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关键词： Osmotic membrane bioreactor   Buffer solution   Organic solution   Bioelectrochemical system   Reverse solute flux  

摘要： By combining the merits of bioelectrochemical systems and osmotic membrane bioreactors (OMBRs), bioelectrochemically assisted OMBRs (BEA-OMBRs) can achieve simultaneous water/electricity recovery and salinity mitigation. One of the key challenges is reverse solute flux (RSF). The "negative effect" of RSF was turned into a "beneficial effect" by using a reverse-fluxed draw solute (DS) as a buffering agent or a carbon source supplement. The reverse-fluxed anions from the alkaline buffering DSs (NaHCO3 and PBS) stabilized the anolyte pH and had a positive effect on system performance, such as a high total Coulomb of 278.16-289.80C, a high recovered water of 261.64-277.80 mL, and a high COD removal of 90.91-91.61%. The reverse-fluxed cations from the acidic buffering DS (NH4Cl) promoted the accumulated ammonium to diffuse from the feed/anode to the cathode side due to the production of ammonia gas in the alkaline catholyte. The organic DS exhibited a lower RSF and a lower anolyte conductivity of 5.12-8.49 mS cm(-1). However, the reverse-fluxed organic DSs (glucose and NaOAc) had a negative effect on the electricity generation due to carbon source competition. These results have demonstrated the advantages of the reverse-fluxed DS to enhance the system performance and to encourage further development of BEA-OMBR technology.

关键词： Anaerobic membrane bioreactor   Gas sparging intensity   Fouling rate   Foulant layer structure   Quantitative relationships  

摘要： Biogas sparging is one of the most commonly used strategies for membrane fouling control in anaerobic membrane bioreactors (AnMBR). However, as a cost-effective sparging pattern, high/low alternate sparging mode was seldom studied, not to mention at a quantitative level. In this study, we systematically assessed the impacts of various parameters of gas sparging (intensity, duration and interval/frequency) on membrane fouling characteristics, on the basis of orthogonal tests coupled with statistical analysis of variance and covariance. The specific gas demand in the high-intensity phase (SGD(H)) was identified as the key factor impacting the overall fouling rate and stagewise rate constants (K-p' and K-c' for pore blocking and cake layer stages respectively) with negative correlation. The product of SGD(H) and time, i.e. the accumulative gas amount in the high-intensity phase (Q(H)), was identified as the key factor affecting foulant layer reversibility (eta) and specific resistance (alpha), with logarithmic models established in terms of log Q(H) versus log eta and log alpha. The validity and robustness of the quantitative models with definite physical meaning were evaluated via Monte Carlo simulation of the regression. The underlying mechanisms were explained from the perspective that hydrodynamic conditions influence mixed liquor and foulant properties (particle size distribution, microbial products amount and component) and, hence, affect fouling rates and foulant layer properties, with a panorama of the interrelated factors and properties delineated by multivariate analysis. This study is expected to provide a quantitative basis for the design of gas sparging conditions, under which sustainable operation of AnMBR could be achieved with the lowest energy consumption. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Simulation   Membrane bioreactor   Petrochemical wastewater   Solid retention time   Model calibration  

摘要： Mathematical modelling of biological treatment is an effective tool to predict effluent quality. Model calibration is critical to improve the accuracy of simulation, which is normally carried out by fine-tuning the values of parameters according to the practical data. It indicated that huge amount of practical date will be consumed, and it cannot predict the treatment performance of new wastewater. In this study, the main objective was to investigate the feasibility of application BioWin software coupled with determination of sensitive parameters to predict the treatment performance of membrane biological reactors (MBRs) treating real petrochemical wastewater (PW). Model calibrations, i.e., COD fractions of petrochemical wastewater and kinetic parameters of biomass, were carried out using the respirometry method and the relationship between observed and true growth yield coefficients of the three lab-scale MBRs which were operated under different solid retention time (SRT). All the three MBRs had good organic and ammonium removal, with removal efficiencies higher than 80% and 99.9%, respectively. Simulation using the calibrated model also obtained good fit for effluent COD concentration, effluent nitrate concentration and bioreactor's MLSS concentration of all the three MBRs. The mean absolute percentage errors (MAPE) of the simulation mostly were lower than 22%. The results indicated that it is feasible to using BioWin, incorporated with appropriate determination methods of sensitive parameters, to simulate and monitor the treatment performance of MBR treating petrochemical wastewater. This is more time-saving and effective than fine-tuning values of all parameters. This study provides a valuable reference for simulation of industrial wastewater treatment using BioWin. (c) 2020 Elsevier B.V. All rights reserved.

关键词： 萱藻   丝状体   气升式光生物反应器   CO2   生长   光合作用   呼吸作用   发育  

摘要： 为实现萱藻丝状体的快速扩增,本实验以萱藻丝状体为研究对象,应用实验生态学方法对三种充气条件(充空气、连续充CO2以及基于培养液pH稳定在7.5~8.0条件的间歇充CO2)下气升式光生物反应器中萱藻丝状体的生长、生理及发育进行了比较研究。结果显示,间歇充CO2可显著提高萱藻丝状体的日均增长率,扩增18 d日均增长率为(24.15±2.34)%,显著高于充空气与连续充CO2组;间歇充CO2条件下萱藻丝状体代谢旺盛,生长良好,光合放氧及呼吸耗氧速率分别为(25.99±1.88)和(15.98±0.97)μmol O2·g^-1 FW·h^-1,较连续充CO2组分别提高了38.23%和55.05%,较充空气组分别提高了57.91%和43.46%;间歇充CO2可促进萱藻丝状体孢子囊的发育,诱导18 d孢子囊比例可达(51.03±0.78)%,显著高于充空气组与连续充CO2组;间歇充CO2条件下扩增获得的丝状体游孢子放散量及附着率最高,经阴干刺激,放散2 h后孢子放散量为(11.33±1.33)×104 ind/mg FW,48 h后附着率为(90.67±2.40)%,较连续充CO2组分别提高了17.24%和3.82%,较充空气组分别提高了99.82%和5.54%。

关键词： 餐厨废水   高温厌氧发酵   厌氧膜生物反应器   膜污染  

摘要： 以除油后的实际餐厨废水为原料,在高温(50±1)℃条件下利用浸没式纤维膜生物反应器(AnMBR)进行连续厌氧消化试验,以水力停留时间(HRT)20d启动,HRT 15d运行,直到发生膜污染,试验共进行了50d.研究了反应器启动和运行期间的发酵特性和膜过滤性能.研究表明,反应器30d完成了启动,在HRT 15d条件下,甲烷产量达到578L/kgVSin,COD和挥发性固体(VS)去除率均达到94%以上,膜出水总挥发性脂肪酸(TVFA)浓度为(103±77)mg/L,其中乙酸浓度为(98±28)mg/L.系统pH 8.26,具有良好的稳定性.膜通量设定为9L/(m2⋅h),运行30d后发生了明显的膜污染,伴随着反应器内挥发性悬浮固体(VSS)浓度由8.1g/L逐渐增加到18/L.在处理高浓度餐厨废水时,AnMBR可以短时间启动且在8.5kgCOD/(m3·d)的高负荷条件下稳定运行,反应器中污泥浓度和溶解性微生物产物的增加导致膜过滤性能下降是导致膜污染的主要因素.

关键词： 盘管式生物反应器   低污染水   脱氮   工艺参数   微生物群落结构  

摘要： 为考察盘管式生物反应器对低污染水的脱氮性能,对比4组不同工艺参数STB的持续运行效果,并对运行后的STB基质进行微生物群落结构进行高通量16S r RNA多样性测序和分析。结果表明:STB在最佳工艺参数下(水体流速为1.5 m/h、处理水量为5.5 L/h)对NH4^+-N、NO3^--N和TN的去除率分别可达62.6%、90.9%和79.5%;基质中反硝化相关菌属占绝对优势(28.8%),表明STB内部具有适于反硝化功能菌群富集和生长的环境,从而为低污染水的持续高效脱氮提供保障。

关键词： 振动格栅紊流   气含率   氧转移系数   雷诺应力   生物膜  

摘要： 为研究紊流脉动对生物反应器运行的影响,针对时均速度为零的振动格栅反应器,构建气-液两相流模型并对其进行验证。借助Fluent软件对反应器中气和水的流动进行数值模拟,得出10种工况下紊流脉动强度与气含率、氧转移系数和雷诺应力的关系。结合实验测得的生物膜理化数据,分析紊流脉动强度对生物膜生长的影响。结果表明,增大紊流脉动可有效提高反应器内的气含率和氧转移系数,促进气液两相进行高效传质。对于本研究所用振动格栅生物反应器,当紊流强度q<2.7 cm/s时,生物膜厚度和密度随着紊流强度的增加而增加。当q>2.7 cm/s时,雷诺应力的作用显著,生物膜逐渐变薄变密。紊流强度q=3.4~4.8 cm/s时,生物膜生长和污染物去除效果最佳。

关键词： 膜生物反应器   膜污染   电化学   膜电极   超滤  

摘要： 电控膜生物反应器(Electrical membrane bioreactor,eMBR)在膜生物反应器中引入电极反应、电场效应,将膜分离技术、微生物降解以及电化学水处理技术有机结合,提升出水水质、减缓膜污染、强化产生物气,对构建"碳中和"型污水处理技术模式具有重要科学意义和应用价值.近年来,膜材料科学和反应器设计不断发展,推动eMBR技术进步,在强化污染物去除、电化学控制膜污染和微生物电化学响应原理方面取得重要进展;对eMBR的研究出现新态势:注重导电膜/膜电极材料研制与应用、回收污水中资源与能源、短流程-无药剂的反应器构造和工艺设计.本文总结回顾了国内外相关研究,分析了eMBR的基本特征和优势功能,重点关注膜污染电控原理以及微生物的电场响应机制,并展望了eMBR的发展趋势,以期推动电驱动膜分离技术的研究与应用.

关键词： 生物反应器   己酸乙酯   乳酸乙酯   窖泥微生物   高通量测序  

摘要： 以浓香型白酒窖泥作为出发菌群,高乳酸盐浓度模拟黄水为载体,在自行设计的生物反应器中构建以乳酸转化为己酸为目的的反应体系。经不同操作条件培养相同时间后发现在37℃培养温度,进料pH值为5.5~6.0,乳酸进料质量浓度为40 g/L,活性炭和改性聚氨酯海绵填充反应容器时,该反应体系降乳增己功能明显加强。对比驯化前后,菌群结构发生显著变化,该体系发酵液中的微生物较窖泥出发菌群的微生物群落多样性显著降低,且与产己酸和降乳酸相关的Clostriduim属占主要优势,参与降解氨基酸的Aminobacterium属显著增多。将上述培养液运用于白酒发酵,常规发酵为对照,结果表明,在白酒发酵不同阶段加入强化黄水,原酒中的己酸乙酯含量均有不同程度的提高。在发酵初始加入强化黄水后的原酒中己酸乙酯含量达561.9 mg/L,相比对照组提高330.9%;发酵7 d后添加强化黄水的原酒与对照组相比己酸乙酯增加154.6%的同时乳酸乙酯下降9.8%,比例合宜。该研究证实了驯化窖泥菌群并将其运用于白酒发酵达到降乳增己的效果现实可行,对改善白酒风味提高品质具有积极意义。

关键词： 硫酸盐还原氨氧化   厌氧   生物反应器   微生物菌群   废水  

摘要： 硫酸盐型厌氧氨氧化(SRAO)可在厌氧条件下,将废水中氨和硫酸盐转化为氮气和低价态硫而同时去除,为污水脱氮除硫提供了新的思路,但对该反应的建立与反应器的启动还认识不清。该文综述了近年来的国内外SRAO脱氮研究进展,分析了SRAO反应的可能机理、微生物菌群以及反应发生的影响因素,提出了SRAO建立的一些关键问题,讨论了氨氮与硫酸盐可能的转化方式,可为今后研究探索方向。