV Chamber and out the bottom of the filter. Details and mechanical aspects of the filter system are discussed below in the following sections.

7.1.1 Filter Model Description As stated, the model for the filter system was created using Solidworks software. The finished product features the completed model in its assembled form, however several of the smaller electrical and hardware components were not modeled, as they were not needed to provide a proof of concept or to aid in solving for dimensions for the larger components. Many of the components modeled were used to then create .stp files so they could later be 3D printed for use in prototyping the filter system. These individual components will be discussed in detail later. A labeled overview of the model exterior is shown below in Figure 14.



Figure 14: Filter Assembly Exterior

The entirety of the assembled filter system measures 15.5” wide by 16.5” long, excluding the height of the Hanging Rod. Starting from the top of the design, the gravity fed system can be hung using the Basket Hanging Rod. This rod is removable, which allows the Support Ring to fold in half around two pivot points and reduce in size for ease of packing. The Support Ring also features two hooks that hold a Geotextile Support Ring. Not shown in the model, the chosen geotextile material will be spread across the Geotextile Support Ring providing a large particle filter to remove dirt or debris from entering the Basket. The design allows the Geotextile Support Ring and material to easily be removed for cleaning or packing.

The Basket of the Filter System will be made of Hyper-D membrane fabric, which is very lightweight and flexible in addition to being waterproof. The Basket will attach to the Support Ring through the use of glue and stitching. This will provide a strong connection which will also add a unique design element to the filter system. The lower portion of the Basket will fit inside the Upper Chamber Adapter and have an attached o-ring (not shown) to provide a watertight



seal. All three of the Chamber Adapters are threaded and will screw into each other so they can be easily taken apart.

The interior of the Filter System is much more detailed and contains many of the functioning components of the model. A section view is shown in Figure 15 below, and is labeled to aid in understanding how it functions. Only a cut view of the UV Chamber is shown as the upper portion of the system does not contain internal components that cannot be understood from an exterior view. As stated previously, some of the smaller internal components are not shown.

Figure 15: UV Chamber Section View

The flow of the water through the UV Chamber starts by passing through the Katadyn Filter. The top of the Middle Chamber Adapter has 3 holes for the water to pass through. Quarter inch diameter tubes (not shown) will be connected to these holes on one end and connect to 3 similar holes in the UV Mounting Plate. These tubes will carry the water through the UV Mounting Plate leaving a dry space for the electrical components to be housed and be easily accessible through the Electrical Opening pictured. The electrical components, minus the switch, are not



pictured. Continuing on, the water will then flow into a cavity surrounding the UV Chamber insert and enter the Chamber through 3 bottom openings (2 shown). The UV Chamber will reach its retention time by using the period it takes for the water to flow in a circular motion from the bottom of the Chamber Insert to the top, where it will once again be carried by tubes to exit through the bottom. The progression and flow of the water is shown as blue arrows in the above Figure. As for the LED Lighting, 9 HCEN LED’s will be held in place using the LED Holder. The center of the rectangular holder is hollow to allow for wiring. To protect the LED’s from water damage, the LED Holder is encased by a glass tube that is sealed at its base on the UV Mounting Plate.

The entirety of the UV Chamber is designed such that it can be taken apart easily. In conjunction with the design objectives, this allows the user to clean the internal components or replace them if needed. Each of the Adapters is threaded and can be twisted off, while the internal components can slide out and taken apart. The electrical components for the filter system can also be accessed and replaced if needed. It is also mentionable that because the filter system can be taken apart, it will increase the transportability and bulkiness due to the ability to break it down into smaller pieces.

7.1.2 Model Components An engineering drawing and a bill of materials was created along with the model detailing all of the components needed to build the assembly. A copy of these documents can be found in Appendix D. Tabulated, the bill of materials is shown below in Table 8.

Table 8: Filter System Assembly Bill of Materials

Item Description Quantity

Support Ring 3D Printed Part 2 halves, with 2pcs per half

Hanging Rod ⅛” Rod 1

Support Ring Pins ¼” Dowel Pins 2

Basket Membrane Fabric 1

Geotextile Ring ⅛” Rod 1

Katadyn Filter 1



Upper O-Ring 1

Upper Chamber Adapter 3D Printed Part 1

Flat O-Ring 1

UV Mounting Plate 3D Printed Part 1

Chamber O-Ring 1

Chamber Insert 3D Printed Part 1

Middle Chamber Adapter 3D Printed Part 1

Lower Chamber O-Ring 1

Lower Chamber Adapter 3D Printed Part 1

Clean Tube ¼” Tubing 3

Dirty Tube ¼” Tubing 3

Bottom O-Ring 1

9V Battery 2

Switch 1

LED Holder 3D Printed Part 1

LED Glass ¾” Diam Quartz Tube 1

HCEN LED 9



Figure 16: Model view of Upper Chamber Adapter

As stated, several of the components were 3D printed. The first of which was the Upper Chamber adapter shown above in Figure 16. The component measures roughly 3.3 inches by 1.2 inches. The inner portion of the adapter is threaded so it can be fastened to the top of the Middle Chamber Adapter. The Katadyn ceramic filter mounts to the top of the adapter where it is sealed by an o-ring on both the top and bottom.



Figure 17: Model of Middle Chamber Adapter

The Middle Chamber Adapter, shown above in Figure 17, houses the UV Chamber itself and is the primary function unit of the filter system. The top of the adapter is built to mount the Katadyn ceramic filter. Once the water has passed through the filter, it will travel through the three holes shown in the Figure and through tubes to the next compartment, leaving an open space in the upper portion of the adapter for the electrical system. The circuitry can be accessed through two openings in the wall of the adapter. On the inside of the adapter, there is a small lip for the UV Mounting Plate, shown in Figure 18 below, to sit.



Figure 18: Model of UV Mounting Plate

The Mounting Plate separates the circuitry from the UV Chamber inside the Middle Adapter. Tubes passing through the Middle Adapter connect to the three holes shown above which allows the water to flow through the Mounting Plate and eventually through the UV Chamber. The square hole in the center of the plate positions the LED Holder and provides a way for the wires connected to the LEDs to reach the power source.



Figure 19: Model of LED Holder

The LED holder will house all nine of the HCEN LEDs. Each of the LEDs will be wired by creating a contact surface via exposed wires which will pass through holes in each of the slots. Due to this method of contact, the LED’s will be able to be replaced or moved. The LED holder will also be encased by a glass tube to keep the circuit dry inside the UV Chamber.



Figure 20: Model of UV Chamber Insert

Shown in Figure 20, the Chamber Insert serves as the functioning member of the filter system as the water is disinfected inside. The dirty water will surround the exterior of the Chamber and the inner wall of the Middle adapter and flow into the bottom of the Chamber through three angled openings. Angling the inlet holes will create a small amount of swirling inside the chamber as the water is exposed to the LED’s ensuring that all the particles in the water will be exposed. Once the water has flowed from the bottom to the top of the chamber, it will be carried through three tubes from the top back to the bottom, utilizing the 6 remaining holes of the Chamber. The tubes are not shown in the Figure. From the tubes, the now clean water will flow into the Bottom Adapter shown below in Figure 21.



Figure 21: Model of Bottom Adapter

The bottom adapter is the final component the water will pass through for the Filter System. The Adapter was fabricated so it will screw into the bottom threads of the Middle adapter and seal with o-rings. The hole in the center of the Bottom Adapter is made so that a small valve can be mounted or for a tube to be inserted to carry the water to a storage location. Two wings on the Adapter also provide the user with a surface to apply torque on so it can be loosened or tightened.

The final 3D printed component for the Filter System is the Support Ring, shown in Figure 22. The ring was created using one model component, which was printed twice. For printing purposes however, the model was split into two components at a midline so it would fit onto the printing surface.



Figure 22: Model of Support Ring

In the Support ring, there are two holes at each end. The larger, and bottom most of the two is a pivot point for the ring allowing it to be folded in half. The upper hole is for the Hanging Rod. The cross section of the ring is similar to an I-beam shape, providing structural integrity and decreasing the amount of material needed.

7.2 Filter System Prototyping

7.2.1 Prototyping Procedure After the 3D printed components were finished, the prototyping process could begin. The first steps were to prepare the printed components by sanding rough edges, boring holes, and sealing seams if needed. The threads on the Upper, Middle and Lower Adapter had to get worn in as they were not smooth and did not thread easily initially. All of the parts did fit together well after working on sanding and smoothing the contact surfaces. There appears to be no major printing errors or warping present in the components. This step was very useful to have outsourced since the team does not have a great deal of 3D printing experience or troubleshooting. Figure 23 and 24 show the adapters and Mounting Plate.



Figure 23: Printed Upper and Lower Adapter and Mounting Plate

Figure 24: Printed Middle Adapter



After the printed components were prepped, some of the o-rings were glued to the sealing surfaces, as shown on the 3D model. However, the lower o-ring for the UV Chamber Insert may not be used in the final adaptation as it does not allow the insert to fit inside the Middle Adapter. Other methods of sealing the chamber are being considered. All of the other o-rings fit well in their respective areas. The UV Chamber Insert also had the tube inserted to allow the clean water to flow out. The tubes were heated with a lighter so they were able to bend at a 90 degree angle. The Chamber is shown below in Figure 25.

Figure 25: Printed and Assembled UV Chamber Insert

The Support Ring for the filter system, as stated before, was in four pieces. Two of the quarters, were epoxied together along with a metal plate to span the gap and provide extra reinforcement, shown in Figure 26. Upon curing, the now halves of the ring were fastened together using screw inserts so it can be folded and expanded for use as depicted in Figure 27. To keep the ring halves expanded, the handle was created, which will fit into ⅛” holes in each ring piece that align. The handle is removeable and can be inserted with ease.



Figure 26: Support Ring Sean and Reinforcement

Figure 27: Folded Support Ring Halves



Figure 28: Support Ring Folding Hinge

The geotextile ring was also fabricated using 3/16” wire bent into a circle. The geotextile fabric has yet to be fastened to the ring, but will be stitched on when that step in the process is reached. The membrane fabric also has not been attached, but is in the process to being completed. The other major area of fabrication is for the electrical system. Currently, the LED’s are being wired into the LED Holder, which will then get glued to the Mounting plate after the LED’s have been completely wired and tested. After this, the rest of the circuitry will be soldered and put together and inserted into the Middle Adapter electrical compartment. A final assembly of the components will help to find any leaks once water is run through. Since several components were 3D printed, there are concerns that the seams of plastic laid down may have small pored or holes that could allow water to escape.These will be treated with silicon sealant upon identification.

At the completion of the Fall 2016 semester, it was projected that the Team would have a working prototype. At this point in the project, the prototyping process is moving along and making great progress, however delays in having the printed components made, set the timeline for the project back a week or two. This has affected the prototyping process, and although a majority has been assembled, the filter system may not be fully built at the semester's closure, but will have enough completed that finalizing the prototype will be quick in the beginning of the Spring Semester to allow for testing to begin.



8. Expenditures and Costs With past plans to begin prototyping this semester, the components were purchased as they were needed. From the previous purchases including a Zen Water Ceramic Dome Filter, a Katadyn Ceramic Pre Filter, and HCEN LED’s, many materials were additionally gathered, as shown below in Table 9. Pictures of these components are shown in the Appendix C. Several other smaller purchases were made to supply equipment for initial testing or to support the use of the filters or UV bulbs. These materials were not included on the cost estimate since they will not be used directly for the completed filter system. Upon completion of the UV LED Dosage Testing, it was found that more LED’s will be needed to sufficiently kill off microbes in the water. 6 more were purchased from the supplier for this reason. In addition, the need for a large sediment prefilter was also realized and a geotextile material was purchased.

Table 9: Purchased Products Information and Cost Summary

Product Information Purchased Price Date Purchased

HCEN UV LED 265nm Diode Samples [8]

(9) for $282.2 October 25th, 2016

Eiko 02449 GTL-2 2W 10V UVC T6 Base Bulb

(1) @ $29.33 February 22nd, 2016

Zen Water Systems Dome (1) @ $18.90 February 26th, 2016

Katadyn Pre Filter [9] (1) @ $18.99 February 22nd, 2016

SRW NW4.5 (Geotextile) Donated, estimated cost $30-$100 (not included in

total)

November 11th, 2016

9V Battery Strap + Switch [10], [11]

(2) + (1) @ $18.41 October 27th, 2016

3D Printed Components (10) @ $96.71 November 3rd, 2016

HyperD PU4000 Membrane Fabric [12]

(2) yds @ $20.45 October 27th, 2016



Acetone (1) @ $7.49 Nov 28, 2016

PVC Tubing (2 ft) @ $0.25/ft Nov 28, 2016

O rings, rubber washers, etc $10.14 Nov 28, 2016

Brass Rod $4.99 Nov 28, 2016

Steel Rod $3.69 Nov 28, 2016

Total: $511.80 - The costs above are all being used for the prototype of the Filter System. The largest expenditures are from the UV LED’s and having the 3D printed components outsourced. The printed components could be made within GEAR Enterprise much cheaper, but at the time they were needed, the Team did not have this capability. For the initial prototype, the model does not include a universal power hookup such as a 9mm plug. Some of the electrical components, such as the power source, may be replaced after testing on the Filter System has been done. With this prototype, the Team will focus on the functionality of cleaning the water and will shift to power resources at a later time. Additionally, a power source, such as a solar panel or external battery, is not included in the cost estimates due to the team deciding this feature can be provided by the user based on availability. The team does not intend to focus on designing a battery or solar panel, so price estimates for these components are not included.



In addition to the monetary cost estimates, the team has put together an estimation of the amount

of time spent working on the project up to this point and an estimated projection of the time needed to complete the project. Table 10 summarizes and details a breakdown of the engineering work done for this project.

Table 10: Engineering Work Hours for Water Filter System

Task Hours

Research 127

Preliminary Design 85

Individual Part Testing 35

3D Modeling + Engineering Drawing 27

Fabrication (Partial Estimate) 40

Prototype Testing (Estimate) 80

The research portion of the estimated work hours includes initial research on the project, looking up possible components, time spent ordering components, and documenting information found. The design portion includes all design calculations, brainstorming, and Pugh Analysis, of parts and potential designs. Individual part testing covers the testing of the LED dosage and Intensity, as well as the filter flow rates. 3D modeling hours were spent creating the Filter System in SolidWorks and fabricating an accompanying engineering drawing. Fabrication will include the fabricating of the prototype for future testing. Prototype testing will take a large portion of the time to ensure that it meets the original objectives outlined at the beginning of this report and to provide a background for future improvements that can be made to the design.



9. Conclusion & Future Plans The Fall Semester has been devoted to further develop and finalize the filter system prototype so its building could begin. So far, all of the major goals for the semester have been met with the completion of the LED Testing, 3D model creation, material selection and 3D printing custom components. The final goal for the semester was to have a working prototype, and as this may not be fully reached, the Team has a majority of the prototype complete and will be ready to wrap up in the Spring.

After completion of the filter system prototype, initial testing can be performed. This would include evaluating the design through use by collecting data regarding flow rates through the system, turbidity of the “clean” water, and contaminants found in the water after the filtration has occurred. For testing flow rates, dirty water will be poured into the reservoir of the filter system. Time will be kept and recorded for a specific volume of water to undergo filtration, and adjusted to meet the desired units if needed. Turbidity will be evaluated on existing turbidity charts and through visual inspection of the water, before and after filtration. This will affect the potency of the UV light as the sediments in the water can block the light from reaching the microbes. Highly transparent water is greatly desired in this application and design modification can be recommended accordingly to try and provide cleaner water. The UV exposure will be verified through a before and after analysis of the water through bacterial counts. Bacteria can be cultured or examined under a microscope to determine the concentration levels in a similar manner that was performed this Fall semester.

After testing, the design may need alterations to meet the original design parameters if the specifications are not met with the current design, or to improve on aspects of the current design. If so, changes will be made and reexamined through testing, mathematical methods, or justification through design analysis. Once the criterion are met and the Team is satisfied with the performance and design of the filter system, real world application for the filter may be performed through a camping trip. This will provide the opportunity to fully reach the filter systems potential use in its intended environment and to determine if there are still useful updates or alterations that could improve the design.



Citations [1] Online, Available at:

ehttp://www.outdoorgearlab.com/Backpacking-Water-Filter-Reviews [2] Online, Available at: http://cavanshannon.blogspot.com/ [3] Environmental Protection Agency. “Drinking Water Contaminants”. 2015. Available at:

http://water.epa.gov/drink/contaminants/index.cfm#List

[4] NSF. “Residential Drinking Water Treatment Standards”. 2015. Available at:

http://www.nsf.org/services/by-industry/water-wastewater/residential-water-treatment/residen tial-drinking-water-treatment-standards

[5] “Guide for Drinking Water Treatment Technologies for Household Use”. 2015. Available at: http://www.cdc.gov/healthywater/drinking/travel/household_water_treatment.html

[6] Mountain Equipment Co-Operative. “Backcountry Water Treatment”. 2015. Available

at:https://www.mec.ca/AST/contentprimary/learn/hikingandcamping/foodandwater/choosingawatertreatmentsystem.jsp

[7] US Government Publishing Office. 2010. “Protection of Environment”. Available at: https://www.gpo.gov/fdsys/search/pagedetails.action;jsessionid=MQ0MV7YTQ5R11Md9609p0GnxlzQm89Zp7jyQxpH78Y0hQ8pqkxvm!1549446635!-1697915083?collectionCode=CFR&searchPath=Title+40%2FChapter+I%2FSubchapter+A&granuleId=&packageId=CFR-2010-title40-vol1&oldPath=Title+40%2FChapter+I&fromPageDetails=true&collapse=true&ycord=509

[8] HCEN 265nm Germicidal LED. <https://hcen.en.alibaba.com/product/60466734380-800756817/265nm_310nm_uvc_germicidal_led_for_disinfection_and_medical.html>

[9] Katadyn Vario Ceramic Prefilter Disc Replacement <https://www.katadyn.com/us/us/216-8015035-vario-replacement-disc-ceramic>


http://www.outdoorgearlab.com/Backpacking-Water-Filter-Reviews



http://cavanshannon.blogspot.com/

https://www.gpo.gov/fdsys/search/pagedetails.action;jsessionid=MQ0MV7YTQ5R11Md9609p0GnxlzQm89Zp7jyQxpH78Y0hQ8pqkxvm!1549446635!-1697915083?collectionCode=CFR&searchPath=Title+40%2FChapter+I%2FSubchapter+A&granuleId=&packageId=CFR-2010-title40-vol1&oldPath=Title+40%2FChapter+I&fromPageDetails=true&collapse=true&ycord=509






https://hcen.en.alibaba.com/product/60466734380-800756817/265nm_310nm_uvc_germicidal_led_for_disinfection_and_medical.html

https://hcen.en.alibaba.com/product/60466734380-800756817/265nm_310nm_uvc_germicidal_led_for_disinfection_and_medical.html


[10] DigiKey Strap Battery ECON 9V I Style 6"LD. <http://www.digikey.com/product-detail/en/keystone-electronics/233/36-233-ND/68726>

[11] DigiKey Rocker Switch SPST 15A (AC) 125V Panel Mount, Snap-In <http://www.digikey.com/product-detail/en/e-switch/R1966ABLKBLKESGRN/EG1859-ND/251347>

[12] Ripstop By The Roll. HyperD PU4000 1.6oz Membrane Fabric. <https://ripstopbytheroll.com/products/1-6-oz-hyperd-pu4000>


http://www.digikey.com/product-detail/en/keystone-electronics/233/36-233-ND/68726

http://www.digikey.com/product-detail/en/e-switch/R1966ABLKBLKESGRN/EG1859-ND/251347

http://www.digikey.com/product-detail/en/e-switch/R1966ABLKBLKESGRN/EG1859-ND/251347

http://www.technicalglass.com/

http://www.technicalglass.com/


Appendix A

UV-C Testing Procedure GEAR Enterprise - Base Camp Water Filtration

Note: May need to focus this study down to just 1-2 hypothesis and 1-2 bacterial strains

Objective: A single HCEN UV LED is quoted to have a radiation flux between 0.2 to 1.5 mW at 20mA of current. One of the objectives of this experiment is to develop a curve of current to radiation flux. The preliminary calculations were performed to estimate retention time (or the length of time the water must be exposed to the UV light). Another objective of this experiment is to determine the effect of overlapping UV light sources. The hypothesis is that overlapping 3 UV LEDs will effectively triple the radiation flux at a given current. As discussed below, microorganisms often times respond differently to UV radiation exposure. Another objective of this experiment is to develop of dose-response curve for several common strains of bacteria typically found in surface water. Traditionally, a wavelength of 254 nm was used in water disinfection. New science has found that this may not be the case. There is no reason to expect that the UV light will have the same disinfecting power at each wavelength. Another objective of this experiment it to compare the disinfection power of 265 nm LEDs. Background: UV LED manufacturers undertake extensive testing measures to give the consumer an idea of expected LED performance. However, the exact application of the LED technology will vary. UV LEDs are a recently developed technology and have not been thoroughly tested. UV-C LEDs are considered to be in the germicidal range of UV light because the radiation causes damage to DNA. Unlike traditional water disinfection methods, there are no by products of UV and it is impossible to overdose. However, optimizing energy consumption with UV output is the aim of the design engineer. LED manufacturers do not usually provide a graph showing the relationship between energy use (current) and radiant flux (UV output). The National Science Foundation recommends a standard UV dose of 40 mJ/cm2. This dose would theoretically inactivate 99.9999% of all waterborne viruses and bacteria. However, not all microorganisms react the same way when exposed to UV light. Several of the most common bacteria include:

● C. parvum ● Cryptosporidium ● Giardia



● Fecal Coliform ● E. Coli ● Salmonella

The Most Probable Number technique for bacteria is basic procedure to be used. Depending on the media available, the procedure and test results will vary. The most applicable test media is petri dishes with starch as the carbon source. Fermentation tubes or broth tubes may also be used if readily available. The Most Probable Number procedure is used to estimate the number and type of bacterial colonies for a given sample. The test is performed multiple times for a given dilution of the sample. As the sample is diluted, the number of positive tests results will decrease. The goal is to determine the dilution that allows the researcher to manually count each bacterial colony. Lightly diluted samples will likely result in too many colonies to accurately count. Figure 1A below depicts the traditional set of a collimated beam UV testing apparatus. This design will be scaled down and modified slightly to allow for monitoring of UV forward current through the UV LEDs. The shutter component of this set up will be controlled by the electronics learning lab equipment, shown in Figure 2A below.

Figure 1A: Traditional Collimated Beam UV Testing Apparatus



Figure 2A: Electronics Learning Lab

The electronics learning lab will serve as the means of varying current through the LEDs. The circuitry has not yet been developed, but is predicted to be relatively straightforward. The circuitry will be developed over the summer of 2016. Equipment:

● UV LED Diodes (3) ● Petri Dish ● Magnetic Mixer ● Power Source and supporting Circuitry ● Test Tubes ● Aluminum Foil ● Safety Glasses ● Microscope ● Inoculation Loop ● Various Microbiology Equipment ● Surface Water Samples

● Portage ● Coles Creek ● MTU tap water ● Hancock City water ● Distilled water (control)



Procedure: 1. 5 test tubes will be filled from each water source. 2. Expose test tubes of dirty water to varying UV intensities at various amounts of time. 3. Culture samples to induce bacteria growth.

4. Observe how UV exposure affects bacterial growth.



Appendix B

Figure 1B: Gantt Chart for Fall 2016 semester project work.



Appendix C

Figure 1C: Katadyn ceramic filter after testing

Figure 2C: Zenwater ceramic filter after testing



Figure 3C: Geotextile Material



Figure 4C: Battery Straps and LED Switch

Figure 5C: HyperD PU4000 Membrane Fabric



APPENDIX D


transportable water purification...

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