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Treatment of Per- and Polyfluoroalkyl Substances (Pfas) in Semiconductor Wastewaters.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Treatment of Per- and Polyfluoroalkyl Substances (Pfas) in Semiconductor Wastewaters./
Author:	Nienhauser, Alec Brockway.
Description:	1 online resource (101 pages)
Notes:	Source: Masters Abstracts International, Volume: 83-06.
Contained By:	Masters Abstracts International83-06.
Subject:	Environmental engineering. -
Online resource:	click for full text (PQDT)
ISBN:	9798759982036

Treatment of Per- and Polyfluoroalkyl Substances (Pfas) in Semiconductor Wastewaters.
Nienhauser, Alec Brockway.

Treatment of Per- and Polyfluoroalkyl Substances (Pfas) in Semiconductor Wastewaters. - 1 online resource (101 pages)

Source: Masters Abstracts International, Volume: 83-06.

Thesis (M.S.Tech.)--Arizona State University, 2021.

Includes bibliographical references

Per- and polyfluoroalkyl substances (PFAS) are anthropogenic chemicals used for a wide variety of products and industrial processes, including being an essential class of chemicals in the fabrication of semiconductors. Proven concerns related to bioaccumulation and toxicity across multiple species have resulted in health advisory and regulatory initiatives for PFAS in drinking and wastewaters. Among impacted users of PFAS, the semiconductor industry is in urgent need of technologies to remove PFAS from water. Specifically, they prefer technologies capable of mineralizing PFAS into inorganic fluoride (F-). The goal of this thesis is to compare the effectiveness of photo- versus electrocatalytic treatment in benchtop reactor systems PFAS in industrial wastewater before selecting one technology to investigate comprehensively. First, a model wastewater was developed based upon semiconductor samples to represent water matrices near where PFAS are used and the aggregate Fab effluent, which were then used in batch catalytic experiments. Second, batch experiments with homogenous photocatalysis (UV/SO32-) were found to be more energy-intensive than heterogeneous catalysis using boron-doped diamond (BDD) electrodes, and the latter approach was then studied in-depth. During electrocatalysis, longer chain PFAS (C8; PFOA & PFOS) were observed to degrade faster than C6 and C4 PFAS. This study is the first to report near-complete defluorination of not only C8- and C6- PFAS, but also C4-PFAS, in model wastewaters using BDD electrocatalysis, and the first to report such degradation in real Fab wastewater effluents. Based upon differences in PFAS degradation rates observed in single-solute systems containing only C4 PFAS versus multi-solute systems including C4, C6, and C8 PFAS, it was concluded that the surfactant properties of the longer-chain PFAS created surface films on the BDD electrode surface which synergistically enhanced removal of shorter-chain PFAS. The results from batch experiments that serve as the basis of this thesis will be used to assess the chemical byproducts and their associated bioaccumulation and toxicity. This thesis was aimed at developing an efficient method for the degradation of perfluoroalkyl substances from industrial process waters at realistic concentrations.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2024

Mode of access: World Wide Web

ISBN: 9798759982036Subjects--Topical Terms:

557376
Environmental engineering.
Subjects--Index Terms:

ElectrochemistryIndex Terms--Genre/Form:

554714
Electronic books.

Treatment of Per- and Polyfluoroalkyl Substances (Pfas) in Semiconductor Wastewaters.
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