Adsorption capacity of the biochar obtained from Pinus patula wood micro-gasification for the treatment of polluted water containing malachite green dye
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Rubio Clemente, Ainhoa | 2021
In this work, the adsorption capacity of the biochar obtained from Pinus patula biomass micro-gasification
was studied using malachite green (MG) as the probe pollutant. For this purpose, the biomass type (wood
pellets and chips) was selected to produce two kinds of biochar (BC). Afterwards, the effects of the adsor-
bent dose (6, 9 and 12 g/L), the solution pH (4, 7 and 10) and the BC particle size distribution (150–300,
300–450 and 450–600 lm) for the maximization of the MG retention by the selected BC were evaluated
using a faced-centered central composite design, as response surface methodology. The results indicated
that the BC derived from wood chips (BWC) exhibited a higher MG dye adsorption capacity than the BC
obtained from the wood pellets (BWP) gasification under the same operating conditions after having
reached the equilibrium. A second-order regression model was built for describing the MG adsorption
behaviour by BWC under the considered experimental domain. The model, which was validated, resulted
to be statistically significant and suitable to represent the MG adsorption by the studied BC with a p-
value of 0.00 and a correlation coefficient (R2) of 95.59%. Additionally, a three-dimensional response sur-
face graph and a contour plot were utilized to analyze the interaction effects between the factors influ-
encing the adsorption system and to discern the optimal operating conditions for the use of BWC. The
maximal MG dye retention (99.70%) was found to be at an adsorbent dose, pH solution and a particle size
distribution of 9.80 g/L, 10 and from 150 to 300 lm, respectively. Therefore, the BWC tested can be uti-
lized for the treatment of water polluted with dyes, contributing to the establishment of a circular
economy.
LEER