OHIO UNIVERSITY Russ College of Engineering & Technology

Department of Mechanical Engineering

DESIGN OF A WATER PURIFICATION SYSTEM

A Water Purification Solution Utilizing Ultraviolet Light for

Village of Konalai in Southern India

Ohio University Mechanical Engineering Senior Design 2010

Team Biological Filtration Technology

AUTHORS: Seth Beachy, David Gallagher, Ben Barkley & Jamison Swope ,

ABSTRACT:

Ohio University mechanical engineering senior design team Bio Filtration Technology has designed a water purification system for the village of Konalai in India. Konalai’s 1800 residents suffer from water related illness due to poor drinking water quality. BFT has designed a water purification system to augment the village’s water distribution system. The system utilizes sediment filtration supplemented with ultraviolet light to effectively filter and sterilize contaminated well water as it is pumped to the village reservoir. The goal of the project was to meet the needs of the village and provide a long term water treatment solution. The purpose of this report is to present an overview of the entire project including: the design solution, project cost, construction, and maintenance information, testing and evaluation results and future field testing plans.

SOLUTION:

The goal of our design process was to meet Konalai’s needs as defined through contact and communication with the village and BFT’s internal review processes. The needs are prioritized in the table below in order of decreasing importance.

BFT received information concerning the village from contacts in India including water quality test results. This indicated an excess of fecal coliforms and fluoride present in the well water supply being pumped to the village. The team looked at a wide range of design possibilities including slow sand filtration, open and closed channel ultraviolet light sterilization, reverse osmosis and point of intake filtration and from each generated multiple concepts for evaluation. Each

of the generated concepts were ranked and scored using metrics that related how well each fulfilled the village’s needs. An ultraviolet light system with pre filtration was chosen for development. The design goals of having a pre packaged stand alone system that was compact and shippable shaped the developed of the prototype. The design consists of two high flow reusable polyester filters in series; a 50 micron followed by a 20 micron. The filtered water enters an ultraviolet sterilization chamber with electronic controller. The design was verified through experimental testing and finalized for shipping and installation in Konalai.

The final design is a packaged solution that can be reproduced and installed in needy locations. The system can be connected to existing water lines from a pump as in Konalai, standard water lines or gravity fed water lines such as from a large tank or reservoir. The purification system is transferable to many locations when they have several conditions present. These include most importantly access to reliable electricity, a moderately level and protected area for installation, personnel available for maintenance and an availability to obtain replacement parts.

Safety and backup features are incorporated into the system design. A pressure relief valve prevents over pressuring of the system and the UV controller has a built in audio failure alarm and visual port to check bulb operation. A pressure gauge has been included to monitor pressure increases due to sediment build up in the filters and assist in determining when cleaning or replacement is needed. A service hose is operated at the entrance valve to bypass the filters and UV chamber to supply water directly from the

50 micron reusable filter 20 micron reusable filter

UV chamber controller

UV chamber bulb ballast

Pressure gauge

Service hose

75 psi pressure relief valve

UV chamber

pump for spray cleaning of the filters or as an emergency bypass. In the event of a failure of a component, the system can function as passive water piping until a repair or replacement is available. Flow can be maintained to the reservoir at previous levels and the village will not be in a worse situation than it is currently in the system fails. The service hose would also be able to supply emergency water in the event that the village piping or reservoir fails or cleaning of each would be necessary.

COST:

A chart of the total project manufacturing costs including labor is given below. These estimates are based on US labor rates.

The total cost of manufacturing was $1181. A majority of this cost is incurred in the UV and filtration hardware. The fixed cost associated with just material expenses is $950. Some goals that our design achieved were providing a simple yet effective stand alone purification system of minimal weight and size (to reduce shipping cost) and an easily serviceable system due to the use of commercially available parts and simple construction methods. The images below show in detail the color coding assembly method and simple bolted frame.

Some of the materials and construction methods used in the design could be

reduced if the purification system were to be built locally. Steel instead of aluminum could be used for the frame since shipping costs would not be an issue, and direct piping adaptors could be installed instead of the flexible connections and multiple adaptors that were required for our system since the team never received feedback concerning the exact layout of the Konalai pump house or the pipe diameters and locations. Employing local labor would reduce the total project cost since most locations would have significantly lower labor rates than the United States. Excluding piping, a complete list of material costs, vendors and part numbers is given below

It is important to note that the design can be scaled to meet specific water volume needs of a population. This system was designed to take advantage of the pre existing pump and closed piping in place in Konalai. Selecting a Sterilight® UV chamber model to match desired water flow and assessing the availability of electricity are the most crucial decisions to make when installing a new system for service. CONSTRUCTION AND MAINTENANCE:

On-site installation of the purification system was simplified by the use of a color coding plan and pre assembled components. 1” standard piping and metric connectors have been used throughout. A detailed parts list is given in the picture based owners’ manual that was developed for the final design. The manual includes installation and operation procedures as well as maintenance and troubleshooting methods.

Maintenance of the design is minimal. A weekly inspection and cleaning of the polyester filters and UV chamber is required. Various components of the system have a finite life and require eventual replacement. The filters are designed to be replaced at least yearly, the UV bulb after 9,000 hours of operation (3 years of operation at Konalai) and the o-rings and piping fixtures on an as needed basis. Yearly maintenance and

Flexible connectors

Pre assembled components

operation cost can be estimated from replacement component cost and electric usage but are designed to be under $100 excluding replacement of a housing or chamber. Proper handling, operation and storage of the design is critical to maintaining its service life. The purification system is designed and adaptable to be a pre packaged unit for purchase and quick installation.

TESTING AND EVALUATION:

Several experiments were performed to evaluate the impact and effectiveness of the prototype design. The effect of adding flow restrictive filters was analyzed by performing a pressure and volumetric flow change experiment. An experimental lab was built using a ¾ horsepower centrifugal pump and pressure transducers. It was determined that the pressure drop across both filters was less that 4 psi with a nominal value of 36 psi at a flow rate of 30 GPM. Konalai’s current pumping schedule of 6 hours per day to fill their reservoir will have to be extended as is necessary to account for flow reduction. The sterilization effectiveness of the prototype was analyzed by performing a before and after E. coli (a fecal coliform) standard plate count. A super saturated E. coli solution was added to a control pre-filtration water tank. The E. coli filled water was then pumped through the prototype and collected. This process was performed with two pre-filtration water sources: de-chlorinated tap water and high turbidity river water both saturated E. coli additions. The resulting collection samples were then plated using standard dilutions methods on the selective media Eosin Methylene blue agar (EMB). This quantitative analysis proved the system to be over 99.999% effective at eliminating E. coli from both the tap and river water sources at a flow rate of 30 GPM.

Though the system was validated in addressing the fecal coliform contamination in Konalai’s water, no viable cost effective solution could be designed to control the excess fluoride. Even highly developed areas face the same problem of being able to efficiently eliminating excess fluoride and its presence in drinking water is not an immediate health concern.

FIELD TESTING PLANS:

As of the time of this report, the shipping and subsequent installation of the purification system in Konalai is under way. The contact in India will be receiving the disassembled unit and will install it in the village with the help of an engineering student from Bishop Heber College. The team hopes to receive feedback over the next year as to how the system is improving the health of residents, problems and concerns with the design including failures and maintenance issues and the performance life of the various components. If the system is proven to be an effective solution for Konalai, a yearly budget for planned maintenance will be developed.

Receiving field performance results from multiple installed units will best enable the purification system to be analyzed. Feedback and data received from communities where a purification system has been installed will enable the long term capabilities and performance issues to be evaluated. The impact potential the design has on improving the health of so many people warrants further study and investment.

• Solar Power Feasibility

The scope of the design did not include adapting and testing the system to operate on solar power. However, we have included a study of the feasibility of using solar power to operate the purification system to demonstrate the possibility of enhancing the system in areas without access to electricity. The efficiency of using solar power would be maximized if a purification system were installed in a solar energy rich region of the world such as southern India.

The 12SQ-PA Sterilight® model operates on an AC source ranging from 100-240

Volts at 50-60 Hz. The unit has a 48W draw and operates at 0.6 Amps. The wattage required is fairly low and could be supplied by panels as small as the BP Solar 350 which is commercially available for around $450. Solar panels of this size are designed to produce lower DC voltages so the use of a step up transformer and inverter ($75) would be needed to power the UV controller. An energy storage system is also required to insure continuous powering of the UV system when the pump is in operation regardless of the weather conditions. A single 12V car battery at 90Ah appears to be a sufficient backup source. Additional work would be necessary to design and implement the solar option and determine an accurate cost estimate, but it is technically feasible and the additional cost would likely be less than $1000 CONCLUSIONS:

The final water purification design satisfies the needs of Konalai. The designed purification system provides a low cost long term solution that is maintainable by the local residents. Ultraviolet water purification technology in couple with local planning and cooperation is a strong water quality solution for underdeveloped or rural areas because of its adaptability and low cost per amount of purified water. Our system is adaptable to help populations where a reliable electrical source is present and the local

population is able to install, maintain and service a system as required. Water distribution systems that utilize all manners of closed piping are viable candidates for the installation of a purification system. Given the local availability to purchase and obtain the system components, a purification unit can be easily manufactured and installed by the local population.