铁锰氧化物改性秸秆生物炭吸附去除水体中Pb的研究OACHSSCD

In order to effectively remove Pb from water,Fe-Mn oxide modified straw-based Hydrochar(FM/HC)is prepared,and the effects of pH value,coexisting Na+and other factors on its adsorption performance are studied,at the same time,pseudo second order kinetic model and Langmuir isotherm adsorption model are used to fit and analyze the adsorption behavior.The results show that under the condition of pH value being 5.0,the adsorption capacity of FM/HC for Pb reaches 357.14 mg/g,significantly higher than the maximum adsorption capacity(161.29 mg/g)of unmodified straw-based Hydrochar(HC).Dynamics studies have shown that the adsorption process of FM/HC follows a pseudo second order kinetic model,and Pb adsorption is mainly controlled by surface chemical reactions.Thermodynamic studies have shown that the adsorption of Pb is a spontaneous endothermic process,with an adsorption enthalpy of 15.53 kJ/mol and a negative adsorption free energy of-8.11 kJ/mol to-6.63 kJ/mol.X-ray Photoelectron Spectroscopy(XPS)analysis shows that Pb is fixed by complexation reaction with oxygen-containing functional groups on the surface of FM/HC.As a coexisting ion,Na+has a relatively small effect on the adsorption of FM/HC,indicating that FM/HC has strong selectivity and stability.FM/HC is an efficient Pb adsorbent material with broad application prospects.