蚯蚓辅助堆肥处理蔬菜废弃物及其温室气体减排效果

蚯蚓辅助堆肥是近年兴起的处理有机废物的有效方法,为探明蚯蚓辅助堆肥法处理蔬菜废弃物的效果及其温室气体排放规律,该文以牛粪和新鲜番茄秧作为原料,在蚯蚓养殖场分别设置蚯蚓辅助堆肥和常规堆肥处理,对比研究了腐熟度指标变化和温室气体排放规律。结果表明:蚯蚓辅助堆肥堆垛温度较低,达不到无害化温度标准(50～55℃以上持续5～7d),但可满足蚯蚓生存需求,蚯蚓生物量在堆肥前期(0～10d)较低,为14.6×103～20.8×103条/m3,其后随着堆体温度的降低逐渐增长,至堆肥结束时达到90.2×103条/m3。综合pH值、电导率(EC)、碳氮比(C/N)、发芽率指数(GI)等腐熟度指标分析,蚯蚓辅助堆肥处理的腐熟度优于常规堆肥处理,并提前达到腐熟,堆肥周期缩短;蚯蚓辅助堆肥氮素损失较常规堆肥减少30.8%,CH4、NH3和N2O排放比常规堆肥分别减少12.8%、17.4%和46.1%,温室气体总量减排35.9%,因此蚯蚓辅助堆肥可有效降低堆肥过程中的氮素损失和温室气体排放量。研究结果可为有机固体废弃物循环利用和温室气体减排控制提供参考。

Vermicomposting treatment of vegetable waste and its greenhouse gas emissions

Vermicomposting is a new effective method in disposing organic waste these years.In order to investigate the effect and greenhouse gas emission rules of vermicomposting,an experiment of vermicomposting used cow dung and fresh tomato stems as raw material was carried out in earthworm culturing farm,taken conventional-composting as control treatment.The changes of maturity indexes and greenhouse gas emission rules were compared and studied.Results showed that the temperature of vermicomposting was lower than that of conventional-composting,which could not reach the harmless standard(the temperature should be above 50-55 ℃ and lasts for 5-7 days),but the low temperature was beneficial to earthworm,so the earthworms of earthworm increased from(14.6-20.8) ×10 3 /m 3 in 0-10 d to 90.2×10 3 /m 3 in the final period.According to the maturity indexes of pH,electric conductivity,C/N ratio and germination index,vermicomposting can shorten the composting cycle and had a higher degree of maturity.Compared with conventional-composting,N losses was reduced by 30.8%,greenhouse gas emissions reduced by 35.9%,CH4,N2O and NH3 by 14.7%,17.4% and 46.1% respectively for vermicomposting.Therefore,vermicomposting can reduce N losses and greenhouse gas emissions during composting.This study can provide a new approach and reference to organic solid waste recycling and reduction of greenhouse gas emissions.