Modeling lead adsorption in aqueous solutions using rose stem biomass

Resumen

The study investigates the use of rose stems as a bioadsorbent for the removal of lead in contaminated aqueous solutions, taking advantage of plant waste from the flower markets of Arequipa, Peru. For this reason, the capacity of rose stems treated by a sequential process of acid and alkaline hydrolysis will be evaluated. The chemical activation of the rose stem biomass was carried out with a sequential process of acid hydrolysis and alkaline hydrolysis (TRHS) and was characterized by the Fourier Transform Infrared Spectroscopy (FTIR) technique before and after interacting with lead. The experimental equilibrium data are related to the Langmuir isotherm model and the lead biosorption kinetics fit better to the pseudo-second order Ho model. Therefore, a sequential acid-alkaline hydrolysis treatment (SAHT) was carried out to activate the biomass, resulting in a maximum adsorption capacity of 344.827 mg Pb(II)/g of rose stem and a lead removal rate of 99.325%, exceeding the results of other previous studies. The optimum pH for the biosorption process was determined to be 4, and ideal contact conditions and adsorbent dosage were established. The results suggest that the use of rose stems not only contributes to the circular economy by reusing waste, but also offers an effective solution for the removal of heavy metals in contaminated waters, highlighting its potential in environmental management and sustainability.