TY - EJOU
AU - Lacuesta, Jonathan
AU - Erramuspe, Iris Beatriz Vega
AU - Sobhana, Liji
AU - Kronlund, Dennis
AU - Peltonen, Jouko
AU - Gutiérrez, Soledad
AU - Fardim, Pedro
TI - Rice Husk Bio-Chars as Adsorbent for Methylene Blue and Ethinylestradiol from Water
T2 - Journal of Renewable Materials
PY - 2020
VL - 8
IS - 3
SN - 2164-6341
AB - Biobased adsorbents are eco-friendly materials used for water and wastewater treatment and air cleaning. This research work explores the potential use
of rice husk chars as a low-cost adsorbent for pollutants from water, such as
methylene blue and ethinylestradiol. Rice husk chars are prepared by combustion
of rice husks (RH-Char) or pre-treated rice husks (PT-Char). A third char
(M-Char) supplied by a local company which uses rice husks as combustion material is also studied. The chars are characterized by field emission scanning electron
microscopy (FE-SEM) in conjunction with energy dispersive X-ray spectroscopy
(EDX), X-ray powder diffraction (XRD), and zeta-potential measurements. The
three bio-chars are tested as adsorbent for the removal of two wastewater contaminants: methylene blue (MB) and ethinylestradiol (EE2). According to the results,
RH-Char and PT-Char present zeta-potential values near −52 mV, whereas
M-Char shows a zeta-potential value of −32 mV. Both RH-Char and PTChar
are rich in amorphous SiO2 and M-Char has crystalline SiO2 (cristobalite). The
bio-chars remove MB and EE2 efficiently showing the following results for the
adsorption capacity of MB (in μmol g−1
): 769.2 (RH-Char), 41.2 (PT-Char),
and 31.7 (M-Char). The adsorption capacity values for EE2 (in μmol g−1
) are:
33.1 (RH-Char), 19.1 (PT-Char), and 16.9 (M-Char). The information gathered
in the present work evidences the potential of rice husks bio-chars for bio-remediation and may in future contribute to the conversion of a side-stream from the
rice industry into value-added materials.
KW - Rice husk; bio-char; thermal treatment; adsorption; methylene blue; ethinylestradiol
DO - 10.32604/jrm.2020.08861