厌氧序批式反应器的特征与应用

厌氧序批式反应器(ASBR)作为一种新型的高效厌氧反应器具有污泥持留量高、水力停留时间短、处理效率高等优点,可以单独或与其他工艺相结合有效的处理食品加工废水、家畜饲养废水、屠宰场废水等高浓度有机废水．还可以应用于处理城市污水和低浓度工业废水。介绍ASBR的工艺特点,国内外研究概况,并对ASBR的应用现状和发展前景进行了分析．认为ASBR反应器在我国的废水处理中有良好的应用前景。     

SBR工艺研究进展

近年来，间歇式活性污泥法由于其工艺简单、运行灵活、基建和运行费用低，已成为国内外竞相研究和开发的热门污水生物处理工艺。在阐述了SBR反应器的工艺特点及计算的基础上，对近年来其主要的变形丁艺(ICEAS，CAST，IDEA，DAT—IAT，UNITANK等)和其他新型SBR工艺的发展进行了综述。同时指出随着对该工艺的研究和开发，它必将成为一种很有竞争力的污水处理工艺，拥有良好的发展前景。     

Simulation of a jet-assisted circulation jacketed batch reactor for polymerization of methylmethacrylate

A simulation of a five-liter, agitated, nonisothermal, jet-assisted circulation, jacketed methylmethacrylate polymerization batch reactor considering all the available physical-chemical properties and related correlations for agitation and heat transfer coefficients is presented. From the calculated cumulative radical population, the phenomena of early runaway, thermal ignition and gel effect ignition are identified. Variations of medium viscosity over the course of the polymerization reaction affect the performance of the agitator and the overall heat transfer coefficient. The simulation results indicate that much higher heat duties can be removed by this special equipment design than in the case of a conventional vessel design.     

厌氧序批式反应器的厌氧氨氧化工艺启动运行

在厌氧序批式反应器中接种好氧硝化污泥,进行了培养厌氧氨氧化污泥的研究。在进水pH值为7.2～7.8,温度为30±1℃的条件下运行142d,成功培养出厌氧氨氧化污泥。反应器内的污泥量(以VSS计)由原来的9.90g/L增加到18.99g/L,水力停留时间为1.20d,总氮容积负荷为0.4318kg/(m·3d)时,总氮去除率最高达到93.3%,平均为80.5%,氨氮和亚硝酸盐氮的去除率最高分别达到93.9%和99.8%,平均去除率分别为81.2%和85.7%,氨氮和亚硝酸盐氮去除的比例为1∶1.387±0.024。对该工艺优化实验研究表明,适宜pH值为7.2～7.8,最适宜温度为35℃;且适度强化反硝化作用有利于提高反应器的脱氮性能。     

Investigation of thermochemical conversion of biomass in supercritical water using a batch reactor

This study focused on gasification of biomass and a biomass model compound. Data are presented that show the presence of supercritical water enhances gasification efficiency, as it participates as both a solvent and a reactant. It is established that biomass gasification efficiencies are in the same range for all types of biomass. The thermodynamic changes of state are functions of elemental composition, not biomass species. The oxidation state of carbon atom of biomass is a key variable in determining the changes in enthalpy during both conventional combustion and supercritical water gasification. The oxidation state of the feed (together with the reaction conditions that influence the degree to which water participates as a reactant) also determines the vapor product composition.Decomposition reactions to vapor products are rapid and complete at high temperature (?550 °C), catalytic mediation is not required. Temperature and residence time are important operating parameters for SCW gasification. Less important are the pressure of gasification (in the range of 40-67 MPa) and the presence of catalyst. The vapor yield, gas composition, the carbon and hydrogen balance of SCW gasification are functions of gasification temperature, residence time and biomass load (concentration).     

多功能水处理剂高铁酸钾的制备与应用

高铁酸钾是一种集氧化、吸附、絮凝、助凝、杀菌、除臭为一体的新型高效多功能水处理剂。作者综述了国内外有关高铁酸钾的制备方法、性质及应用领域的研究进展,讨论了高铁酸钾在制备与纯化工艺以及实现大规模工业化生产方面所面临的若干技术问题。指出,随着人们对高铁酸钾独特的水处理功能认识的不断深化及其应用领域的逐步拓宽,研究其高效、低耗、减污的清洁生产工艺具有十分广阔的开发前景。文中引用了近年相关文献26篇。     

序批式膜生物反应器处理生活污水的特性

研究了中试规模序批式膜生物反应器处理生活污水的特性.发现其对COD_Cr、NH₃-N及TN的去除效果可分别达到95.0%、96.3%及38.0%;过膜阻力增加率为1.032 kPa•m^-1.TN去除率偏低的主要原因在于缺少搅拌装置,在静置阶段时,污泥大部分沉积在反应器底部（系统运行期间30 min沉降比均低于40%）,从而使反硝化细菌不能充分与水溶液中的NO_x-N接触.采用空间排阻液相色谱法对混合液及膜污染物进行分子量分布测定,发现大量大分子物质在反应器内、膜面及膜孔内积累,相对分子质量大于10⁴的有机物分别占64.0%、38.0%.经过物理及化学清洗,膜通量恢复了73.4%,多糖含量为清洗前的30.4%,说明多糖是造成不可逆污染的主要物质.     

废水处理光催化反应器的发展

光催化是一项很有前途的水处理技术,光催化反应器是影响光催化反应效率的重要因素之一。作者对影响光催化反应器效率的因素如光源种类、反应器结构、催化剂状态等进行了分析,并总结了近年来在国内外研制及应用的一些典型的光催化反应器．给出了其结构图．并对其优缺点进行了评价。     

厌氧序批式反应器快速形成颗粒污泥技术研究

厌氧序批式反应器(ASBR)初次启动用厌氧消化污泥接种,比较了投加聚季铵盐(A柱)与空白对照(B柱)2个反应器的颗粒污泥形成过程。启动后以每隔2 d投加1次的投加方式向反应器中不断补充聚季铵盐,聚季铵盐投加质量与污泥质量之比取1.6 mg/g。结果表明,A柱颗粒污泥平均粒径达到0.72 mm仅需73 d,比B柱提前了25 d。A柱在启动56 d后COD负荷达到10 g/(L.d),形成的颗粒污泥平均粒径大于B柱(0.55 mm),产甲烷活性也较高。所以投加聚季铵盐能有效促进污泥颗粒化进程。     

Novel batch reactor design for the adsorption of arsenate on chitosan

BACKGROUND: The sorption of arsenate, a poison of acute toxicity found in natural waters, onto chitosan, a biosorbent derived from waste seafood shells has been studied. A batch adsorber design model was developed to determine how much chitosan adsorbent is required to reduce the arsenate concentration in solutions to the WHO standard of 10 µg L^?1. RESULTS: A series of batch kinetic experiments has been carried out at different initial pH values. The initial arsenate sorption appears to be completed after 30 min, however, a steady reversible reaction takes place resulting in the desorption of arsenate over 48 h. These phenomena in the batch kinetic data have been correlated simultaneously using the newly developed pseudo‐first order reversible model. Two batch reactor design models have been developed and compared. The first model is a conventional approach based on the equilibrium isotherm capacity equation. A second batch adsorption reactor design is based on the principle of contacting time required, t_max, for the chitosan to achieve its maximum adsorption capacity, q_max. The practical outcome from the second batch adsorber model results in a saving in adsorbent mass per batch of approximately 39.4%, 96.2% and 92.3% chitosan adsorbent at pH conditions of 3.5, 4.0 and 5.0, respectively. CONCLUSION: The adsorbent cost and handling costs are reduced in the second batch adsorber model. There is also a significant savings in the batch turnaround time required in the batch adsorber design when the design is based on the maximum adsorption capacity rather than the equilibrium adsorption capacity. Copyright © 2010 Society of Chemical Industry     

Application of parametric control concepts to decoupler design and heating control design for a batch reactor

Parametric control involves expressing the manipulated variables of a process in terms of a new set of variables, called parametric variables. The control engineer can choose the functional relationships between the two sets of variables to provide added flexibility in control loop design. The design of a static decoupler and the linearization of a batch reactor heating system are provided as examples.     

Modeling and scale-up simulation of U-tube ozone oxidation reactor for treating drinking water

In the present study, we developed a novel simulation model of the U-tube reactor for treating drinking water, which is composed of a coaxial inner tube serving as an efficient concurrent down-flow ozone dissolver and an outer column carrying out reactions between ozone and organic substances including odorous materials (2-methylisoborneol: 2-MIB) dissolved in the raw water. We assume that the U-tube is composed of a plug flow section (inner tube) followed by a tanks-in-series section (outer bubble column) and take into account the effect of the hydrostatic pressurization on the flow and absorption equilibrium for the gaseous components including ozone and other inactive species in developing the mass balance models. An algorithm is constructed of the differential multiple mass balance equations for the inner tube sections and multiple difference mass balance equations in the series tanks in the outer column section to enable the scale-up from a pilot plant to a full-scale plant. The gas holdup and gas-liquid mass transfer coefficient were measured in a model reactor and correlated for the use of the simulation calculation. Available literature data and correlations on the rates of reactions between ozone and organic substances including odorous material 2-MIB, gas-liquid equilibrium for active and inactive gases and axial fluid mixing properties are also incorporated in the simulation calculation. The simulation results well explained the available data of the ozone absorption efficiency and the removal efficiency of the odorous material in a pilot U-tube reactor. The simulation procedure was also successfully extended to verify the performance of a full-scale U-tube reactor. It is shown that the ozone absorption is practically a single function of the gas/liquid ratio while the removal efficiency of the odorous material is a single function of the ozone dose for a specified U-tube configuration.     

Self-adaptive predictive functional control of the temperature in an exothermic batch reactor

In this paper we study a self-adaptive predictive functional control algorithm as an approach to the control of the temperature in an exothermic batch reactor. The batch reactor is located in a pharmaceutical company in Slovenia and is used in the production of medicines. Due to mixed discrete and continuous inputs the reactor is considered as a hybrid system. The model of the reactor used for the simulation experiment is explained in the paper. Next, we assumed an exothermic chemical reaction that is carried out in the reactor core. The dynamics of the chemical reaction that comply with the Arrhenius relation have been well documented in the literature and are also summarized in the paper. In addition, the online recursive least-squares identification of the process parameters and the self-adaptive predictive functional control algorithm are thoroughly explained. We tested the proposed approach on the batch-reactor simulation example that included the exothermic chemical reaction kinetic model. The results suggest that such an implementation meets the control demands, despite the strongly exothermic nature of the chemical reaction. The reference is suitably tracked, which results in a shorter overall batch-time. In addition, there is no overshoot of the controlled variable T, which yields a higher-quality production. Finally, by introducing a suitable discrete switching logic in order to deal with the hybrid nature of the batch reactor, we were able to reduce the switching of the on/off valves to a minimum and therefore relieve the wear-out of the actuators as well as reduce the energy consumption needed for control.     

ASBR反应器中污泥沉降性能研究

厌氧序批式反应器(ASBR)是一种间歇运行的高速厌氧生物反应器,污泥颗粒化、非稳态运行和反应与沉淀集于一体等重要特征,为其高效的固液分离提供了条件.试验考察了ASBR反应器在MLSS为9.0～30g/L,进水OLR(COD)为=3～10g/(L·d),进水F/M(COD)为0.19～1.1g/(g·d)时,对其颗粒污泥沉降性能的影响因素.结果表明,ASBR表现出优良的沉降性能,影响污泥ZSV和SV、SVI的主要因素是MLSS,ZSV和SV、SVI对MLSS呈现出较好的相关性.而进水F/M与SV和ZSV、SVI之间无明显的变化规律.     

Mixed integer optimal control of an intermittently aerated sequencing batch reactor for wastewater treatment

Optimal aeration control strategies for sequencing batch reactors in WWT with bypass nitrification are hereby studied. The operation is defined alternating aerobic and anoxic phases with high frequency. The controlled variable, the aeration, can only adopt fixed values, on and off, leading to a discrete trajectory of bang–bang type. The problem is to compute the number of switches and individual length of each aerobic and anoxic stage. This leads to a mixed integer nonlinear optimal control problem (MINTOC). The solution is challenging, since both integer and continuous variables ought to be considered in the optimization. In contrast to previous work, where optimization is performed based on the separation and independent solution of the integer and continuous problem, we apply an algorithm originally proposed by Sager (2005). The optimization program minimizes operation time and energy consumption. Effluent concentrations are considered as nonlinear constraints in accordance to environmental regulations.     

序批式反应器中反硝化除磷脱氮的研究

为了提高污水脱氮除磷的效率,研究采用序批式反应器(SBR工艺)厌氧、好氧和缺氧(AOA)的运行方式富集反硝化聚磷菌(DPB),实现同步脱氮除磷。结果表明:在好氧段投加甲醇作为碳源(25—40 mg/L)可有效抑制好氧吸磷,对硝化反应影响较小,能够在缺氧段实现同时反硝化脱氮除磷。SBR反应器稳定运行10个月,当进水NH4+-N、PO43--P分别为30,15 mg/L时,总氮(TN)和PO43--P的平均去除率分别为82.5%和92.1%。聚磷菌能够利用硝酸盐作为电子受体,DPB占总聚磷菌的比例达到44.8%。与A2O运行方式相比,AOA运行方式更有利于实现DPB的富集。     

利用结构逼近式混合神经网络实现间歇反应器的建模

提出了一种新的混合神经网络建模方法——结构逼近式混合神经网络。基于此结构建立的混合神经网络可以充分利用已知非线性系统的结构信息,使神经网络“灰盒”化,更好地解释和描述系统各变量间的因果关系,从而提高网络的建模精度和模型的可靠性。本文介绍了这类神经网络的基本特性、拓扑结构和训练方法。报告了一个典型放热液相二级平行间歇反应的建模过程;并针对间歇反应过程测量滞后的情况,与两种不同的混合神经网络模型作了比较,仿真和比较结果证明了方法的有效性。     

Design of a novel sequencing batch internal micro-electrolysis reactor for treating mature landfill leachate

A novel sequencing batch internal micro-electrolysis reactor (SIME) was specifically designed to treat mature landfill leachate. The idea of simulating the biological process of a sequencing batch activated sludge reactor (SBR) was employed in the design of the new reactor. The innovative concepts behind this design are the combination of the processes of reductive internal micro-electrolysis (IME) without aeration and oxidative IME with aeration, and the integration of electro-aggregation and electro-coagulation. The automated operating system in this reactor is centralized automation which rewards for safe control, convenient operation and the possibility of commercial application. The SIME reactor exhibited a COD removal efficiency of 86.1% for mature landfill leachate in this study, which is much higher than that of conventional treatments, such as electrolysis, coagulation–sedimentation, and the Fenton process. A pilot-scale experiment showed that the reactor was also particularly efficient in the removal of color, humic acids, and metal ions. The BOD₅/COD ratio of the leachate was significantly improved after the treatment. All of these results show that the SIME reactor is a promising new technology because it is efficient and automated, and has the potential to be applied to the practical treatment of mature landfill leachate.