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Sludge and sediments

The Testing Laboratory Directorate (TLD) is accredited to perform testing of over 80 characteristics of sludge and sediments. The type of the characteristics tested complies with the requirements and normative documents for the order and manner of sludge utilization from the purification of waste waters. The characteristics, which are determined mainly include tests for heavy metals after extraction with aqua regia and a subsequent measuring with ICP-AES and AAS.
The content of total extractable substances and petroleum products (nonpolar hydrocarbons С10–С40) is determined with a gas chromatograph, equipped with a flame ionization detector. The content of organic contaminants – polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls is determined using a gas chromatograph, equipped with a mass spectrometry detector.
The determination of moisture, dry matter and loss on ignition is performed using weight methods.
The determination of calorific value consists of combustion in a calorimetric bomb.
The determination of surful and carbor is performed using high temperature combustion in an oxygen environment, with infrared absorption. The content of total organic carbon, total inorganic carbon and total carbonate content is determined in accordance with validated intralaboratory methods.
Humus content is determined using a titrimetric method.
Nitrogen content is determined using the Kjeldahl method.
The forms of cyanides are determined spectrophotometrically after distillation.
TLD also performs characteristics of mineral composition (qualitative and quantitative X-ray diffraction analysis) and that method is beyond TLD’s accreditation scope.

If the client requires it, the test reports can also be issued both in Bulgarian and in English.