Application Note: Sludge Analysis with Precisa's prepASH® Thermogravimetric Analyser
Sewage sludge has valuable agronomic properties in agriculture. In using sewage sludge account must be taken of the nutrient needs of the plants without, however, impairing the quality of the soil and of surface and ground water. Some heavy metals present in sewage sludge may be toxic to plants and humans.
The sewage sludge contains mainly the microbes of the biological treatment of wastewater, sand, and water. Dry mass and ash determination are done in the standard analysis of sewage sludge and in wastewater (usually done after filtration to reduce the water).
This analysis gives first information on organic and inorganic content of the sludge.
Use of Sewage Sludge In Agriculture
https://environment.ec.europa.eu/topics/waste-and-recycling/sewage-sludge_en
The European Union regulates use of sewage sludge in agriculture to prevent harmful effects on soil, vegetation, animals, and humans. In particular it sets limits on the concentrations of certain substances in these sludges, bans the use of these sludges in certain cases and regulates the treatment of sludge. ACT Council Directive 86/278/EEC of 12 June 1986 on the protection of the environment, and in particular of the soil, when sewage sludge is used in agriculture (See amending acts).
PrepASH® – Optimal Solution For The Water Treatment Analysis
Reduced time and effort
prepASH is a fully automatic drying and ashing machine, so no multiple weighing back after time consuming cooling down in the desiccator but automatic calculation of results.
Working in groups of similar samples in a single run will rise efficiency of and optimise time of analysis.
Improved safety and efficiency
No more dangerous analysis with the open flame. With prepASH Analyses can be done in time slots unused or hardly ever used so far, e.g., at night.
Increased quality
Up to 20% of each ash determination has to be re-analysed because of faulty/undefined results.
prepASH is highly repeatable and reliable!
Detailed analysis reports.
Due to the permanent recording of measurements during the entire process and the automatic saving of the final results, all data are retrievable at any moment.
prepASH 129: Filtered Wastewater/Sludge Samples
Sample information:
Wastewater/Sludge Samples
Analysis procedure: Samples are filtered with an ash free filter, dried and ashed.
The steps for the complete analysis in prepASH are listed in detail below. The samples used for this application have already been filtered and dried by the customer, therefore only the ashing step has been done in prepASH.
All fundamental data and operating parameters, such as changes in sample weight, temperature, gases, etc. are stored and graphically displayed. Automatic calculation of results.
| Step | Time | Temp 1 | Temp 2 | Auto Stop | Gas |
| 1 | 30 min | 25°C | 550°C | ||
| 2 | 3 h* | 550°C | 550°C | ||
| 3 | 30 min | 550°C | 550°C | ||
| 4 | 30 min | 550°C | 550°C |
*3 hours given by customers method. Samples would reach stable weight much earlier (see graphic)
Results
| No. | Sample Name | Weight | Ash [g] after 3 h | Ash [g] after 3.5 h | Ash [g] after 4 h |
| 1 | 87 LUMMEN | 0.1103 | 0.0116 | 0.0115 | 0.0116 |
| 2 | 92 LUMMEN | 0.0912 | 0.0029 | 0.0029 | 0.0029 |
| 3 | 103 LUMMEN | 0.0897 | 0.0023 | 0.0023 | 0.0023 |
| 4 | filter | 0.0784 | -0.0001 | -0.0001 | 0.0000 |
Procedure For Automatic Measurement of the Samples:
- Tare all crucibles (done fully automatic in prepASH)
- Put empty filters into crucibles, weigh in (done in prepASH)
- Filter the samples
- Enter filters with samples into crucibles (make sure to enter the filters in the same crucibles as in step (2))
- Start run (drying and ashing fully automatic)
Data in grey are automatically given, data in blue have to be calculated in prepDATA.
Dry mass and ash can be correlated to the volume too.
| No. | Sample Name | Tara=automatic taring in step 1 | Filter Weight [g] = weighing in step 2 | Filter + Drymass = result after drying in prepASH | Dry mass in [g] = E-D | Ash [g] = result after ashing in prepASH | Ash [%] rel to dry mass = G/F*100% |
| 1 | Probe 1 | 29.1619 | 0.0969 | 0.6680 | 0.5711 | 0.0175 | 3.06 |
| 2 | Probe 2 | 29.5602 | 0.1196 | 0.6643 | 0.5447 | 0.0176 | 3.23 |
| 3 | Probe 3 | 30.0026 | 0.0991 | 0.6481 | 0.5490 | 0.0171 | 3.11 |
| 4 | Probe 4 | 28.5821 | 0.1010 | 0.7960 | 0.6950 | 0.0177 | 2.55 |
Download The Application Note
Download the Application Note: Sludge Analysis using prepASH
prepASH – Optimal Solution To Determine Ash
Reduced time and effort. prepASH is a fully automatic drying and ashing equipment, so no multiple weighing back after time consuming cooling down in the desiccator but automatic calculation of results. Working in groups of similar samples in a single run will rise efficiency and optimise time of analysis.
Improved safety and efficiency. No more dangerous analysis with the open flame. With prepASH analyses can be done in time slots unused or hardly ever used so far, e.g., at night.
Increased quality. Up to 20% of each ash determination has to be re-analysed because of faulty/undefined results.
prepASH is highly repeatable and reliable!
Detailed analysis reports. Due to the permanent recording of measurements during the entire process and the automatic saving of the final results, all data are retrievable at any moment.
| Working Steps of Moisture and Ash Determination | ||
| Standard Method With Oven | Vs. | prepASH |
| Heating out crucibles for constant weight before | Dry Matter | Possibility to pre-define a “heating out program” |
| Measuring tare of crucible one by one | AUTOMATICAL PROCEDURE | |
| Sampling | Sampling | |
| Weighing + documentation of each crucible | AUTOMATICAL + entering the sample name/ID | |
| Samples in drying oven + START | START PROGRAM | |
| Removing samples from oven + cool down | RESULTS (moisture) | |
| Back weighing samples, calculation (moisture) | ||
| Pre-ashing with rapid incinerator or hot plate | Ash | RESULTS (ash) |
| Samples in muffle furnace | ||
| Removing samples + cooling down in exicator | ||
| Back weighing for stable results (repeat?) | ||
| Calculation and documentation (ash) | ||
prepASH Thermogravimetric Analyser | TGA
If you would like to find out more about TGA Analysis, and how it can help your moisture and ash content determination needs, we have a excellent range of Thermogravimetric Analysers our website. Please don’t hesitate to get in touch, someone from our team will be happy to assist you.
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