高氨氮难降解猪粪沼液的处理工艺探究

发布时间：2018-02-27 18:13

本文关键词： 沼液 SBR A/O 粉末活性炭芬顿　出处：《北京化工大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着畜禽养殖业的规模化发展,养猪场粪污经厌氧消化后产生的沼液对周围环境造成了严重污染。沼液具有高氨氮、难生物降解的特点,直接采用常规的生物法,如SBR工艺、A/O工艺,难以达到稳定的去除效果。根据处理目标的差异,本文分别采取了生物法以及物理化学法对猪粪沼液的处理进行研究。在常规SBR工艺的基础上,分别向两个SBR反应器中投加椰壳粉末活性炭和煤基粉末活性炭,在进水条件为COD:1000-1600mg/L氨氮：200-1000mg/L的情况下,运行68d,COD的平均去除率为59.09%(1$反应器)、53.13%(2#反应器),优于文献中直接采取SBR工艺的处理效果；氨氮的平均去除率为36.08%(1#反应器)、32.26%(2#反应器),两个反应器对NH4+-N的去除效果较差,出水硝氮只在运行初期和补充污泥时有较高的积累,主要原因是生物脱氮所需碳源严重不足,体系对高浓度NH4+-N(进水中的平均含量为444mg/L)的进水条件并不能适应,NH4+-N在水中解离生成的游离氨达到一定浓度时会影响硝化细菌的活性。A/O体系在进水量为0.5 L/h,好氧池污泥负荷0.06 kg COD/(kg MLSS.d)的情况下,加入椰壳粉末活性炭后,好氧池对有机物的去除效率得到一定的改善,投加碳源对氨氮脱除的强化效果不明显,至运行后期去除率跌至20%以下；催化臭氧化预处理能够有效改善A/O中好氧池COD去除率,且能在一定程度上稳定出水水质,在80-104d好氧池出水有机物在1000mg/L上下小范围波动,去除率约为50%。通过对芬顿试剂法降解沼液有机物的研究,分别进行了单因素实验以及正交实验,得出最佳的实验条件是H202与Fe2+摩尔比为6,反应40min,pH=4。根据效应曲线图和正交实验,进行优化验证试验,芬顿试剂法对未经絮凝的沼液原水的去除效果为87.43%,处理后COD:491.57mg/L通过静态吸附实验,用人造沸石对模拟废水(NH4+-N含量1500mg/L)进行影响因子的研究,即粒度、投加量、pH及初始NH4+-N含量等。根据不同浓度NH4+-N废水的吸附实验数据,分别拟合出了Langmuir、 Freundlich等温吸附方程,两个方程的R2均在0.99以上且Langmuir模型更符合人造沸石对445-1485 mg/L氨氮废水的吸附规律,每克人造沸石可吸附28.32 mg NH4+-N;通过考察人造沸石对实际猪粪沼液的吸附随着时间的变化,对数据进行拟合分析后,准二级动力学能够很好的描述人造沸石对猪粪沼液中NH4+-N的吸附行为(R20.99)。人造沸石吸附可脱除猪粪沼液中79.0%NH4+-N,处理后氨氮含量：333.92 mg/L,平衡吸附量：17.95 mg/g。对于不同的循环流速、循环时间、天然沸石粒径以及投加量,在动态条件下,考察了天然斜发沸石对猪粪沼液中NH4+-N的脱除情况。得出最佳的实验条件是循环反应时间90min、流速18 mL/min、粒径1-2 mm的天然斜发沸石250 g(水样体积100 mL),在此实验条件下,可脱除猪粪沼液中23.99%的NH4+-N。
[Abstract]:With the large-scale development of livestock and poultry breeding, the biogas liquid produced by the anaerobic digestion of pig manure has caused serious pollution to the surrounding environment. The biogas liquid has the characteristics of high ammonia nitrogen and difficult biodegradation, so it adopts the conventional biological method directly. For example, SBR / A / O process is difficult to achieve stable removal effect. According to the difference of treatment objectives, this paper studies the treatment of pig manure biogas liquor by biological method and physicochemical method respectively. On the basis of the conventional SBR process, the treatment of pig manure biogas liquid is studied in this paper. Coconut shell powdered activated carbon and coal-based powdered activated carbon were added into two SBR reactors, respectively. Under the influent condition of COD:1000-1600mg/L ammonia nitrogen: 200-1000 mg / L, The average removal rate of SBR was 59.09 ~ (1 $) and 53.13 ~ (13) respectively, which was better than that of directly adopting SBR process in the literature, and the average removal rate of ammonia nitrogen was 36.08 ~ (th) ~ (th) ~ (32. 26) ~ (2) ~ (2) ~ (18) ~ (2) ~ (2) ~ (2). Nitrate in effluent only accumulated in the initial stage of operation and when the sludge was replenished, mainly due to the serious shortage of carbon sources required for biological denitrification. The influent condition of high concentration NH4 -N (the average content in influent is 444mg / L) can not adapt to the concentration of free ammonia produced by dissociation of NH _ 4-N in water, which will affect the activity of nitrifying bacteria. A- / O system can affect the activity of nitrifying bacteria at the influent rate of 0.5L / h, aerobic. Under the condition of sludge loading of 0.06 kg COD/(kg MLSS. D), After adding powdered activated carbon from coconut shell, the removal efficiency of organic matter in aerobic tank was improved to a certain extent, but the enhancement effect of adding carbon source to ammonia nitrogen removal was not obvious, and the removal rate dropped to below 20% at the later stage of operation. Catalytic ozonation pretreatment can effectively improve the COD removal rate of aerobic tank in A / O, and stabilize the effluent quality to a certain extent. The effluent organic matter fluctuates in a small range of 1000 mg / L at 80-104 d. The removal rate is about 50. Through the study on the degradation of organic matter in biogas liquid by Fenton reagent method, single factor experiment and orthogonal experiment were carried out. The optimum experimental conditions were as follows: the molar ratio of H 202 to Fe2 was 6, and the reaction time was 40 min, pH 4. According to the effect curve and orthogonal experiment, The optimal verification test was carried out. The removal efficiency of raw water from unflocculated biogas was 87.43 by Fenton reagent method. After treatment, COD:491.57mg/L was used to study the influence factors of NH _ 4-N content in simulated wastewater by static adsorption experiment with artificial zeolite, I. E. particle size. According to the experimental data of adsorption of NH4 -N wastewater with different concentrations, the isothermal adsorption equations of Langmuir and Freundlich were fitted respectively. The R2 of the two equations is above 0.99 and the Langmuir model is more consistent with the adsorption law of synthetic zeolite for 445-1485 mg/L ammonia-nitrogen wastewater, which can adsorb 28.32 mg NH4 -N per gram of artificial zeolite. After fitting and analyzing the data, The quasi-second-order kinetics can well describe the adsorption behavior of artificial zeolite for NH4 -N in pig manure biogas. The adsorption of artificial zeolite can remove 79.0 NH _ 4-N from pig manure biogas. After treatment, ammonia nitrogen content: 333.92 mg / L, equilibrium adsorption capacity: 17.95 mg / g 路g. Cycle time, particle size and dosage of natural zeolite, under dynamic conditions, The removal of NH4-N from pig manure biogas by natural clinoptilolite was investigated. The optimum experimental conditions were as follows: reaction time 90 min, flow rate 18 mL / min, diameter 1-2 mm, water volume 100mL ~ (-1). The NH4-N of 23.99% in pig manure biogas can be removed.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X713

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