Stage 5 - Testing/Results!

The two highlighted dishes show the sterilised e.coli bacteria, the other dishes prove the sterilisation worked.

Tests Worked!!!

I have proven that my filter will filter soiled water from 464NTU down to 71NTU the water was then exposed to UV and sterilised making it safe to drink.

Stage 4 - UV Sterilisation

The water was sterilised and tested as before. It included:
2 – UV soiled
2 – Soiled (control)
2- UV clean
2 – Clean (control)
2 – Original water 10-1
2- Original water 10-2
2- Original water 10-3
The original water enabled me to count the number of bacteria in the original water

Stage 3 - Water Filtration

I passed both the clean water and the soiled water through the fish filter made of synthetic fibre and active carbon.

Stage 2 - Water Turbidity

I added compost to the water to give it a soiled effect then measured the turbidity using a turbidimeter. The results are:

Soiled water: 464 NTU
Original water: 83 NTU

(NTU is measure of turbidly – tap water is approximately 5-10 NTU)

Step 1 - Collection

I was given some water from the Loughborough sewer, this was clear but full of bacteria and e.coli.

UV + Filter = Sterile drinking water??

I have proven that UV works to kill bacteria and e.coli, I have also carried out initial tests that show filtration will clean soiled water will the two elements work together?

Step 1 – Water Collection
Step 2 – Quality Test + Add Soil
Step 3 – Filtration
Step 4 – UV Sterilisation
Step 5 – Test

Water Quality Results

Results:

1. Fish tank filter – Active Carbon and synthetic fibre 4.32mins
2. House Filter – Synthetic Membrane and Active Carbon 14.49mins
3. Active Carbon particles 3.24mins
4. Britta Filter 2.48mins

The best for quality and speed was the fish tank filter, I will carry out scientific experiments to prove this is the best to use.

Initial Filtration Test

I made lots of test tubes and adapted a filter for each one, I poured 100ml of soiled water though and measured the time taken and water quality. This was just done quickly to see which filter worked best.

Filtration ... more options

I am looking into a number of different filtration methods, water quality and flow through rate is important. The options include:

Fish tank filter – Active Carbon and synthetic fibre

Britta Filter – Carbon and lime

House Filter – Synthetic Membrane and Active Carbon

Dense Active Carbon

Carbon particles of various sizes

Hydrocyclone ... it's just too complicated

The idea of a hydrocyclone will not be possible for my water bottle. The size of the cyclone would exceed that of a normal bottle, it would need a pump feed the water. The pump would need to accelerate the water at a velocity of 7m/s which is unattainable in this size of bottle.

UV Results!

The dark coloured dishes show the growth of e.coli and other bacteria colonies, the clear pink dishes show the sterilisation worked and the bacteria has been neutralised! This is safe to drink.

There are too many bacteria colonies to count, but we can see how they have grown. 2 UV sterilised dishes failed, this is suspected to be due to high concentration of bacteria and not enough exposure time to UV. I will investigate this further.

UV Tests

To test the UV I collected some water down stream of a chemical plant, this water had a high concentration of e.coli and other bacteria. I used the UV light to sterilise the water.

A process called Membrane filtration is used to test for e.coli bacteria, by filtering the water though a membrane of 0.45 micron the e.coli bacteria will stay on the surface. Put the infected membrane into a growth mixture and incubate for 24 hours. You can then see if there are any e.coli colonies formed. A number of control samples had to be carried out at the same time to verify the results.

UV Bulb

A company called SteriPEN produce a UV wand for sterilising water, my plan is to use this bulb. I will carry out test first to ensure it works.

Cafetiere Filter?

I need to reduce the particle size down to below 10micron. Would a cafetiere filter work? - I set up a microscope and measured the pour hole size .... No luck, it was 200 micron. Though this would make a good pre-filter.

Filtration ... Cool Ideas

I want to use a Hydrocyclone to filter the water. A Korean journal described a process which reduced particle size down to 3micron, if this was put into my product it would be really cool. Tests to follow...

Will wind-up work?

Wind-up torch stripped down and connected to a volt meter, to test the power output. It produced enough to power my 3W UV bulb. A successful test!

User research!

I have spoken to 4 completely different individuals to get an idea of the market. Online research has also been carried out.
The estimated market size is 9 million adventure travellers per year, which is set to double by 2015.

Feasibility

To ensure the project is viable I am carrying out the following feasibility tests:
Wind up power for UV
UV experiments (ensure it kills all bad bacteria)
Filtration Experiments

Concept

My project aim is to design a water bottle for adventure tourists that will enable them to drink water from any source safely. Within 2 minutes the water bottle will filter and UV sterilise water. This enables travellers to take safe drinking water from any stream, lake or dirty puddle they come across. The bottle will have wind-up on-demand power that will enable it to be battery free and used anywhere in the world without worry.

Senario

Progress so far...

I am already 10 weeks into the project so I will post my progress so far…

The Idea:
Following a year working for The Technology Partnership (www.ttp.com) I was struggling to think of a final year project. I looked into new processes and technologies that TTP were using in some of the products. UV stood out and I felt it had not been fully exploited yet. After many brainstorms I came up with this concept:

Welcome!

Hello and welcome to Timothy Whitehead’s blog. Here you will be able to see my full design process from; initial investigation, research, testing, experimentation, concepts and prototyping. I aim to document it all in chorological order. Feel free to comment and suggest improvements at any point.

Tim