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APPLICATION 5 : Water Quality

from Chapter 5 of

Engineer's Toolkit : Maple V for Engineers

Douglas B. Meade and Etan Bourkoff

Addison Wesley Longman, 1998

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Environmental engineers use criteria such as the level of dissovled oxygen, temperature, and indirect measures of the concentration of various organic and inorganic compounds to assess natural water quality. Fish in a natural stream typically reuire between 4 and 10 mg/L of dissolved oxygen (DO) to survive. Cooler water is denser and contains a higher concentration of dissolved oxygen than warmer water. Thus, the summer months place greater stres on aquatic life, and fish typically seek deeper (cooler) water during this season. We will use the Streeter-Phelps equation to model the DO sag curve for a stream exposed to pollutants that compete with aquatic life for the available DO.

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Fundamentals

Step 1: Define the problem

Step2: Gather Information

Step 3: Generate and evaluate potential solutions

Step 4: Refine and implement a solution

Step 5: Verify and test the solution

What If?