OGDEN — Aliyah Grijalva doesn’t care much for science and math, she says, but that hasn’t stopped her from winning awards at the Diocesan Science Fair for the past two years. Last year, during her first competition, she placed first in the Behavioral/Social Science category for sixth grade and advanced to the regional competition. This year, at the Feb. 8 fair, she was named the Young Scientist of the Year, taking home first place in her grade in the Earth and Environmental Science category as well as the Overall Seventh Grade Award and the Overall Earth and Environmental Science Award. With the win, she qualified for the regional University of Utah Science & Engineering Fair, scheduled for March 10-12.
“I’ve never been, like, the biggest fan of like math and science … but I really do love science fair,” she said.
Sibling rivalry might contribute to her enjoyment. Her brother, who is two years older than she, “is really good at math” and goes to the regional science fair every year, she said, “so it’s always been like, ‘try to do as good as him.’”
Her winning experiment last year was in Behavioral Science, but this year she changed to Earth and Environmental Science.
“I believe I’m more skilled in social sciences so this year I was really interested in challenging myself,” she said. “I mostly wanted to do something that was more scientific. … It’s a lot harder to do the math and actual science stuff.”
Grijalva got the idea for her winning experiment, “Heavy Metal Concentrations in the Water from China,” just before a family trip last summer. During the two-week trip to China, while visiting Shanghai, Bejing and Zhangjiajie (“where Avatar was filmed”), she collected water samples in sample-sized shampoo bottles from hotels that she cleaned out.
The idea sprang from the articles she read warning travelers to China to drink only filtered or bottled water, and to avoid tap water.
“I was really interested in this, so I pretty much wanted to see if it was true or false if the water was really bad or not,” she said.
Returning with 24 mini-shampoo bottles filled with water samples – “because we weren’t able to have test tubes” – didn’t raise any eyebrows at Customs, but did allow her to craft a winning experiment with the help of a Weber State University professor.
To test for inorganic elements and heavy metals in the water, Grijalva first prepared her samples for testing by passing them through a .22 micromillimeter filter to get rid of particulates in the water but “didn’t get rid of any of the heavy metals or inorganic elements,” she said.
Then, with the help of Dr. Marek Matyjasik of Weber State University, she tested her samples using an inductively coupled plasma atomic emission spectrometer. As Grijalva explains her experiment, the ICP pumped the water into a nebulizer, which turned the water into a mist. The water molecules of the mist were atomized by a plasma torch, and created a light spectrum.
“That light spectrum characterizes what type of metal element it is,” she said.
A prism then separated individual light waves from the spectrum, and each light wave was passed through a detector that measured the intensity of the water. “The intensity measures how much of that certain metal or element is in the water, and the light wave tells what kind of element or metal it is,” she said.
One difficulty she had was with the calibration, because every element had a different standard. Because of issues with the machinery, she wasn’t able to test for mercury and aluminum, she said. Another complication she had to adjust for was whether the material from which the shampoo bottles were made might have skewed the results; she compensated for this by setting a base line, she said.
The ICP tests resulted in a mass of data that she plotted on at least 40 graphs; she had scatter plots for every water sample, graphs for every element and graphs comparing the results of the tap and filtered water. With her mother’s help, she began preparing the graphs before Christmas. At school she wrote the essay and the abstract for the display.
The week before the science fair, she practiced her oral presentation at least once and sometimes twice a night, “and a lot on the weekends,” she said.
For her experiment she had three hypotheses. First, that she would find all the metals that she tested for in the water; her second hypothesis was that the water would test above both the U.S. and Chinese standards for those metals and elements. Her third hypothesis was that the filtered water would test better than the tap water.
Her first hypothesis proved true, she said. “Even if it was tiny amounts, everything I tested for was in the water.”
She got mixed results for her second hypothesis. Some elements, such as arsenic, were above the standards in all her samples, while cadmium was below the standards. Other elements such as lead were above the standards in some samples and below in others.
“In conclusion, it was extremely harmful,” she said, adding that the one bottled water she tested had the highest level of arsenic.
She is contemplating an experiment for next year, this time, perhaps in the chemistry category, she said.
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