A University College Dublin competition challenges teams of innovative mechanical engineers to think like environmentalists, writes Dick Ahlstrom.
Even the most ecologically minded person squanders one of our most precious natural resources: clean drinking water. A third of the 270 litres of water used daily in the typical domestic household gets flushed down the toilet.
Finding an answer to this appalling waste was the challenge put to teams of first-year engineering students at University College Dublin, says Tom Curran, who lectures in environmental engineering in the department of biosystems engineering at UCD. It was part of an innovative competition to get first-years up and running on engineering design, teamwork, project management and biologically based engineering.
The competition, late last year marked the initial intake of students to UCD's new biosystems engineering course, says Curran.
It was a challenge in the truest sense of the word given the students had only eight weeks to build teams, design a system and then producing a working bench-top prototype. There were spoils for the victors, however, with cash awards for the winners sponsored by waste management company greenstar.
"We were trying to mimic a real-life situation after graduation for an environmental engineer," says Curran.
The goal was to design and build a biologically based treatment system that could recycle domestic "grey" water from sinks, showers and washing machines for reuse as supply water for toilets. The assumption was the system would be installed in apartment-sized domestic buildings, and biological methods were essential.
"They had a very short time span to get everything together. We were pleased with the way it worked out," Curran adds. "It was a remarkable achievement given they were first-years and didn't know one another coming into the course."
Independent judges included Sara Smyth, a chartered engineer from greenstar; Shane Colgan, research programme administrator from the Environmental Protection Agency; and Gerry Murphy, weather forecaster and presenter from Met Éireann. Marks were given for teamwork, design, inventiveness, achieving low costs, safety, performance and the project report. Each team had a staff "mentor" to help them but not assist in the design. The teams had a €150 budget to build their treatment systems, which were meant to process five litres of "synthetic" grey water in five days. Curran used a time-honoured recipe that included water, detergent, vegetable oil and food waste, which was as grey as it comes.
The students applied a wide range of techniques to clean up the water including reed beds, sand filtration, grease traps, air pumps, evaporation systems and textile membranes. Most came through using no more than half their budget limit and the best designs reduced the pollutant load by up to 98 per cent, more than clean enough for use in toilet flushing systems, says Curran.
The winning project used sand and pebble filtration followed by secondary filtration behind a trickle valve to control water flow into a "reed bed" - a plastic box, possibly a former ice-cream container, holding layers of sand, pebbles and a geotextile membrane to delay water flow long enough for growing plants to absorb nitrates and phosphates.
The project matched the remit of UCD's biosystems engineering course, which is meant to integrate engineering and biology for sustainable development, and to service biologically based industry, says Curran. It was also a lot of fun, so much so that the competition will be repeated next year.
The sponsor, Greenstar, has agreed to fund the event through 2006, now all Curran has to do is come up with a fresh challenge.
Prize winners in the competition were: First prize of €1,000, Team Bigger is Better, Paraic Whelan (leader), Paul McKenna and Neill O'Connor; two second prizes of €500 per team to Team Viscous, Marcus Foley (leader), Robyn Kelly and Damien Farrelly; and Team Wee Cats, Liam Brennan (leader), James O'Neill and Sean Fitzpatrick; third prize of €300 went to Team Water Boys, Nicola Green (leader), David Wall, Ian Murphy and Richard Bruton.