سؤال في mass transfer مين بيعرف يحلو ؟

غسان مارديني

عضو جديد
إنضم
17 مارس 2006
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مرحبا جميعاً،
سوري يمكن أنا عضو جديد وبادي مشاركاتي بغلاسة .. بس إزا ممكن حدا من المهندسين أو الطلاب اللي درسوا كورس ماس ترانسفير يفيدوني بحل هاي المسألة ، وخصوصا نوع الكودينات سيستيم المستخدم ، لأنو كان موضوع نقاش حامي بين وبين أحد الدكاترة فياريت يوصلني حلو قبل يوم الأربعا .. إزا ممكن وحكون كتير ممنونكم .. وشكرا مقدما
Dilute solution of toxic organic solutes in aqueous solution can often be degraded by a biofilm attached to an inert, nonporous solid surface. A biofilm consists of living cells immobilized in a gelatinous matrix. A toxic organic solute (species A) diffuses into the biofilm and is degraded to harmless product, hopefully SO2 & water by the biofilm. For engineering applications, the biofilm is considered a homogeneous substance (i.e., species B). The rate of degradation of the toxic solutes per unit volume of the biofilm is described by a kinetic rate equation of the form RA= - (RA,max cA)/(KA + cA) where RA,max is the maximum possible degradation rate of species A in the biofilm, and KA is the half-saturation constant for the degradation of species A within the biofilm. In the present process, a biofilm of 1 mm diameter thickness is immobilized around an inert, nonporous spherical pellet of 1 cm diameter. The concentration of the toxic containment in the bulk aqueous phase is constant. Furthermore, there are no resistances to convective mass transfer across the fluid boundary layer between the bulk fluid and the biofilm surface. The containment is equally soluble in both water and the biofilm and water can be neglected. Finally, the concentration of species A in so dilute that KA << cA and the kinetic-rate equation approximates a first-order process.

(a) Draw a picture of the physical system and state at least five assumptions for the mass-transfer aspects of this process. What coordinate system should be used?
(b) What is the general differential equation for mass transfer in terms of concentration cA? Propose 2 boundary conditions for species A needed to solve the resulting differential equation.
 

مواضيع مماثلة

مهندس 2006

عضو جديد
إنضم
5 يناير 2006
المشاركات
45
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0
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أخوي ان شاء الله بكره الساعة 2 صباح الاربعاء في توقيت السعودية راح يكون عندك الحل
 
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