"The Chlorinator"
Cleans Rural Water

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A simple and cheap, flow-dependent injector developed by a Penn State University professor and his students has the potential to provide rural villages throughout Morocco with a consistent supply of clean drinking water. The injector, an adaptation of a common venturi-type injector, is being tested by Morocco's environmental quality agency, Office National Eau Potable (ONEP), to disinfect small water systems with chlorine.

"It's a very simple device," says Penn State Professor Richard Schuhmann, the Walter L. Robb director of Engineering Leadership Development. "It has no moving parts and is similar to how you'd apply fertilizer to your lawn with a garden hose."

Schuhmann says small villages in Morocco typically store drinking water in small surface impoundments and distribute it through pipes to household connections. Keeping it safe to drink is often a hit-or-miss proposition, he says.

"These systems typically require an operator to dose manually on a daily basis," he says. The operator, however, often is not trained or does not understand the concept, and doses the system perhaps once a week with a large dose instead of daily with smaller doses.

"So for most of the week people aren't drinking disinfected water," he says. "And for one day, they've got water they shouldn't be drinking [because of over-chlorination]."

Challenges

Schuhmann has traveled and worked in Morocco for years, and brings a variety of engineering challenges to his students in Penn State's engineering leadership minor program. Students work on projects during the school term and travel abroad over breaks to further refine the project and implement it with local engineers and villagers.

Penn State and Moroccan engineering students work on chlorinator in the lab.
Photo credit: Curtis Chan for Pennsylvania State University College of Engineering

In 2010, working with a grant from the U.S. Environmental Protection Agency, Schuhmann tasked one of his students, Lydia Karlheim, with researching and designing a flow-dependent chlorinator injector based on existing venturi design to restrict the flow of water flowing through a pipe. The vacuum created at the point of restriction draws chlorine—or sodium hypochlorate—from a container below the main pipe and mixes it with the water.

Karlheim and Schuhmann altered the design by substituting an "oriface plate," really nothing more than a common washer, for the venturi.

"It is a big difference on a number of fronts," says Schuhmann. "For one thing, we haven't figured out how to design a venturi that people in the developing world could make easily. And it is a lot cheaper."

The washer costs about 50 cents, compared with between $25 and $50 for a venturi, he says.

Travel

The work was picked up by other students in the 2010-11 school year and in spring 2012 they scaled down the device and traveled to Morocco. There, they worked with engineering students from Ecole Mohammadia d'Ingenueurs (EMI) to reconfigure the device using local materials in a technology transfer lesson. The session culminated in a presentation to ONEP scientists, who were delighted with device and began their own tests in the laboratory and the field.

ONEP senior scientist Mustapha Hajji says the chlorinator was installed in the tiny village of Assoul, about a four to five-hour drive north from the capital city of Rabat with a population of about 300. Its water supply system consists of a well and a small pump that discharges water through a pipe to a stand post where people draw water. So far, he says, it is working as designed. ONEP is expected to publish the test results soon, he says.

"The system of course needs to be improved to be more robust and adapted to support different pressures, water quality and pumping systems," he says. Based on test results, he believes the chlorinator will be adapted to rural Morocco, where about 48% of the country's people live.

"One thing for sure is that this small and simple device will save the lives of thousands of kids, men, and women and improve their sanitary life," he says. "Priceless."

Design

The chlorinator is an example of simplicity, consisting of common PVC pipe, two valves, a threaded O-ring PVC coupler that contains the orifice plate and plastic tube to draw the chlorine from a container. Schuhmann and Hajji believe it can help provide a reliable supply of disinfected drinking water to small villages throughout the country.

Penn State engineering leadership minor emphasizes collaboration with students from other cultures on projects to improve living conditions in impoverished areas.
Photo credit: Curtis Chan for Pennsylvania State University College of Engineering

Small, rural villages have water needs up to about 50,000 gallons per day, depending on the population. "There are a lot of people in Morocco hooked up to these small distribution systems," he says. "For a village of 1,000 people it is common to draw water from a well and put it into a [surface] storage tank. From there, it flows by gravity to connections in homes."

Schuhmann says rural systems in developing countries around the world are growing. The problem is that system operators often don't know accurate demand, and may not change the dose of chlorine as needed. Schuhmann cites World Health Organization statistics showing that in Morocco, rural house connections for potable water grew from 7.9% in 1987 to 25% in 2007.

For operations, the device is positioned between the well or water source and the ground storage tank. The chlorinator automatically injects the proper amount of chlorine into the water as it flows through the washer, adjusting for variable flow rates. Chlorine is not introduced at the point where water flows from the tank into the distribution system because it requires some contact time in the tank for disinfection to occur.

"Basically what we've done is take an idea from a different venue and apply it creatively," says Schuhmann. "What I'd love to see is joint Moroccan and American engineering teams going into villages and collecting data. In my mind, this now belongs to the Moroccan people and I'm hoping they'll advance and make it even better."

One thing for sure is that this small and simple device will save the lives of thousands of kids, men, and women and improve their sanitary life. Mustapha Hajji, ONEP senior scientist

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