Degradation and mineralization of bisphenol A using ozone and hydrogen peroxide

• Main Author: Mok, Pei Han
• Other Authors: Tuti Mariana Lim
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Civil engineering
• Online Access: http://hdl.handle.net/10356/77624
• Institution: Nanyang Technological University

Bisphenol A (BPA) has a chemical formula of (CH3)2C(C6H4OH)2. It is an organic compound with two hydroxyphenyl groups. BPA is utilized as a raw material to produce epoxy resins and polycarbonate plastic which can be commonly seen in man-made daily life products such as plastic bottles, metal food storage containers and personal care products. Over the years, humans and wildlife encounter BPA compounds that can cause harmful disruptions in the body’s endocrine system. Traces of BPA is frequently detected in natural water bodies due to the effluent from manufacturing and wastewater treatment plants. This raises the need to develop a cost-effective method to remove BPA compounds from water sources and reduce the endangerment to living things. Several efforts have been explored to remove BPA compounds and one of the more efficient methods is advanced oxidation process. In this project, ozone will be used together with hydrogen peroxide (H2O2) to degrade and mineralize BPA. Analysis will be conducted to investigate the degradation using High Performance Liquid Chromatography (HPLC) while mineralization kinetics to be studied using Total Organic Carbon (TOC) Analyzer. The experiments were conducted by varying initial BPA concentrations, ozone feed rates, pH levels and concentration of H2O2 to investigate the effect of these parameters on the degradation and mineralization of BPA. It is found out that through ozone process, up to 10 mg/L of BPA could be 100% degraded while its mineralization could only reach ~36%. A lower BPA concentration of 5.0 mg/L was fixed to investigate the effects of other parameters. When ozone feed rate increases, more ozone molecules are available for reaction and hence increases the efficiency of the system. When pH level increases, the rate of reaction is significantly improved due to more hydroxyl radicals available in the solution to react with the BPA molecules. However, more intermediate products are formed, leading to lower mineralization at high pH levels. Higher ozone feed rate result in higher mineralization, likewise when initial concentration of BPA increases. Concentration of H2O2 does little to the degradation and mineralization of BPA compounds when added into an ozonation process. Therefore, the most optimal condition for the degradation and mineralization of BPA in this study was observed to occur at initial BPA concentration of 5.0 mg/L, ozone flow rate of 400 mg/h and pH value of 3.