SIST EN 13342:2001

Overview

EN 13342:2000 (CEN) specifies a laboratory method for the determination of Kjeldahl nitrogen in sludges and sludge products. The standard defines a digestion procedure in which the decomposition is catalysed by selenium or copper and the digestion temperature is raised using a high concentration of sodium sulphate. Although analyses are normally run on wet samples, results are conventionally reported on a dry mass basis (g/kg); therefore the dry residue of the homogenised sample used for analysis must also be determined (see EN 12880).

Key topics and requirements

• Scope: Procedure applies to sludges and sludge products for quantifying Kjeldahl nitrogen.
• Digestion catalysts: Use of selenium or copper as catalysts in the digestion step is specified.
• Temperature control: Temperature elevation is achieved by adding a high concentration of sodium sulphate to the digestion mixture.
• Sample basis: Samples are typically taken wet but results should be reported on a dry mass basis (g/kg).
• Dry residue determination: The dry residue of the homogenised sample used in analysis must be determined in accordance with EN 12880 to allow correct reporting on a dry mass basis.
• Documentation and traceability: Follow standard laboratory practices for sample homogenisation, documentation and reporting to ensure comparable, reproducible results (as implicit in CEN standardization practice).

Applications

EN 13342:2000 is used where accurate measurement of Kjeldahl nitrogen in sludge is required for environmental management, process control and regulatory compliance. Typical users include:

• Wastewater treatment laboratories performing sludge characterization
• Municipal and industrial sludge management facilities monitoring nutrient content
• Environmental consultants and laboratories conducting analyses for permit compliance
• Regulatory agencies and auditors assessing sludge quality and reporting
• Research institutions studying sludge composition and treatment performance

Reporting results on a dry mass basis (g/kg) supports consistent comparisons between samples and across treatment processes.

Related standards

• EN 12880 - Determination of dry residue of the homogenised sample (referenced by EN 13342:2000)
• Other CEN/ISO standards and national methods for sludge and wastewater analysis may be used alongside EN 13342 for comprehensive sludge characterization.

Keywords: EN 13342:2000, Kjeldahl nitrogen in sludge, characterization of sludges, CEN standard, sodium sulphate digestion, selenium catalyst, copper catalyst, dry mass basis (g/kg), EN 12880.