Analysis of Tracer Response Curves Overfow rate: 32.8 m3/m2.d V/O= 48.7 min 08 Center feed 8000m 4000m3 tank Peripheral feed tank s6c8o Theoretical detention time E0.2 0 bmmoeboomop 010203040506070809010 10 Time, min Time, min Fig. 4-8 Typical tracer response curves: two different types of circular clarifiers and open channell disinfection system
Analysis of Tracer Response Curves Fig. 4-8 Typical tracer response curves: two different types of circular clarifiers and open channel UV disinfection system
4-4 Reactions, Reaction Rates, and reaction rate Coefficients The stoichiometry of reaction refers to the definition of the quantities of chemical compounds involved in a reaction The rate expressions discussed in this section will be integrated with the hydraulic characteristics of the reactors discussed previously, to define treatment kinetics Types ofreactions The two principal types of reactions that occur in wastewater treatment are classified as homogeneous and heterogeneous(non-homogeneous)
4-4 Reactions, Reaction Rates, and Reaction Rate Coefficients The stoichiometry of reaction refers to the definition of the quantities of chemical compounds involved in a reaction. The rate expressions discussed in this section will be integrated with the hydraulic characteristics of the reactors, discussed previously, to define treatment kinetics. Types of Reactions The two principal types of reactions that occur in wastewater treatment are classified as homogeneous and heterogeneous (non-homogeneous)
Homogeneous Reactions In homogeneous reactions, the reactants are distributed uniformly throughout the fluid so that the potential for reaction at any point within the fluid is the same, Homogeneous reactions are usuall carried out in the batch, complete-mix and plug-flow reactors
Homogeneous Reactions In homogeneous reactions, the reactants are distributed uniformly throughout the fluid so that the potential for reaction at any point within the fluid is the same, Homogeneous reactions are usually carried out in the batch, complete-mix, and plug-flow reactors
Examples of irreversible reactions are a. Simple reactions A B A+A aA+bB b. Parallel reactions a+B A+B D c Consecutive reactions a+B A+C D Examples of reversible reactions are A B a+B C +D
Examples of irreversible reactions are a. Simple reactions A——>B A + A——> C aA + bB ——> C b. Parallel reactions A + B ——> C A + B ——>D c. Consecutive reactions A + B ——> C A + C——> D Examples of reversible reactions are A <——> B A + B <——> C + D
Heterogeneous reactions Heterogeneous reactions occur between one or more constituents that can be identified with specific sites, such as those on an ion exchange resin These reactions are more difficult to study because a number of interrelated steps may be involved. The typical sequence of these steps is as follows 1. Transport of reactants from the bulk fluid to the fluid-solid inter face(external surface of catalyst particle)
Heterogeneous Reactions Heterogeneous reactions occur between one or more constituents that can be identified with specific sites, such as those on an ion exchange resin . These reactions are more difficult to study because a number of interrelated steps may be involved. The typical sequence of these steps is as follows: 1. Transport of reactants from the bulk fluid to the fluid-solid interface (external surface of catalyst particle)