What is ISO 21741 about?
ISO 21741 discusses stationary source emission of mercury. ISO 21741 describes a method for the sampling and measurement of mercury of both vapour and solid phases on stationary source flue gas streams. Mercury generally exists as elemental (Hg0) and oxidized (Hg2+) forms, both in the vapour and solid phases in flue gases. The vapour-phase (gaseous) mercury is captured either isokinetically or non-isokinetically with a gold amalgamation trap after removing solid-phase (particulate) mercury with a filter.
The gold amalgamation method is intended for short-term (periodic) measurements of gaseous mercury ranging from 0,01 μg/m3 to 100 μg/m3 with sampling volumes from 0,005 m3 to 0,1 m3 and sample gas flow rate between 0,2 l/min to 1 l/min. The measurement range of particulate mercury is typically from 0,01 μg/m3 to 100 μg/m3 with sampling volume from 0,05 m3 to 1 m3.
Who is ISO 21741 for?
ISO 21741 on sampling and determination of mercury compounds in flue gas is useful for:
- Regulatory authorities
- Coal combustion plants
- Cement kilns
- Metal refinery factories
- Waste incineration facilities
Why should you use ISO 21741?
Due to the mass emission of mercury compounds the monitoring of the stationary sources has become increasingly important for preventing global environmental pollution and health damage caused by mercury.
ISO 21741 describes a method for the sampling and determination of mercury concentrations in a flue gas passing through ducts or chimney stacks. ISO 21741 helps you to determine both total vapour-phase mercury and total solid-phase mercury concentrations in flue gases. ISO 21741 helps you to keep your operations mercury emission levels within the limitations set by national authorities. As a regulatory body or an in-house quality auditor, ISO 21741 assists you in monitoring mercury emission levels for your industry.