Alternative uses for algae

Pond algae could create biofuel for heating, a Lincoln High School student found out as part of his science project for this year’s Canterbury-Westland Schools’ Science and Technology Fair. Thomas Ferguson, 17, won Environment Canterbury’s senior prize this year, winning $400 for himself, $1000 for his school and an opportunity for work experience with the regional council. Thomas also won a Lincoln University Scholarship for his algal biofuel experiment.

A pond near his school’s art rooms had attracted criticism after it became over-run with duckweed and algal bloom. Thomas decided to work out a way to use the unwanted green growth and algae without too many extra chemicals or energy-sapping processes. Normal herbicides had little effect on it - bleaching it on top, but leaving its underside alive and well. Snails thrived on it, as did the weed with the snails. Harvesting it by raking it off and drying it, using a solvent and glycerol to separate the oil, provided his oily biofuel result. Thomas is chair of the school’s environmental council and recently won a youth leadership award, sponsored by Environment Canterbury and Ngāi Tahu.

The awards took place on August 29, with Environment Canterbury commissioner David Caygill presenting the regional council’s awards to the young entrepreneurs and scientists.

Second place in the senior Environment Canterbury section went to Rachel Robilliard, 17, St Margaret’s College. She used her home farm at Leeston to find out if herbicide use had any effect on stream life/invertebrates living in its Rakaia River water races. Whilst there was no direct link between herbicide use and the number of invertebrates, Rachel is keen to repeat her tests in summer when the weed is growing fastest and also when invertebrates are more reproductive.

Third place went to three Cashmere High year nine students - Delcie Holmes, 14, Caitlin Hooft, 13, and Melissa Reid, 13. They created a community sustainability model, powered by wind, biofuel and solar and mostly using bicycles, foot power and horses instead of tractors and cars.

Junior winner was Dinuki Karunasekera, 11, a year seven pupil at Cobham Intermediate, who wanted to find ways to reduce the threat to groundwater and surface water from nitrogen and phosphorus-rich dairy run-off. She received $1000 for her school and a $400 for herself. She found that duckweed was extremely effective at absorbing nitrogen and phosphorus from enriched water for the first ten days, but the effect reduced soon after that. Oxygen weed was not much use at all. She also found that countries like Bangladesh already use similar systems to manage waste-water in sediment tanks and reuse the clean water.

Second equal in the junior section was Rowan McComish with ‘Enviro Blocks’ and Emma Clucas with 'Polystyrene Recyclene', both from Cobham Intermediate in year eight. Third place went to Alex Pickering and Holly Harris, Heathcote Valley School year eights, with ‘Help keep tui in Canterbury,’ a biodiversity project.