污泥好氧堆肥过程臭气释放特征与防控研究
发布时间：2018-11-10 19:36
【摘要】：污泥堆肥过程释放的恶臭气体已成为制约污泥无害化生产的重要因素,其中挥发性有机物(VOCs)在臭味贡献中占了很大比重。VOCs主要包括含硫化合物、含氮化合物和挥发性脂肪酸,组分复杂且治理困难。影响VOCs排放的因素主要有通风策略、温度和p H值,其中通风策略是最重要的影响因素。本文通过在堆肥处置厂选点取样,分析了臭气从堆体内部至外界的扩散规律,讨论了对人体的危害和对大气圈的二次污染臭氧生成潜势;对生产中的多种两种通风策略进行了讨论和比较,确定生产中更适合的通风工艺。1.利用气相色谱-质谱联用仪分析了污泥处置厂污泥好氧堆肥发酵高温期(第五天)的挥发性有机物(VOCs)的产生与释放特征。结果表明,污泥堆肥过程中主要致臭VOCs为甲硫醇、甲硫醚、二甲二硫醚、丙酮、乙醇、1-丁烯;从堆体内部到车间人员活动处的扩散过程中,主要VOCs成分降低了89.3%-99.9%。主要致臭组分如甲硫醇、二甲二硫醚、甲硫醚浓度均高于检知嗅阈值,对人类嗅觉具有危害;烷烃、芳香烃、酮类、烯烃类的最大臭氧生成潜势值依次增加,存在大气污染风险;通过VOCs组分间的相关性分析,认为甲硫醇宜作为评估VOCs排放情况的指示气体。2.研究了污泥处置厂污泥堆肥过程在不同通风模式下产生和释放的挥发性有机物(VOCs)浓度水平和反应活性;考虑到含氧有机物类VOCs光解反应对O3生成的贡献,用增量反应活性(臭氧生成潜势)法比等效丙烯浓度法更为适合评价堆肥过程释放臭气对近地大气圈的污染潜势;与其他行业相比,污泥堆肥厂所释放总VOCs的臭氧生成潜势较大,其中各组分间以含氧有机物类VOCs贡献污染潜势最大。3.比较了实际生产中不同风机和多种通风策略下的发酵效果,系统分析了不同堆肥发酵阶段和不同通风状态阶段的温度、氧气浓度、NH3浓度和VOCs浓度的变化规律;认为选用罗茨风机能够提升升温速率和高温维持时间,以及减少VOCs的释放量,对堆肥生产中的翻抛时机和翻抛效果进行了讨论,找到了能够有效降低臭气二次污染的生产工艺。
[Abstract]:The odor gas released from sludge composting process has become an important factor restricting the harmless production of sludge, in which volatile organic compounds (VOCs) account for a large proportion of the odor contribution. VOCs mainly includes sulfur compounds. Containing nitrogen compounds and volatile fatty acids, the components are complex and difficult to control. The main factors affecting VOCs emission are ventilation strategy, temperature and pH value, among which ventilation strategy is the most important factor. In this paper, by sampling at the site of composting disposal plant, the diffusion law of odor from the inside of the reactor to the outside world is analyzed, and the harm to human body and the ozone formation potential of secondary pollution to the atmosphere are discussed. This paper discusses and compares two kinds of ventilation strategies in production, and determines the more suitable ventilation technology in production. 1. The production and release characteristics of volatile organic compounds (VOCs) in aerobic composting of sludge from sludge disposal plant at high temperature (day 5) were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that the main smelling VOCs during sludge composting was methyl mercaptan, methyl sulfide, dimethyl disulfide, acetone, ethanol and 1-butene. During the diffusion from the body of the reactor to the activity of the workers in the workshop, the main components of VOCs decreased by 89.3- 99.9. The main smelling components, such as methyl mercaptan, dimethyl disulfide and methyl sulfide, were higher than the detection threshold, which was harmful to human olfaction. The maximum ozone formation potential of alkanes, aromatics, ketones and olefins increased in turn, and there was a risk of atmospheric pollution. Through the correlation analysis among the components of VOCs, it was concluded that methylmercaptan should be used as an indicator gas to evaluate the emission of VOCs. 2. The concentration and reactive activity of volatile organic compounds (VOCs) produced and released from sludge composting process in sludge disposal plant under different ventilation modes were studied. Considering the contribution of VOCs photolysis to the formation of O _ 3, the incremental reaction activity (potential of ozone generation) is more suitable than the equivalent propylene concentration method to evaluate the pollution potential of ozone released from composting process to the near earth atmosphere. Compared with other industries, the total VOCs released from sludge composting plants has greater ozone formation potential, among which VOCs with oxygen containing organic compounds contributed the largest potential. 3. The fermentation effects of different fans and different ventilation strategies in actual production were compared, and the variation of temperature, oxygen concentration, NH3 concentration and VOCs concentration in different compost fermentation stage and different ventilation state stage were analyzed systematically. It is considered that the roots blower can increase the heating rate, maintain the high temperature and reduce the amount of VOCs released. The time and effect of flipping in composting production are discussed, and the production process which can effectively reduce the secondary pollution of odor is found.
【学位授予单位】：郑州轻工业学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703;X701
本文编号：2323412
[Abstract]:The odor gas released from sludge composting process has become an important factor restricting the harmless production of sludge, in which volatile organic compounds (VOCs) account for a large proportion of the odor contribution. VOCs mainly includes sulfur compounds. Containing nitrogen compounds and volatile fatty acids, the components are complex and difficult to control. The main factors affecting VOCs emission are ventilation strategy, temperature and pH value, among which ventilation strategy is the most important factor. In this paper, by sampling at the site of composting disposal plant, the diffusion law of odor from the inside of the reactor to the outside world is analyzed, and the harm to human body and the ozone formation potential of secondary pollution to the atmosphere are discussed. This paper discusses and compares two kinds of ventilation strategies in production, and determines the more suitable ventilation technology in production. 1. The production and release characteristics of volatile organic compounds (VOCs) in aerobic composting of sludge from sludge disposal plant at high temperature (day 5) were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that the main smelling VOCs during sludge composting was methyl mercaptan, methyl sulfide, dimethyl disulfide, acetone, ethanol and 1-butene. During the diffusion from the body of the reactor to the activity of the workers in the workshop, the main components of VOCs decreased by 89.3- 99.9. The main smelling components, such as methyl mercaptan, dimethyl disulfide and methyl sulfide, were higher than the detection threshold, which was harmful to human olfaction. The maximum ozone formation potential of alkanes, aromatics, ketones and olefins increased in turn, and there was a risk of atmospheric pollution. Through the correlation analysis among the components of VOCs, it was concluded that methylmercaptan should be used as an indicator gas to evaluate the emission of VOCs. 2. The concentration and reactive activity of volatile organic compounds (VOCs) produced and released from sludge composting process in sludge disposal plant under different ventilation modes were studied. Considering the contribution of VOCs photolysis to the formation of O _ 3, the incremental reaction activity (potential of ozone generation) is more suitable than the equivalent propylene concentration method to evaluate the pollution potential of ozone released from composting process to the near earth atmosphere. Compared with other industries, the total VOCs released from sludge composting plants has greater ozone formation potential, among which VOCs with oxygen containing organic compounds contributed the largest potential. 3. The fermentation effects of different fans and different ventilation strategies in actual production were compared, and the variation of temperature, oxygen concentration, NH3 concentration and VOCs concentration in different compost fermentation stage and different ventilation state stage were analyzed systematically. It is considered that the roots blower can increase the heating rate, maintain the high temperature and reduce the amount of VOCs released. The time and effect of flipping in composting production are discussed, and the production process which can effectively reduce the secondary pollution of odor is found.
【学位授予单位】：郑州轻工业学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703;X701
【参考文献】
相关期刊论文 前2条
1 沈玉君;陈同斌;刘洪涛;高定;郑国砥;;堆肥过程中臭气的产生和释放过程研究进展[J];中国给水排水;2011年11期
2 程水源;李文忠;魏巍;李国昊;王海燕;蒋翠珍;周颖;;炼油厂分季节VOCs组成及其臭氧生成潜势分析[J];北京工业大学学报;2013年03期
，本文编号：2323412
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