Changes of distribution and chemical speciation of metals in hexavalent chromium loaded algal-bacterial aerobic granular sludge before and after hydrothermal treatment.

Algal-bacterial aerobic granular sludge (AGS) was applied for hexavalent chromium (Cr(VI)) biosorption from wastewater and the dynamic distribution and mobility of different metals in granules were systematically examined before and after hydrothermal treatment. The loaded Cr on algal-bacterial AGS was found to mainly localize in microbial cells and mineral particles; little Cr was detected in extracellular polymeric substances (EPS) after 6 h contact, which increased to 5.1% after 24 h biosorption.