Heavy metals interact with the microbial community and affect biogas production in anaerobic digestion: A review

Abstract The search for sustainable development has led countries around the world to seek the improvement of technologies that use renewable energy sources. One of the alternatives in the production of renewable energy comes from the use of waste including urban solids, animal excrement from livestock and biomass residues from agro-industrial plants. These materials may be used in the production of biogas, making its production highly sustainable and environmentally friendly, in addition to reducing public expenses for the treatment of those wastes. The present study evaluated the cultivated and uncultivated microbial community from a substrate (starter) used as an adapter for biogas production in anaerobic digestion processes. 16S rDNA metabarcoding revealed domain of bacteria belonging to the phyla Firmicutes, Bacteroidota, Chloroflexi and Synergistota. The methanogenic group was represented by the phyla Halobacterota and Euryarchaeota. Through 16S rRNA sequencing analysis of isolates recovered from the starter culture, the genera Rhodococcus, Vagococcus, Lysinibacillus, Niallia, Priestia, Robertmurraya, Luteimonas and Proteiniclasticum were recovered, groups that were not observed in the metabarcoding data. The groups mentioned are involved in the metabolism pathways of sugars and other compounds derived from lignocellulosic material, as well as in anaerobic methane production processes. The results demonstrate that culture-dependent approaches, such as isolation and sequencing of isolates, as well as culture-independent studies, such as the Metabarcoding approach, are complementary methodologies that, when integrated, provide robust and comprehensive information about the microbial communities involved in various processes, including the production of biogas in anaerobic digestion processes.

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Effect of Heavy Metals in the Performance of Anaerobic Digestion of Olive Mill Waste

Processes ◽

10.3390/pr8091146 ◽

2020 ◽

Vol 8 (9) ◽

pp. 1146 ◽

Cited By ~ 1

Author(s):

Khalideh Al bkoor Alrawashdeh ◽

Eid Gul ◽

Qing Yang ◽

Haiping Yang ◽

Pietro Bartocci ◽

...

Keyword(s):

Heavy Metals ◽

Anaerobic Digestion ◽

Organic Acid ◽

Biogas Production ◽

Methanogenic Bacteria ◽

Inhibitory Influence ◽

Olive Mill Waste ◽

Acid Load ◽

Mill Waste ◽

Olive Mill

This study presents an investigation on the effect of heavy metals on the production of biogas during the process of anaerobic digestion (AD) of olive mill waste (OMW). The poisonous effect and the inhibitory influence of Fe, Ni, Pb, Zn, Cu, and Cr on the digestion process are investigated and determined. Biomethanation potential tests are performed for this sake. Adding some of the heavy metals to the AD decreases the efficiency of biogas production and methane concentration and decreases the reduction in the VS, the TCOD, the SCOD, and the organic acid load. A critical increase in the total organic acid and inhibition of methanogenic bacteria was observed due to its toxicity. The toxicity of the heavy metals can be arranged according to increasing order: Cu > Ni > Pb > Cr > Zn > Fe, which leads to rapid poisoning of the active microorganisms. Iron may also exhibit stimulatory effects, but with a low rate and at a certain level. The conclusions of this work are important for the industry and help to understand how to carefully manage the presence of heavy metals in the digestate.

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Influence of Temperature on Biogas Production Efficiency and Microbial Community in a Two-Phase Anaerobic Digestion System

Water ◽

10.3390/w11010133 ◽

2019 ◽

Vol 11 (1) ◽

pp. 133 ◽

Cited By ~ 10

Author(s):

Shiwei Wang ◽

Fang Ma ◽

Weiwei Ma ◽

Ping Wang ◽

Guang Zhao ◽

...

Keyword(s):

Community Structure ◽

Microbial Community ◽

Anaerobic Digestion ◽

Production Efficiency ◽

Biogas Production ◽

Two Phase ◽

Influence Of Temperature ◽

Influence Of Temperature On ◽

Acidogenic Phase ◽

Methanogenic Phase

In this study, the influence of temperature on biogas production efficiency and the microbial community structure was investigated in a two-phase anaerobic digestion reactor for co-digestion of cow manure and corn straw. The results illustrated that the contents of solluted chemical oxygen demand (SCOD) and volatile fatty acid (VFA) in the acidogenic phase and biogas production in the methanogenic phase maintained relatively higher levels at temperatures ranging from 35–25 °C. The methane content of biogas production could be maintained higher than 50% at temperatures above 25 °C. The microbial community structure analysis indicated that the dominant functional bacteria were Acinetobacter, Acetitomaculum, and Bacillus in the acidogenic phase and Cenarchaeum in the methanogenic phase at 35–25 °C. However, the performances of the acidogenic phase and the methanogenic phase could be significantly decreased at a lower temperature of 20 °C, and microbial activity was inhibited obviously. Accordingly, a low temperature was adverse for the performance of the acidogenic and methanogenic phases, while moderate temperatures above 25 °C were more conducive to high biogas production efficiency.

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