Study On Organic Matter Transformation And Electron Transfer Of Compost Mixed With Different Solid Wastes And Traditional Chinese Medicine Residues

Composting has become a reduced,harmless and resource-friendly method to treat organic solid waste.The composted products can be applied to soil to repair and improve,and can also promote the migration and transformation of pollutants and heavy metals.Dissolved organic matter（DOM）is considered to be the most active organic component in aerobic composting process,and humus（HS）,as an electron shuttle,bears the role of electron transfer.Therefore,through the study of DOM and HS,it is helpful for us to analyze the relationship between the transformation and structural evolution of organic matter and electron transfer ability.In this study,three common organic solid wastes（conventional dehydrated sludge,chicken manure and cow dung）were mixed with Chinese medicine residues for aerobic composting,and the changes of basic physical and chemical indexes of samples in different composting periods were analyzed.Humic acid（HA）and fulvic acid（FA）,which are important components in DOM and HS,were extracted.The adjustments of structure and composition of organic be counted in compost have been analyzed with the aid of diverse contemporary spectral techniques,inclusive of ultraviolet-visible spectrum,Fourier rework infrared spectrum and 3-dimensional fluorescence spectrum.The electron transfer ability of organic matter was characterized by electrochemical station method,and the relationship between the transformation and structural evolution of organic matter and electron transfer ability in the co-composting process of different organic solid wastes and Chinese medicine residues was explored.The main results of this study are as follows:（1）The analysis of basic physical and chemical properties shows that the changing trends of temperature,organic matter,p H and conductivity are similar.During the composting process,the temperature gradually increased,and the high temperature period of different treatment groups was maintained for more than 7 days.The microbial activity increased,the organic matter content decreased,the p H gradually increased from weak acidity to neutral or weak alkalinity,and the electrical conductivity remained in the range harmless to plants at the end.In elemental analysis,the C/N value and C/O value decreased,and the C/H value increased,indicating that the compost products reached the maturity standard.（2）The spectroscopic evaluation effects of DOM,HA and FA display that materials with easy structure,low diploma of conjugation and easy to decompose（including protein-like substances,polysaccharides,aliphatic materials and carbohydrates）are decomposed and utilized by microorganisms,and after complicated biochemical reactions,they condense to form humus substances with complicated shape and high degree of conjugation,and polar purposeful corporations inclusive of carboxyl,hydroxyl and carbonyl companies boom,and the contents of quinones and semi-quinones growth.PARAFAC model combined with three-dimensional fluorescence spectrum analysis showed that protein-like substances and monoaromatic compounds were degraded in the early stage of composting,humus-like substances increased,and the humification degree deepened.（3）The analysis of electron transfer ability showed that the electron transfer ability（ETC）,electron acceptance ability（EAC）and electron supply ability（EDC）of the three composting groups showed a downward trend,which may be due to the low content of electron-accepting groups and high content of electron-donating groups in humus and aromatic components.Correlation analysis shows that the electron transfer ability is positively correlated with humus-like substances,SUVA₂₅₄and HIX,and negatively correlated with organic matter content,C/O and protein-like substances.