模拟胃肠道反应器的参数建立与冷模实验研究

体外消化和发酵实验紧密结合才能模拟完整消化道的功能,现有的模拟胃肠消化和大肠发酵的反应器结构各异且不通用,组合多个独立反应器则增加了实验的复杂程度和设备成本。集成了两类反应器的优势特征,开发了一种采用可编程逻辑控制器(PLC)的模拟胃肠道反应器(GSR),模拟了整体的胃肠道动态特征并与体内数据进行了比较。结果表明模拟胃肠道反应器既可准确模拟胃和小肠的蠕动、排空和混合等动态特征,又可提供肠道微生物的发酵环境。尾气排放和收集装置的设计实现了尾气快速排出和尾气体积的准确计量。模拟胃肠道反应器可为体外探索益生元对肠道微生物作用等研究提供帮助。     

污泥厌氧消化功能微生物群落结构的研究进展

污泥厌氧消化处理技术因其具有无害化、资源化和稳定化的特征备受关注。污泥厌氧消化涉及水解发酵、产氢产乙酸和产甲烷多种微生物,并发挥不同的功能。本文介绍了污泥厌氧消化体系中常见的细菌(门水平)和古菌（属水平）群落,如拟杆菌门（Bacteroidetes）、变形菌门（Proteobacteria）、厚壁菌门（Firmicutes）、绿弯菌门（Chloroflexi）、螺旋体门（Spirochaetes）（细菌）和甲烷杆菌属（Methanobacterium）、甲烷八叠球菌属（Methanosarcina）、甲烷短杆菌属（Methanobrevibacter）、鬃毛甲烷菌属（Methanosaeta）（古菌）等。同时也综述了影响厌氧体系中的微生物群落结构的因素,如pH、营养物质、温度、氨氮(NH₄⁺-N)及有毒有害物质等。最后展望了稳定同位素标记、宏基因组学和蛋白质组学等分子生物技术在探查微生物功能方面的应用前景,为进一步分析厌氧体系中未识别的功能微生物提供技术支撑。     

微塑料对污泥厌氧消化的影响和机理

污泥厌氧消化对实现污水处理厂“碳减排”具有重要意义,然其产甲烷效率和工艺稳定性易受多种因素干扰。微塑料作为新兴污染物经污水处理后,约有99%富集在污泥中,对污泥厌氧消化过程产生影响。因此,本文重点总结了污水中微塑料的来源、性质及其在污水处理工艺中的归宿,详细阐述了聚苯乙烯（PS）、聚酰胺6(PA6)、聚氯乙烯（PVC）等常见微塑料对污泥增溶、水解、酸化和产甲烷阶段的影响,并从细胞结构、微生物群落、酶活性等角度进一步归纳了微塑料影响厌氧消化的机理。最后,在概括当前研究成果的基础上,提出应从系统工程研究（预处理技术、运行条件、反应器类型等）、微塑料及其浸出物的抑制机制（微塑料与胞外聚合物、细胞膜的作用、标志性辅酶和辅因子、特征微生物方面）、微塑料与污泥其他组分间的协同/抑制机理等方面开展深入研究,为污泥资源化利用提供理论基础和技术支持。     

气升式振荡环流反应器的数值模拟和结构优化

气升式振荡环流反应器（ARLR）作为一种新型的气升式环流反应器,能够有效地提高反应器的气含率和传质系数,并已得到生物发酵实验的验证。本文通过CFD的手段研究了反应器内的流动和传质状况,并利用CFD模拟和响应面分析相结合的方法,优化了反应器的结构参数,如高径比（H/D）、升液区降液区面积之比、导流筒高度等。经过实验测量,优化后的气升式振荡环流反应器与传统的气升式环流反应器相比,气含率提高了32%以上,传质系数提高了11%以上。结果表明,气升式振荡环流反应器作为生化反应器有着非常广阔的应用空间。     

低温等离子体辅助去除含碳固态混合物

柴油发动机尾气中存在大量颗粒物,它易被人体吸入,对人的身体健康造成极大危害。其主要成分——碳烟及可溶性有机成分（SOF）等,可通过氧化燃烧的方法除去。本文从柴油机尾气颗粒物的治理出发,介绍了传统的颗粒物后处理技术,包括颗粒捕集器结合再生、微粒催化氧化转化（DOC）、静电捕集等技术。主要介绍了近年所发展起来的低温等离子体（NTP）辅助去除含碳固态混合物（PM）技术,包括等离子体反应器中的化学反应,常见的低温等离子体反应器结构及等离子体产生的放电类型。此外,根据等离子体反应器的安装位置不同,还介绍了两种不同的等离子体PM处理方法——直接等离子体方法和间接（远程）等离子体方法,后者可避免高温对等离子体过程的不利影响。总结了等离子体技术的应用特点,提出对等离子体辅助PM去除过程的研究可着眼等离子体技术本身,研究各种对气体放电产生影响的因素,为等离子体反应器的开发和应用提供参考。     

贝壳固定化微生物处理黄姜皂素废水

采用厌氧＋好氧工艺,考察以贝壳为载体固定化微生物（以下简称B组）与游离污泥床（以下简称A组）处理黄姜皂素废水的启动运行特征。研究结果表明：（1）由于B组反应器内载体贝壳中的CaCO3的溶解为反应提供碱度,使反应器里的微生物免受酸性的抑制,致使B组的启动时间缩短;（2）贝壳本身特有的三层层状结构,使许多微生物聚居其中,免受废水中的有害的抑制成分的毒害,在整个实验运行期间,其COD去除率和NH3-N的去除率均高于对照组A组。     

发酵制氢废液的微生物电解池产氢

采用单室微生物电解池（MEC）反应器为实验装置,通过预处理技术强化发酵制氢废液中乙酸的积累,并将该发酵废液作为底物,考察了以废液中累积的乙酸作为主要电子供体、碳布为阳极、涂布有Ni纳米颗粒的不锈钢网为催化阴极的产氢效果。结果表明,在MEC中,以预处理的发酵制氢废液积累的乙酸为底物,最高产氢率可达(1.31±0.04) m3H2/(m3?d)和(2.78±0.11) mLH2/mgCOD,同时可获得138.6%±3.1%的能量效率和99.0%±0.3%的COD去除率。实验表明,利用MEC可将发酵末端产物进一步降解,从而减弱了“发酵障碍”现象,实现了治污和产能的统一。     

“双碳”下金属纳米颗粒优化暗发酵制氢策略及前景

氢能是“双碳”下推动化石能源低碳转型的重要方向,微生物暗发酵制氢是实现生物质绿氢转化的有效途径。其中,利用具有量子尺寸效应、比表面积大和电导率高的金属纳米颗粒（MNPs）优化暗发酵制氢技术是近年研究热点。综述和评论了国内外添加MNPs用于优化暗发酵制氢性能的作用机制、技术难点和制氢效果等,重点阐述并比较了铁、镍和锌基三类热门MNPs优化策略在提高产氢酶系活性、增强代谢产氢途径和优化微生物群落结构等方面的作用,展望了暗发酵制氢可深入MNPs优化氢化酶活性、拓宽生物质发酵底物以及产氢菌筛选和反应器设计、生物质发酵技术开发等研究方向和应用前景。     

搅拌桨组合数值模拟优化及在谷氨酰胺转胺酶发酵中的应用

搅拌是影响发酵过程的主要因素之一,组合不同类型搅拌桨、发挥其各自优势,势必能够优化搅拌性能、提高微生物发酵生产效率。本研究采用计算流体力学（CFD）方法,模拟六直叶涡轮桨（DT）和DT、DT和抛物线桨（BT6）、六斜叶桨（CM6）和DT以及CM6和BT6四种搅拌桨组合对流场和混合时间的影响。对模拟得到的混合时间进行实验验证。结果表明,最优组合为：上桨叶为CM6桨,下桨叶为BT6桨。吸水链霉菌WSH03-13产谷氨酰胺转胺酶（TG）的发酵实验结果表明：CM6和BT6桨组合可获得最高的谷氨酰胺转胺酶活性和生物量,分别为4.7U/mL和42.9g/L,较优化前（DT和DT桨）分别提高了53%和40.9%,说明优化后的搅拌桨组合更有利于微生物生长和发酵。研究结果为组合搅拌桨在微生物发酵过程中的应用提供了借鉴。     

变压吸附回收高纯乙烯的工艺模拟

石化装置的烯烃尾气存在无法回收的情况，利用变压吸附过程可以实现烯烃尾气的回收。为得到较高浓度的乙烯回收产品，创造更高的经济价值，应用Aspen Adsorption吸附模拟软件，对乙烷、乙烯吸附过程建模。经过实验验证，模型可以准确提供实验参考，从而减轻变压吸附过程对实验的完全依赖。面向乙烯回收的工艺过程，应用软件对工艺操作参数进行了模拟，得到了高纯度的乙烯回收产品，从机理上验证了方案的技术可行性。     

A discussion of maximal extent of an isothermal reversible gas phase reaction in double-membrane reactors

The maximal reactant conversions in cocurrent isothermal double-membrane reactors are discussed theoretically, in comparison to single-membrane reactors. A method for calculation of the limiting conversion is proposed and demonstrated on the elementary reversible gas phase reaction A=B+C. Owing to the disturbing separation and reaction equilibrium, double-membrane reactor without sweep gas could provide complete conversion. When the sweep gas is introduced, large but not infinite sweep gas flow enables complete conversion. The criteria for approaching the limiting conversions are presented, in terms of values of dimensionless model parameters. To demonstrate the validity of the conclusion that double-membrane configuration is superior to the single-membrane configuration considering the maximal attainable conversion, the results of simulation of thermal water splitting are presented. As to the applicability of double-membrane reactor model that assumes reaction equilibrium, that approximation could be reasonable only when the maximal attainable conversion is lower than unity.     

Numerical simulation of flow field and residence time of nanoparticles in a 1000-ton industrial multi-jet combustion reactor

In this work, by establishing a three-dimensional physical model of a 1000-ton industrial multi-jet combustion reactor, a hexahedral structured grid was used to discretize the model. Combined with realizable k–ε model, eddy-dissipation-concept, discrete-ordinate radiation model, hydrogen 19-step detailed reaction mechanism, air age user-defined-function, velocity field, temperature field, concentration field and gas arrival time in the reactor were numerically simulated. The Euler–Lagrange metho...     

小球藻流加补料强化处理发酵废水联产高质蛋白饲料

考察利用小球藻强化处理曲霉发酵废水(发酵废水)并联产高质蛋白饲料的可行性。小球藻在流加补料模式下使得发酵废水总磷(TP)、总氮(TN)、氨氮(NH₃-N)、化学需氧量(COD)、生化需氧量(BOD)去除率分别达到99.5%、95.1%、99.4%、98.2%和99.7%,较分批模式下污染物去除率提高了1.47倍、1.45倍、1.22倍、1.13倍和1.19倍,且其出水水质符合GB 25463—2010排放标准。联产获得小球藻生物量和蛋白高达48.53g/L和27.20g/L,藻蛋白中18种氨基酸含量为58.56%,8种必需氨基酸含量为26.44%,氨基酸评分65.3,属优质单细胞蛋白源。小球藻脂肪酸以C₁₆～C₁₈为主(＞86%),亚油酸和亚麻酸含量分别为27.06%和25.82%。小球藻重金属(铅、砷、镉、汞、铬)和微生物(沙门氏菌、霉菌、细菌)安全指标符合GB 13078—2017饲料卫生标准。进一步地,体外模拟猪肠胃液对藻粉干物质、粗蛋白、粗脂肪和淀粉消化率为79.02%、90.17%、92.93%和87.81%,...     

向日葵盘精油的化学成分及抗氧化活性

为明晰采收后向日葵盘精油的成分及其体外抗氧化活性,应用水蒸气蒸馏法提取采收后向日葵盘精油,利用气相色谱-质谱联用法（GC-MS）分析其化学成分,通过DPPH自由基和ABTS自由基清除法对精油的体外抗氧化活性进行测定。结果显示：从向日葵盘精油中共鉴定出49种化学成分（占精油总量91.16%）,其中α-蒎烯（28.22%）、柠檬烯（6.55%）、α-蛇麻烯（4.99%）、反式-β-金合欢烯（3.58%）和莰烯（3.39%）为其主要成分。向日葵盘精油具有一定的体外抗氧化活性,其清除DPPH自由基、ABTS自由基的半数有效浓度（EC₅₀）值分别为0.47、0.30 g/L,明显高于阳性对照BHT的EC₅₀值（分别为8.21和6.16 mg/L）。     

Simulation of a catalytic turbulent fluidized bed reactor using the sequential modular approach

Combustion of natural gas in fluidized bed reactors is considered as an economical way for producing energy and food-grade CO₂ largely needed in food and chemical industries. Therefore, their simulation and modeling could be of great industrial importance. In this study, a model is developed based on the sequential modular approach for combustion of natural gas in a catalytic turbulent fluidized bed (TFB) reactor. The proposed model integrates hydrodynamic parameters, reaction model and kinetic data necessary to simulate the combustion of natural gas in the catalytic turbulent fluidized bed reactor. For the purpose of this study and based on hydrodynamic considerations, a number of ideal reactors have been considered to simulate the overall performance of the reactor. The validity of the proposed model was demonstrated using the pilot plant experimental data from the literature. The agreement between the simulation results and the experimental data was found to be satisfactory.     

Recent Studies on Nonspecific Aspects of Intraoral Adhesion

There is usually a high number of microorganisms present in the oral cavity, yet it takes some time for the first microorganisms to attach in vivo on clean solid surfaces. Similar patterns of microbiological adhesion can be observed in vitro and, conversely, in vivo attachment of non-biological colloidal particles occurs readily. This indicates that primary physical forces rather than biological specificities are responsible for initial adhesion of microorganisms and similarly shaped particles to teeth and restorations. Under physiological conditions, oral adhesive events are probably based on general types of physico-chemical interactions, and might be mainly controlled by the properties of the spontaneously adsorbed biological films that precede particle attachment. A variety of surface physico-chemical techniques, monitoring formation of biological films and attachment of biological, as well as nonbiological particles of colloidal dimensions both in vivo and in vitro on various solid surfaces, indicated that the formation of oral biological films proceeds at high speed and precedes particle attachment. Further, when different surfaces were clinically exposed to saliva and covered with such biological films, their significant original differences in surface properties could no longer be detected. Continuing differences in strength of particle adhesion to these surfaces must result, therefore, from differences in binding of the initial salivary films.     

1-脱氧野尻霉素控释微丸的制备工艺优化及其药动学研究

1-脱氧野尻霉素控释微丸采用挤出滚圆和流化床方法进行制备。首先使用羟丙基甲基纤维素和微晶纤维素等辅料制备分散体、丸芯,再使用羟丙基甲基纳米纤维素邻苯二甲酸酯作为主要包衣材料进行包衣,并装入胶囊。采用SEM观察微丸的微观形态,以及测定其产率、脆碎度、密度、水分含量和粒径分布等物理性质,研究结果显示微丸性质符合中国药典标准规定。在体外释药试验中,溶出介质和放置方式对药物释放无显著影响,释放过程符合Baker-Lonsdale模型。对比研究1-脱氧野尻霉素原料药、分散体微丸和控释微丸在比格犬体内的控释特性,结果表明：与1-脱氧野尻霉素原料药相比,分散体微丸和控释微丸分别使1-脱氧野尻霉素的生物利用度提高了183.37%和243.87%。此外,1-脱氧野尻霉素控释微丸的体内-体外研究的相关性分析可知体外溶出和体内吸收之间呈现良好的线性关系。     

Kinetics and slurry-type reactor modelling during catalytic hydrogenation of o-cresol on Ni/SiO2

The effect of kinetic parameters (reactant concentrations, temperature) was investigated on the initial reaction rate for the catalytic hydrogenation of o-cresol on Ni/SiO₂, carried out in a batch or semi-batch agitated slurry-type reactor.

The data were interpreted by a kinetic model based on the Langmuir-Hinshelwood mechanism with non-dissociative and non-competitive adsorption of o-cresol and hydrogen on different sites, where the limiting step is due to the reaction of adsorbed reactants. The activation energy (E_a = 82 kJ/mol) is in good agreement with previous literature values reported for the catalytic hydrogenation of phenol.

Taking into account thermodynamic (solubilities) and mass transfer kinetics (k_La) data measured in situ, the integral reactor conversion rate of this three-phase catalytic reaction was simulated accurately in the physical regime by taking into account external and internal mass transfer resistances.     

Dynamic simulation of a cascade fluidized-bed membrane reactor in the presence of long-term catalyst deactivation for methanol synthesis

In this work, a dynamic model for a cascade fluidized-bed hydrogen permselective membrane methanol reactor (CFBMMR) has been developed in the presence of long-term catalyst deactivation. In the first catalyst bed, the synthesis gas is partly converted to methanol in a water-cooled reactor, which is a fluidized-bed. In the second bed, which is a membrane assisted fluidized-bed reactor, the reaction heat is used to preheat the feed gas to the first bed. This reactor configuration solves some observed drawbacks of new conventional dual type methanol reactor (CDMR) and even fluidized-bed membrane dual type methanol reactor (FBMDMR) such as pressure drop, internal mass transfer limitations, radial gradient of concentration and temperature in both reactors. A dynamic two-phase theory in bubbling regime of fluidization is used to model and simulate the proposed reactor. The proposed model has been used to compare the performance of a cascade fluidized-bed membrane methanol reactor with fluidized-bed membrane dual-type methanol reactor and conventional dual-type methanol reactor. The simulation results show a considerable enhancement in the methanol production due to the favorable profile of temperature and activity along the CFBMMR relative to FBMDMR and CDMR systems.     

MODELING AND SIMULATION OF A NONISOTHERMAL CATALYTIC MEMBRANE REACTOR

A two-dimensional nonisothermal mathematical model has been developed to simulate a tube-and-shell configuration, catalytic membrane reactor. The three-layer membrane consists of an inert large-pore support, an o₂ semipermeable dense perovskite layer and a porous catalytic layer. The model is applied to the simulation of the partial oxidation or methane to syngas (oxyreforming). The membrane reactor simultaneously supplies oxygen to the catalytic reaction along the reactor length, and separates oxygen from the air feed, using a dense perovskite layer which is a mixed conductor, thus allowing rapid oxygen permeation without the use of an external circuit. Two configurations of catalytic membrane reactors are simulated, for both bench-scale and industrial-scale conditions. Comparisons are made to the conventional fixed-bed reactor, and to membrane reactors which are isothermal, adiabatic or wall-cooled. The simulation results imply that the temperature rise in exothermic partial oxidation reactions may be mitigated substantially by the use of a dense membrane reactor,