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). Supported by Instrumental Analysis Fund of Peking University