Abstract

Ultraviolet advanced oxidation processes were compared using sodium perborate (UV/NaBO3 AOP) or hydrogen peroxide (UV/H2O2 AOP) for 1,4-dioxane removal from tertiary wastewater effluent. Both UV/H2O2 and UV/NaBO3 AOPs were also tested with the addition of acetic acid. Results revealed that sodium perborate performed similarly to hydrogen peroxide – the UV/NaBO3 AOP with 6 milligrams per liter (mg/L) as H2O2 resulted in 43.9 percent 1,4-dioxane removal, while an equivalent UV/H2O2 AOP showed 42.8 percent removal. Although the oxidants performed similarly, NaBO3 is an average of 3.3 times more expensive than H2O2. However, the solid form of NaBO3 can provide a major benefit to remote and mobile operations. Unlike H2O2 solution, which degrades over time and requires repeated costly shipments, NaBO3 is a convenient source of H2O2, and a long-term supply can be shipped at once and mixed into solution as needed. Additionally, acetic acid addition increased 1,4-dioxane removal by 5.7 percent in an UV/H2O2 AOP. It is proposed that the UV irradiation of acetic acid produced the acetoxyl radical, which cohesively works with the hydroxyl radical, produced via H2O2 irradiation, to enhance 1,4-dioxane degradation in a combined, novel UV/H2O2/acetic acid AOP. Other UV-AOP observations relate to a decrease of up to 29 percent in total dissolved solids (TDS), an inverse relationship between TDS and turbidity removals, and degradation of organic matter. Despite organic matter changes, the UV/NaBO3 AOP did not reduce trihalomethane formation due to the increased chlorine demand from hydrogen peroxide residual. Additionally, new insights into limitations of H2O2 residual test methods are included.

Notes

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Graduation Date

2023

Semester

Spring

Advisor

Duranceau, Steven

Degree

Doctor of Philosophy (Ph.D.)

College

College of Engineering and Computer Science

Department

Civil, Environmental, and Construction Engineering

Degree Program

Environmental Engineering

Format

application/pdf

Identifier

CFE0009601; DP0027626

URL

https://purls.library.ucf.edu/go/DP0027626

Language

English

Release Date

May 2024

Length of Campus-only Access

1 year

Access Status

Doctoral Dissertation (Open Access)

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