Sludge recycling as opportunity

The path to phosphorous recycling: Sludge drying

Waste and raw material source

Sludge is the unloved yet valuable waste product of wastewater treatment in sewage plants. At present, disposing of this mixture of materials poses an increasing challenge to communities and companies. Sludge can be used as an important source of raw materials because it contains the scarce and essential resource phosphorous, a great organic agricultural fertiliser.

Disposal and recycling are changing

To date, sludge has been incinerated in waste disposal plants, coal-fired power stations and cement works, disposed of in landfills or used for agricultural purposes. After renewing the sludge ordinance 2017 (AbfKlärV) and the obligation of major sewage plants to recover phosphorous, intelligent processing methods are now more in demand than ever. The Bavarian Environment Agency has informed us that as of 2023, all sewage plant operators will have to publish their phosphorous recovery methods. From 2029, this will finally be mandatory for all communities with sewage plants with a population equivalent of more than 100,000, and from 2032 for all those with more than 50,000 inhabitants. Personal and municipal initiatives to dispose of and recycle sludge are therefore being encouraged.

Site-independent drying

In the case of solar drying, pre-drained sludge that has been spread over a large area is dried using solar energy, a method not very suited to Central Europe with plenty of precipitation. Alternatively, a belt dryer can take over the drying process, by distributing the bulk material onto an endless air-permeable conveyor belt and drying it with air. The BURKHARDT DRYLINE® has proven itself as a two-belt dryer with four levels! With this process, sludge can even be dried in locations far from the sewage plant. In the future, anyone who wants to will be able to operate such a system. BURKHARDT is a reliable partner with experience both as a manufacturer and operator.

Energy source of the future 

For communities and companies, the advantages of this way of sludge drying are manifold: by removing the water, the dried sludge loses three quarters of its mass and becomes half the volume of the original wet sludge. The result is a granulated, dry end product that is easier to store and transport. This method of drying is also hygienically harmless, a plus in terms of work safety, as viruses and bacteria are killed off. And don't forget that the smell of dried sludge is not as bad as that of wet sludge.

Drying sludge produces a heating value comparable to that of lignite, making it a compelling choice as the energy source of the future: as a recycling product, it is classified as carbon neutral and can be co-incinerated in conventional cement works and coal plants, among others, up until 2029.

Tackling phosphorous recovery together

Regional phosphorous recycling should be an important part of achieving current climate protection goals and a sustainable circular economy. Legislators will require cities and communities to do this from 2029. Against such a backdrop, BURKHARDT presents itself as an experienced partner for sludge drying as an intermediate step to recovering the vital substance that is phosphorous. Our goal is to develop possibilities, recognise potential and establish reliable partnerships to shape the upcoming transformation processes in the energy sector together. Get in touch with us!

Not an operator?

We’re happy to accept your sludge and properly recycle it for you. Info at: BURKHARDT sludge removal

Your contact for sludge removal:

« back to sludge drying