Thesis
Assessing copper and zinc adsorption to thermally treated lignocellulosic biomass
Washington State University
Master of Science (MS), Washington State University
2015
Handle:
https://hdl.handle.net/2376/102917
Abstract
Anthropogenic activity in urban areas introduces high concentrations of contaminants, including dissolved metals, to stormwater runoff. Copper and zinc cations present in stormwater runoff should be treated to ensure a healthy environment and ecosystem for both human and aquatic life. Several stormwater best management practices have shown success for metal concentration reduction. Adsorption systems generally require a smaller footprint and are desired when space is restricted. This study evaluated the efficacy of two sorbents, torrefied wood and biochar, for their ability to adsorb metal contaminants. The sorbents’ physical and chemical properties were defined by CO2 adsorption surface area analysis, Fourier transform infrared (FTIR) spectrometry, and background metal concentrations. Sorbent surface area did not change during torrefaction (270 °C). However, pyrolysis (400 °C) yielded a surface area for biochar approximately 100 times greater than that of torrefied wood. FTIR showed the transformation of lignocellulosic material from the cellulosic to the ligneous fraction as sample treatment temperature increased, resulting in the formation of carboxylic acid functional groups in torrefied wood and biochar. Single- and multi-solute isotherm data and continuous flow column data was collected to quantify the sorbents’ potential for metal removal. The Freundlich v equation was shown to yield the best fit of equilibrium data. Both single- and multi-solute isotherm data showed that for both torrefied wood and biochar, Cu yielded higher sorption capacities and outcompeted Zn. Through 10 simulated storm events performed in preliminary continuous flow columns, biochar had average removals of 91% Cu and 76% Zn, and torrefied wood had 67% Cu and 37% Zn average removals. The data indicated that torrefied wood and biochar show potential as metal sorbents for stormwater treatment and should be further evaluated in lab and pilot scale systems.
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Details
- Title
- Assessing copper and zinc adsorption to thermally treated lignocellulosic biomass
- Creators
- Joseph Paul Smith
- Contributors
- David Yonge (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Civil and Environmental Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525074501842
- Language
- English
- Resource Type
- Thesis