(Source: Kwarciak-Kozłowska, 2019)
Sludge Transformation Methods
Adoption of sludge treatment and disposal options inside the wastewater
treatment plant area, such as incineration and moist air oxidation, is
rising because to increased competition for space in landfills, disposal
prices, legislative limits, and incentives to sludge recycling countries
(Kelessidis & Stasinakis, 2012). Sludge combustion, on the other hand,
raises severe problems about air pollution and the proper disposal of
remaining ashes. The following sludge transformation processes are
covered in this section with their advantages and disadvantages:
Thermal Drying
Thermal drying is a very adaptable procedure for making pellets for
agricultural reuse, sanitary landfill disposal, or incinerated. Heat is
used to remove the moisture in the sludge (Andres, 2011). The pellets
generated can be utilized to power boilers, industrial heaters, cement
kilns, and other appliances. Thermal air heaters, tray dryers, and a
condenser are used in the drying process. It has the following benefits
and drawbacks (Table 9).
Table 9. Advantages and disadvantages thermal drying process in
sludge transformation