Determining the Elemental Content in Sewage Sludge

Operators of wastewater treatment plants need reliable data to identify the elemental content in the sludge and assess its recycling potential. With the PlasmaQuant 9100, Analytik Jena offers a suitable measuring instrument for this purpose. With this multi-element analyser, elements can be determined precisely and rapidly.

Phosphorus recovery is also a legal issue. Classified as a critical raw material by the European Commission, the German Sewage Sludge Ordinance (AbfKlärV) makes recovery mandatory starting January 2029. Wastewater treatment plant operators must - depending on the size of their municipal discharge area - gradually implement phosphorus recovery from sewage sludge or its incineration ash if the phosphorus content exceeds 20 grams or more per kilogram of dry matter.

However, sewage sludge also contains heavy metals and other pollutants that must not be released into the environment. In addition, sewage sludge yields are high matrix samples. They contain a very wide range of elements in very different concentrations, as well as high proportions of salt compounds. This presents a challenge for high-throughput measurement.

The PlasmaQuant 9100 uses the principle of inductively coupled plasma optical emission spectrometry (ICP-OES). Samples are atomised, activated, and then ionised over 5,000-10,000 Kelvin argon plasma. A spectrometer measures the emitted electromagnetic radiation. The resulting signal intensities provide information about the concentration of the contained elements. The application is described in the EPA methods 3050B and 6010C, as well as in the standards DIN EN 16174:2012-11 and ISO 11885:2007.

High measurement sensitivity is particularly relevant for the critical elements (e.g., cadmium, mercury, and thallium), as strict limits apply to their release into the environment. The DualView Plus feature of the PlasmaQuant 9100 extends the linear dynamic range and greatly simplifies multi-element analysis by allowing the entire element screening to be performed simultaneously in one measurement run through different plasma observation modes, while maintaining the best possible detection strength for critical elements.

The entire analysis process becomes faster, more reliable, and more economical. Since the PlasmaQuant 9100 is characterised by very stable plasma, high-matrix samples can be measured with long-term stability also at high throughput. Also, sample dilution becomes obsolete.

More information online