不同城乡有机垃圾堆肥碳磷特征分析.

[Objective] The present paper aimed to provide a basis for the recycling of nutrient resources of organic solid waste in urban and rural areas of China and the rational application of compost.[Method] The organic carbon (C) and phosphorus (P) characteristics of four organic waste composts, i.e., food waste (FW), garden waste (GW), chicken manure (ChM) and cattle manure composts (CaM), were systematically analyzed by Hedley P sequential fractionation method, infrared spectroscopy and thermogravimetric analysis. [Result] The obvious differences in the content and fraction of P and the content and composition of organic C among four composts were observed. The total and labile P content of animal manure composts (ChM and CaM) were significantly higher than those of plant-derived organic waste compost (FW and GW), in which the highest content of water extracted P (H2O-P) and NaHCO3 extracted P (NaHCO3-P) was observed in ChM and CaM composts, respectively. FW compost had high total organic C (TOC), but low humification index (i.e., humic C/fulvic C = 0.09) . Meanwhile, FW compost had the highest content of labile organic C (LOC), i.e., dissolved organic C (DOC), light molecular organic acids (LMOA) and amino acids (AA), the lower degree of aromatization with more carboxylic acids and polysaccharide structures, and the lowest thermal stability. GW compost had the highest content of readily oxidizable organic C (ROC) and humic substances C (HSC), and a high aromatized structure and thermal stability. Animal manure compost had the lowest HSC content and the medium DOC content. ChM compost had the highest free AA content and rich LMOA species, while the CaM compost contained a certain amount of AA and oxalic acid. Two animal manure composts had a similar aromatization degree and thermal stability, which was between FW and GW. [Conclusion] Manure composts with high P content and labile organic C can be used as a good P source to completely or partially replace chemical fertilizer. FW compost had low P content but high LOC content, which can improve the availability of P fertilizer via promoting P by C. GW compost with low P content and high stable organic C, in the long run, can improve soil fertility, which in turn can enhance soil P availability. Thus, rational application of composts according to their C and P characteristics or combined application of different composts or compost with chemical fertilizers can realize the C and P synergy and the highly efficient recycling of P nutrient resources. [ABSTRACT FROM AUTHOR]