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关键词： 养猪废水   栅藻LX1   附着培养   污染物去除   光生物反应器  

摘要： 养猪废水是一种高浓度有机废水,利用微藻吸收其中的氮磷等营养物质转化为生物质及高价值产物,能实现废水净化与资源化耦合,近年来备受关注。目前微藻处理养猪废水多采用悬浮培养,处理后微藻采收困难,通过附着培养可能解决该问题。本文以栅藻LX1（Scenedesmus ***1）为研究对象,筛选可供其在养猪废水中良好附着的载体,考察了废水的稀释度、附着方式、培养条件（光照强度、光暗周期和初始藻密度）对其附着处理养猪废水时生长、污染物去除和胞内高价值物质的积累规律。设计了微藻附着培养光生物反应器并考察了反应器中材料间距对净化效果和微藻生长的影响,根据热力学理论解释了藻细胞表面能对附着的影响,并评估了微藻处理养猪废水后的含藻出水作为生物肥料的潜力。选用棉布、尼龙滤布、纱布、毛绒布料、海绵和土工布共6种附着材料,发现土工布上的微藻附着量最高,在5×10～5 cells/m L和1×10～6 cells/m L接种密度下分别可达到131.3 mg/L和404.2 mg/L。材料的结构和亲疏水性对微藻附着起着重要作用,表面光滑导致附着量低,而含有支架结构则可使藻稳定附着,且微藻的附着量与疏水性材料的接触角呈现一定正相关性。在土工布上附着培养栅藻LX1,当养猪废水不灭菌时附着量与污染物去除率均较灭菌时更高。在四个稀释度中（×1,×5,×10和×20）,COD、TN、NH-N和TP的最高去除率分别为86.92%、60.75%、71.81%和96.13%,最高附着量为414.5 mg/L,附着微藻蛋白质含量最高为44.57%。四种附着方式中（水平静置,竖直静置,竖直旋转和半浸没）,竖直旋转的方式最适合于栅藻LX1附着培养处理养猪废水,其中COD和NH-N的去除率分别高达87.44%和61.85%,并可获得最高的生物量299.3 mg/L。土工布上微藻的附着量随着光照强度的增加,光照周期的延长和初始接种密度的增大而升高,其中在光照强度3000 Lux,光照周期18:6 h,初始接种密度4×10～6 cells/m L的条件下,栅藻LX1的附着量高达692.2 mg/L。设计了微藻附着培养光生物反应器,并设置了不同的土工布间距,发现藻附着量随着间距减小而升高,间距4 cm时微藻附着量最大（0.53 g/L）,且污染物去除率比其他两个间距（16和8 cm）条件下高。分析藻细胞表面能发现低表面能的藻细胞由于胞间存在较低粘附功,可促进微藻的附着。最后,考察了净化后的含藻出水对小麦种子发芽和幼苗生长的影响,发现含藻出水不影响发芽但能促进小麦幼苗的生长。培养10 d后,添加净化后藻液废水（1×10～6 cells/m L）处理组中的小麦幼苗茎长最长为14.16 cm,较添加蒸馏水的小麦空白对照组提高20.10%。另外,茎鲜重和干重最高分别为0.13 g和0.015 g,较空白对照组显著增大,分别是1.98倍和1.41倍。

关键词： Membrane bioreactor (MBR)   Salinity   Simultaneous nitrification and denitrification (SND)   Nitrification activity   Microbial community  

摘要： Physical and chemical treatments of Tungsten smelting wastewater, with high salt content and low C/N ratio, are often tedious. As a solution, this study suggested a simultaneous nitrification and denitrification membrane bioreactor (SND-MBR) for salinity gradient domestication. During the salinity acclimation period, we observed 20% and 11% removal of NH4+-N and Chemical Oxygen Demand (COD), respectively. However, the SND efficiency reached 95.55% after stable operation at 3.0% salinity. Through stoichiometric and kinetic analyses, we confirmed that increased salinity significantly inhibited electron transport system activity, nitrification, and denitrification, evidenced by the extremely low ammonia monooxygenase and nitrite reductase activities. Further high throughput sequencing showed that Nitrosomonas dominated the functional microbial flora succession and de nitrification in high salinity environments. In comparison with a control, the Kyoto Encyclopedia of Genes and Genomes analysis showed that wastewater salinity weakened the functional gene level of MBR microbial flora, and the enzyme key to the assimilation nitrate reduction changed from nitrate reductase to assimilation nitrate reductase. (C) 2021 Published by Elsevier B.V.

关键词： 中华蚊母树   扦插   基质   “根盼”生根剂   生根率  

摘要： 为分析不同基质和生根剂浓度对中华蚊母树(Distylium chinense)扦插生根的影响，本研究以中华蚊母树半木质化枝条为实验材料，选取：有机营养土、蚯蚓土、河沙：珍珠岩=3：1，泥炭土、泥炭土：珍珠岩=3：1作为基质，分别与不同浓度“根盼”生根剂(0， 100， 500， 1 000， 2 000 mg/L)组合试验。扦插60 d后统计生根指标(成活率， 生根率， 不定根数， 平均根长， 最长根长等)。结果显示，基质种类和“根盼”生根剂浓度对生根指标均有显著影响。蚯蚓土中插穗全部死亡。泥炭土：珍珠岩=3：1+500 mg/L“根盼”生根剂组合成活率和生根率最高，插穗的最长不定根的长度最长，且主成分分析表明该组合的综合得分最高，是中华蚊母树扦插的最佳组合。进一步对基质的物理化学性质和生根指标相关性分析表明基质的通气孔隙度、pH和电导率与生根指标呈显著相关。推测透气性高、电导率较低、弱酸性基质更有利于中华蚊母树插穗根系发育。

关键词： Membrane fouling   Soluble microbial product   Excitation-emission matrix fluorescence   spectroscopy   Statistical analysis  

摘要： The application of anaerobic membrane bioreactors (AnMBRs) for wastewater treatment is seriously challenged by membrane fouling. Online monitoring of the fouling potential would promisingly support smart control of fouling. The monitoring is most likely achievable using spectroscopic methods, but the spectroscopic indicators are yet to be qualified. In this study, 11 ultraviolet (UV) indicators, 19 fluorescence excitation-emission matrix indicators and 2 infrared scattering indicators were screened during 151-day operation of a lab-scale AnMBR. The critical filtration volume for flux declining to 50% or 25% (V0.5 or V0.25) and the specific resistance (Kcf) were employed as benchmarks of fouling potential for initial pore blocking and subsequent gel/cake layer growth. The 254 and 280 nm UV absorbances (UV254 and UV280) displayed significant correlation coefficients of 0.57-0.77 with the fouling indexes, while the Peak 1 and Peak 2 fluorescence intensities (FIP1 and FIP2) displayed 0.84-0.92. Statistical variance partitioning and Fourier transform infrared analyses showed that polysaccharidelike solutes were mostly responsible for fouling and were UV/fluorescence-sensitive due to the chromophoric/ fluorophoric segments they carried. X-ray photoelectron spectra revealed a correlation of fouling and fluorescence with the O=C-(R N O) content. Ultrahigh-performance liquid chromatography-mass spectrometry substantiated the direct connection of sugar units with chromophoric/fluorophoric groups. Regression models were then established to predict the fouling potential during AnMBR operation. The combined use of FIP1 and UV280 achieved the best prediction of V0.5, V0.25 and Kcf with R2 = 0.763, 0.891 and 0.845, respectively, showing the viability of spectroscopic sensing in membrane bioreactor applications.

关键词： Chlorophyll content   Prunus rootstock   Inhibition of endophytes growth   In vitro micropropagation   Low pH  

摘要： Overgrowth of endophytes in some in vitro cultures may disrupt the normal shoot tip growth and proliferation, being necessary to obtain endophytes-free cultures to achieve a normal plant micropropagation process. To remove these contaminations from the culture medium, antibiotics are commonly added to the culture medium. However, its use in plant production must be urgently reduced because of the current restrictions imposed by the European Union. For that purpose, the effect of acidic low (pH 3) and neutral (pH 7) pH was tested in the GreenTray (R) TIS bioreactor as an alternative to control endophytes growth without affecting the micropropagation of the Prunus rootstock RP-20 explants. The results demonstrated that culture at pH 3 did not affect the number of shoots, shoot FW, shoot length and the amount of chlorophyll pigments, but significantly reduced endophytes population. The identification also revealed that Roseomonas mucosa, Microbacterium oxydans, Bacillus subtilis and Luteibacter yeojuensis were the bacterial isolates responsible of those contaminations. These results might suppose a real breakthrough in the in vitro tissue culture field, although more research is required to meet the pH requirements for the different plant species and other endophytic microorganisms.

关键词： Biohydrogen   Organic loading rate   Electron flow model   Anaerobic membrane bioreactor  

摘要： This study investigated the evaluation of a new operational protocol for increasing the membrane lifetime during bioH(2) production by the anaerobic membrane bioreactor-sequencing batch reactor (AnMBR-SBR) along with a kinetic and membrane fouling study. The certified electron (e(-)) flow model was applied to investigate the structure of microbial community and metabolism pathway. The AnMBR-SBR was operated under varying applied organic loading rates (OLR). At applied OLR of 0.5 g COD/L.d, the bioH(2) production was around 0.39 +/- 0.21 L/d, and an increase of applied OLR to 8.0 g COD/L.d led to improve bioH(2) production to 14.57 +/- 9.06 L/d. At the OLR of 0.5 g COD/L.d, the dominant e(-) sinks were acetate (52.2%) and butyrate (22.5%). While significant augmentation in butyrate production (49.9%) was observed at OLR of 8.0 g COD/L.d, indicating that bioH(2) production was followed by acetate/butyrate pathway. According to the e flow model, NADH(2) balance error at OLR of 0.5 and 1.0 g COD/L.d ranged 3-8%, demonstrating the ferredoxin:hydrogenase system as the main route of bioH(2) production by the spore-forming H-2 producing bacteria viz., Clostridium or Ethanoligenes species. For other OLRs, the error balance of NADH(2) ranged from 21 to 24%, indicating the activation of non-spore-forming bacteria, e.g., Enterobacter, Escherichia, or Klebsiella species that coincide with the spore-forming bacteria.

关键词： Data mining   Multivariate statistical analysis   Data-driven decision-making   Principal Components Analysis (PCA)   Multivariate Statistical Process Control (MSPC)  

摘要： Despite the widespread application and plentiful benefits of membrane bioreactors (MBR), this technology is constrained by membrane fouling, which is regarded as the most serious drawback of process efficiency, especially for treating complex industrial wastewater. In order to control membrane fouling, a large set of variables that are often strongly correlated must be investigated and therefore data mining techniques can be used to extract relevant information from monitoring data sets. This work investigates the relations between different analytic and operating variables (mixed liquor volatile suspended solids, sludge filterability, pH, chemical oxygen demand of the feed, temperature, sequential days without cleaning (SDWC) and membrane permeability) of a pilot-scale MBR treating an oil refinery wastewater by applying Principal Components Analysis (PCA) and Multivariate Statistical Process Control (MSPC). The analyses were performed in R based on a five-year monitoring database. PCA identified sludge filterability, temperature and SDWC as the most influential variables on membrane permeability and it was effective in predicting MBR performance (R-2 = 0.71 and Q(2) = 0.78), enabling to detect atypical observations and thus identify operating faults. Besides, T-2 and Q control charts were able to detect 100% and 96%, respectively, of the low membrane permeability operation (lower than 100 L h(-1) m(-2) bar(-1)) and also to alert preventively about permeability decrease. Therefore, the multivariate control charts could be applied as tools for supporting the decision-making regarding fouling control, e.g., guiding when to perform chemical cleanings and/or dose membrane permeability improvers.

关键词： Enzymes  

摘要： Chiral recognition and quantification of amino acid (AA) enantiomers are of great significance in many fields such as biology and biomedicine. Herein, a general enzyme-driven fluorescence sensing model is proposed to achieve this goal. The designed fluorescent probes consist of three components: a natural enzyme for enantioselective and chemoselective recognition, a borate ester-based fluorescent molecule as a fluorescent response reporter, as well as an ordered mesoporous Ce-based MOF (OMUiO-66(Ce)) for the integration of an enzyme and fluorescent reporter as a cascade response system. In the presence of L-AA oxidase, the sensory platform exhibited highly efficient L-type enantioselectivity toward a series of common AAs and the enantioselective enhancement ratios (ef or Delta I-L/Delta I-D) reached 212 for phenylalanine (Phe), 213 for leucine, 194 for tryptophan and so on. Furthermore, using a specific AA oxidase of l-glutamate oxidase was also exemplified to ensure the rapid quantification of l-glutamate (l-Glu) among numerous free amino acids with high enantioselectivity and chemoselectivity. The specificity of probes toward AA enantiomer recognition was scarcely disturbed by other possibly coexistent interfering species. The direct checking of l-Phe and l-Glu from mixed AA enantiomers in simulated body fluid samples was successfully achieved, indicating their great potential for the high-throughput screening of specific chiral AAs in complex biological samples.

关键词： 气体溶解度   发酵罐   化学物质   微生物转化   生物反应器   测量和控制   二氧化碳   温室气体  

摘要： 据报道,生物发酵工艺可用于将温室气体转化为增值化学品。比利时法兰德斯技术研究院通过采用新高压(高达10bar)发酵罐优化发酵工艺。BioRECO2VER项目中定制生物反应器能测量和控制二氧化碳与氢气(或氧气)、甲烷(或合成气)的发酵,气体被专门细菌转化为有用化学物质。微生物转化发生在液相,试剂以气态注入。在较高压力下进行反应可增加气体溶解度,提高发酵速率。