68 / 2023-05-31 20:37:48

The Influence of Organic Carbon Component Transformation and the Collaborative Evolution of Microbial Community in the Biological Fermentation Process of Organic Solid Waste

Organic Carbon Component,Collaborative Evolution,Biological Fermentation

The production of organic solid waste in my country is large, and aerobic fermentation is often used to obtain soil conditioners. Traditional soil conditioners take macromolecular humus carbon as the core to promote the formation of soil aggregates, but the detonation effect of small molecular organic carbon components on soil microorganisms is often ignored. Therefore, this article takes the organic solid waste as the research goal. Under different biological treatments, traditional fermentation for 30 d (CK), staged inoculation fermentation for 15 d (JJ) and rapid moist heat fermentation for 24 h (RC) are carried out to prepare different organic carbon. The component of the soil conditioner, that is, the macromolecular humus carbon promotes the condensation of soil aggregates, and the small molecules can easily use organic carbon to provide a carbon source and nutrient source for microorganisms in the soil to increase the abundance and diversity of the microbial community. Spectroscopy is used to characterize the transformation and fate of organic carbon components, and high-throughput sequencing methods are used to characterize the succession of microbial community structure to explore the relationship between environmental factors, organic carbon component transformation and functional microorganisms. The main conclusions are as follows:

(1) The results of spectral characterization show that CK has the highest aromaticity, the largest molecular weight and the most humic substances in the three treatment groups. JJ contains higher COO-, indicating that its organic carbon components are rich in carboxylic acids. Acidic substances, RC has the lowest aromaticity and the smallest molecular weight compared to CK and JJ.

(2) Correlation analysis shows that pH has a significant or extremely significant positive correlation with the SUVA₂₈₀ of the three treatment groups, indicating that pH has a significant effect on the molecular weight of organic carbon components, and improving the pH of the material can promote the formation of macromolecular organic carbon components. potential. Organic matter (OM), TOC, and protein-like substances in CK and JJ groups are significantly or significantly positively correlated with the formation of humus-like substances, and there is a very significant negative correlation. Improving the content of organic matter in materials may promote the content of different types of organic carbon components The content of humus-like substances in RC is greatly affected by temperature.

(3) The analysis of microbial diversity showed that the abundance of nitrogen-fixing bacteria Bacillus and Rhizobia in the fermentation products of CK and JJ was higher, and Pseudomonaceae with carbon-fixing function in RC products Genus higher abundance. Analysis of fungi found that Ascomycota was the main dominant phyla in CK and JJ products, and Basidiomycota was the dominant phyla in RC fermentation products. The abundance was 86.15%, and its abundance was 5 of JJ. It is 4 times that of CK and its main function is to fix carbon. The above results show that the products treated with CK and JJ have better nitrogen fixation effects, and the RC products have stronger carbon fixation ability.

(4) Analysis of the response relationship between environmental factors, organic carbon component conversion and functional microbial community structure succession showed that TOC and OM have a significant impact on the abundance of functional microbes, and small molecular protein substances and soluble microbial side effects The product is negatively correlated with the nitrogen-fixing bacteria Bacillus and Rhizopus, and the macromolecular humus substances are positively correlated with the carbon-fixing bacteria Pseudomonas and Basidiomycota. The correlation between carbon-fixing bacteria and organic carbon components is the same as that of nitrogen-fixing bacteria, while carbon-fixing fungi have a significant positive correlation with fulvic acid-like substances.

In summary, small molecular organic carbon components may be transformed into macromolecular humus-like substances by microorganisms, and small molecular organic carbon components have a certain promoting effect on the abundance of carbon-fixing fungi. This study investigated the effects of different aerobic fermentation methods on the conversion of organic carbon components, and analyzed the conversion patterns of organic carbon components from the response mechanisms of microorganisms and environmental factors. This study can provide theoretical basis and technical support for exploring the mechanism of aerobic fermentation treatment of organic solid waste.