982857 - Assessment of Factors That Affect Hydrogen Sulfide Corrosion of Manhole Shafts

Thursday, June 17, 2021

1:40pm – 2:00pm US EDT

Primary Author(s)

Sunakshi Hada, MS

Graduate Research Assistant (PhD)
University of Texas at Arlington
Arlington, TX

Slides Document

Co-Author(s)

Mithila Chakraborty, MSc

Graduate Student (PhD)
The University of Texas at Arlington
Arlington, TX
Ketan Shah, BE, MBA-TM

Graduate Research Assistant
The University of Texas at Arlington
Arlington, Texas
Niloofar Parsaeifard, Doctorate

Assistant Professor of Instruction
University of Texas at Arlington
Arlington, TX
Aiswarya Acharath Mohanakrishnan, MS

Graduate Research Assistant
University of Texas, Arlington
Arlington, TX
HR

Hoda Rahimi

University of Texas at Arlington
Arlington, Texas
Ankita Sinha, MEng

Environmental Engineer
Jacobs
Arlington, TX
OA

Opeyemi Adelegan
Dravid Sabarish Villavan Kothai, BS Civil engineering, MS Environmental Engineering (Thesis) on going

Student|Graduate Research Assistant|Environmental Scientist Intern
The University of Texas at Arlington
Arlington, Texas
HA

Hussain Ali
PC

Pablo Choquis
Bria N. Wooten, Bachelors of Science (Expected December 2020)

Undergraduate Research Assistant
University of Texas at Arlington
Arlington , Virginia
Gomathy Radhakrishna Iyer, PhD

Project Professional
SCS Engineers
RM

Rafatuzzama Mohammad
ST

Sorakrich Techapaphawit, Bachelors

King Mongkut's University of Technology Thonburi
Bangkok, Krung Thep, Thailand
Melanie L. Sattler, PhD, P.E.

Professor
Univ of Texas-Arlington
Arlington, Texas
VC

Victoria Chen, PhD

Professor
The University of Texas at Arlington
Arlington, Texas
Arpita Bhatt, PhD

Assistant Professor of Instructions
UT Arlington
Arlington, TX

Manhole shafts in sewers are prone to deterioration due to Microbially Induced Concrete Corrosion (MICC), which can reduce their life from 100 years to 30-50 years, and in extreme cases to 10 years. MICC is facilitated by sulfuric acid formed by the generation and volatilization of hydrogen sulfide (H2S). Corrosion of manholes on roads can create safety hazards from manhole lids falling through the structure, streets giving way, or sewers flowing beyond their capacity.

Accordingly, this project sponsored by the City of Arlington aims to identify factors that contribute to hydrogen sulfide corrosion of manholes, so that these factors can be mitigated, or so that manholes most vulnerable to corrosion can be lined with protective coatings. The initial phase of the project involved collection of data from 350 manholes in the City of Arlington, including liquid- and gas-phase parameters that influence corrosion, as well as corrosion depth. The manholes were divided into 5 categories based on their characteristics: presence of drop, pipe diameter, type of flow, inlets and bends, and control. Our results showed that manholes with >2-foot drop or a hydraulic jump had the highest H2S concentrations, and lowest was observed in manholes with subcritical flow. This indicates that turbulent flow increases rates of corrosion. Based on the field data, a multiple linear regression equation was developed which helped to identify the factors which majorly contributed to hydrogen sulfide generation and corrosion rates. The model identified upstream manhole conditions, and flow type to be the major contributing factors.