The removal mechanism of lead from wastewater on pharmaceutical sludge-based biochar

作者：Chunhong Shao, Junjian Li, Yingjie Dai · 发表于：Desalination and Water Treatment · 年份：2024 · DOI：10.1016/j.dwt.2024.100499 · 被引用次数：8 · 研究领域：Adsorption and biosorption for pollutant removal、Heavy metals in environment、Recycling and utilization of industrial and municipal waste in materials production

This study aims to enhance the resource utilization of waste sludge and mitigate the environmental risks associated with Pb2+ contamination. Municipal sludge biochar (MBC) and pharmaceutical sludge biochar (PBC) were selected as the experimental subjects. The experiment systematically investigated the influential factors affecting adsorption, including adsorbent dosage, reaction time, and pH. The physicochemical attributes of the biochar (BC) were assessed through techniques such as scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction analysis, and point of zero charge analysis. The Pb2+ adsorption process was described by the pseudo-second-order kinetic model and Freundlich isotherm model, the highest adsorption capacities were established as 18.56 mg/g and 19.07 mg/g for MBC and PBC, respectively. The adsorption of Pb2+ on BCs is related to chemical and physical adsorption mechanisms. Ligand bonding, monolayer chemisorption, electrostatic interactions and pore filling were considered as possible mechanisms involved in the adsorption system. It was shown that MBC and PBC are efficient adsorbents for the Pb2+ removal in water.