The researchers used a method called wet air oxidation to break down a harmful chemical called bisphenol A in wastewater from a polycarbonate plant. They found that by heating the wastewater to 150°C, adding air pressure, and letting it react for 2 hours, they could completely remove the bisphenol A. This process also improved the wastewater's ability to be broken down by bacteria. Overall, wet air oxidation was shown to be a cost-effective and environmentally friendly way to treat this type of industrial wastewater.