Introduction to Sludge Treatment
Sludge accumulates as a residue in all sorts of wastewater treatment. Sludge comprises the solids and colloids separated from wastewater as well as substances from biological and chemical operation units. Some sludges are produced during wastewater treatment, including primary sludge, which comprises settleable solids removed from the primary clarifier, and secondary sludge, which comprises biological solids generated in the secondary wastewater treatment plant. Figure 1 illustrates a waste activated sludge sample collected from a local sewage treatment works. Furthermore, drinking water producers produce coagulated solids-coagulant matrix, which contains all of the impurities in the raw water and the dosed coagulant. Additionally, numerous kinds of industrial sludges exist which are generated from treating different industrial wastewaters. The shared features of these sludges are high moisture content that is difficult to remove mechanically, relatively weak flocs that are easily torn off during shear, and concentrated pollutants that require further stabilization for safe disposal.
KeywordsActivate Sludge Anaerobic Digestion Sludge Treatment Floc Size Primary Sludge
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