Effects of sonication, heating and fungal enzymatic digestion on the ability of activated sludge supernatant to bind Pb and Cd

► Supernatants of sludges from disintegration treatments used to reduce the production of sludge were characterized. ► The biochemical and mineral composition, the size distribution of molecules are affected by sludge disintegration treatments. ► Sludge disintegration treatments modify the ability of the sludge supernatants to bind Cd or Pb.