Effect Of Additives On The Humification Process Of Aerobic Co-composting Of Rural Organic Waste

As special form of resources,rural organic waste has the characteristics of large output,high pollution,high cost of collection and transportation,and its resource treatment has been a research hotspot.Aerobic composting technology can eliminate rural organic waste on the spot,and the compost product produced has potential for resource utilization.It is widely used in rural areas of China,but at the same time,there are problems such as insufficient compost maturity,low humification efficiency and poor product quality.In this paper,the aerobic co-composting test was carried out with perishable waste,chicken manure and corn stover.Combined with phy-chemical and spectral analysis,the effects of additives?medical stone,brown sugar,backmixed matured compost?on the phy-chemical parameters,organic matter composition,and the structural characteristics of dissolved organic matter?DOM?and the quality of compost product in the process of composting were studied.Through experimental research,the following results and conclusions are drawn:?1?Compared with the control treatment,the initial addition of medical stone and backmixed matured compost accelerated the start of composting process,shortened the warming time of composting by 1d.The high temperature period was extended by1²d by the initial addition of medical stone,backmixed matured compost,backmixed matured compost combined with the high-temperature addition of brown sugar,and the maximum temperature was increased by 1.5⁶.5°C;?2?The control treatment and the initial addition of brown sugar did not fully meet the requirements of maturity index?C/N,T value and seed germination rate?on the 21st day.The initial addition of medical stone,the addition of brown sugar in the high temperature period and the backmixed matured compost promoted the compost maturity,shortened the composting period to less than 21d.And the treatment of the separate backmixed matured compost can effectively promote compost maturity and lower cost,which is more suitable for rural areas;?3?In the composting process,the degradation of different organic matter components from large to small was soluble organic matter,hemicellulose,cellulose and lignin.The degradation rate of each component was 38.67%⁴8.16%,22.26%³0.86%,19.40%²4.58%,6.19%⁸.88%.Lignin was hardly degraded in the early stage of composting,other organic components were degraded to varying degrees from the early stage of composting,and the degradation process of hemicellulose and cellulose were similar;?4?The initial addition of medical stone and brown sugar had no significant effect on promoting the degradation of lignocellulose?including hemicellulose,cellulose and lignin?.The backmixed matured compost and the addition of brown sugar in the high temperature period could promote the degradation of lignocellulose,and the combination of the two measures had the strongest effect;?5?After the completion of composting,the UV-visible absorption spectra of all treatments SUVA₂₅₄,SUVA₂₈₀,E₂₅₃/E₂₀₃,E₂₅₃/E₂₂₀,A_260²80 increased to varying degrees,protein-like substances,microbial lysate content decreased,and it was negatively correlated with the content of fulvic acids and humic acids;?6?After the composting,compared with the control treatment,the initial spectral parameters of adding brown sugar were smaller,which was not conducive to the composting humification process.The spectral parameters of the backmixed matured compost combined with the high-temperature addition of brown sugar were the largest,indicating that he humification process worked best;?7?At the end of composting,the total nutrient content of the backmixed matured compost and the brown sugar added in the high-temperature period were more than 4%,which can be used as organic fertilizer;the total nutrient content of the initial addition of medical stone and the addition of brown sugar in the high temperature period were less than 4%,which cannot be directly used as organic fertilizers,but these two treatments had reached maturity,can be used as a carbon-based fertilizer to increase soil fertility.