Wastewater Sludge Dewatering

Sludge is a common type of residue produced as a by-product of wastewater treatment processes. The purpose of sludge dewatering is to concentrate the wastes into solids for easy and effective disposal. Aquasan’s chemicals help you achieve high dryness by optimizing for the equipment used, the dryness discharge objectives and the water’s discharge objectives.



There are multiple benefits to achieving the right chemistry for your sludge dewatering:

  • Helping you meet increasingly strict water quality standards
  • Reducing transportation costs, storage costs and disposal costs.
  • Reducing odour potential.
  • Improving your treatment capacity without requiring more land area.
  • Improving the full-cycle analysis for this resource.
  • Minimizing nutrient pollution effects.
  • Reducing your organization’s environmental footprint.


Sludge Dewatering Treatment Process

The dewatering of sludge is a crucial step to your wastewater system. Sludge can be produced at many different steps of your treatment chain. From your DAF, to your clarifier, to your filtration system, to your biological system or directly from your sludge digester, solids need to be taken out of your system. Once isolated these solids go through the sludge dewatering treatment process.   


1. Thickening

Usually the first step in the sludge dewatering, the goal is to increase the level of solids in the slurry in order to make it more practical to handle. Through a gravity settling tank, a Dissolved Air Flotation unit or a filtration system, the slurry is concentrated in order to increase the level of solids in the slurry. This in turn reduced the amount of water hauled or pumped through the downstream system. 


2. Digestion

Anaerobic digestion is a biological process which breaks down a significant amount of organic solids in the sludge and at the same time as the potential to produce natural gas. Furthermore, digestion kills pathogens, makes it easier to dewater the sludge and ultimately reduces the final volume of sludge. 


3. Dewatering

The dewatering step is where most of the water is separated from the solids. Usually the last step before disposal, this step is crucial for both the economical and environmental aspect. Through the addition of a Aquasan polymer as well as a mechanical means of separation such as a centrifuge, a press or a filtering bed, it is possible to increase the level of solids to treat the sludge as a solid material.  Sludge handled as a solid material is much cheaper to transport and to dispose of. Furthermore, a solid material is much easier to compost leading to the possibility to use the sludge as a very effective soil amendment. 


4. Disposal

Disposal is the last step of the process where the sludge goes back to land, either through a sanitary landfill or to land through compost and agricultural land application. Aquasan specializes in the selection of polymers and other chemicals to optimize the performance of your dewatering equipment. With periodic on-site testing and dosage optimization, we can assure you that we will extract the maximum performance from your investment. Aquasan’s large product range of dry and emulsion polymers combined with our technical expertise will represent a great asset for your organization.