🌡️ Dry Residue and Water Content of Sewage Sludges
In short
Determination of the dry residue and water content of sewage sludges and sludge products from the loss of mass of the sample on drying to constant mass at (105 ± 5) °C — the standard does not cover water or waste water. The test is performed according to PN-EN 12880:2004; Drying temperature: (105 ± 5) °C, to constant mass (PKN catalogue card of PN-EN 12880). The procedure comprises 5 steps; it is used for: Sewage sludges and sludge products — dry residue and water content (scope of PN-EN 12880), Calculation of the results of analyses of sludges, treated biowaste, soil and waste on a dry matter basis (scope of PN-EN ISO 11465:2026-03), Liquid waste and samples with volatile substances other than water — water content by the Karl Fischer method (method B of the new edition).
At a glance
- Standard: PN-EN 12880:2004
- Category: Physicochemistry
- Procedure steps: 5
- Drying temperature: (105 ± 5) °C, to constant mass (PKN catalogue card of PN-EN 12880)
- Result: dry residue and water content as a mass fraction of the sample, %
- Status: PN-EN 12880:2004 withdrawn on 04.03.2026; successor — PN-EN ISO 11465:2026-03 (English version)
Overview
STATUS (as of 29.10.2026). PN-EN 12880:2004 — Polish version, published 21.09.2004, implements EN 12880:2000 [IDT]; it replaced PN-EN 12880:2002 (English version). The standard was WITHDRAWN on 04.03.2026 — replaced by PN-EN ISO 11465:2026-03 (English version, published 04.03.2026), which implements EN ISO 11465:2025 and ISO 11465:2025 [IDT] and at the same time replaced PN-ISO 11465:1999 and PN-EN 15934:2013-02. ISO 11465:2025 (second edition, 28.08.2025) merged the content of EN 12880 and EN 15934 with the earlier ISO 11465:1993.
SCOPE OF PN-EN 12880 (PKN catalogue card). A method for determining the dry residue and water content of sludges and sludge products, based on the loss of mass of the sludge sample on drying it to constant mass at (105 ± 5) °C. The standard does not cover water or waste water: the dry residue of water and waste water is described in a separate Knowledge Base entry “Dry residue, residue on ignition and loss on ignition in water and wastewater — gravimetric method (105 °C / 550 °C)”.
NEW EDITION — PN-EN ISO 11465:2026-03 (PKN catalogue card, table of contents of ISO 11465:2025). Methods for calculating the dry matter of sewage sludge, sludge products, treated biowaste, soil and waste, for which the results of analyses are calculated on a dry matter basis. The calculation is based on the determination of the dry residue (method A — drying at 105 °C) or of the water content (method A or method B — direct Karl Fischer titration with volumetric or coulometric detection). Method A is applied to sludges, sludge products, treated biowaste, soil and solid waste; method B — to liquid waste and to samples that contain or may contain volatile substances other than water. The standard applies to samples containing more than 1 % (mass fraction) of dry residue or more than 1 % of water; in method A the water content is calculated on a field-moist basis or on a dry residue basis (7.2.2–7.2.3).
WHAT WE DO NOT GIVE HERE. We could not obtain the text of EN 12880, and only the table of contents and the foreword of ISO 11465:2025 are available. We do not give the size and preparation of the test portion, the type of dishes, the constant-mass criterion, the drying time, the equations of the standard or the precision data; the drying procedure is described according to EPA Method 1684 (determination of solids in sludges), marked in the steps as the second source.
Method principle
A portion of sludge is dried to constant mass at (105 ± 5) °C: the loss of mass is water, and the residue after drying is the dry residue, both expressed as a mass fraction of the sample (PKN catalogue card of PN-EN 12880). In the new edition (ISO 11465:2025), drying at 105 °C is method A, from which the dry residue or the water content and the dry matter fraction are calculated; method B determines the water content by direct Karl Fischer titration when the sample is a liquid waste or contains volatile substances other than water.
The same drying procedure is described by EPA Method 1684 (second source, a different document): a 25–50 g portion of sludge is dried in a weighed dish at 103–105 °C, cooled in a desiccator and weighed to constant mass.
Applications
- Sewage sludges and sludge products — dry residue and water content (scope of PN-EN 12880)
- Calculation of the results of analyses of sludges, treated biowaste, soil and waste on a dry matter basis (scope of PN-EN ISO 11465:2026-03)
- Liquid waste and samples with volatile substances other than water — water content by the Karl Fischer method (method B of the new edition)
Key parameters
| Parameter | Value |
|---|---|
| Drying temperature | (105 ± 5) °C, to constant mass (PKN catalogue card of PN-EN 12880) |
| Result | dry residue and water content as a mass fraction of the sample, % |
| Status | PN-EN 12880:2004 withdrawn on 04.03.2026; successor — PN-EN ISO 11465:2026-03 (English version) |
| New edition — methods | A: drying at 105 °C (dry residue or water content); B: direct Karl Fischer titration, volumetric or coulometric (water content) |
| New edition — field of application | samples containing more than 1 % (mass fraction) of dry residue or of water |
Standard
- Standard number
- PN-EN 12880:2004
- Title (PL)
- Charakterystyka osadów ściekowych — Oznaczanie suchej pozostałości i zawartości wody
- Title (EN)
- Characterization of sludges — Determination of dry residue and water content
Step-by-step procedure
-
Dish
Dry the dish at the drying temperature, cool it in a desiccator and weigh it (EPA 1684, second source).
-
Test portion
Weigh a portion of the mixed sludge into the dish (in EPA 1684: 25–50 g); the size of the portion according to EN 12880 — outside the available text.
-
Drying
Dry to constant mass at (105 ± 5) °C (PKN catalogue card of PN-EN 12880; in EPA 1684: 103–105 °C).
-
Weighing
Cool in a desiccator and weigh; repeat drying and weighing until constant mass is reached (EPA 1684).
-
Calculation
Dry residue, % = mass of the residue after drying / mass of the test portion × 100; water content, % = loss of mass / mass of the test portion × 100 — a calculation following from the definition of the loss of mass; equations of the standard outside the available text.
Required equipment and apparatus
| Equipment | Example | Indicative price |
|---|---|---|
| Drying oven | maintaining (105 ± 5) °C (PKN catalogue card of PN-EN 12880); in EPA 1684 — a thermostatically controlled oven maintaining 103–105 °C throughout the drying chamber | — |
| Drying dishes and desiccator | according to EPA 1684 (second source): 100 ml evaporating dishes and a desiccator; requirements of EN 12880 — outside the available text | — |
| Balance | for weighing the dish with the test portion before and after drying; accuracy — outside the available text of the standards | — |
| Karl Fischer titrator | volumetric or coulometric — only method B of the new edition (ISO 11465:2025, clause 8) | — |
Reagents, media and consumables
| Reagent | CAS | Details |
|---|---|---|
| Karl Fischer reagents | — | only method B of the new edition (ISO 11465:2025, 8.2) — composition outside the available text; method A (drying) needs no reagents |
Health and safety (OHS)
- The hazards of method A (drying) are covered by 6.3 of ISO 11465:2025 — outside the available text
- When working with sewage sludge, personal protective equipment is used in accordance with the laboratory risk assessment
Frequently asked questions
Which standard describes this test?
The test is performed according to PN-EN 12880:2004 — “Characterization of sludges — Determination of dry residue and water content”.
How does this method work?
A portion of sludge is dried to constant mass at (105 ± 5) °C: the loss of mass is water, and the residue after drying is the dry residue, both expressed as a mass fraction of the sample (PKN catalogue card of PN-EN 12880). In the new edition (ISO 11465:2025), drying at 105 °C is method A, from which the dry residue or the water content and the dry matter fraction are calculated; method B determines the water content by direct Karl Fischer titration when the sample is a liquid waste or contains volatile substances other than water.
What is the measuring range and accuracy?
Drying temperature: (105 ± 5) °C, to constant mass (PKN catalogue card of PN-EN 12880); Result: dry residue and water content as a mass fraction of the sample, %; Status: PN-EN 12880:2004 withdrawn on 04.03.2026; successor — PN-EN ISO 11465:2026-03 (English version); New edition — methods: A: drying at 105 °C (dry residue or water content); B: direct Karl Fischer titration, volumetric or coulometric (water content).
How long does the test take?
The procedure comprises 5 steps. The standard does not give a duration for every stage — the laboratory's own procedure decides.
What equipment is required?
Drying oven, Drying dishes and desiccator, Balance, Karl Fischer titrator.
Where is this test used?
Sewage sludges and sludge products — dry residue and water content (scope of PN-EN 12880); Calculation of the results of analyses of sludges, treated biowaste, soil and waste on a dry matter basis (scope of PN-EN ISO 11465:2026-03); Liquid waste and samples with volatile substances other than water — water content by the Karl Fischer method (method B of the new edition).
What safety precautions apply?
The hazards of method A (drying) are covered by 6.3 of ISO 11465:2025 — outside the available text; When working with sewage sludge, personal protective equipment is used in accordance with the laboratory risk assessment.
Which laboratory can perform this test?
The test is performed by laboratories accredited to ISO/IEC 17025. On LabCoda you can find them by the standard number PN-EN 12880.