Getachew, Bezawit2024-05-222024-05-222024-052024-04-17May 2024Semanate, Eliana Cadena. Evaluating the Swelling/Degradation Behavior of Calcium Alginate Beads in Synthetic Wastewater Under Varied Environmental Conditions. Masters thesis, Rice University. https://hdl.handle.net/1911/116186https://hdl.handle.net/1911/116186Bacteria encapsulation has gained attention as a promising technique to enhance the biodegradation of contaminants in wastewater. While encapsulation offers substantial benefits, including enhanced biological stability, higher biomass concentration, enhanced symbiotic relationships, and partition advantages, 1 it also presents challenges such as mass transfer limitations and matrix instability. This research seeks to gain insight into the behavior of calcium alginate beads under conditions simulating real-world wastewater environments. Dynamic weight change of beads was measured over time considering varying crosslinking degrees of CaCl2 (0.1M, 0.3M, 0.5M), different wastewater strengths (NaCl concentrations of 0 g/L, 15g/L, and 35g/L), and high turbulence (shaking at 200rpm). Results suggest that higher crosslinker concentrations yield smaller beads, but this does not significantly alter the maximum water uptake in synthetic wastewater. Moreover, beads show varying swelling and degradation rates depending on the medium’s ionic composition, especially in the presence of Na+ ions. Water uptake increased, and bead stability decreased with high NaCl concentrations. Similarly, high turbulence conditions increased the water uptake ratio. Overall, all of the beads resisted degradation and didn’t dissolve completely for at least 78 days. The study suggests a crosslinker concentration of 0.3M or higher is promising for optimal stability in wastewater applications. This research provides insights into the chemical and physical factors that affect the stability of calcium alginate beads in synthetic wastewater. However, further research is required to develop more effective matrixes for bacteria encapsulation for wastewater applications.application/pdfengCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.bacteria encapsulationalginate beadswastewaterstabilityThesis2024-05-22