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For assessing compliance with the emission standards of incineration plants, a correction needs to be applied to the measured concentrations of air pollutants. The emission standard (based on 11% O\(_2\)) for HCl is 50 mg/Nm\(^3\), and the measured concentrations of HCl and O\(_2\) in flue gas are 42 mg/Nm\(^3\) and 13%, respectively. Assuming 21% O\(_2\) in air, the correct statement is:

1. No compliance, as the corrected HCl emission is greater than the emission standard.
2. Compliance is there, as the corrected HCl emission is lesser than the emission standard.
3. Compliance is there, as there is no need to apply the correction since oxygen is greater than 11% and HCl emission is lesser than the emission standard.
4. No compliance, as the oxygen is greater than 11% in the flue gas.

Correct answer: Compliance is there, as the corrected HCl emission is lesser than the emission standard.

Solution

Emission concentrations are corrected to a reference oxygen level using the standard correction formula. Since the measured O\(_2\) is 13%, which is higher than the reference 11%, the corrected HCl concentration becomes lower than 42 mg/Nm\(^3\). Therefore it remains below the standard of 50 mg/Nm\(^3\), so the plant complies.

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