Synthesis, characterization and absorbability of Crocus sativus petals hydrothermal carbonized hydrochar and activated hydrochar

An environmentally friendly adsorbent for the removal of lead (II) ions from aqueous solutions was prepared by hydrothermal carbonized of KOH activated Crocus sativus petals, generated as an agricultural residue. The influence of the operating parameters in the hydrothermal carbonization process on Pb2+ adsorption capacity was evaluated by an artificial neural network method. The pore structure, morphology, functional groups and elemental composition of the activated hydrochar were characterized. The reaction temperature and residence time were found to be the main parameter affecting the physicochemical properties of the produced hydrochar. The optimal conditions of hydrothermal carbonization towards lead ions adsorption were as follows: temperature of 180 degrees C, residence time of 11.5 h, water/biomass ratio of 10 and ZnCl2/biomass ratio of 1.5, resulting in an adsorption capacity of 89.52 mg g(-1). The optimal hydrochar was selected for further investigation, including the kinetics and isotherms of adsorption.

Automated summary

An environmentally friendly adsorbent for lead (II) ions removal was prepared by hydrothermal carbonization of Crocus sativus petals activated by KOH. The optimal conditions for Pb2+ adsorption were determined through evaluating the operating parameters, leading to a high adsorption capacity. Further investigation on kinetics and isotherms of adsorption was conducted on the optimal hydrochar.