Novel Optimization of Photocatalytic Degradation of Wastewater Pollutants Using Piezoelectric and Paraelectric Materials

Wastewater pollution has a detrimental impact on the environment, including harming aquatic ecosystems, causing eutrophication, and posing risks to human health. Existing catalysts commonly used for pollutant degradation in wastewater can demonstrate a low percent degradation of pollutants within certain time periods, have long reaction times, only work under limited conditions, work on a large or small scale, or possess a combination of these limitations. In recent advances, some piezoelectric materials and certain paraelectric materials have been shown to have catalytic activity in degrading pollutants. Lead zirconate (piezoelectric) and strontium titanate (paraelectric) are examples of materials that possess these properties. The purpose of this study was to utilize multiple piezoelectric materials and other catalysts with favorable properties, such as lead zirconate and strontium titanate, to develop a novel catalyst to degrade pollutants in wastewater. In the experiment, catalysts were created by mixing various ratios of lead zirconate, strontium titanate, and titanium dioxide powders–the latter being the currently most used photocatalyst for wastewater purification. These catalysts were added to four different wastewater samples obtained from different sources: three were industrial wastewater samples containing inorganic and organic pollutants with one sample being mixed with dye pollutants in addition. The other wastewater sample was a lab-created solution of methylene blue and water. Each sample of wastewater and catalyst mixed together was subjected to controlled conditions and specified durations of visible and UV light exposure. Spectroscopy was used to analyze the effectiveness of the different catalysts. The absorption of each mixture of wastewater and catalyst was recorded at both the beginning and end of the reaction period and compared, and the percent difference in absorption at peak length between the beginning and end of the reaction period was used to calculate the photodegradation efficiency. The catalyst that was created using a 1:1 ratio of strontium titanate to lead zirconate sample had a 19.57% greater percent degradation efficiency compared to the traditionally used catalyst (titanium dioxide) when both were used on the third industrial wastewater sample under the study’s experimental conditions. A higher percent degradation efficiency signifies a greater a reduction in the initial pollutants. This decrease could potentially signify the breakdown of pollutants into smaller particles, which may be less harmful. The findings in this study underscore the potential of the catalyst, strontium titanate and lead zirconate in a 1:1 ratio, for the use of wastewater treatment and hence to protect the environment from wastewater pollution, possibly with a higher percent degradation efficiency than the currently used catalyst for this application.