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关键词： 膜生物反应器   膜污染   曝气强度   跨膜压差  

摘要： 以聚四氟乙烯制中空纤维膜生物反应器(MBR)为研究对象,将膜组件中的九根膜丝以3×3方阵排列,考察了改变膜间距对不同位置膜丝污染的影响。结果表明,在相同的跨膜压差和曝气强度下,1mm膜间距下的膜污染程度比5mm膜间距的严重,膜表面颗粒物浓度较大。在1mm膜间距下,中心位置膜丝存在最大的“渗透竞争”,而同时又由于“束阻力”的存在,角膜丝和边膜丝的膜表面能受到较好的水力冲刷,造成中心膜丝污染程度远大于角膜丝和边膜丝。在相同的膜间距下,跨膜压差的改变相对于曝气强度的改变对膜污染的影响较小。因此通过优化膜间距和曝气强度是改善膜传质特性的关键因素。

关键词： 动物细胞悬浮培养   流场动力与测控   生物反应器   参数测控  

摘要： 为满足不断增长的生物医药制品需求,动物细胞培养技术备受关注,其中生物反应器是细胞培养的基石,为了获得高质高量的细胞产物,有必要对其流场力学和测控技术进行分析。对此,基于对动物细胞悬浮培养技术的理解,重点探讨了动物细胞悬浮培养流场动力分析方法与测控技术要点,以供参考。

关键词： 膜生物反应器   臭氧工艺   工业区污水处理  

摘要： 随着经济社会的发展,大力发展循环经济是社会持续发展的必然要求,将膜生物反应器与臭氧技术应用在工业区污水处理中,具有良好的经济与社会效益。因此,本文研究应用膜生物反应器和臭氧工艺对工业区污水进行处理,以推进工业区实现节能减排,实现工业污水排放的清洁化和资源化。

关键词： N,N-Dimethylformamide   SAnMBR   Methanogenic degradation   Co-culture   Hydrolysis   F/M ratio  

摘要： The anaerobic treatment of wastewater containing approximately 2000 mg L-1 N,N-dimethylformamide (DMF) was conducted by a lab-scale submerged anaerobic membrane bioreactor (SAnMBR). The inoculum consisted of aerobic DMF-hydrolyzing activated sludge (DAS) and anaerobic digested sludge (ADS). A rapid start-up was achieved with thorough DMF methanogenic degradation on the first day. The results of a 250-day long-term experiment demonstrated that under a low organic loading rate (OLR) of 3.14-4.16 g COD L-1 d(-1), SAnMBR maintained excellent DMF removal efficiency along with high methane conversion. However, the elevation of OLR significantly limited DMF hydrolysis. When OLR exceeded 6.54 g COD L-1 d(-1), both removal efficiency and methane production dramatically dropped. The DMF-hydrolyzing bacteria originating from the DAS gradually decayed under the anaerobic condition, resulting in the weak hydrolysis of DMF. The shortening of hydraulic retention time (HRT) is not recommended for the SAnMBR because severe membrane fouling occurred when HRT was shortened to 8 h. To handle high OLRs, an appropriate solution is to maintain a low F/M ratio by increasing both the influent DMF concentration and sludge concentration. The high CH4 content in the biogas, exceeding 85%, was shown to be the reason for the suitability of anaerobic treatment to DMF. Some improvements which would help to maintain the effective hydrolysis are proposed: a side-stream system to replenish DAS to the SAnMBR is helpful;slight dosage of nitrate could also help to enrich the DMF-hydrolyzing bacteria;and the co-digestion of DMF and other organics might be convenient to establish a stable DMF-degrading consortium. (C) 2019 Elsevier B.V. All rights reserved.

关键词： 农村生活污水   MBR   陶瓷膜   强化脱氮   除磷填料  

摘要： 传统膜生物反应器是农村生活污水处理的重要工艺之一,但其存在氮磷去除效果差等问题,本文旨在探究陶瓷膜生物反应器对农村生活污水的处理效果,并提高其脱氮除磷效果。陶瓷膜-生物反应器(C-MBR)是将好氧生物反应与无机陶瓷平板膜过滤技术相结合的工艺,具有占地面积小、维护简单、排泥量少等优点。本文利用陶瓷膜代替传统膜-生物反应器中的有机膜,对C-MBR进行强化脱氮除磷工艺研究,通过优化回流比、DO、HRT等进行强化脱氮,采用粉煤灰多孔填料吸附进行强化除磷。结果表明:在进水COD和TN、NH_3-N、TP浓度分别为360.00～661.00、33.90～57.60、16.80～32.30 mg·L^(-1)和4.78～5.70 mg·L^(-1),MLSS为3000 mg·L^(-1),膜孔径为50 nm条件下,C-MBR出水对应指标平均浓度分别为34.90、22.59、1.13 mg·L^(-1)和4.57 mg·L^(-1),平均去除率分别为93.68%、47.86%、95.00%和12.32%。优化回流比至200%、DO浓度为2.00 mg·L^(-1)、好氧池HRT为4 h时,TN平均去除率显著提高,最佳可达69.39%,出水平均浓度为12.52 mg·L^(-1),且此时出水稳定、能耗低;粉煤灰多孔填料在水力负荷0.33 m^3·m^(-3)·d^(-1)条件下,对TP去除率可达90.90%,出水平均浓度为0.42 mg·L^(-1),满足一级A标准。使用1000 mg·L^(-1)的次氯酸钠水溶液,以每片膜500mL·30 min^(-1)速度对膜进行在线清洗时,跨膜压差恢复速率最快,膜污染去除效果恢复最佳。优化回流比、DO、好氧池HRT能有效强化C-MBR脱氮效果,填料吸附磷能有效强化除磷效果。本研究为农村生活污水就地处理、提高C-MBR脱氮除磷效果提供了有益参考。

关键词： 氮   污染控制   生物反应器   农业排水   反硝化   固体碳源  

摘要： 农田排水氮素输出是造成水环境污染的重要原因。近年来涌现的生物反应器除氮技术通过在排水末端增设固体碳源装置,将农田排水部分或全部导入后,使其中的硝态氮通过反硝化反应得到去除。该文回顾了国际上现有生物反应器净化农田排水的研究进展,并分析了农田生物反应器在中国南方湿润区应用的潜力。现有研究结果表明,除氮生物反应器可以有效净化排水水质,平均每年可降低 23%~98%的氮素负荷;是一种占地面积少且水质净化效率高的农田控污措施。生物反应器的除氮效果与农田排水过程密切相关,并受到介质特性、入流、出流条件以及环境因子等的影响。中国南方平原作物生长及排水过程相对集中,气象等环境条件非常适于生物反应器的反硝化反应。如何因地制宜确定反应器安装位置与设计尺寸,筛选填料介质,并通过对排水过程的调控来优化生物反应器的除氮效果是需要进一步研究的问题。生物反应器系统后期管理与内部反应动态监测是保证系统正常运行的重要手段。利用生物反应器来净化农田排水具有良好的应用前景,该文可为推动生物反应器在中国的应用研究以及排水污染治理提供理论依据与技术支撑。

关键词： Anisotropic hydrogel membrane   Bacterial nanocellulose   High transparency   Rotary drum bioreactor   Tray static cultivation   Promoted productivity  

摘要： Since anisotropic hydrogel membranes have great potential in tissue engineering and bioseparation, the aim of this study was to produce an anisotropic BNC hydrogel membrane for the first time with enhanced BNC productivity by using a newly designed 30-L horizontal rotary drum bioreactor. As compared with the traditional tray static cultivation, the BNC hydrogel from the rotary drum bioreactor showed anisotropic morphology, sparser network, lower dry matter content of 0.16 w/w%, thicker fiber diameter, and lower degree of polymerization that was still 1.8 times higher than cotton, and featured with much higher ultraviolet-visible light transmittance, as well as demonstrated anisotropic tensile properties, lower Young's modulus of 0.23 MPa and compressive modulus of 0.99 kPa. The productivity of dry and wet BNC was enhanced by 1.65 times and 3.73 times, respectively. The proposed technology may not only obtain anisotropic BNC hydrogel membranes with high transparency, but also promote the BNC productivity.

关键词： 厌氧序批式反应器(ASBR)   化学需氧量(COD)   厌氧氨氧化(ANAMMOX)   启动   脱氮性能   贡献率  

摘要： 采用厌氧序批式反应器(ASBR)处理NH4+-N和NO2--N浓度分别为(25. 00±0. 40) mg·L^(-1)和(33. 00±0. 60) mg·L^(-1)的模拟废水,在温度为30℃时,投加乙酸钠控制COD浓度分别为5. 00、15. 00、30. 00和50. 00 mg·L^(-1),研究对厌氧氨氧化启动的影响.结果表明:①4种COD浓度下分别经过74、94、106和129 d均能成功启动厌氧氨氧化. COD浓度为15. 00 mg·L^(-1)和30. 00 mg·L^(-1)时,反应器脱氮性能较好,稳定运行后,平均出水NH4+-N浓度分别为1. 98 mg·L^(-1)和1. 89 mg·L^(-1),平均出水NO2--N浓度低于0. 62 mg·L^(-1),平均出水TN浓度分别为2. 37、2. 28 mg·L^(-1);②启动过程中反硝化对脱氮的平均贡献率逐渐降低至4. 78%、9. 59%、10. 21%和36. 50%,厌氧氨氧化对脱氮的平均贡献率逐渐上升至95. 22%、90. 41%、89. 79%和63. 50%;③厌氧氨氧化活性分别在第44、76、86和114 d时超过反硝化活性,最后分别达到0. 700、0. 690、0. 670和0. 510mg·(g·h)^(-1),反硝化活性分别为0. 110、0. 130、0. 240和0. 410 mg·(g·h)^(-1).该研究结果可为厌氧氨氧化技术在实际工程中的应用提供参考.

关键词： Hydraulic residence time   Pilot-scale   Woodchip bioreactors   Water quality   Nutrient removal  

摘要： Nitrate (NO3-N) export from row crop agricultural systems with subsurface tile drainage continues to be a major water quality concern. Woodchip bioreactors are an effective edge-of-field practice designed to remove NO3-N from tile drainage. The NO3-N removal rate of woodchip bioreactors can be impacted by several factors, including hydraulic residence time (HRT). This study examined the impact of three HRTs, 2 h, 8 h, and 16 h, on NO3-N removal in a set of nine pilot-scale woodchip bioreactors in Central Iowa. NO3-N concentration reduction from the inlet to the outlet was significantly different for all HRTs (p < 0.05). The 16 h HRT removed the most NO3-N by concentration (7.5 mg L-1) and had the highest removal efficiency at 53.8%. The 8 h HRT removed an average of 5.5 mg L-1 NO3-N with a removal efficiency of 32.1%. The 2 h HRT removed an average of 1.3 mg L-1 NO3-N with a removal efficiency of 9.0%. The 2 h HRT had the highest NO3-N mass removal rate (MRR) at 9.0 g m(-3) day(-1), followed by the 8 h HRT at 8.5 g m(-3) day(-1), and the 16 h HRT at 7.4 g m(-3) day(-1), all of which were statistically different (p < 0.05). Significant explanatory variables for removal efficiency were HRT (p < 0.001) and influent NO3-N concentration (p < 0.001), (R-2 = 0.80), with HRT accounting for 93% contribution. When paired with results from a companion study, the ideal HRT for the bioreactors was 8 h to achieve maximum NO3-N removal while reducing the impact from greenhouse gas emissions.

关键词： Bioreactors  

摘要： This preliminary study investigates how the removal of human adenovirus in a membrane bioreactor (MBR) depends on the MBR configuration. Results from a sidestream MBR (ssMBR) are compared with data from an immersed MBR (iMBR) and literature data for another iMBR with 0.45-m pore size hollow-fiber membranes used in all three reactors. The central premise of the study is that different fouling mitigation approaches in the ssMBR and iMBR lead to differences in membrane fouling and human adenovirus 40 (HAdV 40) removals. The hypothesis tested is that the fouling layer acts as an additional separation barrier and is largely responsible for virus removal in MBRs. Higher HAdV 40 rejection observed in the ssMBR is attributed to a higher density fouling layer formed in the ssMBR under conditions of cross-flow shear. The interpretation is supported by the measured differences in the dissolved organic carbon (DOC) removal and in the specific UV254 absorbance (SUVA254) reduction as well as in the transmembrane pressure response to periodic cleaning in the two MBRs (average decreases in HAdV 40 log removal value of 0.30 and 0.85 in ssMBR and iMBR, respectively). Although the additional energy required to create cross-flow in the ssMBR does not result in permeate flux enhancement over the iMBR baseline, the denser fouling layer in the ssMBR is a more effective barrier for viruses. This trade-off should be considered when weighing the priorities of energy savings and effluent quality.