反硝化法降解污泥干化废气挥发性有机物研究

发布时间：2018-06-24 02:06

本文选题：VOCs + 反硝化　；参考：《扬州大学》2017年硕士论文

【摘要】：污水厂剩余污泥干化过程会产生大量挥发性有机物(VOCs),影响大气环境。针对污泥干化VOCs减排,本文提出了采用反硝化微生物降解污泥干化废气中VOCs的方法。通过试验,研究了反硝化生物处理技术处理污泥干化废气VOCs的有效性,分析了抽吸风量、干化废气中无机物等因素对VOCs处理的影响。主要结论如下:(1)针对剩余污泥干化废气VOCs去除,反硝化生物法明显优于普通生物法。在多组不同的干化温度和进气浓度实验条件下,反硝化装置都比好氧装置对挥发性有机物的去除率高12-30%,能有效降低干化废气排入大气中的VOCs总量。(2)研究发现,试验采用的反硝化装置内同时发生生物反硝化作用和生物好氧作用。实验条件下,反硝化反应在VOCs去除作用中占比为12-27%。(3)不同污泥干化温度所产生的废气有机物组分不同,对普通生物处理装置VOCs去除效率有明显影响,但对反硝化装置的影响较小。较高干化温度下,废气VOCs种类变多,其中含有更多的分子量较高的VOCs,有着更多的苯系物和酯类物质,这些物质有着更为稳定的化学性质,更难被微生物代谢利用。对于一些种类的VOCs,反硝化微生物比好氧微生物有更高的代谢利用能力。(4)干化废气中的氨氮基本转移到液相并被好氧硝化作用转化为硝态氮,这部分硝态氮也为反硝化反应提供氮源。可以节省外加硝态氮的量。实验条件下,废气中的氨气为反硝化反应提供约40%的氮源。(5)干化废气抽吸风量影响反硝化装置的反硝化状态,当抽吸风量较大时,装置内溶解氧浓度高,反硝化反应受到抑制,装置内反硝化作用占比减少会导致VOCs去除率降低。(6)从干化废气VOCs成分分析结果可以看出,废气中VOCs中成分较为复杂,种类繁多,其中药物残留成分较多,如醋酸泼尼松龙、倍氯米松、维醋酸氢化可的松等物质,也存在蓖麻油酸等表面活性剂物质、二氯甲烷等涂料残留物。
[Abstract]:A large number of volatile organic compounds (VOCs) will be produced during the drying process of excess sludge in wastewater treatment plants, which will affect the atmospheric environment. In view of the emission reduction of sludge drying VOCs, a method of denitrification microorganism was proposed to degrade VOCs from sludge drying waste gas. The effectiveness of denitrification biological treatment technology in treating VOCs from dry sludge waste gas was studied, and the effects of suction volume and inorganic substances in dry waste gas on the treatment of VOCs were analyzed. The main conclusions are as follows: (1) for the removal of VOCs from dry waste gas of excess sludge, the denitrification biological method is obviously superior to the ordinary biological method. Under the experimental conditions of different drying temperature and inlet concentration, the removal rate of volatile organic compounds by denitrification unit is 12-30% higher than that of aerobic unit, which can effectively reduce the total amount of VOCs discharged into the atmosphere by drying waste gas. (2) it is found that, Both biological denitrification and biological aerobic action occurred in the denitrification plant. Under the experimental conditions, the proportion of denitrification in VOCs removal was 12-27. (3) the organic components of waste gas produced by different sludge drying temperature had obvious influence on the removal efficiency of VOCs in common biological treatment plant, but had little effect on denitrification unit. At higher drying temperature, there are more kinds of VOCs in exhaust gas, which contain more VOCs with higher molecular weight, more benzenes and esters, which have more stable chemical properties and are more difficult to be metabolized by microorganisms. For some kinds of VOCs, denitrifying microorganisms have higher metabolic utilization ability than aerobic microbes. (4) ammonia nitrogen in dry waste gas is basically transferred to liquid phase and converted to nitrate by aerobic nitrification. This part of nitrate also provides nitrogen source for denitrification. The addition of nitrate can be saved. Under the experimental conditions, ammonia in waste gas provides about 40% nitrogen source for denitrification. (5) the amount of dry waste gas suction affects the denitrification state of the denitrification unit. When the suction volume is large, the dissolved oxygen concentration in the unit is high and the denitrification reaction is restrained. The decrease of the proportion of denitrification will lead to the decrease of VOCs removal rate. (6) from the analysis of VOCs in dried waste gas, it can be seen that the composition of VOCs in waste gas is more complex and varied, among which there are more drug residues, such as prednisolone acetate, Beclomethasone, hydrocortisone acetate and other substances, such as castor oil surfactant substances, dichloromethane and other paint residues.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X701

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