@conference{
author = "Tomašević, Anđelka and Jovanović, Aleksandar and Bošnjaković, Jovana and Stevanović, Marija and Rusmirović, Jelena and Marinković, Aleksandar",
year = "2021",
abstract = "With the development of the industry and growth of
the population, there is an increasing amount of waste,
which, due to inadequate treatment, pollutes water. The
group of the most dangerous pollutants present in water
includes heavy metals, such as As, Cd, Pb, Ni, Hg, Cr,
etc. [1]. Heavy metal ions are highly toxic and not biodegradable,
but are prone to accumulation in the body in
certain tissues and organs [2].
In recent years, natural materials, originating from
waste or renewable sources, have been increasingly
used as adsorbents in the removal of heavy metal ions
from water, due to their low cost, high prevalence and
beneficial impact on the environment [3]. Lignin, cellulose
and hemicellulose are the main polymers of wood
biomass [4]. Lignin is represented as a by-product in the
paper and pulp industry [5]. Chemical modification of
lignin was performed using acrylate derivatives (L-AC).
Modified lignin microspheres (LMS) were synthesized
by inverse suspension copolymerization using L-AC,
trimethylolpropane triacrylate (TMPTA) and methacryl
functionalized magnetite modified with MEMO silane
or with methacryloyl chloride (MACM1 or MACM2).
The procedure of inverse emulsion-suspension copolymerization
developed by Popović et al. [6] was used. In
a summary, disodium laureth sulfosuccinate (surfactant)
was stirred in water solution for 30 min at 80 °C. Afterwards,
TMPTA, L-MAC, MACM1 or MACM2 and the
initiator AIBN (1 wt. %) were added, followed by the
mixture of pore-forming solvents (tetradecanol and toluene),
stirred for 18 h at the same elevated temperature.
LMS microspheres were characterized by zero
charge point determination, FT-IR and SEM. The efficiency
of pollutants (chromium(VI) and arsenic(V)
ions) removal was analysed in terms of varying the
experimental conditions: the mass of adsorbent, the pH
of solution, the temperature of reaction and the contact
time. The best sorption was observed for the pH between
5.0 and 7.0. Synthesized bio-adsorbents showed
high efficiency, with capacities of 35.5 and 54.0 mg g-1
for the LMS adsorbents loaded with magnetite modified
using methacyl functionalized silane (LMS-1) or
methacryloyl chloride (LMS-2), respectively, obtained
according to Freundlich isothermal model. Adsorption
kinetics are described according to a pseudo-second
order model. Based on the obtained results, both adsorbents
showed excellent adsorption abilities.
Thermodynamic parameters, including the Gibbs
free energy (ΔGΘ), enthalpy (ΔHΘ) and entropy (ΔSΘ),
proved that adsorption is viable, spontaneous and endothermic
process (LMS-1) and exothermic process
(LMS-2) at temperatures between 25 and 45 °C.",
publisher = "Belgrade : Serbian Chemical Society",
journal = "21th European Meeting on Environmental Chemistry EMEC 21",
title = "Removal of Chromium(VI) and Arsenic(V) from Water Solution Using Modified Lignin Microspheres",
pages = "115-115"
}
