Characteristics of Pb2+ biosorption with aerobic granular biomass

Experimental studies were conducted on the feasibility of aerobic granular biomass as a novel type of biosorbent for Pb2+ removal. The results show that the initial pH, Pb2+ concentration (C-0) and biomass concentration (X (0)) affected the biosorption process significantly. Both the Freundlich and Langmuir isotherm models describe the biosorption process accurately, with correlation coefficients of 0.932 and 0.959 respectively. The Pb2+ biosorption kinetics is interpreted as having two stages, with the second stage described reasonably well by a Lagergren pseudo-second order model. Moreover, the surface change of granular biomass after the Pb2+ biosorption process appears to be caused by ion exchange and metal chelation according to the analysis results of Environmental Scanning Electron Microscopy (ESEM) and Energy Dispersive X-ray Spectroscopy (EDX).