News

Fresh water solutions


1 November 2005

More than 40 groups of first-year engineering students competed against each other to build low-cost desalination devices using solar energy to produce fresh drinking water. The students had only two hours to prove their equipment could work.

The winning team members Da Hong Cai, Chao Chen, Xi Chen, Mohd Samhan Kambali, Christopher Peponis and Salehen Ahmed
The winning team members Da Hong Cai, Chao Chen, Xi Chen, Mohd Samhan Kambali, Christopher Peponis and Salehen Ahmed

The winning team members Da Hong Cai, Chao Chen, Xi Chen, Mohd Samhan Kambali, Christopher Peponis and Salehen Ahmed managed to create 415 millilitres of pure drinking water with their entry which cost just $37.22 to build.

The group formed a pond of seawater in a tray lined with blue plastic and used sand saturated with the seawater to absorb the sun's heat energy. Aluminium foil was used to reflect the sun's rays onto the sand. The evaporated water vapour condensed as droplets on the underside of an inclined 4mm thick glass sheet before running into a collecting channel and plastic milk bottle.

The second place team Lauren Connors, Nathan Byrne, William Channing, Bryan Kidd, Sasha Kovic, Gijs Roeffen and Winey Suen
The second place team Lauren Connors, Nathan Byrne, William Channing, Bryan Kidd, Sasha Kovic, Gijs Roeffen and Winey Suen

Second prizewinner, the 'Bryan Kidd 52nd Hydro Experience' used similar evaporation principles with a 6mm thick glass prism sloping diagonally to one corner. Team members Lauren Connors, Nathan Byrne, William Channing, Bryan Kidd, Sasha Kovic, Gijs Roeffen and Winey Suen generated 560ml of pure water but their entry was more expensive, costing $119.20.

The 'Salt Busters' team, Low Ming Yow, Michael Martin, Keith Ng, Parnel Richards and Sindhuja Shankar won third prize with their device which used a tent-like arrangement with two glass sloping surfaces. It cost $53.71 and created 370ml of pure water.

Associate Professor Rob Wheen, former head of the department of civil engineering who has been running the annual student competition for more than 35 years, said he was astounded by the quality of the entries and the effort and thought that had gone into devising their equipment.

'I think it augurs well for the future with these young engineers progressing through the University of Sydney,' A/Prof. Wheen said.

The ingenuity of the solar desalination devices could also augur well for Sydney's future water needs.