Market Need: Conceptual Designs

The design will meet the following specifications:

1) Will reduce the turbidity of the water to between 5 and 25%.m x to y)

2) Will minimize the presence of harmful bacteria in the water.  The ideal number we want to reach is a zero percent colony count when sample is incubated in a petri dish.

The following are some conceptual designs that we have worked out:

Manual for existing water systems - The Ban Huay Mii village uses storage tanks to keep their water. When the water sits in the storage tanks, the mud, and other particulates in the water sinks to the bottom. These storage tanks are fitted with purge valves, which allow them to be emptied and cleaned. [1] One of the most significant contributors to the poor water quality is that the villagers are unaware of how to take care of their water system. Therefore it might be the best course of action to first produce a comprehensive manual for the maintenance and care of the system they currently have in place.

Slow sand filter - A slow sand filter involves running water through a compact layer of sand. This will remove many particulates and other small or large objects from the water source. This system also serves as a checkpoint to filter out bacteria contaminating the water. The sand filter has proven to work because after a few days of operation a layer of bacteria and other biological material will build up on top of the sand. This layer will trap bacteria as water cruises through it [2].  While this is an excellent, inexpensive method for cleaning water, it requires a lot of maintenance. The bacteria layer must be sifted and cleaned periodically throughout the year for the best results.

Ultraviolet water purification – UV water treatment has proven to be an effective way to purify water. This system operates by running clear water through ultraviolet light. This will kill most if not all bacteria living in a contaminated water supply. While it is a very effective purification method, it will probably be expensive to build, and maintain. The system will require power from a solar panel, which if damaged, would be difficult for the villagers to replace.

Activated Carbon Filtration - Activated carbon is another excellent method to filter out particulates and potentially harmful biological material from water. A filter containing activated carbon would work similarly to a slow sand filter, in relation to the gravity fed system where water is pored over a layer of activated charcoal and filtered out the bottom.  This substance can be made using charcoal from burned corn husks, bamboo, and wood. Because activated carbon is relatively easy to produce this may be a perfect filtration method for the Ban Huay Mii village.

Classification Tree:

Click on image to enlarge

Market Need

In order to create an effective design that meets the needs of those who will use it, we must first establish what those needs are, and determine who will be effected by this project. 

Stakeholders:                                                              Order of importance:

Village of Ban Huay Mii	Primary
Villages in similer situations to Ban Huay Mii	Primary (2)
J. Shanley, J. Shore, E.G. Leon, V.V Milanov	Secondary
Dr. Alexander J. Moseson and Teaching- -Assistants	Secondary (2)
Drexel Thai Harvest	Tertiary
Ken Mallory	Tertiary
Magid Bdeir	Tertiary
Bob Shim and the Sustainable- -Development Research Foundation	Tertiary
The Drexel University College of Engineering	Tertiary

Needs: Primary Stakeholders:

The Village of Ban Huay Mii prioritizes their water need by requesting less turbid, better tasting water over larger quantities of water. Because this is not a wealthy village with abundant resources, a filter system developed for them must be as inexpensive to produce as possible. It is also important to educate the villagers on clean water practices such as keeping animals away from their water supply, and to clean their storage tanks often. The villager’s water needs are the first priority of this project. The main goal of this project is to produce clean water with minimal biological contamination.

Needs: Secondary Stakeholders: It is the goal of all the members of the engineering group working on this project to design this water filtration system. The main driving force behind this goal is the desire to educate ourselves, and use that information toward making the world a better place, even if it just means that several villages have clean water to drink. The members of the design team also have grades depending on this project, however the desire to help others supersedes the desire to get a good grade. 

This project will also directly effect Dr. Moseson and his teaching assistants. Their first priority is for our group to complete all required tasks within the scope of the freshman design lab. The hopeful success of this project will also give testimony to Dr. Moseson's incredible drive and motivation in his humanitarian exploits. 

Needs: Tertiary Stakeholders: While the Tertiary stakeholders needs are important, they will be considered only after all the other's stakeholders needs are fulfilled to the best of our abilities. It is important to note that in fulfilling the needs of our primary and secondary stakeholders, many of the tertiary stakeholders needs will be fulfilled as well. 

Week 3 update

So far we have been diligently working on developing a Project overview. Take a look at it! It's a link on the side bar. We are still brainstorming ways to purify water. We have decided to focus our efforts on the Ban Huay Mii village. We are putting our ducks in line and figuring out exactly what these villagers need. It seems that their main concern is the quality and taste of their water.  Check back next week for another update!

Water filtration method: Slow Sand Filtration

One of the possibilities that the group is considering as a way to improve the biological quality of the water is the slow sand filter. The way that the filter purifies the water is by using the biological layer that forms on the top  10 cm of the fine sand which traps bacteria residing in the water and the rest of the fine sand acts as a medium to help filter the water. This biological layer is formed in the first 10-20 days of operation and after the filter has been used for several weeks it will require cleaning which consists of scraping the biological layer and restarting the process. However cost effective this method is,it can deal only with water of low turbidity levels and therefore may not work for Ban Huay Mii in the rainy season.

Other solutions and combinations of solutions to come in next posts.
References : Integrated Development Assessment,Bo Klua, Thailand,Field Assessment August – September 2009-March 2010,By Alexander J. Moseson,Drexel University,Philadelphia,,Pennsylvania, USA,Bob Shim,Sustainable Development Research Foundation ,(SDRF),Udonthani, Thailand ; Slow Sand Filtration  for community Water Supply
By: J.T.  Visscher,  R. Paramasivan,  A.  Raman,  and  H.A.  Heijnen ; http://www.drinking-water.org/html/en/ImageView/00000294.html

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