Sugarcane bagasse
fly ash is industrial waste produced by incinerating
biomass to generate power and steam. The fly ash contains SiO2 and Al2O3, which can be used to prepare
aluminosilicate. This latter material exhibits high potential as an
adsorbent in various applications, including the livestock industry
where issues related to contamination of aflatoxins in animal feeds
need to be addressed; addition of adsorbents can help decrease the
concentration of aflatoxins during feed digestion. In this study,
the effect of the structure of silica prepared from sugarcane bagasse
fly ash on physicochemical properties and aflatoxin B1 (AFB1) adsorption
capability compared with that of bentonite was investigated. BPS-5,
Xerogel-5, MCM-41, and SBA-15 mesoporous silica supports were synthesized
using sodium silicate hydrate (Na2SiO3) from
sugarcane bagasse fly ash as a silica source. BPS-5, Xerogel-5, MCM-41,
and SBA-15 exhibited amorphous structures, while sodium silicate possessed
a crystalline structure. BPS-5 possessed larger pore size, pore volume,
and pore size distribution with a bimodal mesoporous structure, while
Xerogel-5 exhibited lower pore size and pore size distribution with
a unimodal mesoporous structure. BPS-5 with a negatively charged surface
exhibited the highest AFB1 adsorption capability compared with other
porous silica. However, the AFB1 adsorption capability of bentonite
was superior to those of all porous silica. Sufficient pore diameter
with high total pore volume as well as high intensity of acid sites
and negative charge on the surface of the adsorbent is required to
increase AFB1 adsorption in the in vitro gastrointestinal tract of
animals.