悬浮填料-曝气生物滤池氨氮去除动力学研究

悬浮填料-曝气生物滤池为双层反应器,下层为悬浮填料,上层为沸石曝气生物滤池,试验中分别研究了上下层对温度的动力学响应机制。试验以零级反应和一级反应分别对下层悬浮填料和上层沸石填料进行动力学模拟,模拟效果较好,分别求出上下层动力学方程:v=2.78×1.13~(T-19.3)、ln C_e/C_0=0.79×1.10~(T-9.3)×h,回归系数分别为0.97,0.88。     

两种运行方式对曝气生物滤池的影响

通过动态模拟试验,考察了两种运行方式对曝气生物滤池的影响。试验结果表明,上流式曝气生物滤池的挂膜时间略少于下流式曝气生物滤池,两种运行方式的生物相丰富;上流式与下流式曝气生物滤池在40cm和60cm对有机污染物的去除率分别为62．3％和67．8％,沿水流方向的COD去除率趋于稳定;两种运行方式的曝气生物滤池在填料高度40cm处。对SS的去除率较高,分别为76．7％和74．3％,而上流式曝气生物滤池出水的SS的去除率高于下流式曝气生物滤池,分别为96．5％和92．1％。上流式曝气生物滤池的操作方式优于下流式曝气生物滤池。     

曝气生物滤池及其处理效能因素分析

曝气生物滤池(BAF)是集生物降解、生物过滤于一体的新型污水处理工艺.本文综述了曝气物滤池的工艺原理、工艺特征、工艺构造及其功能;分析了影响曝气生物滤池处理效能的因素.结合传统污水处理方式,得出曝气生物滤池在污水处理中具有的优势及不足.同时,展望了曝气生物滤池的研究方向及在我国污水处理中的广阔的应用前景.     

运行方式对曝气生物滤池的影响研究

通过动态模拟试验,考察两种运行方式对曝气生物滤池的影响。试验结果表明,上流式曝气生物滤池的挂膜时间略少于下流式曝气生物滤池,两种运行方式的生物相丰富;上流式与下流式曝气生物滤池填料高度在40cm和60cm时对有机污染物的去除率分别为62.3%和67.8%,沿水流方向的COD去除率趋于稳定;两种运行方式的曝气生物滤池在填料高度40cm处对SS的去除表现出较高的去除率,分别为76.7%和74.3%,而上流式曝气生物滤池出水的SS的去除率高于下流式曝气生物滤池,分别为96.5%和92.1%。上流式曝气生物滤池的操作方式优于下流式曝气生物滤池。     

曝气生物滤池(BAF)的研究进展

介绍了曝气生物滤池的工艺原理、结构形式、常用设计参数以及影响曝气生物滤池处理效果的因素,指出曝气生物滤池作为一种污水处理的新工艺应在国内广泛应用。     

曝气生物滤池在电厂生活污水处理中的应用实例

曝气生物滤池技术是近几年被广泛应用的一种新技术。随着对污水回用处理和自动化程度要求的提高,曝气生物滤池以其固有的优势越来越受到污水处理同行的重视。本文简要介绍了曝气生物滤池技术在电厂生活污水处理中应用的实例,并给出了相关的主要技术参数,为曝气生物滤池技术得到更为广泛的应用提供参考。     

不同流向对曝气生物滤池处理洗浴废水效果的影响

研究了不同流向对曝气生物滤池的影响情况,结果表明,上流式曝气生物滤池挂膜时间要略小于下流式曝气生物滤池。从CODCr,LAS主要污染物指标的去除效果上看,上流式要优于下流式曝气生物滤池,且所需气水体积比小,承受水力负荷大,沿水流方向相同滤层高度的去除率高。两种流向的曝气生物滤池,对洗浴废水处理后各项指标符合城市杂用水水质标准GB/T1890-2002。     

曝气生物滤池脱氮技术的研究进展

曝气生物滤池(BAF)有着良好的脱氮效果,近年来曝气生物滤池与新型脱氮理论的结合成为研究的热点。详细阐述了传统脱氮理论与新型脱氮理论在曝气生物滤池中的应用,并介绍了其影响因素。对曝气生物滤池的脱氮前景进行了展望,对存在的问题进行了初步分析。指出将新型脱氮理论运用于曝气生物滤池,对于开发低耗高效的脱氮工艺是个非常好的思路,具有广阔的发展前景。     

抑制条件下好氧生物膜模型的建立及模拟

将简化的ASM1与生物膜动力学方程结合,运用均相生物膜概念,建立好氧生物膜的模型,并且针对焦化废水的特征,进行模型修正.对酒钢集团公司焦化厂A/O生物滤池处理中O段曝气生物滤池COD和氨氮组分的降解过程进行了模拟,并且研究了酚浓度变化、生物膜脱落速率、温度和溶解氧浓度变化对出水COD、氨氮和硝态氮的影响.     

曝气生物滤池技术研究进展

介绍了曝气生物滤池的工作原理、结构形式、工艺特点及影响因素,综述了曝气生物滤池对有机物和SS、氨氮、磷去除效果的研究进展,指出曝气生物滤池是符合我国国情的新型固定膜生物处理技术。     

Purification of water containing agricultural organophosphorus pollutant using titania nanophotocatalysis: Laboratory studies and numerical modeling

This paper deals with the degradation of Fenitrothion (an agricultural organophosphorous pollutant) in aqueous solution by titania nanophotocatalysis. The immersion type method was used for the treatment of polluted water. UV-Vis, ion chromatography and chemical oxygen demand analyses were employed to obtain the details of the photocatalytic degradation and mineralization of Fenitrothion. The numerical model was used to solve mathematical equation describing pollutant degradation process. The simulation results were compared to those results obtained from experimental tests and close agreement was achieved. Results show that the immobilized titania nanophotocatalysis is the effective method for removing Fenitrothion from contaminated water.     

The effects of mass transport and chemical reaction on pollutant removal in a three-phase slurry adsorber-reactor

The analysis of the effects of mass transport and chemical reaction on pollutant removal from a gas-phase in a three-phase slurry adsorber-reactor is presented. A mathematical model, consisting of four coupled differential equations, was developed to describe the process and solved numerically. The modeling assumptions included: perfect mixing in the three-phase slurry, Henry's law, a linear adsorption isotherm and a second order, irreversible chemical reaction. The model was found to adequately represent limited existing experimental data and to qualitatively predict the effects of the various transport coefficients on the pollutant removal efficiency of the process. The model was also used for design analysis. Although the model-process achieved significant pollutant removal for representative operating conditions, the percent removal was ultimately limited by mass transport from the gas bubbles to the liquid slurry.     

活性污泥法处理餐饮废水的动力学研究

通过对餐饮活性污泥法生化处理过程的实验研究,得到了好氧生化处理过程中总化学需氧量与溶解性化学需氧量的浓度变化,确定其降解趋势符合一级反应动力学,降解常数为0,346±0．005h^-1。据此建立了模型并模拟了活性枵泥法处理餐饮废水时溶解性化学需氧量随时阅的变化,确定了达到排污标准所需的最低水力停留时间,为餐饮废水生化处理工程设计提供了依据。     

Particle size distribution based evaluation of biodegradation and treatability for leachate from organic waste

BACKGROUND: The study evaluated the relationship between particle size distribution (PSD) of chemical oxygen demand (COD) and treatability of leachate generated by organic waste. PSD determinations were performed together with physico‐chemical and biological treatability studies. Leachate biodegradation was also evaluated by means of oxygen uptake rate (OUR) profiles and experimental results were used for calibration of the adopted mathematical model. RESULTS: The leachate was characterized by a COD content of 80 000 mg L^?1 in summer. PSD analysis showed a bimodal distribution with around 60% of the COD below 2 nm and 25% above 1600 nm. Chemical treatment by lime and alum provided limited COD removal (30‐35%). The extent of COD removal was higher than the particulate COD fraction above 1600 nm, it also occurred in the soluble range below 2 nm through adsorption. A modeling study indicated three major COD fractions that could be correlated with PSD analysis: readily biodegradable COD and slowly biodegradable COD in the soluble range and hydrolyzable COD fraction in the particulate range. CONCLUSION: PSD‐based COD fractionation adequately explained limitations of chemical treatment efficiency; it was also a reliable complement to the currently used respirometric tests for biodegradation, providing insight to the fate of different COD fractions included in the soluble range (<2 nm) and yielding concrete supporting information on the generation of soluble residual microbial products. Copyright © 2011 Society of Chemical Industry     

Improving Pulverized Coal and Biomass Co‐Combustion in a Cement Rotary Kiln by Computational Fluid Dynamics

The cement industry is one of the largest pollutant emitters. One way to cope with high pollutant emissions is to co‐combust biomass with pulverized coal. A mathematical model was developed, which is detailed enough to consider the complex physical and chemical behavior of the co‐combustion process but simple enough to perform simulations with a real geometry of cement rotary kiln within reasonable time. Numerical simulation with a 20‐% share of pulverized biomass of total fuel heating value was performed. An industrial rotary kiln geometry was simulated; temperature and velocity fields along with mass fractions of released volatiles and combustion products were analyzed. The model allows better insights in the co‐firing process with the main goal to reduce CO₂ emissions by optimizing the combustion process inside the rotary kiln.     

基于模糊层次分析的燃煤电厂脱硫废水处理可利用技术评价

至2015年左右,我国电力行业的大气污染物控制已经随着最新大气控制要求整治完毕,环境治理重点开始逐步转向水污染防控。燃煤电厂全厂水处理包括水污染物去除、水资源回用、减少取水和排水,该领域问题开始上升为主要的环境难题。燃煤电厂脱硫废水是全厂终端废水,其悬浮物、化学需氧量、重金属、无机盐污染物浓度高,对环境危害大。本文根据工程技术方案评价中常用的模糊层次分析（FAHP）模型,对不同的脱硫废水处理技术进行了详细的建模、影响因素选取及模型计算过程研究,得出了几种参评脱硫废水处理技术的优劣综合排序以及最佳可利用技术,以期对燃煤电厂脱硫废水深度处理的方案选择提供参考。     

醋酸生产的仿真研究(Ⅲ)--分离系统的仿真

在MATLAB的SIMULINK环境中对醋酸生产的分离系统进行动态仿真。建立醋酸蒸发器的数学模型，根据实际流程并结合数学模型建立相应的SIMULINK方框图，进行实际生产的动态仿真；建立精馏塔的通用动态数学模型，在SIMULINK中以S-函数的方式进行实现，相平衡计算采用严格的热力学模型，针对醋酸分离流程中的低沸点塔按两种开工情况进行仿真。     

石油污染物在地下环境系统中运移的多相流数值模型

在综合考虑有石油污染物在地下环境体系中扩散、吸附解吸、界面间分配以及微生物降解等作用下,建立了有机污染物在多孔介质迁移转化的多相流动力学模型,并采用特征有限差分方法和隐式压力显式饱和度方法对耦合模型进行数值离散,编制了相应的计算程序;利用该程序对石油污染物在地下环境系统中运移机制进行定量化研究.研究结果表明：石油污染物在地表泄漏以后,将在重力和毛细力的作用下,产生水平位移和垂直位移.当污染物迁移到地下毛细管区后,其向下的运动将整体受到毛细张力的阻碍,污染物要想进入毛细饱和带必须克服油-水界面的进气压力,这时污染物在毛细饱和带顶部聚集以期获取压力,同时将产生以水平方向为主的迁移,最终随着污染物的压力超过其进气压力,导致污染物进入毛细饱和带,在地下水水位上形成一个透镜体.数值模拟曲线与实验测试曲线吻合较好,验证了模型的可靠性.这为定量化研究石油污染物在地下环境系统中分配与归宿及污染预测、预报提供了理论依据.     

多产品间歇化工过程最优设计的研究——启发法

修正了modi等人提出的多产品间歇化工过程最优设计的混合整数非线性规划(MINLP)模型,使之不仅允许中间贮罐的存在,还可调整以同步或异步方式操作的平行单元数.还提出了对以上模型求解的启发算法,其特点是对决策变量的初值要求低,计算速度快,所需内存小,与严格的数学规划法相比较,其相对误差小于1%.以实例说明了方法的有效性.     

Catalytic wet-air oxidation of high strength industrial wastewater

Treatment of desizing wastewater, a typical high strength industrial wastewater, by catalytic wet-air oxidation (WAO) is studied. The desizing wastewater sample was obtained from a large textile dyeing and finishing plant. Experiments were conducted to investigate the effects of temperature and catalyst dosage (CuSO₄ and CU(NO₃)₂) on the pollutant (chemical oxygen demand or COD) removal. It is observed that over 80% of the COD removal can be realized in an hour of the catalytic WAO process. A kinetic model was also developed and a two-stage, first-order kinetic expression was found to represent well the treatment reaction. The correlations between the reaction rate coefficients and the temperature and catalyst dosage were also determined.