移动床生物膜反应器SHARON工艺半亚硝化特性

采用移动床生物膜反应器（MBBR）对城市垃圾渗滤液进行SHARON工艺研究。主要研究了该反应器的启动情况和氨氮浓度、溶解氧（DO）以及pH等因素对反应器半亚硝化效果的影响。结果表明,在控制HRT=1 d、温度30℃、DO=0.5～1.0 mg·L^-1、pH=7.5左右、无污泥回流等条件下,经过4周的运行,成功地选择培养出亚硝化型生物膜,实现了短程硝化。研究表明通过控制进水氨氮浓度、DO和pH,可以达到出水半亚硝化的处理效果。当进水氨氮浓度为500 mg·L^-1时,出水半亚硝化的控制条件是pH=7.0,DO=1.5 mg·L^-1;而在进水氨氮浓度为300 mg·L^-1时,控制pH=7.0,DO=1.0 mg·L^-1,出水也可实现半亚硝化。最大可能计数法（MPN）测定发现,亚硝化菌在数量上的绝对优势是反应器能始终保持高效稳定的亚硝氮积累的主要原因。     

Evaluation of the effects of AlkylPhenolic compounds on kinetic coefficients and biomass activity in MBBR by means of respirometric techniques

The presence of AlkylPhenols (APs) in aquatic systems is considered as one of the environmental concerns in recent decades which are generally used as surfactants. APs are endocrine disruptors and estrogen-mimicking, causing harmful effects such as feminization and carcinogenesis on aquatic environment and human health. The most commercially important APs are 4-NonylPhenol (4-NP) and 4-tert-OctylPhenol (4-t-OP). Moving bed biofilm reactor (MBBR), which combined attached and suspended growth advantages, is an advanced biological treatment process for municipal and industrial wastewaters that has drawn considerable attention from many researchers to remove toxic pollutants from wastewater. The aim of this research was to evaluate Bacterial activities and kinetic coefficients in the presence of APs. This study was carried out using laboratory-scale MBBR fed with synthetic wastewater containing 4-NP and 4-t-OP. The reactor was operated at different loads of chemical oxygen demand (COD) and APs and different hydraulic retention time (HRT). The respirometric technique was applied to investigate the effect of APs on heterotrophic and autotrophic activity and kinetic coefficients in biomass obtained from MBBR. Respirometric technique demonstrates a reliable tool in order to assess the biofilm kinetic coefficients and biomass viability to insert in the mathematical models. The calculated kinetic parameters were in the range of conventional and extended aeration activated sludge processes. The results demonstrate that APs have significant inhibitory effects on activity and growth rate of heterotrophic and autotrophic bacteria, heterotrophs have been less affected by the presence of 4-NP and 4-t-OP, and these compounds had greater inhibitory effects on autotrophic bacteria.     

移动床生物膜反应器脱氮除磷技术

本文简要介绍了移动床生物膜反应器的特点,总结了移动床生物膜反应器脱氮和除磷的影响因素,指出序批式的运行方式可以同时达到脱氮和除磷的效果。     

Advanced treatment of textile dyeing wastewater through the combination of moving bed biofilm reactors and ozonation

A four-stage lab-scale treatment system [anaerobic moving bed biofilm reactor (MBBR)-aerobic MBBR-ozonation-aerobic MBBR in series] was investigated to treat textile dyeing wastewater. The MBBRs were operated in a continuous horizontal flow mode. To determine the optimum operating conditions, the effect of hydraulic retention time (HRT) and ozonation time on pollutant removal were analysed by continuous and batch experiments. The optimum operating conditions were found to be 14 h HRT for both anaerobic and no. 1 aerobic MBBRs, 14 min ozonation time and 10 h HRT for no. 2 aerobic MBBR. The average influent concentrations of chemical oxygen demand (COD), suspended solids (SS), ammonia and colour were 824 mg/L, 691 mg/L, 40 mg/L and 165°, respectively. Under these conditions, the average effluent concentrations of COD, SS, ammonia and colour were 47 mg/L, 15.2 mg/L, 5.9 mg/L and 6.1°, respectively, corresponding to total removal efficiencies of 94.3%, 97.8%, 85.3% and 96.3%, respectively. The final effluent could meet the reuse requirements of textile industry. The anaerobic MBBR process improved the biodegradability of the raw wastewater, while the two aerobic MBBRs played an important role in removing COD and ammonia. The ozonation process enhanced the biodegradability of no. 1 aerobic MBBR effluent, and finally, deep treatment was completed in no. 2 aerobic MBBR. The combined process showed a promising potential for treatment of high-strength dyeing wastewater.     

MBBR中HRT与pH对短程硝化反硝化的影响

为了开发经济高效的生物脱氮工艺,在MBBR中进行了短程硝化反硝化的研究,考察了HRT与pH对短程硝化反硝化的影响。结果表明,在短程硝化反硝化过程中,在室温、不控制溶解氧的条件下,NH_4~+-N与COD去除率随着HRT的延长而增大,出水NO_2~--N随着HRT的延长先增大后减少,当HRT为8h时出水NO_2~--N最高;当pH由5增加到10时,COD去除率的变化较小,NH_4~+-N去除率和出水NO_2~--N则随着pH的增大先增大后减小,pH在8~9时对NH_4~+-N的处理效果最好,出水NO_2~--N最高。     

Effect of kinetic models on hot spot temperature prediction for phthalic anhydride production in a multitubular packed bed reactor

Although there are several kinetic models for the production of phthalic anhydride from the partial oxidation of o‐xylene, only few studies have compared the effect of the kinetic model on the prediction of the hot‐spot temperature. In this work, the predicted temperature profile for the partial oxidation of o‐xylene to phthalic anhydride in a multitubular packed bed reactor was obtained for different kinetic mechanisms using one‐dimensional pseudo‐homogeneous and heterogeneous models. The predicted temperature profile using the one‐dimensional heterogeneous model with the kinetic model of Calderbank et al. but with the adjusted kinetic and transport parameters proposed by Anastasov presented a good correlation with regard to experimental data. Nevertheless, in the hot‐spot zone deviations, up to 30 K were presented. In conclusion, the temperature performance in the production of phthalic anhydride is suitably predicted by the one‐dimensional heterogeneous model and the Calderbank et al.'s kinetic model. Though, prediction using bidimensional models should be done to establish the best correlation with experimental data.     

移动床生物膜反应器工艺在污水处理厂改造中的应用

为改变石家庄经济技术开发区污水处理厂出水无法达标的状况,将原有的氧化沟工艺,改造成(生物膜法 活性污泥法)串联好氧组合的移动床生物膜反应器(Moving Bed Biofilm Reactor,MBBR)工艺,改造完成后,处理效果良好,出水达标,出水水质稳定,取得了良好的经济效益和社会效益.     

Estimation of kinetic parameters of benzene hydrogenation in a trickle bed reactor

A high pressure and high temperature catalytic hydrocracking unit based on trickle-bed reactors was constructed. Data obtained under conditions simulating those of industrial processes, were evaluated. Partial wetting characteristics of trickle beds were especially taken into account in the interpretation of results together with combined contributions of gas and liquid phase reactions.     

不同操作模式对移动床生物膜反应器脱氮除磷效果的影响

考察了连续进出水方式(CMBBR)、单级好氧序批式［SBMBBR(O)］和厌氧/好氧序批式［SBMBBR(A/O)］3种操作模式下移动床生物膜反应器(MBBR)对模拟污水的处理效果。实验结果表明,3种操作模式下COD去除差异不大,TN、TP去除效果不同。SBMBBR(O)相似文献   

序批式移动床生物膜反应器脱氮除磷影响因素及特性

考察了曝气量、进水C/N比（COD/TN）及进水氮、磷浓度对序批式移动床生物膜反应器（SBMBBR）脱氮除磷效果的影响,分析了该复合生物系统的污染物去除特性。实验结果表明,反应器脱氮主要是基于好氧段发生的同时硝化反硝化（SND）作用实现的,而除磷是基于常规生物除磷和反硝化除磷过程而完成;在保持载体良好流化状态的前提下,反应器硝化效果和TP去除受曝气量变化影响不大,反硝化效果随曝气量的减小而改善;采用厌氧/好氧序批式运行方式,能够使进水中的有机物被反硝化聚磷菌优先利用,实现一碳两用,节省了脱氮对外部碳源的需要,在进水C/N为2.8～4.0时能获得良好的硝化、反硝化和TP去除效果;随着进水氮、磷浓度的提高,反应器除磷效果相对稳定,脱氮效果变差,最大氮、磷去除负荷分别达到0.17 kg TN·m^-3·d^-1和0.06 kg TP·m^-3·d^-1。     

混凝沉淀-陶粒悬浮填料移动床处理漂染废水的性能研究

采用混凝沉淀-生物陶粒移动床(BCMBBR)组合工艺处理典型漂染废水.研究结果表明,在HRT为6h,气水体积比5∶1,PAC、PAM投加量分别为200、2 mg/L的条件下,出水CODCr、SS的平均质量浓度分别为46.8、21.0 mg/L,色度平均值为27倍,pH值为7.48～7.53,出水水质达到GB 4287-...     

Biodegradation kinetics of a mixture of phenols in a sequencing batch moving bed biofilm reactor under starvation and shock loads

BACKGROUND: The objective of this research was to study the biodegradation kinetics of a mixture of phenol, 4‐chorophenol 2,4‐dichlorophenol and 2,4,6‐trichlorophenol in a moving bed sequencing batch reactor (SBR) subjected to starvation and shock loads. The effect was evaluated on the degradation time and on the specific degradation rate. RESULTS: The bacteria present in the system degraded effectively the mixture of phenols. Degradation efficiencies were higher than 98% as total phenols and greater than 95% as organic carbon. It was observed that starvation and shock loads had only a transient effect on microorganisms degradation rate. The substrate removal rate decreased when the perturbations were applied, but for subsequent SBR cycles the previous activity was recovered. Results also demonstrated that suspended biomass was more sensitive to changes than the attached biomass present in the moving bed. CONCLUSIONS: The moving bed SBR presented robust performance under variable influent concentrations of a mixture of inhibitory compounds. Copyright © 2011 Society of Chemical Industry     

Modeling of an industrial fixed bed reactor based on lumped kinetic models for hydrogenation of pyrolysis gasoline

In this work, a mathematical model of an industrial fixed bed reactor for the catalytic hydrogenation of pyrolysis gasoline produced from olefin production plant is developed based on a lumped kinetic model. A pseudo-homogeneous system for liquid and solid phases and three pseudo-components: diolefins, olefins, and parraffins, are taken into account in the development of the reactor model. Temperature profile and product distribution from real plant data on a gasoline hydrogenation reactor are used to estimate reaction kinetic parameters. The developed model is validated by comparing the results of simulation with those collected from the plant data. From simulation results, it is found that the prediction of significant state variables agrees well with the actual plant data for a wide range of operating conditions; the developed model adequately represents the fixed-bed reactor.     

Experimental study of the inverse fluidized bed biofilm reactor

A new apparatus, the inverse fluidized bed biofilm reactor, is described. Introduction of the so called inverse fluidized bed, in which low density particles covered by a biofilm are fluidized by downflow of the liquid, allows control of the biofilm thickness and provides a high oxygen concentration in the reacting liquid. Characteristics of the reactor were studied by carrying out two important biotechnological processes: aerobic wastewater treatment by a mixed bacterial culture, and ferrous iron oxidation by the bacteria Thiobacillus ferrooxidans. The bioreaction rates per unit volume of the reactor were up to 14 times higher than those in the equivalent airlift bioreactor. The structure of the liquid flow was determined by a tracer method.     

水解酸化-好氧MBBR耦合Fenton法处理抗生素废水研究

采用水解酸化—好氧移动床生物膜(MBBR)串联Fenton工艺处理抗生素废水,探讨了pH、HRT等对水解酸化以及Fe2 浓度和H2O2投加量对Fenton工艺的影响。实验结果表明,对于COD为6800.62mg/L、B/C<0.3的抗生素废水,当水解段pH和HRT分别为6.5和12h时,挥发酸(VFA)质量浓度为931.75mg/L,COD去除率为26.59%,此时水解酸化—好氧段出水COD为1229.80mg/L,COD总去除率为81.92%。再经Fenton工艺深度处理,当Fe2 最佳投加质量浓度为240mg/L,H2O2投加量为3.19mL/L时,总COD去除率可达97.38%,最终出水COD为178.50mg/L,达到制药工业废水排放标准。     

Buoyancy effects on objects moving in a bubbling fluidized bed

The effect of buoyant forces on the motion of a large object immersed in a bubbling fluidized bed (BFB) was experimentally studied using digital image analysis. The experiments were performed in a 2-D bubbling fluidized bed with glass spheres as bed material and cylindrical objects with different densities and sizes. The object motion was measured using non-intrusive tracking techniques. The effect of gas velocity was also analyzed.The circulation of an object in a BFB is defined by several parameters. The object might be able to circulate homogeneously throughout the bed or stay in preferred regions, such as the splash zone or the bottom zone. While circulating, the object moves back and forth between the surface of the bed and the inner regions, performing a series of cycles. Each cycle is composed by sinking and rising paths, which can be one or several, depending on whether a passing bubble is able to lift the object to the surface or the object is detached from it or its drift at an intermediate depth. Therefore, the number of rising paths or number of jumps that the object undergo in a cycle, interleaved with sinking paths, and the maximum attained depth characterize each cycle, together with the mean sinking and rising velocities of the object. In this work, experimental measurements of the probability distributions of the number of jumps and the maximum attained depth, the axial homogeneity of object motion and rising and sinking object velocities are presented for objects with different sizes and densities. The results show a coherent behavior, independent of density and size, for the probability distributions of the number of jumps. This is also true for the maximum attained depth, but only when a proper circulation throughout the bed is ensured. Such a proper circulation and axial homogeneity is, on the other hand, much affected by object density, size and gas velocity. Rising and sinking velocities are highly dependent on gas velocity, as established in well-known models of bubble and dense phase velocities. Nevertheless, rising velocities are practically unaffected by object density or size, while sinking velocities show a low dependence on density and a steeper one on size. These results suggest that buoyant forces are relevant during the sinking process, and almost neutral during the rising path.