翻堆频率对堆肥减量化、腐殖化和稳定化的影响

好氧堆肥是有机固体废弃物处理处置的有效手段之一,堆肥还田也是贫瘠土壤改良的常用措施。但好氧堆肥是一个典型的CO_2等温室气体的释放过程。如何减少堆肥过程中的CO_2释放,强化堆肥的腐殖化过程对于实现有机固体废弃物的低碳化堆肥、提高作为优良土壤改良剂的腐殖质产量具有重要意义。本文选取农林秸秆和餐厨垃圾作为堆肥原料,研究不同翻堆频率对堆肥过程中的物料减量化、腐殖化和稳定化的影响,以期发现一个较低碳的堆肥工艺,并从微生物角度初步探索了其影响机制。研究结果显示,不同的翻堆频率(分别为每2 d、4 d和6 d翻堆一次),堆料的减量化和腐殖化程度有一定差异,翻堆频率为4 d的堆肥工艺物料减量率最高为50.5%,但碳减量率最低为77.4%;而翻堆频率为2 d的堆肥工艺腐殖质产量最高;3种堆肥工艺经62 d堆肥都达到了腐熟程度,翻堆频率为4 d的堆肥工艺腐熟化程度最高。不同的翻堆频率可能通过影响堆肥过程中堆料的温度、含氧量等因素从而改变堆料中活性微生物量、种类和生物酶活性,进而影响堆料的矿化和腐殖化进程。

Effects of different turning frequency on reduction,humification and stabilization of composting

Aerobic composting is a useful way of organic solid waste treatment, and composting products returning to soil is a common measure for improving poor soil. However, the aerobic composting is a typical process of releasing greenhouse gases such as CO2. How to reduce CO2 releasing during composting and strengthen humification process is important for low-carbon composting of organic solid waste and for improving the quality of soil conditioner. In this research, agroforest- ry waste and restaurant garbage were chosen as raw materials of compost to discuss effects of difference turning frequency on quantitative reduction, humification, stabilization and as well as its mechanism, so as to select a relatively low-carbon treatment. Results indicated that reduction and humification level of treatments differed with different turning frequency （2 d, 4 d or 6 d）. The treatment turning every 4 d had the highest mass reduction rate of S0.5% but the lowest TC reduction rate of 77.4%. The treatment turning every 2 d had the highest production of 1034.5 g humus. All the three treatments made raw materials matured for 62 d, and the treatment turning every 4 d had the highest maturity. Variations in temperature and 02 supply caused by different turning frequency might influence microbial biomass and enzyme activity, and then influence the process of mineralization and humification.