Question

describe the examples of treatment sludges for solar drying, thermal drying and combustion applications in summary with their technical details.

Answer 1

Sludge treatment is a process that is being used to dispose of the sludge produced at the time of treatment of water. It is mostly water will less concentration of solid in it. Below are discussed some applications and examples of sludge treatment :

Solar drying

In this process sludge is being supplied in batches. The sludge is being aerated and transported by the shovels used. While transporting the sludge in the shovels continuous heat is being provided and the water is being evaporated and only the solid parts are left drying. High temperature not being provided as some amount of water is left to pass out the remaining solid impurities and this process is used for evaporating water which may be used further in different kind of works.

Thermal Drying

Thermal Drying is an advanced method of solar drying. The heat required for drying the sludge is generated from the gases present in the sludge itself. The gas is being used to heat the fluidized bed dryer with a very high efficiency of around 90% . At the same time heat is also produced to heat the digester. Its example is fluidbed drying system in which the role of that fluid bed is very much and it is also being heated continuously by providing thermal heat.

Combustion

Combustion and Co-combustion is considered as most suitable and appropriate methods for the treatment of sludge in the power systems. This method helps in reducing the net amount of CO2 emissions to the atmosphere due to it's biogenic nature. The result of the combustion showed that the Sewage sample is burned at very low temperature as compared to the woody fuel. The CO emissions in this process is also very low. It has advantages like fuel flexibility and good mixing at relatively low temperature.