Towards decomposition of phosphonates in water using catalytic membranes: paraquat on silica as a proxy

Phosphonate compounds are acutely toxic and have strong interactions with surfaces, which makes the detection and cleanup of such compounds necessary, but difficult, in a water treatment plant. If materials capable of catalyzing phosphonate decomposition are identified, the combined application of catalytic materials and membranes can lead to the effective treatment of wastewater with phosphonates and ensure subsequent removal of degradation by-products. The focus of this MSc thesis is to conduct a feasibility study of using silica supported catalysts as membrane materials to treat wastewater containing phosphonates. Because adsorption confounds the ability to study phosphonate decontamination chemistry, an equally important but easier to study compound, paraquat dichloride, has been selected for initial investigation. Both adsorption and decomposition kinetics have been explored utilizing different analytical techniques such as liquid chromatography mass spectrometry and UV-Vis spectrometry. The results demonstrate strong adsorption by the contaminant onto silica surfaces. Competitive binding model predictions are found to be consistent with experimental adsorption data. Addition of an exogenous agent (e.g. H2O2) was also attempted to assist paraquat decomposition; however, investigation of paraquat-H2O2 interaction both in presence and absence of the catalysts indicate that peroxide functionality was not effective for chemical decomposition of paraquat.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2012

Author dc:creator

• Barna, Shama

Contributors dc:contributor

• Shannon, Mark A.
• Scheeline, Alexander

• Adsorption
• Paraquat Removal
• Silica Adsorbents
• Peroxide Functionality

Statement dc:rights

• Copyright 2011 Shama Barna

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/29578

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/29578