Date of Award
5-17-2025
Document Type
Dissertation
Abstract
This dissertation explores biofilm dynamics in water distribution and acid mine drainage (AMD) treatment, focusing on their roles in resource recovery and public health. Biofilms consist of microbial communities in a self-produced extracellular polymeric substance (EPS) matrix, which influences their mechanical and structural properties based on EPS composition, environmental conditions, and biofilm age. In drinking water distribution systems (DWDS), biofilms pose health hazards as they harbor pathogens and encourage metal corrosion. The composition of extracellular polymeric substances (EPS), particularly its high protein content, is noted in downstream areas, facilitating biofilm development in conditions of reduced chlorine and higher temperature turbidity. Traditional antimicrobial strategies often fail due to the protective EPS matrix, highlighting the need for targeted biofilm control strategies. On the other hand, biofilms show promise in AMD treatment, where biofilm-based bioreactors utilizing sulfate-reducing bacteria (SRB) effectively neutralize acidity and recover valuable metals, including rare earth elements. SRB bioreactors demonstrated sulfate reduction rates of up to 92.8% and near-complete removal of essential metals, showcasing the ability of biofilms to facilitate precipitation and biosorption under extreme conditions. The mechanical properties (as Young’s modulus) of biofilms were observed to vary with environmental conditions and biofilm age, influencing their resilience to mechanical stress. In DWDS, these properties impact biofilm control and removal efforts, while in AMD treatment, increased biofilm stiffness supports structural stability for effective metal removal. Advanced techniques like confocal laser scanning microscopy (CLSM) and atomic force microscopy (AFM) assessed biofilm characteristics, emphasizing the need for site-specific management strategies. Findings indicate that successful biofilm management necessitates an understanding of mechanics, EPS composition, and environmental factors. Future research should enhance biofilm control technologies and explore enzyme-based disruptors, balancing sustainability and public health concerns while optimizing resource recovery.
Recommended Citation
Hasan, Md Ibnul, "Mechanical properties of biofilms in water distribution and bioremediation systems" (2025). Engineering . 529.
https://ualaska.researchcommons.org/uaf_grad_engineering/529
Handle
http://hdl.handle.net/11122/15969