Sanitary sewer overflows are caused by the accumulation of insoluble calcium salts of fatty acids, which are formed by the reaction between fats, oils and grease (FOG) and calcium found in wastewaters. Different sewer structural configurations (i.e., manholes, pipes, wet wells), which vary spatially, along with other obstructions (roots intrusion) and pipe deformations (pipe sags), may influence the detrimental buildup of FOG deposits. The purpose of this study was to quantify the spatial variation in FOG deposit formation and accumulation in a pilot-scale sewer collection system. The pilot system contained straight pipes, manholes, roots intrusion, and a pipe sag. Calcium and oil were injected into the system and operated at alkaline (pH = 10) and neutral (pH = 7) pH conditions. Results showed that solid accumulations were slightly higher at neutral pH. Fourier transform infrared (FTIR) analysis on the solids samples confirmed that the solids were indeed calcium-based fatty acid salts. However, the fatty acid profiles of the solids deviated from the profile found from FOG deposits in sewer systems, which were primarily saturated fatty acids. These results confirm the work done previously by researchers and suggest an alternative fate of unsaturated fatty acids that does not lead to their incorporation in FOG deposits in full-scale sewer systems.
Skip Nav Destination
Article navigation
Research Article|
October 01 2013
Understanding the spatial formation and accumulation of fats, oils and grease deposits in the sewer collection system
Christopher Cyril Sandeep Dominic;
Christopher Cyril Sandeep Dominic
1Department of Civil & Environmental Engineering, North Carolina State University, Raleigh, North Carolina, 27695, USA
Search for other works by this author on:
Megan Szakasits;
Megan Szakasits
2Department of Chemical Engineering, North Carolina State University, Raleigh, North Carolina, 27695, USA
Search for other works by this author on:
Lisa O. Dean;
Lisa O. Dean
3Market Quality and Handling Research Unit, USDA, ARS, Raleigh, North Carolina, 27695 – 7624, USA
Search for other works by this author on:
Joel J. Ducoste
1Department of Civil & Environmental Engineering, North Carolina State University, Raleigh, North Carolina, 27695, USA
E-mail: [email protected]
Search for other works by this author on:
Water Sci Technol (2013) 68 (8): 1830–1836.
Article history
Received:
April 14 2013
Accepted:
June 14 2013
Citation
Christopher Cyril Sandeep Dominic, Megan Szakasits, Lisa O. Dean, Joel J. Ducoste; Understanding the spatial formation and accumulation of fats, oils and grease deposits in the sewer collection system. Water Sci Technol 1 October 2013; 68 (8): 1830–1836. doi: https://doi.org/10.2166/wst.2013.428
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
eBook
Pay-Per-View Access
$38.00