Open AccessThe fate of carbon in two-stage anaerobic digestion of vegetable waste
Author(s) -
Pham Van Dinh,
Toru Fujiwara,
Hoang Minh Giang,
Song Toan Pham Phu
Publication year - 2019
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/307/1/012019
Subject(s) - biogas , anaerobic digestion , effluent , methane , pulp and paper industry , mesophile , carbon fibers , waste management , chemistry , hydrolysis , raw material , environmental science , environmental engineering , materials science , organic chemistry , engineering , biology , composite number , bacteria , composite material , genetics
This study aims to investigate the fate of carbon in two-stage anaerobic digestion (TAD) of vegetable waste. The TAD including a hydrolytic reactor and a methane reactor were controlled at mesophilic temperature (36 ± 1°C) with a retention time (RT) of 9 days and 20 days, respectively. Carbon tracking was conducted step by step throughout the system. Non-hydrolysable carbon accounted for a significant proportion of total initial carbon (25%). Meanwhile, a large amount of carbon in the feedstock (23.5%) was hydrolysed but remained in the effluent including water and suspended solids. It was mostly inorganic carbon which is not harmful to the environment. The only 41.3% initial carbon was converted to biogas in both reactors. In the hydrolytic reactor, biogas was mainly carbon dioxide (99%), accounted for 11.3% of total biogas and 35.8% of total CO 2 product. In the methane reactor, biogas was 373.9 Nml/g-VS including 73.3% CH4, 21.9% CO2 and 4.8% others. Non-hydrolysable materials can be a source of thermal energy. Meanwhile, a large amount of hydrolysed carbon was not converted into biogas, was still in the effluent, it was a significant energy loss. Therefore, how to further increase the effectiveness of TAD is an issue that needs to study.