Civil Engineering

 

Date of this Version

4-2015

Citation

Schaepe, S. (2014). Engineering Graphene Oxide Membranes for Contaminant Removal and Bacterial Inactivation. Master's Thesis, University of Nebraska Lincoln, Department of Civil Engineering, 2015.

Comments

A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Civil Engineering, Under the Supervision of Professors Yusong Li & Xu Li. Lincoln, Nebraska: April, 2015

Copyright (c) 2015 Stefan Schaepe

Abstract

The need for improved water filtration technologies continues to grow on a global scale. Membrane filtration devices are increasing in use because they can remove a variety of contaminants efficiently. The major issue with membrane filters is biofouling. Coating membranes with nanoparticles such as graphene oxide (GO) can increase contaminant removal and decrease microbial growth.

This research characterizes the properties of the GO itself, two procedures for producing GO coated membranes, the properties of the created membranes and the contaminant removal and bactericidal efficiencies of the membranes. Pure water flux values for GO coated membranes prepared using a direct deposition method via vacuum filtration had flux values that ranged from 16 to 133 L m-2 h-1bar-1. The GO coated membranes had 92% and 72% of E. coli remaining 1 hour and 5 hours after the cells were deposited on the membrane surfaces, respectfully. Insignificant removal of salts or organic dyes was measured. The low contaminant removal properties are likely due to the swelling of GO flakes when in a hydrated state that cause the effective pore size to increase. The GO coated membranes prepared using a chemical layer-by-layer deposition method provided high flux values, but no observed contaminant removal or bactericidal properties. As revealed by the Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectrometry (FTIR), the lack of sufficient GO coverage over the supporting membrane was the cause of the poor filtration properties.

Advisors: Yusong Li and Xu Li

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