Screening Corrosion Inhibitors Using Traditional and Alternative Bench-Scale Methods

Author

• Samuel R. Laing, University of Central FloridaFollow

Keywords

Bench-scale, screening evaluation, corrosion inhibitor, drinking water, Lead and Copper Rule, orthophosphate

Abstract

A study that compared two bench-scale testing methods employed to evaluate the effectiveness of phosphate-based corrosion inhibitors for the control of lead and copper release at a central Florida drinking water utility treating groundwater has been completed. Two bench-scale corrosion control evaluation methods were compared: (1) a traditional metal coupon immersion test using glass jars under batch changeout conditions, and (2) a modified metal coupon immersion test utilizing a flow-through glass separatory-funnel under flowing changeout conditions. The flow-through method was used for the overall study that compared the effectiveness of different inhibitor formulations for corrosion control, while the traditional immersion test was used for a subset of the conditions to accomplish a comparison of methods. It was found that the traditional batch method provided copper concentration results that statistically exhibited data with a greater variance and wider standard deviation than the funnel flow-through method. Statistical analysis using two-way ANOVA showed that both bench-scale methods and the five inhibitors tested (identified as A to E) were significantly different from each other at a 95% confidence level. Standard deviations in inhibitors A, B, and C were, respectively, 59%, 71%, and 51% higher in traditional method samples compared to their flow-through method counterparts. Although the funnel method was shown to statistically provide a greater degree of precision and accuracy in the results, both methods would result in the same engineering outcome regarding the identification of the more acceptable corrosion control chemicals based on the conditions experienced in this study. The traditional and alternative bench-scale test methods revealed that four of the inhibitors outperformed the existing inhibitor used by the utility for copper corrosion at the South WTP. However, only two of the five alternative inhibitor formulations reduced lead release as compared to the inhibitor currently added to the South WTP treated water supply.

Completion Date

2025

Semester

Fall

Committee Chair

Duranceau, Steven

Degree

Master of Science in Environmental Engineering (M.S.Env.E.)

College

College of Engineering and Computer Science

Department

Civil, Environmental, and Construction Engineering

Format

PDF

Release Date

12-15-2026

Document Type

Thesis

Campus Location

Orlando (Main) Campus

Subjects

Corrosion and anti-corrosives--Research; Corrosion and anti-corrosives--Testing; Water-pipes--Corrosion--Testing; Copper--Corrosion--Testing; Lead--Corrosion

STARS Citation

Laing, Samuel R., "Screening Corrosion Inhibitors Using Traditional and Alternative Bench-Scale Methods" (2025). Graduate Thesis and Dissertation post-2024. 534.
https://stars.library.ucf.edu/etd2024/534