课程文献中心 更多>>

关键词： 无泡充氧   膜生物反应器   生活污水   影响因素   碳、氮转化途径  

摘要： 针对低碳氮比的实际生活污水,设计了一种以疏水性微孔膜作为无泡充氧和生物膜载体的膜生物反应器,研究了水力停留时间(HRT)、充氧方式、水温对反应器处理效果的影响,并探究碳、氮元素的转化途径。结果表明,在HRT为24 h、水流速度为0.068 m/s、水温为28~36℃、DO为(1.6±0.2)mg/L、充氧强度为0.035 MPa条件下,系统对COD、NH4^+-N和总氮的平均去除率可分别达到85.43%、72.22%、57.95%。在碳、氮元素的转化途径上,污水在通过由无泡充氧形成的生物膜的不同氧浓度梯度分层结构后,可进行同步硝化反硝化,对氨氮的去除主要依靠硝化菌完成,去除率为72.18%,对TN的去除率约为56%,而在反硝化过程中COD主要作为碳源被大量消耗,平均去除率达到85%以上。反应器主要耗能为空压机、循环泵和进水隔膜泵的电耗,无泡充氧的氧体积传质系数约为传统鼓泡式充氧的8.7倍,节约充氧电耗的潜能可达88.5%。

关键词： 膜生物反应器   校园废水   污泥性能  

摘要： 为了缓解市政排水的压力,提高高校校园废水的处理效果和回用效果,降低环境压力,减轻环境污染,本文使用一体式膜生物反应器对校园废水的处理进行实验研究,探讨了一体式膜生物反应器内分别添加颗粒污泥和传统絮状污泥时污泥浓度MLSS,污泥Zeta电位、污泥体积指数SVI等参数的变化。实验研究结果表明,添加了颗粒污泥的一体式膜生物反应器中的污泥浓度MLSS比添加了絮状污泥的一体式膜生物反应器中的污泥浓度MLSS增长幅度大、污泥疏水性能好、污泥沉降性能好。

关键词： Anaerobic fluidized bed bioreactor   Wastewater reuse   Forward osmosis   Thin film composite membranes   Energy  

摘要： A laboratory-made high-performance thin-film composite (TFC) forward osmosis (FO) membrane supported by a polyacrylonitrile (PAN) support was firstly employed to treat the effluent produced by an anaerobic fluidized bed bioreactor (AFBR). Synthetic wastewater was prepared to operate the AFBR, which produced the effluent for the FO process as post-treatment. The performance of the FO membrane was characterized via the measurement of the permeate flux, reverse salt (NaCl) flux and the rejection efficiency of ammonium nitrogen (NH4-N) mostly present in the AFBR effluent having low removal characteristics. An ultrathin and highly-crosslinked polyamide selective layer combined with the PAN support having a low structural parameter of the prepared PAN-supported TFC (PAN-TFC) membrane resulted in higher rejection to both nitrogen and salt compared to a commercial FO membrane. Importantly, the rejection of NH4N higher than 70% was achieved by the PAN TFC FO membrane. At 0.5 M NaCl draw solution, the PAN TFC membrane exhibited the nitrogen flux of 0.92 +/- 0.01 g m(-2) h(-1) and the permeate flux of 25 L m(-2) h(-1). The results demonstrate that the FO membrane can be one of the promising ways to effectively control the removal of contaminants present in AFBR effluent such as NH4N as a post-treatment.

关键词： 复合改性   PhACs   生物膜   生物反应器   二级出水  

摘要： 针对石英砂(OQS)表面特征及特性,进行表面形貌重构改性及表面涂覆改性,并根据涂覆改性差异,制备出亲水改性砂(IMS)、疏水改性砂(OMS)、阳离子改性砂(CMS)和氨基改性砂(AMS)。以实验室模拟二级处理出水为研究对象,考察以6种石英砂[4种复合改性砂、表面重构砂(对照1)及原始砂(对照2)]为核心的生物砂滤工艺对碳氮磷及突发药物活性物质(PhACs)的削减效果,分析了各组生物砂滤池微生物种群结构,并进行了生态风险评估。结果表明,各类工艺对常规污染物的去除率在24.22%~90.35%之间,CM-BSF对常规污染物的去除效果最好;6种生物砂滤工艺对5大类12种PhACs的去除率在7.9%~50.3%之间,改性砂滤工艺CM-BSF去除效果更好;高通量检测表明各组微生物物种高度相似,但丰度有差异,总体来说,具备PhACs降解能力的功能菌在复合改性石英砂覆膜生物样品中的丰度较高;通过生态风险评价方法分析,CM-BSF工艺出水产生生态风险最小。

关键词： 厌氧膜生物反应器(AnMBR)   工业废水   膜污染  

摘要： 工业废水的妥善处理办法一直是各国积极研究和探索的方向。An MBR技术将传统厌氧消化与膜过滤系统相结合,具有设备占地面积小,出水水质好,运行简便,可实现能量回收等优势,近年来受到越来越多的关注。本文就AnMBR技术处理工业废水近年来的研究现状,面临的问题和应用前景进行了介绍和讨论,以期为AnMBR技术后续研究及应用提供参考。

关键词： 氮   磷   吸收速率   米氏方程   大叶藻  

摘要： 营养盐是影响海草生长的关键因子,目前有关海草不同组织对不同形式氮和磷的吸收特征尚不明确。该研究通过利用海草地上和地下组织分隔培养装置,设置不同的氨态氮、硝态氮和磷酸盐浓度,探究了大叶藻(Zosteramarina)植株及其地上和地下组织对氮磷营养盐的吸收动力学特征。结果显示:(1)大叶藻对氮磷的吸收符合饱和吸收动力学特征,吸收速率和水体氮磷浓度可用米式方程描述;(2)大叶藻植株对NH4+-N的最大吸收速率(Vmax,52μmol·g–1·h–1)显著高于其对NO3–-N的Vmax(39μmol·g–1·h–1);(3)大叶藻地上组织和地下组织均可吸收氮磷,但地上组织对氨态氮、硝态氮、磷酸盐的Vmax分别为43.1、30.5和15.6μmol·g–1·h–1,为地下组织的2.6、1.2和6倍。结果表明,大叶藻对氨态氮的吸收能力高于硝态氮,且对氮磷的吸收可能主要依赖地上组织(叶片)。结果为查明大叶藻对氮磷的吸收利用机制及评估大叶藻的海洋生态效应提供了理论依据。

关键词： Bioreactors  

摘要： This review seeks to summarize the current literature regarding the removal of viruses from wastewater using membrane bioreactors (MBRs). Membrane bioreactors are an effective technology for the removal of viruses from wastewater and do so with greater efficiency than conventional activated sludge treatment plants. However, much is unclear about the capabilities and mechanisms of this process. Membrane pore size is commonly thought to be an important factor impacting virus removal, but this effect is primarily observed when the pore size is smaller than the virus diameter, and the effects vary by virus. A variety of factors can impact the effectiveness of MBRs in virus removal, with the presence of a biofilm foremost among them. Balancing the presence of a biofilm with regular membrane backwashing and cleaning to maintain consistent flux remains a critical consideration in MBR operation. Differences in reported removal efficiencies of human viruses compared to model viruses (such as bacteriophages) call into question the reliability of these model viruses in assessing the effectiveness of virus removal in MBRs. More investigation, particularly with full-scale MBR systems, must be performed to further understand the potential of MBRs in virus removal.

关键词： bioreactor   cell therapy   diabetes   insulin   iPSCs  

摘要： Clinical use of pancreatic beta islets for regenerative medicine applications requires mass production of functional cells. Current technologies are insufficient for large-scale production in a cost-efficient manner. Here, we evaluate advantages of a porous cellulose scaffold and demonstrate scale-up to a wicking matrix bioreactor as a platform for culture of human endocrine cells. Scaffold modifications were evaluated in a multiwell platform to find the optimum surface condition for pancreatic cell expansion followed by bioreactor culture to confirm suitability. Preceding scale-up, cell morphology, viability, and proliferation of primary pancreatic cells were evaluated. Two optimal surface modifications were chosen and evaluated further for insulin secretion, cell morphology, and viable cell density for human-induced pluripotent stem cell-derived pancreatic cells at different stages of differentiation. Scale-up was accomplished with uncoated, amine-modified cellulose in a miniature bioreactor, and insulin secretion and cell metabolic profiles were determined for 13 days. We achieved 10-fold cell expansion in the bioreactor along with a significant increase in insulin secretion compared with cultures on tissue culture plastic. Our findings define a new method for expansion of pancreatic cells a on wicking matrix cellulose platform to advance cell therapy biomanufacturing for diabetes.

关键词： bioanalytics   bioprocess development   lactic acid production   microfluidics   Saccharomyces cerevisiae(S   cerevisiae)   screening phase   sensor  

摘要： A key challenge for bioprocess engineering is the identification of the optimum process conditions for the production of biochemical and biopharmaceutical compounds using prokaryotic as well as eukaryotic cell factories. Shake flasks and bench-scale bioreactor systems are still the golden standard in the early stage of bioprocess development, though they are known to be expensive, time-consuming, and labor-intensive as well as lacking the throughput for efficient production optimizations. To bridge the technological gap between bioprocess optimization and upscaling, we have developed a microfluidic bioreactor array to reduce time and costs, and to increase throughput compared with traditional lab-scale culture strategies. We present a multifunctional microfluidic device containing 12 individual bioreactors (V-t = 15 mu l) in a 26 mm x 76 mm area with in-line biosensing of dissolved oxygen and biomass concentration. Following initial device characterization, the bioreactor lab-on-a-chip was used in a proof-of-principle study to identify the most productive cell line for lactic acid production out of two engineered yeast strains, evaluating whether it could reduce the time needed for collecting meaningful data compared with shake flasks cultures. Results of the study showed significant difference in the strains' productivity within 3 hr of operation exhibiting a 4- to 6-fold higher lactic acid production, thus pointing at the potential of microfluidic technology as effective screening tool for fast and parallelizable industrial bioprocess development.

关键词： nitrogen   phosphorus   denitrification   sorption   hydraulic loading rate   hydraulic retention time   woodchip bioreactors   constructed wetland  

摘要： Nutrient losses from agricultural fields have long been a matter of concern worldwide due to the ecological disturbance this can cause to surface waters downstream. In this paper a new design concept, which pairs a surface-flow constructed wetland (SFW) with a woodchip bioreactor (WB), was tested in relation to its capacity to reduce both nitrogen (N) and phosphorus (P) loads from agricultural tile drainage water. A nutrient mass balance and a comparative analysis were carried out together with statistical regressions in order to evaluate the performance of four SFW+WBs under different catchment conditions. We found marked variations between the systems in regard to hydraulic loading rate (0.0 to 5.0 m/day) and hydraulic retention time (1 to 87 days). The paired system worked as nutrient sinks throughout the study period. Total N and total P removal efficiencies varied from 8% to 51% and from 0% to 80%, respectively. The results support the use of the new design concept for nutrient removal from tile-drained agricultural catchments in Denmark as part of national management plans, with the added advantage that smaller areas are needed for construction (0.1% to 0.2% of the catchment area) in comparison to standalone and currently used SCWs (similar to 1%).