Plant-based modified cellulose obtained from Populus nigra as a potential adsorbent for pesticides removal from aqueous media

Abstract

In this study, cellulose was extracted from Populus nigra plant biomass and subsequently modified for use as an adsorbent for the removal of pesticide acetamiprid from wastewater. The extracted cellulose was purified using sodium oxychloride and hydrogen peroxide, acetylated with acetic acid, and further functionalized with polyvinyl alcohol. The prepared adsorbent was characterized via FTIR, UV-Vis spectroscopy, EDX, SEM, and XRD. The effects of various parameters, including the initial concentration of pesticide, adsorbent dosage, contact time, pH, and temperature on adsorption were examined using batch adsorption approaches. Maximum removal was obtained at 80 mg/L pesticide concentration, pH 8, 60 min contact time, and 0.08 g adsorbent dosage. The isothermal data for acetamiprid is matched perfectly to the Freundlich, Temkin and Harkins-Jura isotherm models with regression constant values approaching to 1, whereas good agreement was observed for kinetic data with the pseudo-second-order model. Thermodynamic analysis indicated the adsorption process as favorable and exothermic, with ∆H° = -81.65 kJ/mol, ∆S° = 305.62 J/mol·K, and ∆G° = - 116.90, -150.17 and 180.20 kJ/mol at 293, 313 and 333 K respectively. These findings suggest that the prepared cellulose-based adsorbent is an effective and promising material for pesticide removal from wastewater.

Keywords: Populus nigra; Acetamiprid; Acetylated cellulose; Isothermal study; Kinetic study; Polyvinyl alcohol.

Fig. 1

Chemical structure of acetamiprid.

Fig. 2

(a) EDX spectra of plant based cellulose acetate (PBCA) sample. (b) EDX spectra of PBCA–PVA particles.

Fig. 3

SEM images of Populus nigra powder (a), PBCA–PVA adsorbent at 430 (b) and (c) 600 X magnifications.

Fig. 4

FTIR spectra of Populus nigra plant.

Fig. 5

FTIR Spectra of PBCA–PVA after adsorbtion.

Fig. 6

X-ray Diffraction pattern for Populus nigra powder (a) and plant based cellulose acetate-PVA particle (b).

Fig. 7

Selected pesticide adsorption plots: (a) Concentration Effect on adsorption ofPBCA–PVA (b) plot of Langmuir isotherm (c) Diagram of Freundlich isotherm (d)Diagram of Temkin isotherm (e) Jovanovich isotherm (f) Diagram ofHarkins–Jura isotherm.

Fig. 8

Adsorption kinetics of selected pesticide adsorption on PBCA–PVA (a) Kinetics plot (b) Pseudo-first order plot (c) Pseudo-second order plot (d) Power function plot (e) Khalaf and Natarajan plot (f) Intra-particle model.

Fig. 9

(a) pH Effect for acetamiprid (b) Determination of pH by point zero charge for PBCA–PVA particles (c) Effect of adsorbent dose (d) Van’t Hoff plots.

Fig. 10

Recycling plot of PBCA–PVA adsorbent.