Hydrothermal synthesis of similar mineral-sourced humic acid from food waste and the role of protein

Pengfei Chen; Renjie Yang; Yuhou Pei; Yang Yang; Jiong Cheng; Daoping He; Qing Huang; Heng Zhong; Fangming Jin

doi:10.1016/j.scitotenv.2022.154440

Hydrothermal synthesis of similar mineral-sourced humic acid from food waste and the role of protein

Sci Total Environ. 2022 Jul 1:828:154440. doi: 10.1016/j.scitotenv.2022.154440. Epub 2022 Mar 8.

Authors

Pengfei Chen¹, Renjie Yang², Yuhou Pei², Yang Yang², Jiong Cheng², Daoping He³, Qing Huang⁴, Heng Zhong⁵, Fangming Jin⁶

Affiliations

¹ China-UK Low-carbon College, Shanghai Jiao Tong University, Shanghai 200240, PR China.
² School of Environmental Science and Engineering, State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, PR China.
³ Earth-Life Science Institute (ELSI), Tokyo Institute of Technology, 2-12-IE-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
⁴ College of Ecology and Environment, Hainan University, Haikou 570228, PR China.
⁵ School of Environmental Science and Engineering, State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, PR China; Center of Hydrogen Science, Shanghai Jiao Tong University, Shanghai 200240, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China. Electronic address: zhong.h@sjtu.edu.cn.
⁶ School of Environmental Science and Engineering, State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, PR China; College of Ecology and Environment, Hainan University, Haikou 570228, PR China; Center of Hydrogen Science, Shanghai Jiao Tong University, Shanghai 200240, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China. Electronic address: fmjin@sjtu.edu.cn.

PMID: 35276141
DOI: 10.1016/j.scitotenv.2022.154440

Abstract

Food waste is a challenging biomass resource due to its high moisture content, low calorific value, and complex composition. Natural humification of animal and plant residues is highly related to microorganism activity, but natural hydrothermal conditions are also speculated to play a significant role. In this work, a novel method for the conversion of food waste into artificial humic acid (HA_a) under hydrothermal conditions is proposed. The results revealed that an optimum HA_a yield of 43.5% from food waste was successfully obtained at 215 °C for only 1 h. Detailed analyses, including elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), and Fourier transform infrared (FT-IR) spectroscopy, showed that the produced HA_a had similar structures and compositions with natural HA extracted from minerals. Moreover, the proteins contained in the food waste significantly promoted HA formation through the reaction of saccharides with amino acids, in which Maillard-like reactions were the key steps. These results not only provide experimental evidence for verifying the role of hydrothermal reactions in transforming food waste into humic acid but also provide insight into effective resource utilization of food waste.

Keywords: Artificial humic acid; Food waste; Hydrothermal humification; Protein.

MeSH terms

Animals
Food
Humic Substances* / analysis
Minerals
Proteins
Refuse Disposal*
Spectroscopy, Fourier Transform Infrared

Substances

Humic Substances
Minerals
Proteins