Vici Riyani and Adrienne Trinovia Sulistyo, second-year and third-year students at Santa Laurensia senior high school in Tangerang, have found a waste treatment solution for styrofoam.
Through a series of simple research and experiments they conducted at the school's science lab, the two students proved that orange peel extract could be used to dissolve styrofoam.
The young scientists' discovery even brought recognition to the country when they won a silver medal at the 2nd International Environmental Project Olympiad (INEPO Euroasia) held from April 1-6 in Baku, Azerbaijan, beating out 35 other entries.
The students' entry was titledWaste Treatment Using a Chemical Sulfonation*Process and Traditional Treatment with Crude Extract From Sunkist Orange Peel".
"Our experiment started from a concern, because we realize that styrofoam cannot be recycled and if such non-organic waste is ignored, it will contribute to environmental damage," Riyani told The Jakarta Post during an interview at her school Thursday.
She added that the use of styrofoam containers for packaging fruits, vegetables and prepared foods sold at supermarkets had become more and more commonplace.
Riyani said orange peel extract contains d-limonene, which can be converted into a polymer flocculant and used to break down styrofoam into water. The environmentally friendly process requires no complicated equipment or chemicals.
"This method is very simple and it can be done by everyone," she said.
As part of their research, Riyani and Adrienne observed that restaurants in Jakarta and Yogyakarta could each produce at least 120 cubic meters of styrofoam food containers.
"The problem is that after use, the styrofoam is thrown away at a dumpsite. The mounds of styrofoam waste has become a serious problem because it cannot be recycled; nor can it be decomposed by microorganisms in the soil or air," she said.
Adrienne noted that the old treatment method for styrofoam waste was to burn it in an incinerator, but this produced the greenhouse gas carbon dioxide. This also produced carbon monoxide, which is harmful to the human respiratory system.
"So far, there have been no safe and effective way to overcome the piles of styrofoam waste," she added.
Under the guidance of their science teachers at Laurensia, Riyani and Adrienne referred to books, the Internet and experiments to come up with their own trials.
Their initial experiment showed that orange peels could break down styrofoam because it contains d-limonene, which is found in the peel of all citruses and is frequently used in cleaning fluids.
"D-limonene has proven to be effective in dissolving grease, but using it to dissolve polystyrene-based waste has never been introduced," said Adrienne.
During their trial experiement, Riyani and Adrienne liquefied orange peels in a blender and then distilled the liquid to collect an extract. They then soaked styrofoam cut into small pieces in the orange peel extract, and stirred the mixture until the styrofoam melted away.
The resulting liquid of orange peel extract and dissolved styrofoam is safe to dispose, because it can be decomposed by microorganisms in the air and soil.
"It's easy to obtain orange peels, which is also garbage. So we treat waste with waste," said Adrienne. The two students also invented another way to destroy styrofoam through a chemical process called sulfonation.
Cut-up styrofoam is mixed with chloroform and sulfuric acid and left for two hours at 45 degrees Celsius, which turns the mixture into a liquid form of sodium polystyrene sulfonate (PSSNa). After a separation and neutralization process using sodium hydroxide (NaOH), the liquid is dried to produce polymer powder.
While this treatment method is more complicated, it produces additional benefits.
"The polymer powder can be used as a super-plastifier in the cement industry and as a polymer in water purification," Adrienne said.
With such inexpensive and efficient solutions, the country, its businesses and its people now have no reason to keep contributing to environmental destruction by throwing out styrofoam waste.