Research Projects

Endocrine-disrupting phthalates (PAEs) are emerging contaminants of growing concern due to their persistence, bioaccumulative nature, and toxicity even at low concentrations. These compounds interfere with hormonal signaling by mimicking or blocking natural hormones, resulting in reproductive disorders, developmental abnormalities, metabolic dysfunctions, and an increased risk of cancer. Conventional wastewater treatment methods are largely ineffective in completely degrading PAEs, necessitating the development of advanced and sustainable remediation strategies. Scientific Rationale and Hypothesis: Advanced Oxidation Processes (AOPs), particularly SO4•- based systems, have demonstrated potential in degrading persistent pollutants. Hydrodynamic cavitation (HC), which generates localized hotspots of high temperature and pressure, offers a cost-effective and scalable AOP platform. Coupling HC with persulfate activation could yield a hybrid system with enhanced degradation efficiency due to synergistic interactions between physical and chemical oxidation processes. This study hypothesized that the combination of HC and persulfate oxidation will generate an enhanced oxidative environment, facilitating rapid degradation of PAEs. Objectives: 1. Investigate the degradation efficiency of phthalate esters (e.g., Dimethyl phthalate, Diethyl phthalate, Dibutyl phthalate) using a hydrodynamic cavitation + persulfate system. 2. Optimize key process parameters, such as persulfate dosage, inlet pressure, and orifice/venturi geometry, using a hybrid ANN-GA approach. 3. Elucidate the mechanistic pathways of phthalate degradation by mapping the spatial and temporal distribution of reactive radicals through radical scavenging experiments and identifying degradation intermediates using LC-MS/MS. 4. Assess the safety of the process by evaluating the toxicity of by-products through in silico predictive tools (e.g., ECOSAR), supported by DFT-based reactivity analysis. Methodology: The work will involve designing a hydrodynamic cavitation reactor integrated with persulfate addition. Batch experiments will be conducted to assess degradation efficiency across varying operational parameters. Scavenger studies will identify dominant radicals. LC-MS/MS will confirm degradation intermediates. Computational toxicology and DFT simulations will assess safety and reactivity of intermediates. Significance: This project aims to develop an energy-efficient, scalable AOP for degrading endocrine-disrupting phthalates. It will provide mechanistic insights into radical generation and degradation pathways in HC-persulfate systems. The ANN-GA model will enable robust process optimization that can be extended to other emerging pollutants. The identification of intermediates and their toxicity profiles will ensure environmental safety. The outcomes will advance fundamental knowledge of cavitation-based AOPs, supporting SDG 6 (Clean Water and Sanitation).