摘要
为了优化羊粪好氧堆肥的工艺条件,研究初始含水率对羊粪堆肥腐熟度及污染气体排放的影响。该研究以高湿新鲜羊粪为堆肥原料(含水率为75%),添加玉米秸秆调节初始物料含水率分别为70%、65%、60%和55%,堆肥在60 L密闭发酵罐中共持续35 d。结果表明:75%含水率羊粪堆体单独不能顺利启动升温,且在试验期间释放了大量的甲烷和氧化亚氮等温室气体,在所有处理中产生的总温室效应最大(41.4 g/kg)。玉米秸秆与羊粪联合均能成功启动堆肥过程,且堆肥产品均可以达到无害化卫生要求和腐熟标准。其中初始含水率为65%时,堆体不仅高温期持续时间长,且有机质降解程度高,物料干质量降解率达45%,同时比其他处理可降低4.81%~16.99%的总氮损失和7.56%~48.62%的总温室气体排放量。因此,在羊粪和玉米秸秆联合堆肥时,初始含水率65%左右为最佳条件。
With the development of intensive and large-size livestock farming,a large amount of livestock manure has brought environmental pollution in some areas.Aerobic composting is a widely-used and efficient technology for the treatment and utilization of organic waste,which realizes harmless treatment,quantity reduction,stabilization and reutilization.However,there are several issues such as low maturity degree of compost product and emission of polluting gases during the process of composting,moisture content(MC)is one of the most important factors of composting.In order to study the effects of initial MC on maturity and pollution gas emissions during the sheep manure composting and optimize the process conditions,an experiment was carried out in 60 L sealed fermenters for 35 days.In this research,sheep manure and cornstalk were used as raw composting materials.According to the different initial MC,high-humidity sheep manure without any cornstalk was set as MC75 treatment,cornstalks were thoroughly mixed with sheep manure in certain proportions to adjust the initial MC to be 70%,65%,60%and 55%,respectively.C/N ratio of the composting mixture of five treatments was adjusted to 22 approximately by adding urea.The chemical and physical characters and maturity indicators such as temperature,germination index,electric conductivity,and pH value were analyzed,and continuous monitoring of pollution gases(CH4,N2O,and NH3)were conducted.The results demonstrated that the sheep manure composting pile with the MC of 75%could not be activated successfully,the compost product still had the risk in farmland utilization because it did not experience the thermophilic period(>50℃).However,lots of greenhouse gases such as CH4 and N2O were released and the greenhouse gas emissions equivalent was the largest among all treatments during the experiment(41.4 g/kg).While the co-composting process could be started effectively for all treatments with sheep dung and cornstalks.MC70%,65%,60%and 55%treatments all entered into thermophilic stage and reached the peak values of temperature on the 2nd and 4th day,respectively.The thermophilic phase lasted for 8-10 d to reach the compost sanitary requirements.Moreover,the germination index of all treatments under the addition of cornstalks were higher than 80%,the electric conductivities were below 4 mS/cm and the pH values were in the range of 8 to 9 at the end of composting,which could be biologically non-toxic and meet the maturity standard completely.The treatment with the initial MC of 65%had long thermophilic phase(10 d)and high biodegradation degree,whose degradation rate of dry material reached 45%.Meanwhile,compared to the other treatments,the total nitrogen loss and the total greenhouse effects were decreased by 4.81%-16.99%and 7.56%-48.62%,respectively.Consequently,sheep manure with high moisture content should be collected and disposed frequently in sheep farming,and it is not environmentally friendly to pile up without any bulking agent.The optimal initial moisture content is about 65%in this study during the aerobic co-composting of sheep manure and cornstalk.In addition,the control of ammonia emissions by adding additives could be taken into account in future research.
作者
李丹阳
马若男
亓传仁
袁京
李国学
孙少泽
刘燕
Li Danyang;Ma Ruonan;Qi Chuanren;Yuan Jing;Li Guoxue;Sun Shaoze;Liu Yan(Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation,College of Resource and Environmental Science,China Agricultural University,Beijing 100193,China;General Office,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2020年第20期254-262,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家现代农业产业技术体系建设专项(CARS-39-19)。
关键词
含水率
粪
堆肥
腐熟度
污染气体
moisture content
manure
composting
maturity
pollution gas
