CHICAGO (CBS) — The top 300 science projects from Chicago Public School students in grades 7 through 12 were on display this weekend at the Museum of Science and Industry.

Four will get the esteemed opportunity to be evaluated at the Intel International Science and Engineering Fair in Los Angeles.

As WBBM Newsradio 780’s Michele Fiore reports, the students presented their projects to judges on Friday, International Science and Engineering Fair judging was held on Saturday, and awards were presented on Sunday.

LISTEN: Newsradio 780’s Michele Fiore reports

Angela Dumas is the science fair coordinator and as she stands beside rows and rows of tables filled with the city’s top science projects. She says many had to do with current events, such as the Gulf oil spill.

“You see a light in their eyes that make all of their preparations worthwhile,” Dumas said.

Dumas says this shows that students are paying attention to the world around them.

“We also saw a lot of projects that were about alternative energy – wind turbines, solar panels and biodiesel – so I think the kids are listening to what’s going on in the world,” Dumas said.

Alexander Gaska of Walter Payton High School is an alternate for the international fair. His project sought an alternative method for water purification.

“A common method of disinfection is chlorination, and a lot of developing countries don’t have access to that – they don’t have the money, they don’t have the professionals,” Gaska said. “My project was using a sand and iron filtration as an alternative to chlorine. My hope is really to impact people on a global scale, really, in their water disinfection; to provide a lot of people with clean water.”

The winners of the science fair include Anthony Surganov and Saed Khan from Lane Tech, and Daniela Flax and Leah Balay-Wilson, both from Lincoln Park High School.

Flax is a sophomore at Lincoln Park, and won for a second year in a row. She says her project started with an apparatus she built in her kitchen.

The subject was the study of “solar power plants, such as ones that are existing in places like Seville, Spain, that use parabolic mirrors to heat liquid in a tower and produce electrical power,” she said.

The Non-Public Schools science fair, in which private and parochial school students compete, was held on March 12 and 13 at the MSI.

First-place finishers for both science fairs will compete at the Illinois Junior Academy of Science statewide science fair, which will be held on May 6 and 7 at the University of Illinois in Urbana-Champaign.

The MSI has hosted public and private school science fairs for decades. More than 300 teachers, scientists, engineers and health care professionals come in to judge projects, and many of them have been doing so for more than 30 years.