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摘要： 285

关键词： Ibuprofen-degrading bacteria   Immobilized cell bioreactor   Acidification   Novosphingobium   Rhodanobacter   Non-steroidal anti-inflammatory drug (NSAID) degradation  

摘要： An enrichment process was employed by applying high ibuprofen concentration in an immobilized cell bioreactor in order to favor the ibuprofen-degrading community present in activated sludge. Experimental data showed the ability of the immobilized cell bioreactor to achieve high ibuprofen removal efficiencies (98.4 +/- 0.3%), the tendency of the enriched biomass to acidify the treated liquor, and the inhibition of the nitrification process. Illumina sequencing revealed a massive increase in the relative abundance of Alphaproteobacteria and Gammaproteobacteria (from 29.1 to 80.8%) and a dramatic decrease in the proportion of Bacteroidetes, Planctomycetes, and Verrucomicrobia (from 42.7 to 2.1%) when pure ibuprofen served as the sole carbonaceous feeding substrate. This shift in the feeding conditions resulted in the predominance of Novosphingobium and Rhodanobacter (25.5 +/- 10.8% and 25.2 +/- 3.0%, respectively) and demonstrated a specialized ibuprofen-degrading bacterial community in activated sludge, which possessed the selective advantage to cope with its degradation. To the best of our knowledge, this bioreactor system was capable of effectively treating the highest ibuprofen concentration applied in wastewater treatment plants.

关键词： Biofiltration   Histopathology   Particle size distribution   Water quality monitoring  

摘要： The effect of bioreactor design on nitrification efficiency has been well studied, but less is known about the overall impacts on water quality. Besides nitrification, submerged fixed bed bioreactors (FBBR) trap fine solid particles, whereas moving bed bioreactors (MBBR) grind solids, possibly increasing solids and particle accumulation in the system. In this experiment, the effects of different combinations of fixed bed and moving bed bioreactors on water quality, solids removal, particle size distribution, fish health based on histopathological changes and nitrification efficiency were studied in laboratory scale recirculating aquaculture systems (RAS) with rainbow trout (Oncorhynchus mykiss). Three set-ups with triplicate tanks were used: 1. two consecutive fixed bed bioreactors (FF);2. a fixed bed bioreactor followed by a moving bed bioreactor (FM) and 3. two consecutive moving bed bioreactors (MM). Fish performance was not influenced by the design of the bioreactor, specific growth rate (SGR) being between 1.59 and 1.64% d(-1) and feed conversion ratio (FCR) between 0.95 and 0.98. Water nitrite concentration was higher in the FF systems compared to FM and MM systems, whereas the average total ammonia nitrogen concentration (TAN) was not influenced by the treatments. Nitrification rate, which was measured in the laboratory, followed the water nitrite levels, indicating highest total ammonium oxidation rates in the MM systems. UV254 absorbance and total organic carbon (TOC) concentrations were higher in the groups with moving bed systems, indicating accumulation of organic substances in the circulating water. The total volume of particles was higher in the MM systems as compared to the FF systems. The total solids balance was similar in all the bioreactor groups, since the removal of solids by the FBBR backwash was compensated by the drum filter in the FM and MM systems. In general, no significant histopathological difference in gill, kidney, heart and liver tiss

关键词： Staged anaerobic fluidized membrane bioreactor   Pharmaceutical   Municipal wastewater   Hydraulic retention time   Sorption   Nitrogen balance  

摘要： The staged anaerobic fluidized membrane bioreactor (SAFMBR) is effective to remove organic substances with reduced sludge production by minimizing excess waste sludge. This study investigated the removals of four pharmaceuticals present at trace levels in municipal wastewater by using a SAFMBR. The target pharmaceuticals included ibuprofen, naproxen, carbamazepine, and diclofenac. A pilot-scale SAFMBR with hydraulic retention times (HRTs) from 4.5 to 13.5 hr was established and operated for 450 days with a municipal wastewater spiked with four pharmaceuticals. In the results, the BOD and COD removals were effective and limitedly affected the presence of pharmaceuticals. The BOD removal efficiencies in the anaerobic fluidized membrane bioreactor (AFBR) and anaerobic fluidized membrane bioreactor (AFMBR) were 63.5 +/- 28.6% and 81.6 +/- 25.1%, respectively. However, the treatment efficiencies of four pharmaceuticals varied. Naproxen that contains electron donating group was treated efficiently (63.8%similar to 72.1%), whereas the removal efficiencies of ibuprofen (25.0%similar to 32.4%), carbamazepine (16.6-18.5%), and diclofenac (non-detected) remained low. Ibuprofen was less efficient to compete with other electron acceptors in an anaerobic environment. For pharmaceuticals such as carbamazepine with a high acid dissociation constant (pKa = 13.9) or diclofenac with a high octanol-water partition coefficient (log K-ow = 4.51), sorption onto the sludge could be one critical process affecting their concentrations in the water phase. By being positively charged at neutral pH and/or hydrophobic, the pharmaceuticals were initially adsorbed onto sludge, followed by being desorbed when sludge decayed after long operating hours. Nitrogen balance was analyzed to indicate the decay of the bacteria in the AFMBR. Increasing the HRTs only slightly improved the treatment efficiencies (e.g., the naproxen removal was increased from 63.8% to 72.1% when the HRT was increased from 4.5 t

关键词： antibody glycosylation   cell culture   in situ dielectric spectroscopy   real-time monitoring   specific cell growth rate  

摘要： The cell-specific growth rate (mu) is a critical process parameter for antibody production processes performed by animal cell cultures, as it describes the cell growth and reflects the cell physiological state. When there are changes in these parameters, which are indicated by variations of mu, the synthesis and the quality of antibodies are often affected. Therefore, it is essential to monitor and control the variations of mu to assure the antibody production and achieve high product quality. In this study, a novel approach for on-line estimation of mu was developed based on the process analytical technology initiative by using an in situ dielectric spectroscopy. Critical moments, such as significant mu decreases, were successfully detected by this method, in association with changes in cell physiology as well as with an accumulation of nonglycosylated antibodies. Thus, this method was used to perform medium renewals at the appropriate time points, maintaining the values of mu close to its maximum. Using this method, we demonstrated that the physiological state of cells remained stable, the quantity and the glycosylation quality of antibodies were assured at the same time, leading to better process performances compared with the reference feed-harvest cell cultures carried out by using off-line nutrient measurements.

摘要： 90

关键词： Membrane bioreactor   Chemical P removal   P recovery   Sludge acidogenesis   Co-fermentation  

摘要： A novel acidogenic phosphorus recovery (APR) process was developed in combination with Fe(III)-based chemical phosphorus removal and a membrane bioreactor (MBR) for enhanced wastewater treatment and effective P recovery. Two different system configurations were evaluated: Fe-dosing MBR (Fe-MBR), with the Fe-dosing into the MBR, and Fe-enhanced primary sedimentation followed by the MBR (FeP-MBR). The results show that both systems performed well for enhanced nutrient (N and P) removals and P recovery, with approximately 50% of the total P recovered from the municipal wastewater in the form of vivianite. Compared to the Fe-MBR system, FeP-MBR achieved more efficient P recovery under low food-waste loading conditions, maintained a higher ratio of biomass in activated sludge and experienced a slower rate of membrane fouling. Important functional bacteria were identified, including Prevotella and Selenomonas, which are active in hydrolysis and acidogenesis of sludge, and Aeromonas and Sulfurospirillum, which are involved in dissimilatory iron reduction.

关键词： bioreactor   hypoxia   microcarriers   retina   stem cells  

摘要： Blindness as a consequence of degenerative eye diseases (e.g., age-related macular degeneration and retinitis pigmentosa) is a major health problem and numbers are expected to increase by up to 50% by 2020. Unfortunately, adult mouse and human retinal stem cells (RSCs), unlike fish and amphibians, are quiescent in vivo and do not regenerate following disease or injury. To replace lost cells, we used microcarriers (MCs) in a suspension stirring bioreactor to help achieve numbers suitable for differentiation and transplantation. We achieved a significant 10-fold enrichment of RSC yield compared to conventional static culture techniques using a combination of FACTIII MCs and relative hypoxia (5%) inside the bioreactor. We found that hypoxia (5% O-2) was associated with better RSC expansion across all platforms;and this can be attributed to hypoxia-induced increases in survival and/or symmetric division of stem cells. In the future, we will target the differentiation of RSCs and their progeny toward rod and cone photoreceptor phenotypes using FACTIII MCs inside bioreactors to expand their populations in order to produce the large numbers of cells needed for transplantation.

摘要： 121

关键词： Recirculation frequency   Semi-aerobic bioreactor landfill   Organic pollutants   Nitrogen pollutants   Conversion  

摘要： To study the impact of leachate recirculation frequency on the transformation of carbon and nitrogen pollutants in a semi-aerobic bioreactor landfill (SABL), three laboratory-scale SABLs were investigated, each using a different leachate recirculation frequency (daily, once each 3days, and once each 5days). Results showed that degradation of total nitrogen (TN), ammonium nitrogen (NH4+-N), chemical oxygen demand (COD), and total organic carbon (TOC) could be described using a quadratic polynomial-compound index model. Degradation rates of TN, NH4+-N, COD, and TOC slightly increased from 0.01795, 0.01814, 0.01451, and 0.01166day(-1) to 0.02054, 0.01903, 0.01488, and 0.01203day(-1), respectively, when the recirculation frequency increased from once per 5days to once per 3days. When recirculation frequency was increased to daily, degradation rates of TN, NH4+-N, COD, and TOC significantly increased to 0.03698, 0.02718, 0.02479, and 0.02872day(-1), respectively. Moreover, when recirculation frequency increased from once per 5days to once per 3days, the gasification rate of nitrogenous and carbonaceous pollutants was enhanced between 20.38 and 8.17%, respectively. When the leachate recirculation rate further increased to daily, only a small amount of carbonaceous and nitrogenous pollutants was transformed to the liquid phase. Thus, increasing the leachate recirculation frequency in an SABL benefits the removal of carbonaceous and nitrogenous pollutants from the reactor. In addition, the greater is the recirculation frequency, the lower is the residual carbon and nitrogen in the solid phase, and the higher is the gasification rate. A proper recirculation frequency promotes the stabilization of landfill leachate. This study provides a theoretical reference and experimental evidence for accelerating the stabilization of MSW and contributes to the macro-control of landfills.