Research Objectives
Research Objective 1:
September 2024 - September 2026
Link: Hinkley Center September 2024
Per- and polyfluoroalkyl substances (PFASs) in the landfill leachate are presently of great health concern. Because of the effectiveness and easy operation, adsorption is the commonly adopted method in removing these contaminants from the landfill leachate. We will design a treatment flow to concentrate and remove PFASs through enhanced foam fractionation and a PFAS-tailored biochar barrier. Foam fractionation will be adopted as the first step to beneficially concentrate the PFASs in the landfill leachate before PFAS biochar adsorption. Most importantly, as a screening process, foam fractionation helps eliminate the competition of dissolved organic matter for the sorption on the sorbent surface by reducing the high dosage requirements for the biochar sorbents. PFAS-tailored biochar will be achieved using biosolid as feedstock and constructed with designated pore structures to capture various PFAS molecules, which can guide the enhanced PFAS affinity through surface functional groups and/or surface charges. PFAS-saturated biochar will be addressed by thermal destruction.
Research Objective 2:
May 2024 - September 2026
Phosphorus, primarily as soil phosphate minerals, is vital for living organisms' biochemical energy processes. It is mined using sulfuric acid to produce phosphoric acid, crucial for fertilizer production and widespread agricultural applications. The U.S. phosphorus industry, notably in Florida, is geologically positioned for accessible, concentrated deposits. Phosphate has significant economic importance in Florida, yet its environmental impact has not been comprehensively estimated and addressed. In this study, we propose to conduct comprehensive research on the efficient thermal management of phosphate sludge. Our objective is to enhance the recovery efficiency of elemental phosphorus (P) and rare earth elements (REEs) and address the environmental impacts of byproduct associated with this process. We aim to bolster the overall resource recovery process through the following perspectives: 1) Enhancing elemental P recovery by improving carbon reduction and thermal condition settings. In addition, we will investigate economic benefits and environmental impact via a comprehensive economic benefit analysis alongside a life cycle assessment.
Research Objective 3:
August 2023 - December 2024
Yard waste, consisting of vegetative material from residential properties and landscaping maintenance, is routinely collected by the Landfill. Traditionally, this waste has been processed through mulching and later used as alternative landfill cover. However, the large volume of yard waste demands considerable operational space, prompting the Polk County Landfill to seek more efficient, value-added uses for this material. In response, this project aims to convert yard waste into biochar, investigating its potential as a high-value product for applications such as landfill leachate treatment and soil erosion control. This approach offers a more sustainable solution that enhances the environmental and operational benefits of yard waste management. Utilizing yard waste as a feedstock for biochar production not only diverts organic waste from landfills but also transforms it into a valuable product. This approach aligns with sustainable waste management practices and the principles of the circular economy, where waste materials are repurposed into useful resources.
Research Objective 4:
December 2024 -
This project will evaluate the environmental challenges associated with biosolid management practices and its ultimate effect on sulfur cycling. Sulfur (S) is an important macro-nutrient involved in plant growth. Understanding sulfur availability and its transport with biosolid application is important for soil and plant management. Biosolid naturally containing various speciation and quantity of S due to the accumulation of organic sulfur during wastewater treatment and solid waste collection. The overarching goal is to provide a comprehensive assessment of the fate and transport of elemental S. Tasks will focus on how different sources, post treatment and management affect the sulfur dynamics and its’ resulting environmental impacts. The objectives of the proposed projects include: 1) Estimate the quantity and speciation of sulfur in biosolid with the effect of source and pre-treatment processes; 2) Assess the impact of emerging biosolid management technologies such as hydrothermal treatment and anaerobic digestion in affecting sulfur dynamics. 3) Investigate ultimate fate of sulfur in biosolid-derived byproduct in soil and air environments.