Minimization of excess sludge and cryptic growth of microorganisms by alkaline treatment of activated sludge

Sludge solubilization was induced by the alkaline-thermal treatment to investigate the cryptic growth and reduction of a large amount of activated sludge produced from wastewater treatment. Activated sludge was divided into lysate, supernatant fraction and particulate fraction for a biodegradability test by cryptic growth. Sludge was reduced up to 78% at pH 13 and 44% at pH 10 using the single alkaline-thermal treatment. Also, it was found that alkaline-thermal treatment at pH 13 increased the quantity of intracellular components generated by cell lysis and promoted the power of significant cell destruction. The neutralization of pH after the solubilized activated sludge led to high biodegradability of organic carbon sources generated by cell lysis. This can be utilized in minimizing activated sludge.