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Characterization and Evaluation of Various Biochar
Types as a Green Approach for Lanthanum Recovery from
Aqueous Solutions
Victor Famobuwa, Hassan Amini, Deniz Talan
Mining Engineering Department West Virginia University
Michael Ferrebee, Oishi Sanyal
Chemical, and Biomedical Engineering Department, West Virginia University
ABSTRACT: This study investigates an environmentally benign biochar adsorption process for rare earth
element (REE) recovery from aqueous solutions. The adsorption performance was studied with biochars
produced from Appalachian hardwood (AH), wood chip and chicken litter (WCC), and softwood (SW) after
being subjected to pyrolysis at 675°C, 700°C, and 450°C, respectively. The effect of several test conditions, such
as solution pH, contact time, and initial REE concentrations, were investigated to identify the best separation
performance and develop an understanding of the adsorption mechanism. The findings indicated that the most
favorable pH for the adsorption is 5, with a contact time of 24 hours. AH had superior adsorption capability
with a lanthanum adsorption capacity of 126.85 mg/g compared to WCC and SW. After adsorption, 90%
REE desorption was achieved with 0.2M HNO3, which gave the most promising results among the three
reagents tested. Characterization studies, including SEM, FTIR, BET, and zeta potential measurements, were
also conducted to provide supplemental information. Overall, biochar exhibits potential as an environmentally
friendly, effective, and sustainable sorbent for the recovery of REEs from aqueous solutions as tested both in a
single element and multi element synthetic systems.
INTRODUCTION
Rare earth elements are members of the lanthanide fam-
ily with atomic numbers 57–71 on the periodic table.
They are classified as heavy (HREE) and light rare earth
elements (LREE). Lanthanum, Neodymium, Samarium,
Cerium, and Praseodymium are examples of the former,
while Terbium, Lutetium, Holmium, Erbium, Yttrium,
Ytterbium, and Thulium are examples of the latter. While
they are found in the same deposits, LREE was discov-
ered to be more abundant than HREE (Mclemore, 2015
Moldoveanu &Papangelakis, 2012).
REEs can be found in minerals such as silicates (cerite,
allanite), phosphates (monazite), carbonates (bastnasite),
oxides (fergusomite, samarskite), and halides (yttrocerite)
and have proven to be vital in science and technology, met-
allurgy, and in medicine due to their unique physical and
chemical properties (Dushyantha et al., 2020 Soe et al.,
2008 Vijayan et al., 1989). Lanthanum was discovered to
be more abundant in bastnasite, monazite, and cerite, with
contents of 38%, 25%, and 30%, respectively (Awwad et
al., 2010). It is also proven to be an important constituent
in the manufacture of optical glasses, batteries, ceramics,
Characterization and Evaluation of Various Biochar
Types as a Green Approach for Lanthanum Recovery from
Aqueous Solutions
Victor Famobuwa, Hassan Amini, Deniz Talan
Mining Engineering Department West Virginia University
Michael Ferrebee, Oishi Sanyal
Chemical, and Biomedical Engineering Department, West Virginia University
ABSTRACT: This study investigates an environmentally benign biochar adsorption process for rare earth
element (REE) recovery from aqueous solutions. The adsorption performance was studied with biochars
produced from Appalachian hardwood (AH), wood chip and chicken litter (WCC), and softwood (SW) after
being subjected to pyrolysis at 675°C, 700°C, and 450°C, respectively. The effect of several test conditions, such
as solution pH, contact time, and initial REE concentrations, were investigated to identify the best separation
performance and develop an understanding of the adsorption mechanism. The findings indicated that the most
favorable pH for the adsorption is 5, with a contact time of 24 hours. AH had superior adsorption capability
with a lanthanum adsorption capacity of 126.85 mg/g compared to WCC and SW. After adsorption, 90%
REE desorption was achieved with 0.2M HNO3, which gave the most promising results among the three
reagents tested. Characterization studies, including SEM, FTIR, BET, and zeta potential measurements, were
also conducted to provide supplemental information. Overall, biochar exhibits potential as an environmentally
friendly, effective, and sustainable sorbent for the recovery of REEs from aqueous solutions as tested both in a
single element and multi element synthetic systems.
INTRODUCTION
Rare earth elements are members of the lanthanide fam-
ily with atomic numbers 57–71 on the periodic table.
They are classified as heavy (HREE) and light rare earth
elements (LREE). Lanthanum, Neodymium, Samarium,
Cerium, and Praseodymium are examples of the former,
while Terbium, Lutetium, Holmium, Erbium, Yttrium,
Ytterbium, and Thulium are examples of the latter. While
they are found in the same deposits, LREE was discov-
ered to be more abundant than HREE (Mclemore, 2015
Moldoveanu &Papangelakis, 2012).
REEs can be found in minerals such as silicates (cerite,
allanite), phosphates (monazite), carbonates (bastnasite),
oxides (fergusomite, samarskite), and halides (yttrocerite)
and have proven to be vital in science and technology, met-
allurgy, and in medicine due to their unique physical and
chemical properties (Dushyantha et al., 2020 Soe et al.,
2008 Vijayan et al., 1989). Lanthanum was discovered to
be more abundant in bastnasite, monazite, and cerite, with
contents of 38%, 25%, and 30%, respectively (Awwad et
al., 2010). It is also proven to be an important constituent
in the manufacture of optical glasses, batteries, ceramics,