Schools from across the county presented displays in the Schools Challenge.
Amanda Wright, 12, was the youngest student on the Alford Queen Elizabeth Grammar School stand but was keen to share the work they have been doing.
"Our school has been working hard to reduce the amount of electricity used and reduce our carbon footprint," she said
"We also have a campaign to reduce the use of plastic. Students have a card that gets stamped and, for every 50 bottles collected, they get a £5 gift voucher."
One of the ways the bottles have been recycled was to celebrate Remembrance Day. Teacher Glenn Richardson said: "The bottom of the bottles were used to make poppies. They looked really good."
Boston Grammar School was promoting Health and Happiness by creating a garden. "A lot of us have been doing exams and so we created a garden to help us relax," said Danny Anisjko.
"As a result we were able to make rhubarb chutney and lemonade and we grew lots of flowers to attract wildlife.
"It will help us in the future to create our own gardens."