Civil Engineering Journal
Vol. 12 No. 5 (2026): May

Factors and Kinetics of Fat, Oil and Grease Deposit Formation in Kitchen Wastewater

Xin Yan (School of Ecology and Environment, North China University of Water Resources and Electric Power, Zhengzhou 450046)
Dongyang Ren (School of Ecology and Environment, North China University of Water Resources and Electric Power, Zhengzhou 450046)
Jingtao Feng (Henan Province Construction Group Company Limited, Zhengzhou 450000)
Zhi Tang (School of Civil Engineering, Wuhan University, Wuhan 430072)
Zheng Fang (School of Civil Engineering, Wuhan University, Wuhan 430072)



Article Info

Publish Date
01 May 2026

Abstract

This study systematically investigated key parameters influencing fat, oil, and grease (FOG) deposit formation in kitchen wastewater and elucidated the underlying chemical kinetics. Gas chromatography–mass spectrometry (GC–MS) was employed to characterize the composition of FOG deposits. Single-factor experiments and response surface methodology were used to identify the most significant factors contributing to saponification and determine optimal conditions for FOG accumulation. GC–MS demonstrated lower quantitative error rates than Fourier transform infrared (FTIR) spectroscopy and acid–base titration, with oleic acid identified as the predominant free fatty acid (FFA) component. The optimal saponification conditions were as follows: C₁₈H₃₄O₂:CaCl₂ mass ratio of 1:1.40, pH value of 7, reaction temperature of 30°C, and reaction duration of 1440 min, under which the maximum predicted saponification extent was 77.932%. Additionally, the kinetic model showed that FOG saponification followed a second-order reaction, with an activation energy of 53.1 kJ·mol−1 and a pre-exponential factor of 5.4 × 107 L·mol−1·min−1. Overall, this research enhances the existing theoretical framework of FOG deposit formation by integrating engineering simulation with chemical kinetics and provides quantitative parameters to directly inform pipeline blockage mitigation and wastewater treatment optimization.

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Journal Info

Abbrev

cej

Publisher

Subject

Civil Engineering, Building, Construction & Architecture

Description

Civil Engineering Journal is a multidisciplinary, an open-access, internationally double-blind peer -reviewed journal concerned with all aspects of civil engineering, which include but are not necessarily restricted to: Building Materials and Structures, Coastal and Harbor Engineering, ...