Trên tất cả trong số này, hầu hết của các chất gây ô nhiễm hữu cơ ngoan cố thường có tính hòa tan tối thiểu trong giai đoạn dịch, nơi mà các vi sinh vật được lưu trữ và được coi là tích cực nhất. Những tiến bộ gần đây trong biocatalysis đã chứng minh rằng nó là khả thi để thực hiện | ÁG RT In realgas 78 f1 Here f1 is the fugacity at pressure P1. The fugacity may be considered as an adjusted pressure. It is defined so as to coincide with the pressure at low densities m 7 1 79 P 10P 1 The ratio of fugacity to pressure is called the fugacity coefficient Ộ. Thus the previous equation may be written p- P x 1 80 Chemical Potential Consider a solution consisting of n species A B . . . . The Gibbs free energy of the solution is given by n G ỵ NkBk k 1 81 where Pk is the chemical potential of species k defined by Bk Ì dNk _ V k 82 Fugacity and Activity The chemical potential is generally a function of temperature pressure and composition. It is common practice to write Pa P a T RT ln a A 83 where P a T is the standard chemical potential and a A is the activity of species A. The activity is defined as the ratio of the fugacity fA to a standard-state fugacity f A fA aA fA 84 Activities and standard states are discussed in greater detail in many texts on chemical thermodynamics 11 12 . Copyright 2002 by Marcel Dekker Inc. All Rights Reserved. Phase Equilibrium Consider a multicomponent system that separates into two or more phases denoted I II . . . . The criteria for phase equilibrium are T Tii . . . thermal equilibrium 85 Pi Pii . . . mechanical equilibrium 86 Pa i M-a ii . . . equilibrium for species A 87 M-b i M-b ii . . . equilibrium for species B 88 Reaction E quilibrium Consider a reaction aA bB . . . . . . xX ZZ which as before can be expressed in the shorthand notation 0 Ê v 4 k 1 The criterion for chemical reaction equilibrium is AG Ỳ Wk 0 89 k 1 Reaction equilibrium may also be expressed in terms of the standard Gibbs free-energy change AG0 RT ln Ka 90 Here Ka is the equilibrium constant defined by Ka nakVk 91 k 1 6 ENGINEERING FLUID MECHANICS Fluid mechanics deals with the flow of liquids and gases. For most engineering applications a macroscopic approach is usually taken. Copyright 2002 by Marcel Dekker Inc. All Rights .
