【作者】 隋倩雯；

【导师】 董红敏；

【作者基本信息】 中国农业科学院 ， 农业水土工程， 2014， 博士

【摘要】 沼气工程处理畜禽粪污、回收生物能源在我国得到广泛示范应用，但产生的大量厌氧消化液，在无法还田利用的区域，由于缺乏适当的深度处理技术造成环境污染。针对这一个问题，本研究以猪场厌氧消化液深度处理为研究目标，在调研分析了水质参数、单一采用氨吹脱与膜生物反应器（MBR）工艺实验基础上，探讨了氨吹脱与膜生物分反应器组合工艺与运行参数，分析了脱氮细菌的群落演替规律，明确了高氨氮污水短程硝化的控制措施，为猪场厌氧消化液深度处理、畜禽养殖污染防治提供理论与技术支持。主要研究结论如下：（1）通过测试4家猪场的沼气工程厌氧消化液，分析了水质参数，其具有高氨氮、低碳氮比的特性。厌氧消化液氨氮浓度范围300-2000mgN/L、COD/TN仅为1.0-3.5，直接生物脱氮处理存在硝化碱度不足、反硝化碳源不足的问题。（2）采用氨吹脱工艺处理猪场厌氧消化液，分析了pH值、气液比、温度对氨吹脱的影响，并对参数进行了优化。在pH为10.5、气液比为2000-3000、沼液温度为30oC条件下，氨氮去除率为81.84%。经吹脱处理后，沼液碳氮比更为协调，有利于进一步生化处理。（3）采用MBR处理猪场厌氧消化液，明确了碳氮比、氨氮浓度对生物脱氮的影响。在相同的有机负荷（0.5kgCOD/(m3·d)）条件下，COD/TN为1.78-8.76，MBR有机物去除不受碳氮比影响，COD平均去除率75%。在COD/TN为8.76±0.30、BOD5/TN为3.02±0.09时，TN去除率最高为83%。MBR实现了较高的氨氮去除速率0.08kgN/(kgMLSS·d)和95%的氨氮去除率，AOB数量为107-109copies/mL。氨氮浓度对AOB结构具有选择作用。随着氨氮浓度降低，AOB菌群结构多样性降低，Nitronomonas eutropha逐渐消失，Nitrosomonas sp. OZK11表现出较强的底物亲和性，发挥了高效的厌氧消化液氨氧化作用。（4）采用氨吹脱与MBR组合工艺处理猪场厌氧消化液，优化“低pH氨吹脱+短程脱氮MBR”耦合工艺与参数。与“高pH氨吹脱+传统脱氮”相比，采用“低pH氨吹脱+短程脱氮MBR”耦合工艺可实现厌氧消化液脱氮的高效、低成本运行。氨吹脱采用添加NaOH2.37±0.16g/L、pH值为9.39±0.04时，氨氮去除73%，TN去除65%，COD/TN提高至5.0-6.0。后续MBR中，在DO为6.12±0.69mg/L时，通过提高好氧区氨氮负荷至0.12-0.16kgN/(kgMLSS·d)，FA浓度为4-11mgNH3/L时，获得亚硝酸盐积累率53%-71%。通过低pH氨吹脱和MBR中短程脱氮可分别去除厌氧消化液TN的64%和30%，处理后污染物浓度低于国家排放标准（GB18926-2001）。该组合工艺不外加碳源、不影响产沼气过程且可回收氨氮，总处理时间仅为2.0天，处理成本为7.76元/m3。（5）比较了高氨氮污水的短程硝化控制措施，明确了高DO下FA的短程控制条件。FA为10.61±2.89mgNH3/L、DO为4.48mg/L条件下实现了氨氧化率91%、亚硝酸盐积累率83%和较高的氨氮负荷（2.05±0.16kgN/(m3·d)、1.41±0.06kgN/(kgMLSS·d)），该运行负荷比低DO、低FA处理（DO为1.75±0.09mg/L、FA为1.67±0.73mgNH3/L）高4倍。在高DO条件调控高效短程硝化FA浓度应为7-16mgNH3/L。更多还原

【Abstract】 Biogas plants are widely used in confined animal farms in China, for waste treatment andrenewable energy recovery, and it produces large amount of anaerobically digested liquid. Where thedigested liquid could not be applied to the farmland, it poses large threat to the environment due to thelack of appropriate treatment technologies. The object of this study is the deep treatment ofanaerobically digested swine wastewater. The characteristics of the wastewater were investigated. Basedon the sole treatment study of ammonia stripping and membrane bioreactor (MBR), the combinedprocesses were conducted to treat the digested liquid, and the coupling parameters were optimized.Additionally, the shifts of biological nitrogen removal bacteria communities were analysed. Finally,comparison study of influencing factors on shortcut nitrification of high-strength ammonia wastewaterwas investigated. The main conclusions drawn in this study are as follows.（1） Four swine farm biogas plants were surveyed, and the characteristics of digested wastewaterwere figured out, which had high ammonia nitrogen and low carbon to nitrogen ratio. The ammonianitrogen concentration was300-2000mgN/L and COD/TN ratio was1.0-3.5, which realved thatalkalinity deficiency for nitrification and lack of carbon source for denitrification.（2） Ammonia stripping was carried out to treat digested liquid. The effects of pH, air to liquidratio, and temperature on ammonia stripping was investigated and the parameters were optimized. Itsuggested that under the condition of pH of10.5, air to liquid ratio of2000-3000, and temperature of30oC, the ammonia removal rate was optimal of81.84%. After the treatment of ammonia stripping,ammonia was reduced and carbon to nitrogen ratio was increased, which was beneficial for subsequentbiological treatment.（3） MBR was implemented for the treatment of digested swine wastewater, and the effects of C/Nratio and ammonia concentration on biological nitrogen removal were investigated. The MBR showedsteady COD removal rate of about75%when COD/TN was at the range of1.78-8.76with a constantorganic load of0.5kgCOD/(m3·d). TN removal rate was highest of83%at COD/TN of8.76±0.30andBOD5/TN of3.02±0.09. MBR displayed high ammonia oxidizing efficiency with0.08kgN/(kgMLSS·d) and95%of ammonia was oxidized. The AOB abundance was stable at a high level of107-109copies/mL. The ammonia concentration had selective effect on AOB community. With decreaseof ammonia concentration, the diversity of the AOB community decreased. Nitrosomonas eutrophagradually disappeared, whereas Nitrosomonas sp. OZK11showed high affinity for the substrate and wasconstantly adapting to survive with the oxidization of digested swine wastewater.（4） The combined process of ammonia stripping and MBR were adopted for the treatment ofdigested swine wastewater, and the combined process of “Low-pH ammonia stripping and shortcutnitrogen removal in MBR” and parameters were optimized. Compared with the “High-pH ammoniastripping and traditional nitrogen removal”, the “Low-pH ammonia stripping and shortcut nitrogenremoval in MBR” could efficiently remove nitrogen with relatively low cost. Under the condition of NaOH addition amount of2.37±0.16g/L and pH increased to9.39±0.04,73%of ammonia and65%of TN were removed and COD/TN was increased to5.0-6.0by ammonia stripping process. In thesubsequent MBR, at DO of6.12±0.69mg/L, enlarging the ammonia loading rate of O zone to0.12-0.16kgN/(kgMLSS·d) and FA concentration increased to4-11mgNH3/L, nitrite accumulation wasenhanced to53%-71%.64%and30%of TN of the digested liquid were removed by Low-pH ammoniastripping and shortcut nitrogen removal in MBR, respectively. The concentration of the effluent fromthe combined process was lower than the national discharge standard (GB18926-2001). The combinedprocess did not input external carbon and did not have impact on biogas production, and it could recoverammonia. The total treatment period was2.0d, and the running cost was7.76RMB/m3.（5） Controlling prarameters of shortcut nitrification of high strength ammonia wastewater wasinvestigated, and the effect of FA on shortcut nitrification at high DO level was studied. With thetreatment of FA of10.61±2.89mgNH3/L and DO of4.48mg/L, ammonia oxidizing rate was91%andnitrite accumulation rate was83%at ammonia volumetric loading rate of2.05±0.16kgN/(m3·d) andsludge loading rate of1.41±0.06kgN/(kgMLSS·d), which was four times higher than that of the lowDO and low FA treatment (DO of1.75±0.09mg/L and FA of1.67±0.73mgNH3/L). Under the high DOcondition, the FA concentration of inhibition effect on NOB was7–16mg NH3/L.更多还原