Modeling of biofilm kinetics in TILT® Moving Bed Biological Reactor (TILT® MBBR)

生物膜是一层复杂的微生物，覆盖在暴露在底物上的表面。生物膜由许多不同类型的微生物菌落组成，包括细菌、真菌、藻类、原生动物和非细胞材料。生物膜的积累是一个动态的过程，它是生长和脱落的净结果，并受到几个外部因素的影响，包括废水的组成和浓度、液体速度、颗粒浓度、颗粒-颗粒碰撞和颗粒-壁面碰撞。微生物菌落分泌一种胞外聚合物(EPS)基质，它包裹着生物膜，保护菌落免受降解、捕食、抗菌剂、聚集和毒素的影响。在附着生长废水处理工艺中，生物膜的形成涉及一系列不同的阶段，包括可逆附着、 不可逆转的依附、成熟和脱离。生物膜附着始于表面和废水环境的固液界面。 TILT®移动床生物反应器(TILT®-MBBR)是包含中等填充生物膜载体(通常为40%至60%的体积填充)的生物膜工艺的替代方法。该反应器中的流体动力强度作为排斥力或吸引力，显著影响微生物与固液界面的黏附，从而影响生物膜动力学的速率。在流速较小的界面区域存在流体动力边界，因此边界层的厚度取决于周围废水介质的线速度和剪切力。该方案的目标是开发TILT®-MBBR的数学模型 该模型将用于确定好氧异养和自养细菌的生物膜动力学，并针对不同的市政和工业废水在生物有机处理过程中开发一个经济、稳健和高效的模型。模型的重点是

Biofilms are complex layers of microorganisms that coat surfaces exposed to substrates. Biofilms consist of many different types of microbial colonies including bacteria, fungi, algae, protozoa, and non-cellular materials. Biofilm accumulation is a dynamic process that is the net result of growth and detachment and is affected by several external factors, including wastewater composition and concentration, liquid velocity, concentration of particles, particle-particle collisions, and particle-wall collisions. The microbial colonies excrete a matrix of extracellular polymeric substances (EPS), which encloses the biofilm and protects the colonies from degradation, predation, antimicrobials, aggregation, and toxins. In attached growth wastewater treatment processes, biofilm formation involves a series of distinct stages consisting of reversible attachment, irreversible attachment, maturation, and detachment. Biofilm attachment begins at the solid-liquid interface of the surface and wastewater surroundings. The TILT® Moving Bed Biological Reactor (TILT®-MBBR) is an alternative approach for biofilm process that contains medium packed biofilm carriers (typically 40 to 60% bulk volumetric fill). The hydrodynamic strength in this reactor significantly affects the microbial adhesion to the solid-liquid interface by acting as a repulsive or attractive force and thereby influencing the rate of the biofilm kinetics. A hydrodynamic boundary exists in the area of the interface where there is an insignificant flow velocity, therefore the thickness of the boundary layer is dependent upon the linear velocity and the shear forces of the surrounding wastewater medium. The objective of this proposal is to develop a mathematical modeling for TILT®-MBBR in collaboration with H2Flow Equipment Inc. The proposed model will be used to determine the biofilm kinetics of aerobic heterotrophic and autotrophic bacteria and to develop an economical, robust, and efficient model for different municipal and industrial wastewater during the biological organic treatment. The focus of the model