Cultures and Ecological Modeling

We will consider chain reactions such as this in Chapter 10. Each Cl atom introduced into the chain can cycle for 104 to 10 times, so that one chlorine atom can destroy up to 1Q5 ozone molecules in the stratosphere. 

Thus we see that environmental modeling involves solving transient mass-balance equations with appropriate flow patterns and kinetics to predict the concentrations of various species versus time for specific emission patterns. The reaction chemistry and flow patterns of these systems are sufficiently complex that we must use approximate methods and use several models to try to bound the possible range of observed responses. For example, the chemical reactions consist of many homogeneous and catalytic reactions, photoassisted reactions, and adsorption and desorption on surfaces of hquids and sohds. Is global warming real [Minnesotans hope so.] How much of smog and ozone depletion are manmade [There is considerable debate on this issue.] 

We can also use chemical kinetics to attempt to model populations of living systems such as single-celled organisms or plant, animal, and human populations. We describe the density of individuals (species A) as Ca, which might be in individualsA olume in a three-dimensional 

F ure 8-18 Coirqifflison of sterns that cai be described by the models of chemical reaction engineering. Reactions include those of molecailes aid Hidng systems. Possible chemical reactors include conventional reactors as well as the enwronment. 

We assume that an organism reproduces by a first-order process 

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