Effect of inoculation during different phases ofagricultural waste composting on spectroscopic characteristics of humic acid

HUANG Hong-li(黄红丽)¹, ZENG Guang-ming(曾光明)^{2, 3}, LUO Lin(罗琳)¹, ZHANG Jia-chao(张嘉超)¹, YU Man(喻曼)⁴, QIN Pu-feng(秦普丰)¹

(1. College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China;
2. College of Environmental Science and Engineering, Hunan University, Changsha 410082, China;
3. Key Laboratory of Environmental Biology and Pollution Control of Ministry of Education (Hunan University),
Changsha 410082, China;
4. Environmental Resources and Soil Fertilizer Institute, Zhejiang Academy of Agricultural Sciences,
Hangzhou 310021, China)

Abstract:The white-rot fungus, Phanerochaete chrysosporium (P. chrysosporium), was inoculated during different phases of agricultural waste composting and its effect on the spectroscopic characterization of humic acid (HA) was studied. Three runs were used in this study: Run A was the control without inoculating, and Runs B and C were inoculated P. chrysosporium during the first and the second fermentation phase, respectively. The elemental analysis, ultra-violet spectroscopy (UV), fluorescence spectra, Fourier transform infra-red (FTIR) and ¹³C nuclear magnetic resonance (¹³C-NMR) of HA all lead to the same conclusion, that is, the degree of aromatization and polymerization of HA increases after 42 days composting. However, the inoculation during different phases presents different effects. P. chrysosporium increases the degree of aromatization and polymerization of HA when it is inoculated during the second fermentation phase, while it does not produce an obvious change on the humification degree of HA when it is inoculated during the first fermentation phase.

Key words:inoculation; composting; Phanerochaete chrysosporium; humic acid; spectroscopic characteristics; agricultural waste