课程文献中心 更多>>

关键词： Greywater   Personal care products (PCPs)   Membrane bioreactor (MBR)   Constructed wetland (CW)  

摘要： Personal care products (PCPs) are contaminants of emerging concern because of their continuous input into the environment. In this study, membrane bioreactor (MBR) and constructed wetland (CW) methods were used to investigate the effect and mechanism of conventional pollutant and PCP removal from greywater. The effluent of both the MBR-and CW-treated greywater met the reclaimed water reuse standard in China. Conventional pollut-ants and five target PCPs had a higher removal efficiency in the MBR than in the CW. The removal rates of the PCPs, including Tuina musk (AHTN), were >80% using MBR and CW methods. The main pathway of removing PCPs in the MBR was sludge adsorption and biodegradation, whereas the contribution of the membrane module was weak. The main pathway of removing PCPs in the CW was the combined action of plant absorption, microbial biodegradation, and substrate adsorption, depending on the PCP type. Ethyl hexyl methoxycinnamate (EHMC) has strong biological oxidizability and was mainly removed by biodegradation, whereas Jiale musk (HHCB) and AHTN were mainly removed by adsorption. Six types of CW substrates were investigated, and perlite showed the best adsorption effect for the five target PCPs. The optimal substrate adsorption pH was 7. This study provides important technical information on the effective removal of conventional pollutants and PCPs in greywater and the preparation of high-quality reclaimed water. (c) 2021 Published by Elsevier B.V.

关键词： Membrane bioreactor   Cellulose nanofiber   Thin-film nanofibrous composite   Anti-fouling  

摘要： The filtration performance, fouling and flux recovery efficiency of a novel thin film nanofibrous compositecellulose nanofiber (TFNC-CNF) coated membrane was studied and compared with polyvinylidene fluoride (PVDF) membranes treating domestic wastewater. The enhanced anti-fouling property of the TFNC-CNF membrane was associated with the super-hydrophilic nature and negative charge on the membrane surface. The deadend cell filtration tests demonstrated the TFNC-CNF membrane recovered more than 90% of the initial flux after mechanical cleaning, compared with 26-43% recovery by PVDF membranes. Continuous wastewater ultrafiltration tests with mechanical air scouring confirmed the outstanding permeability (71.3-138.9 LMH/bar) and the superior anti-fouling characteristics (59.2-86.8% recovery of the initial flux) of the TFNC-CNF membrane. Furthermore, higher total organic carbon rejection rates were also observed in the TFNC-CNF membrane (>83.2%) than the PVDF membrane (<69.8%). Collectively, the superior flux recovery and high permeability makes the TFNC-CNF membrane a promising material for membrane bioreactors.

关键词： MDCK悬浮细胞   流感病毒   高密度增殖   放大培养  

摘要： 目的建立无血清悬浮培养MDCK细胞系,分析该悬浮细胞的生长特性、病毒敏感性、代谢动力学特征及生物反应器线性放大的可行性。方法通过逐步降血清和无血清悬浮驯化的方式获得1株MDCK悬浮细胞,检测其病毒敏感性,在1.2 L四联平行生物反应器中分析该悬浮细胞以不同初始接种密度(50×10^(4)、100×10^(4)、150×10^(4)、200×10^(4)个/mL)培养的细胞生长特性、代谢动力学特征和最佳传代时间,并进行5 L到75 L生物反应器的线性放大培养。结果贴壁培养型MDCK细胞以3%低血清稳定培养5代后,将该细胞直接适应无血清培养基获得1株MDCK悬浮细胞(命名为MDCK-XF03)并建库,复苏活力为96.8%;细胞接种不同型别的流感病毒均能较好增殖;以不同初始接种密度培养MDCK-XF03细胞,其最大增殖浓度均达1000×10^(4)个/mL以上,且差异无统计学意义(P>0.05),在培养前48 h均具有较大比生长速率,且差异有统计学意义(P<0.05),此时倍增时间也较短,且差异有统计学意义(P<0.05),MDCK-XF03细胞在84 h之前可充分利用葡萄糖。结论成功获得1株MDCK悬浮细胞MDCK-XF03,选择以200×10^(4)个/mL的初始接种密度进行生物反应器大规模培养,实现了从5 L到75 L的高密度线性放大培养,为流感疫苗的工业化生产提供了细胞基质。

关键词： Organic loading rate   Acidogenic fermentation   Microbial profiling   Immersed membrane bioreactor   Volatile fatty acids  

摘要： This study was designed to evaluate the microbial profiling of anaerobic digestion during the processing of sewage sludge and food waste to volatile fatty acids (VFAs) in an immersed membrane bioreactor (iMBR) operating with a distinct organic loading rate (OLR). The results indicated that Firmicutes (0.17-0.38) and Actinobacteria (0.20-0.32) phyla dominated in anaerobic digestion with OLRs of 4 and 8 g VS/L/d, while Firmicutes (0.04-0.08), Actinobacteria (0.03-0.08) and Proteobacteria (0.02) were more abundant with OLR of 6 and 10 g VS/L/d in the bioreactors. Subsequently, the abundance of the Clostridium and Lactobacillus genera were responsible for higher yields of acetate, butyrate, caproate and lactate. The species of Clostridium sp. W14A (0.04-0.06), Bacterium OL-1(0.01-0.30) and Lactobacillus mucosae (0.002-0.01) were rich for both OLR dosages. Additionally, network and redundancy analysis confirmed that Clostridium sp. W14A, Bacterium MS4 and Lactobacillus had significant correlations with the VFAs produced, such as acetate, butyrate, and caproate. Variation analysis also demonstrated an appreciable correlation between environmental factors and the bacterial community. Overall, this bacterial community was dominated by the Firmicutes (0.04-0.38) phylum and Clostridium sp. W14A (0.04-0.60) species, which is a clear indicator of a lower population of acetogenic bacteria associated with greater VFAs generation.

关键词： 硫酸盐还原菌   酸性矿山废水   重金属   生物反应器  

摘要： 综述了酸性矿山废水的产生、危害和当前对酸性矿山废水(AMD)的处理方法,重点介绍了应用硫酸盐还原菌(SRB)处理酸性矿山废水的研究进展(厌氧生物反应器技术、联合处理技术、微生物固定化技术以及微生物原位处理技术)。利用硫酸盐还原菌处理酸性矿山废水是很有潜力的处理方法,具有成本低、可去除重金属离子且无二次污染的优点。在应用过程中,酸性矿山废水pH值较低的特点使得普通微生物无法生存,可通过驯化SRB使其具有更低的pH耐受值或者分离嗜酸性aSRB,或应用生物H_(2)S处理酸性矿山废水,使得在脱除重金属的同时能够实现污酸的回用。

关键词： 无泡曝气膜生物反应器   生物膜   同步硝化反硝化   污水处理  

摘要： 系统综述了MABR技术近年来的研究与应用进展,介绍了MABR的构成、基本原理,总结分析了反应器设计、膜材料、关键操作参数、生物膜特性、废水处理特性及工程应用情况,最后讨论了MABR在膜材料、生物膜调控和处理效能等方面存在的问题,并对未来MABR技术的耦合工艺研究和工程应用方向进行了展望。

关键词： 环境   废水   厌氧   氧化   生物反应器   生化工程  

摘要： 抗生素在世界范围内使用广泛,目前已经在多种废水中检测到了不同种类的抗生素。以磺胺甲(口恶)唑(SMX)和土霉素(OTC)为代表,研究其对厌氧氨氧化过程的短期(6 h)和长期(22 d)影响。结果表明:在实验浓度中(1、10、100、1000μg/L),OTC的短期抑制阈值为10μg/L,将厌氧氨氧化活性由14.6降至12.0 mg/(h·g SS);长期抑制阈值为1000μg/L,将厌氧氨氧化活性降至11.1 mg/(h·g SS);1~1000μg/L的SMX对厌氧氨氧化生物膜无显著影响。厌氧氨氧化生物膜对SMX的响应比对OTC的响应更加快速,可以分泌大量的胞外聚合物以抵抗SMX,同时可以诱导反硝化菌降解SMX。OTC导致厌氧氨氧化生物膜的微生物多样性增加,而SMX则促使优势微生物的丰度增加,同时诱导反硝化菌的相对丰度从0.01%最高增加至14.9%,有助于抵抗SMX的抑制。因此,厌氧氨氧化可以处理含有微量SMX的废水,在处理含OTC的废水时,则需要经过长期驯化。

关键词： 血管体外培养   应力   生物反应器   弹性纤维   胶原纤维   血管内皮细胞  

摘要： 目的通过调节液体流量、流速及周期性脉动等参数,研究新西兰家兔颈动脉体外应力培养时血管结构的变化。方法取SPF级新西兰家兔颈动脉置于生物反应器上,构建血管体外培养模型。共分四组,静态组为静态培养,动态组(80、50、25组)在脉冲泵运行位移与频率相同的条件下,保持培养液流速分别为80、50、25 ml/min,维持应力状态培养,培养结束后通过HE、Masson、EVG染色对血管结构的变化进行评价。结果静态组15 d血管内皮细胞保持完整,平滑肌细胞排列混乱,弹性纤维收缩剧烈,胶原纤维基本没有变化;80组弹性纤维未见明显变化,内皮细胞不可见,第8天平滑肌较第4天排列整齐,第8天胶原纤维明显减少。50组内皮细胞不可见,平滑肌排列整齐,15 d时弹性纤维疏松且趋于平直,血管胶原纤维明显减少;25组内皮细胞可见,弹性纤维和胶原纤维改变较50组轻微。结论在模拟动物体内各参数的条件下,血管体外动态培养有助于维持血管的生理结构,培养的难点在于防止污染和补充胶原。高应力条件下,会导致血管内皮细胞受损,进而造成平滑肌细胞增殖,胶原纤维流失更为严重。

关键词： 絮凝   膜生物反应器   奶牛场   污水   运行  

摘要： 针对奶牛场污水有机物和氮磷浓度高、深度处理难度大的问题,采用絮凝-膜生物反应器(MBR)组合工艺处理奶牛场高浓度污水,考察组合工艺中试运行效果。结果表明,化学需氧量(COD)(18973.0±1589.0)mg/L、氨氮(634.0±194.0)mg/L和总磷(213.0±64.0)mg/L的奶牛场污水原水经絮凝-MBR组合工艺处理,出水COD、氨氮、总磷浓度分别为(301.0±94.0)mg/L、(84.0±40.0)mg/L和(4.1±1.8)mg/L,对应COD、氨氮和总磷去除率分别为98.4%±0.5%、84.5%±10.0%和97.9%±1.1%。采用絮凝-MBR组合工艺处理奶牛场高浓度污水是可行的,能够有效降低奶牛场污水中大部分有机物和氮磷污染物,研究结果可为奶牛场高浓度污水絮凝-MBR组合工艺的工程应用提供技术参考,为解决奶牛场废弃物的环境污染问题提供科学依据。

关键词： Biofilter   Constructed wetland   Denitrification   Greenhouse gas  

摘要： Woodchip bioreactors are increasingly used as tools to mitigate nitrogen (N) pollution from agricultural drainage water. They consist of a basin filled with woodchip material through which N contaminated drainage water can flow. During the water transport through the filter matrix, oxygen is rapidly depleted and denitrification removes a fraction of the nitrate N present in the water. However, the N removal efficiency of the bioreactors varies significantly both across systems and seasonally. Furthermore, denitrification can also produce nitrous oxide, which is a potent greenhouse gas. Here, we investigated how variation in hydraulic residence time influenced N removal efficiency and nitrous oxide emissions at eight woodchip bioreactors of different flow designs, monitored for 2-4 years. We also characterised the relative abundance of genes involved in the N cycle at three of the bioreactors using metagenomics. Our results showed that total N removal was 17-73% of the yearly incoming N and that it was influenced by hydraulic residence time and water temperature. Nitrous oxide emissions were variable among the different bioreactors and were higher when the hydraulic residence time was less than 60 h. However, the yearly nitrous oxide release did not exceed 2.4% of the nitrate removal (on N atom basis) and the mean among the bioreactors was 0.6%. Although there were marked differences in nitrate removal and nitrous oxide emissions, there were no clear differences in the relative abundance of N-cycling genes among and within three tested bioreactors. Yet, denitrification genes greatly outnumbered genes related to dissimilatory nitrate reduction to ammonium. Overall, our study showed that all eight bioreactors were effective in removing N from agricultural drainage water and that nitrous oxide emissions were low, especially at hydraulic residence times of 60 h or more.