Electrochemical Pollution Analysis
The recent emergence of ecological interest resulted in quite a challenge for the analytical chemist. It is easy to say: we want clean air, but in practical life, one has to be more specific. The harmful impurities have to be exactly identified and a concentration limit must be established, above which their presence cannot be tolerated. A short digression about the myth of “zero pollution” is timely at this point. The absolute removal of “pollutants” is not only economically impossible (some discussion of this was included in Chapter 7), but may also be definitely harmful in some cases. Copper, for example, can be toxic to aquatic life, but it has been shown that a small trace of it is not only beneficial but absolutely necessary. In waters completely devoid of copper, many species cannot live, severely upsetting the food chain of the aquatic life. The same is true for other “pollutants.” Rather than talking about “zero” contamination, one should strive for the “optimum” concentration of the chemical in question. Furthermore, this optimum concentration is usually not a fixed number, but a rather wide range; while life thrives in this range, any deviation (increase or decrease) will be harmful to life. If one also considers that the removal of the last 1% of an impurity may cost ten times as much as did the removal of the first 99%, it seems foolish (and sometimes harmful) to try to remove this last 1%, unless it is still on the high side of the optimum. Now, the identification of pollutants, and the determination of the optimum concentration range, involves chemical analysis. That is not all, however; after limits for pollutants have been agreed to and laws have been passed to assure the needed purity, there are going to be no useful results unless compliance with the law can be checked. The antipollution laws cannot be enforced unless a continuous check is kept on the level of pollutants both in the air and in the waters. This requires further analytical work.
KeywordsAquatic Life Constant Current Source Harmful Impurity Silver Solution Electroanalytical Technique
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