Date of Graduation

12-2011

Document Type

Thesis

Degree Name

Bachelor of Science in Chemical Engineering

Degree Level

Undergraduate

Department

Chemical Engineering

Advisor/Mentor

Penney, William R.

Abstract

The University of Arkansas competed in the 2011 Waste-Management Education and Research Consortium (WERC) competition. The U of A team participated in Task 7, which was titled “Clean Energy Water Disinfection for Small, Remote Rural Communities”. The task looks for a solution to a continuing problem throughout the world: disinfecting water. The task’s problem statement was to develop and a standalone disinfection system that could be used for a small community. It will need at least 3000 gallons of water per day. The solution must address only bacterial disinfection and must be powered by a non-fossil based energy source. Other considerations must be taken into account as well. It must meet WHO drinking water standards for bacterial contamination. The system must be easily implemented, maintained, and operated. The system needs to be portable, cost effective, and be applicable to rural & third-world settings. The U of A team proposed two systems. One system used bleach as its disinfection method, while the other used an Ultraviolet (UV) system. The proposed systems utilized a pre-filtration system, a human powered pump, as well as their respective disinfection system. The pre-filtration system consisted of a sand filter and a one micron bag that was filled with nine ounces of activated carbon. The sand filter worked very similarly to how a clarifier does in a municipality. The sand filter helps remove cloudiness in the water, as well as some of the color. The one-micron bag helps remove some of the turbidity, as well as many of the large bacterial forms. The activated carbon was used to help remove organics from the water, as well as to improve the taste and color of the water. I worked mainly on the human powered pump. It is operated by two people in a manner that resembles climbing stairs. When someone steps on the walking beam, it will simultaneously charge a piston and discharge a piston on the other end of the beam. Two people of average weight can pump water sustainably at 15 gallons per minute. I designed the instructions and diagrams to build the pump that are listed on the Chemical Engineering department’s website and attached in Appendix I, along with a copy of the final report given at the WERC competition. I also led the construction team that built the pump, as well as a few other pieces of equipment. The water later goes into its respective disinfection system. It can go into through the UV chamber, which is powered by batteries that have been charged by solar panels. The UV provides UVC light at the proper wavelengths that will irradiate the bacteria. The water can also go into a tank to be blended with bleach, which will disinfect the water. There are two 1500 gallons storage tanks that are made from a polyethylene lining and plywood boards. The storage system is used by both systems. The 2011 WERC competition involved many categories to be judged on. The first part to be judged was the written report. This 26 page report covered an introduction to the problem, other technologies considered, experimentation, as well as the process overview. Another judging criteria was the oral presentation, both formal and poster presentation. A final judging criterion was the process design itself and how it addressed the problem, as well as what economic, environmental, health, and safety impacts it had. The U of A team received an award for second place in Task 7 from New Mexico State. The U of A team also received an award from Intel for Innovation. This award is given to a team that has proposed a design that could easily be implemented very soon.

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