中试规模猪粪堆肥挥发性有机物排放特征

为监测堆肥过程挥发性有机物(volatile organic compounds,VOCs)排放情况,该文开展了猪粪堆肥现场试验,采用苏玛罐采样,气相色谱-质谱法分析了猪粪好氧堆肥过程中VOCs浓度。结果表明:猪粪好氧堆肥过程中可以检测出的VOCs有81种,包括烷烃类34种,芳香烃类21种,卤烃类19种,胺类1种,含硫化合物3种,氟利昂类3种;其中检出率高且浓度远远超过其嗅阈值的VOCs包括三甲胺、二甲基硫、二甲基二硫和二甲基三硫,VOCs排放主要发生在堆肥的前2周。该研究将为控制猪粪堆肥过程中VOCs气体排放提供科学数据支持。

Emission characteristics of volatile organic compounds during pilot swine manure composting

The composting process has a characteristic of high concentrations of volatile organic compounds (VOCs) emission. However, the site monitoring data about emission of VOCs during swine manure composting process is relatively limited and the baseline is also ambiguous at present. The composting bins were aerated with ventilation rate of 60 L/(m3·min), the experiment lasted for 31 days from October to November 2015 in Beijing. The daily ambient temperatures ranged from 3.74to 13.76℃during the entire experimental period. The daily average temperature inside each composing bin rose and exceeded 50℃ within 4 days, and kept above 50℃ for 28, 28 and 23 days, respectively, which could secure pathogen inactivation and meet the non-hazardous requirement of national standards. The gas samples were collected using SUMMA canisters, and GC-MS was utilized to analyze the concentrations of VOCs. The results showed that 81 kinds of VOCs were detected, including dibutene, butane, cis/anti-2-butane, 1-butylene, isopentane, amylene, n-pentan, anti-2-pentene, isoprene, cis-2-Pentenenitrile, 2,2-dinethyl butane, 2,3-dimethylbutane, 2-methylpentane, cyclopentane 3-methylpentane, n-hexene, hexane, 2,4-dimethylpentane, methylcyclopentane, cyclohexane, 2-methylhexane, 2,3-dimethylpentane, 3-methylhexane, 2,2,4-Trimethylpentane, heptane, methylcyclohexane, 2,3,4-trimethylpentane, 2-methyl heptane, 3-methylheptane, octane, nonane, decane, undecane, dodecane, trimethylamine, dimethylsulfide, dimethyl disulfide, dimethyl trisulfide, freon 11, freon 13, freon 114, isopropyl benzene, propylbenzene, between-ethyl toluene, ethyl toluene, mesitylene, ortho ethyl toluene, pseudocumene, 1,2,3- three methyl benzene, diethylbenzene, two ethyl benzene, benzene, methylbenzene, chlorobenzene, ethylbenzene, m/p-xylen, ortho-xylene, styrene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2,4-trichlorobenzene, naphthalene, vinyl chloride, methyl bromide, ethyl chloride, 1,1-dichloroethylene, dichloromethane, 1,1-dichloroethane, cis-1,2- two vinyl chloride, chloroform, 1,1,1-trichloro ethane, carbon tetrachloride, 1,2-dichloroethane, trichloroethylene, 1,2-dichloropropane, anti 1,3-two chloride, cis-1,3-Dichloropropene, 1,1,2-trichloroethane, tetrachloroethylene, 1,2-dibromoethane, tetrachloroethane. Among these 81 VOCs, the varieties of alkanes, aromatic compounds, halohydrocarbons, amines, sulfur compounds and freon compounds were 34, 21, 19, 1, 3 and 3, respectively. In addition, trimethylamine, dimethyl sulfide, dimethyl disulfide and dimethyl sulfur had higher detection rate and the concentrations of them were far more than their olfactory threshold, their emission peak were 2.711, 2.479, 5.479, 2.204 mg/m3, respectively. During the composting process, the emission of VOCs focused on the first 2 weeks. Next, we need to study the emission of VOCs from pig manure with different feedstocks and different composting conditions. The study provides data support for mitigating VOCs gas emissions during the composting of pig manure.