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关键词： bioreactor   calanoid copepod   cannibalism   egg collection efficiency   egg separation   free-spawner  

关键词： membrane   membrane bioreactor   nanodiamond   polypropylene  

摘要： The aim of this work is to prepare polypropylene (PP) membrane by embedding carboxylated(-COOH) and also polyethylene glycol(-PEG) functionalized nanodiamond to improve membrane hydrophilicity and decline membrane fouling in pharmaceutical wastewater treatment. Porosity, contact angle, mechanical strength, field emission scanning electron microscopy (FESEM) and membrane pure water permeation analysis were performed for the characterization of the membranes. The membranes with 0.75 wt.% of nanoparticles introduced the highest water flux, porosity and mechanical strength. The performance of PP, PP/ND-COOH (0.75 wt.%) and PP/ND-PEG (0.75 wt.%) membranes was studied in a lab-scale membrane bioreactor (MBR). COD removal was more than 91% in all cases. It was found that antifouling characteristics, membrane resistance (R-m) and specific cake layer resistance (alpha) of nanocomposite membranes were better than of neat PP membrane. PP/ND-PEG (0.75 wt.%) membrane exposed highest hydrophilicity and maximum critical flux and anti-fouling characteristics. The results indicated that embedding nanodiamond in PP membrane can reduce membrane fouling in MBR.

关键词： Dual-flow perfusion bioreactor   3D Scaffold   Fluid dynamics   Tunable radial flow   Polymeric fluorescent nanoparticles  

摘要： An advanced dual-flow perfusion bioreactor with a simple and compact design was developed and evaluated as a potential apparatus to reduce the gap between animal testing and drug administration to human subjects in clinical trials. All the experimental tests were carried out using an ad hoc Poly Lactic Acid (PLLA) scaffold synthesized via Thermally Induced Phase Separation (TIPS). The bioreactor shows a tunable radial flow throughout the microporous matrix of the scaffold. The radial perfusion was quantified both with permeability tests and with a mathematical model, applying a combination of Darcy's Theory, Bernoulli's Equation, and Poiseuille's Law. Finally, a diffusion test allowed to investigate the efficacy of the radial flow using Polymeric Fluorescent Nanoparticles (FNPs) mimicking drug/colloidal carriers. These tests confirmed the ability of our bioreactor to create a uniform distribution of particles inside porous matrices. All the findings candidate our system as a potential tool for drug pre-screening testing with a cost and time reduction over animal models.

关键词： dielectric spectroscopy   perfused-continuous mode   marker expression   umbilical cord mesenchymal stem cells  

摘要： As a clinical dose requires a minimum of 10(6) cells per kilogram of patients, it is, therefore, crucial to develop a scalable method of production of Wharton Jelly mesenchymal stem cells (WJ-MSCs) with maintained inner characteristics. Scalable expansion of WJ-MSCs on microcarriers usually found in cell culture, involves specific cell detachment using trypsin and could have harmful effects on cells. In this study, the performance of batch, fed-batch, and perfused-continuous mode of culture were compared. The batch and fed-batch modes resulted in expansion factors of 5 and 43, respectively. The perfused-continuous mode strategy consisted of the implementation of a settling tube inside the bioreactor. The diameter of the tube was calculated to maintain microcarriers colonized by cells in the bioreactor whereas empty microcarriers (responsible for potentially damaging collisions) were removed, using a continuous flow rate based on MSCs physiological requirements. Thanks to this strategy, a maximal number of 800 million cells was obtained in a 1.5 L bioreactor in 10 days. Lastly, online dielectric spectroscopy was implemented in the bioreactor and indicated that cell growth could be monitored during the culture.

关键词： Eutrophication   Microbial community   Water quality parameters   Removal rates   Viable but non-culturable (VBNC) bacteria   Resuscitation-promoting factor (Rpf)  

摘要： The purpose of this study was to investigate the purification effect of a new adsorption material containing bioreactor and the critical role of viable but non-culturable (VBNC) bacteria in a eutrophication ecosystem. Major water quality parameters of the prepared eutrophic water were determined, and the microbial community was analyzed during 2 years. The results showed that removal rates of total phosphorus (TP), total nitrogen (TN), chlorophyll-a (Chl-a), and chemical oxygen demand (COD) were 90.7-95.9%, 84.5-92.4%, 87.9-95.8%, and 68.3-82.7%, respectively, indicating the high efficiency of the bioreactor in the eutrophic water treatment. Although the bioreactor had been operated for 2 years, water from the treatment group was much clearer and odorless than from the control group, exhibiting the long service life of the bioreactor. Stopping operation in August caused significant decrease of the removal rates of major water quality parameters (p < 0.05). This operational stop event and high temperature in summer exerted a dual effect on the bioreactor, whereas the impact could be minimized when the bioreactor was running. Moreover, the total bacteria under +Rpf (active resuscitation-promoting factor) treatment were higher than under -Rpf (inactive resuscitation-promoting factor) treatment, implying that Rpf could resuscitate VBNC bacteria in the eutrophication ecosystem. Nine strains of VBNC bacteria were isolated based on the BLAST results of the 16S rRNA gene. Also, these bacteria might contribute to the eutrophic water treatment based on their functions of phosphorus collecting and denitrification. These results provided new insights for engineering technology innovations, and consequently these findings had benefits in eutrophic water treatment.

关键词： Extracellular    polymeric substance   Microbial community structure   Biodiversity  

摘要： Compared to the suspended culture (sludge) of a conventional bioreactor, hybrid membrane bioreactors (HMBRs) are more effective at removing pollutants owing to the addition of fillers addition of fillers that facilitate biofilm formation. However, the microbial community structure and composition in an HMBR remain unclear. We ran three laboratory-scale HMBRs at room temperature under different sludge retention times (SRTs;10 d, 20 d, and 30 d) to compare the microbial diversity and community structure among the membrane surface, suspended filler surface, and mixed liquor using high-throughput sequencing. The results showed that SRT can markedly affect microbial community structure in the HMBR, and different trends appeared in the three functional units. The largest number of mutual operational taxonomic units was found in the activated sludge mixture and suspended carrier with an SRT of 20 d and 30 d. Species belonging to Proteobacteria in the 10 d SRT group had the greatest contribution to between-group differences. A longer SRT could mitigate membrane fouling by decreasing the relative abundance of Thauera and Sphaerotilus attached on the membrane surface. Comamonadaceae, a family of denitrifying bacteria, offer high denitrification potential for bioreactors operating under a long SRT.

关键词： Agricultural irrigation   Membrane bioreactor (MBR)   Reverse osmosis (RO)   Microbial quality   Toxicity   Wastewater reclamation and reuse  

摘要： The issue tending toward alternative water resources tremendously becomes important for supplying the increasing water demand all over the world. It may be a good option to evaluate industrial effluents for agricultural irrigation. However, industrial effluent must be cleansed from the factors such as salt, toxic compounds, and microbial load that possibly cause negative effects on soil during agricultural irrigation. In this study, microbiological qualities and toxicity conditions of water sources such as membrane bioreactor (MBR) influent, MBR effluent, and mixture of MBR effluent and reverse osmosis (RO) permeate (MBR:RO = 2:1) were analyzed and evaluated according to irrigation standards. Total aerobic heterotrophic bacteria (TAHB), total coliforms (TC), fecal coliforms (FC), fecal streptococci (FS), and Clostridium spp. were screened and enumerated as indicator microbial groups for the microbial quality of water samples. Analyses of indicator microorganisms showed that loads of different bacterial groups decreased by 5.2 and 6.66 log units at maximum levels in MBR and MBR + RO system at the end of treatment. Also, evaluation of the toxicity effects of MBR effluent and MBR + RO permeate waters on Vibrio fischeri and Daphnia magna was investigated. None of the samples showed any acute toxic effect on D. magna after 48 h and V. fischeri in 5 min and 15 min. From the outputs of this study, it can be said that industrial effluents treated by advanced filtration technologies may provide a significant source of water for agricultural irrigation. This option can have positive impacts on both environmental and economic factors.

关键词： Algae-activated sludge   Biofilm   Fatty acids   Material balance   Micropollutants   Species identification  

摘要： In this study, the efficiency of a trickling photo-bioreactor (TPBR), seeded with activated sludge and microalgae, was evaluated for domestic wastewater treatment. TPBR was operated completely on natural aeration at 2-, 4-, and 6-h hydraulic retention time (HRT) with a 12:12 h light: dark cycle. The total organic carbon (TOC) and total nutrient (TN) removal were negatively affected by decreasing the HRT from 6 to 2 h. The TPBR was able to reduce TOC from 93 to 9 mg/L, TN from 34 to 18 mg/L, and phosphorus from 23.5 to 4 mg/L at 6-h HRT. The chlorophyll concentration (5 - 7 mg per liter of sponge volume) was observed to be highest in the middle of the reactor. Altogether, 106 organic micropollutants of different classes like pharmaceutical, personal care products, pesticides, herbicides, and fungicides were detected in the influent wastewater sample. However, in the treated effluent, only 17 micropollutants were detected at 6-h HRT. This shows that the algal-bacterial consortia are capable of removing micropollutants from wastewater. The energy input was 0.06 kWh/kg COD removed which is much less than the conventional activated sludge processes. The results indicate that this novel system is capable of providing a sustainable wastewater treatment solution. (c) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

关键词： Porous spherical carriers   Membrane biofouling   Extracellular polymeric substances (EPS)   Microbial community   N-acyl-homoserine lactones (AHLs)  

摘要： In this study, porous spherical carriers were fixed around the hollow fiber membrane module to mitigate membrane biofouling. Two MBRs (R1 without carriers, R2 with carriers) were operated for 31 days under identical operating conditions to investigate the effects of the carriers on the reactor performances, the production of extracellular polymeric substances (EPS), the level of N-acyl-homoserine lactones (AHLs), and the microbial communities. The results showed that the presence of carriers in MBR was conducive to nitrogen removal and decreased the total membrane filtration resistance by about 1.7 times. Slower transmembrane pressure (TMP) rise-up, thinner bio-cakes, lower EPS production, and fewer tryptophan and aromatic proteins substances on the membrane surface were observed in R2. The polysaccharides secretion of EPS in bio-cakes was mainly regulated by C4-HSL and 3OC6-HSL in the presence of carriers. The microbial community analysis revealed that carriers addition reduced the relative abundance of EPS and AHL producing bacteria in the membrane bio-cakes and enriched the accumulation of functional bacteria conducive to nutrient removal in the mixed liquor. This study provided an in-depth understanding for the application of porous spherical carriers to alleviate membrane biofouling. (c) 2021 Elsevier B.V. All rights reserved.

关键词： Organic saline wastewater   Anaerobic biological treatment   Anaerobic salt-tolerant flora   Model for salt-tolerant microorganisms   Spiral symmetry stream anaerobic bioreactor  

摘要： In this study, a Spiral Symmetry Stream Anaerobic Bioreactor (SSSAB) was adopted for treating actual saline heparin sodium pharmaceutical wastewater (HSPW). After adaptation, under the influent COD of 8731 mg/L, OLR of 6.98 kg COD/(m3 center dot d) and salinity of 3.57 wt%, the COD removal reached up to 82%. This value is much higher than the reported for the other reactors at similar salinity. Benzenes are the major organic compounds in HSPW. The main rate-limiting steps are the degradations of phenol and p-cresol. In addition, the degradation pathways of typical benzenes in HSPW were analyzed. After adaptation, the soluble salt content in the granular sludge increased, and the bacterial extracellular polymers (EPS), especially tightly-bound EPS also significantly increased. 16S rRNA analysis revealed that the microbial community in the anaerobic granular sludge (AGS) had become adapted to the HSPW treatment since Mesotoga (12.4%), Anaerophaga (9.0%), Oceanotoga (6.1%) and Aminobacterium (4.1%) increased from previously below 1.0% values. The relative abundance of Methanosarcina in the upper layer of the reactor (68.7%) is significantly higher than that at the bottom (3.8%). This proves the superiority of the SSSAB structure. Finally, a model for salt-tolerant microorganisms is given, which proposes a mechanism for this study and provides reference for other anaerobic biological treatments of high-salt containing wastewater.