TITLE:
Evaluation of Physicochemical Parameters of Biosorbents Produced from Groundnut Hull Using Microwave Assisted Irradiation Method
AUTHORS:
Augustus Newton Ebelegi, Newman Tonizibeze Elijah, Jackson Godwin
KEYWORDS:
Agrowastes, Characterization, Physicochemical, Bulk Density, Surface Area, Volatile Matter, Groundnut Hull, Hydrogen Peroxide
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.13 No.1,
February
27,
2023
ABSTRACT: Samples of ground nut hull were converted to
biosorbents using microwave assisted method [groundnut hull treated with
hydrogen peroxide (HP-GH), groundnut hull treated with distilled water (W-GH)
and raw groundnut hull (R-GH)]. The biosorbents were further characterized
using physicochemical procedures (pH dependence, bulk density, surface area,
ash content, and volatile matter, moisture content). The results show that
HP-GH has pH = 8.9, W-GH pH = 8.4 and R-GH pH = 8.5 which is an indication that
all the biosorbents have the appropriate pH values for the uptake of cationic
species within aqueous systems. Surface area analysis revealed that HP-GH has
the largest surface area (74.20 m2·g-1) while W-GH and
R-GH have surface area values of 29.40 m2·g-1 and 21.40 m2·g-1 respectively. This suggests that modification of raw groundnut hull biomass
with hydrogen peroxide possibly instigated delignification of the biomass which
resulted in increased surface area for HP-GH. Results from Bulk density
analysis also confirm the data obtained from surface area analysis. Accordingly,
R-GH displayed the highest bulk density followed by W-GH with HP-GH showing the
least bulk density. The variation in pH values among the biomass used in this
study may be explained by the variation in their ash content as well because pH
and ash content are positively correlated. Hence, HP-GH with a pH = 8.9 has
high ash content (117.31%), W-GH with pH = 8.4 has 97.93% ash content and R-GH
with pH = 8.5 has 94.26% ash content. Results from moisture content analysis
show that HP-GH (99.95%), W-GH (99.97%) and R-GH (99.89%) may necessitate
exposure of the biosorbents to moderate heat before use. The results obtained
from this study suggest that modification of ground nut hull with either
distilled water or Hydrogen peroxide by means of microwave irradiation improves
physicochemical properties which may perhaps increase the adsorption capacity
of the biomass.