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关键词： Pharmaceuticals and personal care products (PPCPs)   Electrochemical advanced oxidation   Membrane bioreactor   Biological degradation   Wastewater treatment  

摘要： A novel electrochemical membrane bioreactor (EMBR) was developed for enhancing PPCPs removal from real municipal wastewater. Compared to the control MBR (CMBR) without applying electric field, EMBR exhibited higher removal efficiencies for 14 PPCPs among all investigated PPCPs, including 3 fluoroquinolones, 2 macrolides, 6 sulfonamides and 3 anti-inflammatory drugs, while no significant difference was observed for the rest 8 PPCPs. The enhanced removal of 14 PPCPs was mainly attributed to electrooxidation by the direct anodic oxidation and reactive oxygen species-mediated indirect oxidation. Moreover, membrane fouling rates of EMBR (0.55 +/- 0.10 kPa/d) were significantly reduced compared with CMBR (0.99 +/- 0.09 kPa/d). Microbial activities and community analyses demonstrated that the applied electric field had no noticeable adverse impact on microbial viabilities, richness and diversity. These findings demonstrated that this EMBR enhanced pollutant removal and mitigated membrane fouling simultaneously, highlighting the potential of the novel technology to be used for removing PPCPs from wastewater.

关键词： Anaerobic digestion   Anaerobic membrane bioreactor (AnMBR)   Forward osmosis (FO)   Fouling   Water resource recovery facility (WRRF)   Municipal sewage  

摘要： The application of anaerobic membrane bioreactors (AnMBR) for mainstream municipal sewage treatment is almost ready for full-scale implementation. However, some challenges still need to be addressed to make AnMBR technically and economically feasible. This article presents an updated review of five challenges that currently hinder the implementation of AnMBR technology for mainstream sewage treatment: (i) membrane fouling, (ii) process configuration, (iii) process temperature, (iv) sewage sulphate concentration, and (v) sewage low organics concentration. The gel layer appears to be the main responsible for membrane fouling and flux decline being molecules size and morphology critical properties for its formation. The review also discusses the advantages and disadvantages of five novel AnMBR configurations aiming to optimise fouling control. These include the integration of membrane technology with CSTR or upflow digesters, and the utilisation of scouring particles. Psychrophilic temperatures and high sulphate concentrations are two other limiting factors due to their impact on methane yields and membrane performance. Besides the methane dissolved in the effluent and the competition for organic matter between sulphate reducing bacteria and methanogens, the review examines the impact of temperature on microbial kinetics and community, and their combined effect on AnMBR performance. Finally, the review evaluates the possibility to pre-concentrate municipal sewage by forward osmosis. Sewage preconcentration is an opportunity to reduce the volumetric flow rate and the dissolved methane losses. Overall, the resolution of these challenges requires a compromise solution considering membrane filtration, anaerobic digestion performance and economic feasibility.

关键词： Pellet fragmentation   Bioreactor hydrodynamics   Shear conditions   Enzyme production   Morphology  

摘要： The hydrodynamic environment in bioreactors affects the oxygen transfer rate and the shear conditions during microbial cultivations. Therefore, assessment of the effect of the hydrodynamic environment on cellular morphology can contribute to favoring the production of metabolites of interest. The aim of this work was to use image analysis in order to quantify the fragmentation of Aspergillus niger pellets in a conventional bioreactor operated using different impeller speeds, air flow rates, and impeller configurations including Rushton turbines and Elephant Ear impellers, with evaluation of the influence of the hydrodynamic environment on the production of cellulolytic enzymes. An empirical kinetic model was proposed to describe the dynamics of pellet fragmentation and quantify the shear conditions. The results showed that the agitation speed affected the dynamics of pellet fragmentation in two ways, by accelerating the damage process and by increasing the magnitude of the fragmentation. Both endoglucanase and beta-glucosidase production exhibited a linear relationship with the pellet fragmentation percentage, which was directly related to the shear conditions. Interestingly, beta-glucosidase production was favored under high shear conditions, while the highest endoglucanase production occurred under low shear conditions. These findings may be useful for defining suitable systems and operating conditions for the production of metabolites including enzymes in bioreactors, as well as defining conditions that favour a specific pre-determined enzyme cocktail.

关键词： Volatile fatty acids   Lignocellulosic biomass   Anaerobic digestion   Membrane bioreactor   Rumen microbial community  

摘要： This study evaluates the feasibility of a novel rumen membrane bioreactor (rumen MBR) to produce volatile fatty acids (VFA) from crop residues (i.e. lignocellulosic biomass). Rumen MBR can provide a sustainable route for VFA production by mimicking the digestive system of ruminant animals. Rumen fluid was inoculated in a reactor coupled with ultrafiltration (UF) membrane and fed with maize silage and concentrate feed at 60:40% (w/w). Continuous VFA production was achieved at an average daily yield of 438 mg VFA/g substrate. The most abundant VFA were acetic (40-80%) and propionic (10-40%) acids. The majority (73 +/- 15%) of produced VFA was transferred through the UF membrane. Shifts in dominant rumen microbes were observed upon the transition from in vivo to in vitro environment and during reactor operation, however, stable VFA yield was maintained for 35 days, providing the first proof-of-concept of a viable rumen MBR.

关键词： Full-scale high-rate bioreactor   Fiber manufacturing wastewater treatment   External circulation sludge bed   Metagenomic analysis   Anaerobic granular sludge   Biodegradation  

摘要： The synthetic fiber manufacturing wastewater (FMW) contained large amounts of tetrahydrofuran (THF), 3-buten-1-ol (BDO) and 1,4-butanediol (BTO) and showed a high chemical oxygen demand (COD) of 7,992 +/- 2,252 mg L-1. Ratio of the biological oxygen demand (BOD5) and COD of the FMW stream was analyzed as only 0.094, which reflected the low aerobically biodegradable property. For complementing existed aerobic biological treatment process, an external circulation sludge bed (ECSB) system consisting of two full-scale anaerobic granular sludge (AnGS) bioreactors was constructed and continuous operation for more than 25 months. Even though feed fluctuations occurred, robust performance of the system was exhibited with consistent high removals of COD (85.5 +/- 4.4%), THF (79.8 +/- 8.6%), BDO and BTO (both 100%). Fractionation analyses of AnGS at nine heights of the two bioreactors showed that the bigger size (>0.5 mm) dominated at the bottom (>92.1%). Morphology and elemental analyses of AnGS were helpful to see surface depositions in line with water analyses. Anaerobic biodegradations were also highlighted in a comprehensive analysis of carbon and nitrogen fractions, phosphates, sulfates and other minerals. Moreover, metagenomic analyses revealed Methanomicrobia and Methanosaeta in archaea and Exilispira in bacteria were the dominant genera in microbial community structure, which given more insights of anaerobic biodegradation in the two full-scale bioreactors.

关键词： Antibiotic resistance genes   Wastewater treatment   Aromatics   Metagenomics  

摘要： Aromatic matters are widely present in wastewater, especially industrial wastewater, and may lead to a high abundance of antibiotic resistance genes (ARGs) in wastewater treatment bioreactors and stimulate horizontal transfers of ARGs. Here, we investigated a practical approach that applying ozone pretreatment to mitigate ARGs in bioreactors treating wastewater containing a typical aromatic pollutant, p-aminophenol (PAP). The results showed that ozone pretreatment could effectively reduce the aromaticity of wastewater, and the relative abundance of ARGs in the bioreactor fed with ozone treated wastewater decreased by over 70% compared to the control reactor. Multidrug, quinolone, mupirocin, polymyxin, aminoglycoside, glycopeptide, beta-lactam, and trimethoprim resistance genes were all reduced in the bioreactors receiving wastewater pretreated by ozone. Metagenomic analysis suggested that the reduction of ARGs could be attributed to the co-occurrence of ARGs and aromatic degradation genes in bacteria. Furthermore, we expanded our analysis to investigate 71 metagenomes from different environments, and the results indicated that the impact of aromatics on ARG abundance widely occurs in various ecosystems and confirmed that high levels of aromatics could lead to high abundance of ARGs. Taken together, our work confirmed that the aromatics played critical roles in selecting ARGs and proposed a feasible approach to reduce ARGs in wastewater treatment bioreactors.

关键词： Anaerobic osmotic membrane bioreactor   Forward osmosis   Mixed draw solute   Moving sponge   Phosphorus recovery  

摘要： For the first time, a novel sponge-based moving bed-anaerobic osmosis membrane bioreactor/membrane distillation (AnOMBR/MD) system using mixed Na3PO4/EDTA-2Na as the draw solution was employed to treat wastewater for enhanced water flux and reduced membrane fouling. Results indicated that the moving sponge-AnOMBR/MD system obtained a stable water flux of 4.01 L/m(2) h and less membrane fouling for a period lasting 45 days. Continuous moving sponge around the FO module is the main mechanism for minimizing membrane fouling during the 45-day AnOMBR operation. The proposed system's nutrient removal was almost 100%, thus showing the superiority of simultaneous FO and MD membranes. Nutrient recovery from the MF permeate was best when solution pH was controlled to 9.5, whereby 17.4% (wt/wt) of phosphorus was contained in precipitated components. Moreover, diluted draw solute following AnOMBR was effectively regenerated using the MD process with water flux above 2.48 L/m(2) h and salt rejection > 99.99%.

关键词： mathematical modeling   computational algorithm   rotational bioreactor   Taylor vortices   Navier–   Stokes equations   laminar flow regime   shear stress   scaffold   laser-induced fluorescence   principal component analysis  

摘要： A technology of bone tissue cultivation on a thin scaffold in a rotational bioreactor is developed. An optimal regime of cell material cultivation is determined for testing the method, and an optical method for diagnostics of the bone growth dynamics during its cultivation is found. Numerical simulations of the fluid flow in the bioreactor make it possible to significantly simplify the medical experiment and to choose the optimal values of the rotation frequencies and shear stresses acting on the cell material placed on the scaffold. The optical diagnostics of the scaffold samples in the course of dynamic cultivation in the bioreactor is performed by the method of laser-induced fluorescence. An algorithm based on the principal component analysis is applied to analyze the spectral data;as a result, the spectra of excitation and fluorescent emission of the basic fluorescent substances in the sample (tyrosine and tryptophan amino acids, structural protein (collagen), and fluorescent structures of polycaprolactone) are calculated. It is found that the contribution of the component corresponding to collagen in the samples increases in the process of dynamic cultivation, which testifies to effective formation of the extracellular matrix of the bone.

关键词： butyrylcholinesterase   plant cell suspension cultures   kifunensine   N-glycosylation   plant-made biopharmaceuticals  

摘要： The production andN-glycosylation of recombinant human butyrylcholinesterase (BChE), a model highly glycosylated therapeutic protein, in a transgenic rice cell suspension culture treated with kifunensine, a strong alpha-mannosidase I inhibitor, was studied in a 5 L bioreactor. A media exchange was performed at day 7 of cultivation by removing spent sugar-rich medium (NB+S) and adding fresh sugar-free (NB-S) medium to induce the rice alpha-amylase 3D (RAmy3D) promoter to produce rice recombinant human BChE (rrBChE). Using a 1.25X-concentrated sugar-free medium together with an 80% reduced working volume during the media exchange led to a total active rrBChE production level of 79 +/- 2 mu g (g FW)(-1)or 7.5 +/- 0.4 mg L(-1)in the presence of kifunensine, which was 1.5-times higher than our previous bioreactor runs using normal sugar-free (NB-S) media with no kifunensine treatment. Importantly, the amount of secreted active rrBChE in culture medium was enhanced in the presence of kifunensine, comprising 44% of the total active rrBChE at day 5 following induction. Coomassie-stained SDS-PAGE gel and Western blot analyses revealed different electrophoretic migration of purified rrBChE bands with and without kifunensine treatment, which was attributed to differentN-glycoforms.N-Glycosylation analysis showed substantially increased oligomannose glycans (Man5/6/7/8) in rrBChE treated with kifunensine compared to controls. However, the mass-transfer limitation of kifunensine was likely the major reason for incomplete inhibition of alpha-mannosidase I in this bioreactor study.