Effects of different types of granular activated carbon on methanogenesis of carbohydrate-rich food waste: Performance, microbial communities and optimization

Hui Mu; Xiaofan Ding; Xiaoyu Zhu; Liguo Wang; Yongfang Zhang; Chunhui Zhao

doi:10.1016/j.scitotenv.2023.165173

Effects of different types of granular activated carbon on methanogenesis of carbohydrate-rich food waste: Performance, microbial communities and optimization

Sci Total Environ. 2023 Oct 15:895:165173. doi: 10.1016/j.scitotenv.2023.165173. Epub 2023 Jun 28.

Authors

Hui Mu¹, Xiaofan Ding², Xiaoyu Zhu³, Liguo Wang², Yongfang Zhang², Chunhui Zhao⁴

Affiliations

¹ School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China. Electronic address: stu_muh@ujn.edu.cn.
² School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China.
³ Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; University of Chinese Academy of Sciences, Beijing 100864, China.
⁴ School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China. Electronic address: stu_zhaoch@ujn.edu.cn.

PMID: 37385489
DOI: 10.1016/j.scitotenv.2023.165173

Abstract

Granular activated carbon (GAC) supplementation is an efficient method for enhancing methane production during the anaerobic digestion of food waste, but it remains unclear which type of GAC is optimal and what potential mechanisms are involved with different types of GAC, particularly for the methanogenic system of carbohydrate-rich food waste. This study selected three commercial GAC (GAC#1, GAC#2, GAC#3) with very distinct physical and chemical properties, and investigated their impacts on the methanogenesis of carbohydrate-rich food waste with an inoculation/substrate ratio of 1. Results indicated that Fe-doped GAC#3 had a lower specific surface area but higher conductivity, yet exhibited superior performance in facilitating methanogenesis compared with GAC#1 and GAC#2, which possessed larger specific surface areas. The addition of 10 g/L GAC#3 enhanced the methane yield by 10-folds through regulating pH levels, alleviating volatile fatty acids-induced stress, enhancing key enzymatic activity, as well as enriching direct interspecies electron transfer-mediated syntrophic partner of Syntrophomonas with Methanosarcina. Furthermore, GAC#1, which had the largest specific surface area but exhibited the poorest performance, was chemically modified to enhance its ability in promoting methanogenesis. The resulting material, named MGAC#1 (Fe₃O₄-loaded GAC#1), exhibited superior electro-conductivity and high methane production efficiency. The methane yield of 588 mL/g-VS showed a remarkable increase of 468 % compared with GAC#1, and a modest increase of 13 % compared with GAC#3, surpassing most values reported in literature. These findings suggested that the Fe₃O₄-loaded GAC with lager specific surface area, was the optimal choice for the methanogenesis of sole readily acidogenic waste, providing valuable insights for the preparation of superior-quality GAC for application in biogas industry.

Keywords: Anaerobic digestion; Fe(3)O(4)-modification; Fe-doped granular activated carbon; Methane production; Readily acidogenic waste.

MeSH terms

Anaerobiosis
Bioreactors
Carbohydrates
Charcoal
Food
Methane
Microbiota*
Refuse Disposal*
Sewage

Substances

Charcoal
Methane
Carbohydrates
Sewage