Batch study for Pb2+ removal by polyvinyl alcohol-biochar macroporous hydrogel bead.
Environ Technol
; 42(4): 648-658, 2021 Jan.
Article
in En
| MEDLINE
| ID: mdl-31287380
ABSTRACT
In this paper, a novel adsorbent which used polyvinyl alcohol, alginate and biochar was successfully made and been used to remove lead from aqueous solutions. Batch experiments were carried out to evaluate the adsorption capacities of Pb (II) on this bead. Experimental data were analysed by the model equations like Langmuir and Freundlich and adsorption kinetic constants were determined using pseudo-first-order (PFO) and pseudo-second-order (PSO). In this study, the adsorption characteristics of Pb (II) were well fitted by the Langmuir isotherm model and pseudo-second-order (PSO) kinetic model. The adsorption of Pb (II) onto PVA-biochar beads are spontaneous and exothermic at 303-333â
K by the evidence of the changes in standard Gibbs free energy, standard enthalpy and standard entropy. The maximum adsorption capacity for Pb (II) was estimated to be 176.40â
mg/g, which is comparable with other adsorbents. While the maximum adsorption increased varying the pH of initial solution from 2 to 6, the effect on the adsorption amount by the sodium ion concentration is not very large. The results of EDS spectra indicated that the existence of lead in polyvinyl alcohol (PVA)-biochar bead after adsorption, which proving the adsorption of lead. In XPS spectrum, the observed Pb elements also demonstrated that the lead was adsorbed by PVA-biochar bead.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Polyvinyl Alcohol
/
Water Pollutants, Chemical
Type of study:
Prognostic_studies
Language:
En
Journal:
Environ Technol
Journal subject:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Year:
2021
Document type:
Article