Sludge dewatering process is the name given to the physical methods applied in order to reduce the percentage of moisture contained in the sludge, which is liquid or semi-solid formed after the wastewater treatment process, has an odor, contains an average of 0.25% to 12% solid matter depending on the type of treatment applied.
The sludge dewatering process reduces the moisture content, making the solidified sludge cake more easily transportable. As a result, the sludge is made suitable for disposal by reducing its moisture content through the dewatering process, making it odorless and unsuitable for decay while also reducing its volume.
Natural Dewatering Methods
Sludge Drying Beds
Sludge drying beds are usually installed in areas with a dry climate. Compared to other methods, sludge drying beds are less expensive and consist of a porous filter medium containing sand and gravel layers, as well as filtration pipes. In this method, the particle size is placed in the filter area, increasing in size from top to bottom.
Mud Lagoons
The mud lagoon method is preferred in fixed areas where odor problems are minimal. It operates by pumping the sludge into a natural lagoon, where it is dewatered. In this method, the sludge settles at the bottom of the lagoon and is removed at regular intervals, while the rested upper layer water is periodically sent to the treatment plant.
Mechanical Dewatering Methods
Vacuum Filtration
Among the oldest mechanical methods used for many years, vacuum filtration is a method that consists of mud feeding pumps, chemical feeding equipment, mud conditioning tank, filter drum, cake conveyor or scraper, vacuum system, and filtrate tank systems.
Belt Press
In belt press filtration systems, which operate on the principle of removing water from mud under pressure, mud is regularly fed and dewatered within the basic principle of the system. Chemical conditioning, gravity drainage, and mechanical pressure application are the most commonly used methods.
Decanter (Centrifuge)
The decanter (centrifuge) method, based on the principle of sludge settling, operates according to a system that separates the liquid and the cake. The method involves pumping the sludge into the pump through a feeding pump and discharging it outside through a drum connected to the pump.
