TY - JOUR
T1 - Biosorption of co2+ ions from aqueous solution by k2hpo4-pretreated duckweed lemna gibba
AU - Reyes-Ledezma, Jessica Lizeth
AU - Cristiani-Urbina, Eliseo
AU - Morales-Barrera, Liliana
N1 - Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2020/12
Y1 - 2020/12
N2 - The wastewater of the many industries that use divalent cobalt (Co2+)-containing compounds has elevated levels of this metal. Thus, novel technology is needed to efficiently remove Co2+ ions from aqueous solutions. Biosorption is a low-cost technique capable of removing heavy metals from contaminated water. This study aims to evaluate the performance of KH2PO4-pretreated Lemna gibba (PLEM) as a biosorbent of Co2+ in aqueous solutions tested under different conditions of pH, particle size, and initial Co2+ concentration. Kinetic, equilibrium, and thermodynamic studies were conducted. The capacity of biosorption increased with a greater initial Co2+ concentration and was optimal at pH 7.0 and with small-sized biosorbent particles (0.3–0.8 mm). The pseudo-second-order sorption model best describes the experimental data on Co2+ biosorption kinetics. The Sips and Redlich-Peterson isotherm models best predict the biosorption capacity at equilibrium. According to the thermodynamic study, biosorption of Co2+ was endothermic and spontaneous. The effect of pH on the biosorption/desorption of Co2+ suggests that electrostatic attraction is the main biosorption mechanism. SEM-EDX verified the presence of Co2+ on the surface of the pretreated-saturated biosorbent and the absence of the metal after desorption.
AB - The wastewater of the many industries that use divalent cobalt (Co2+)-containing compounds has elevated levels of this metal. Thus, novel technology is needed to efficiently remove Co2+ ions from aqueous solutions. Biosorption is a low-cost technique capable of removing heavy metals from contaminated water. This study aims to evaluate the performance of KH2PO4-pretreated Lemna gibba (PLEM) as a biosorbent of Co2+ in aqueous solutions tested under different conditions of pH, particle size, and initial Co2+ concentration. Kinetic, equilibrium, and thermodynamic studies were conducted. The capacity of biosorption increased with a greater initial Co2+ concentration and was optimal at pH 7.0 and with small-sized biosorbent particles (0.3–0.8 mm). The pseudo-second-order sorption model best describes the experimental data on Co2+ biosorption kinetics. The Sips and Redlich-Peterson isotherm models best predict the biosorption capacity at equilibrium. According to the thermodynamic study, biosorption of Co2+ was endothermic and spontaneous. The effect of pH on the biosorption/desorption of Co2+ suggests that electrostatic attraction is the main biosorption mechanism. SEM-EDX verified the presence of Co2+ on the surface of the pretreated-saturated biosorbent and the absence of the metal after desorption.
KW - Biosorption
KW - Desorption
KW - Divalent cobalt
KW - Lemna gibba
KW - SEM-EDX
UR - http://www.scopus.com/inward/record.url?scp=85097025871&partnerID=8YFLogxK
U2 - 10.3390/pr8121532
DO - 10.3390/pr8121532
M3 - Artículo
AN - SCOPUS:85097025871
SN - 2227-9717
VL - 8
SP - 1
EP - 21
JO - Processes
JF - Processes
IS - 12
M1 - 1532
ER -