Degradation of cationic surfactants using immobilized bacteria: its effect on adsorption to activated sludge.

•Removal of cationic surfactants from industrial activated sludge.•Adsorption of cationic surfactants to activated sludge depends on its hydrophobicity.•QACs desorption from sludge is inversely proportional to the extent of adsorption.•An immobilized consortium of QACs-degrading bacteria avoid its adsorption to sludge.