The right dryer is key to getting the best value out of your product.
Swedish Exergy dryers helps our client achieve the best value for their application.
Municipal and industrial wastewater treatment processes generate large amounts of sludge. Sludge is a solid, semisolid, or slurry residual material that comes from different processes that contains up to 80% water. There are different types of sludge like high quality sludge without contaminants, for example, that contains valuable nutrients like phosphorus and humus.
Sewage sludge generated during wastewater treatment must be treated and disposed of in a safe and effective manner, which can be accomplished through many different methods such as landfilling, incineration, or digestion. Treatment and disposal of sewage sludge are important factors in the design and operation of a wastewater treatment plant. The basic goals in treating sewage sludge are to reduce the volume and stabilize the organic matter.
Most large wastewater treatment plants use a digestion system in which the organic matter is treated anaerobically or aerobically to produce biogas. In Europe, sewage sludge (after digestion) is mainly disposed of in landfills, while the remainder is used as a soil conditioner/fertilizer. However, landfilling is a costly and environmentally damaging process that is increasingly banned in many countries and is therefore undesirable. In addition, sludge is often transported long distances away from treatment plants for disposal, resulting in unnecessary water transport and high costs.
Digested sewage sludge is usually dewatered before disposal. Dewatered sewage sludge still contains a significant amount of water – often up to 70 percent. The resulting waste can be a valuable source of energy because of the nutrients it contains, or it can be used as a fertilizer instead of simply being disposed of in landfills by further removing the water through an efficient drying process.
Exergy for sludge drying
Drying the sludge also significantly changes its texture and consistency. Dried sludge is easier to handle and transport than the dewatered sludge with higher moisture content.
Thanks to the Exergy Superheated Steam Dryer the sludge from effluent treatment plants becomes a a source of revenue instead of a cost. The steam dried sludge is:
- 100% sterilized, free of odor, stabilized and possible to store indefinitely.
- Significantly reduced in weight and size, resulting in a reduction in costs for transportation and disposal by up to four times.
- More suitable for treatment by certain thermochemical processes, primarily incineration and pyrolysis.
ExergyPSSD® sludge dryer also gives the waste water treatment plant the flexibility to shift sludge disposal route and create value from waste.