Characterization of Residual Biomasses and Its Application for the Removal of Lead Ions from Aqueous Solution

Abstract

The removal of water pollutants has been widely addressed for the conservation of the environment, and novel materials are being developed as adsorbent to address this issue. In this work, different residual biomasses were employed to prepare biosorbents applied to lead (Pb(II)) ion uptake. The choice of cassava peels (CP), banana peels (BP), yam peels (YP), and oil palm bagasse (OPB) was made due to the availability of such biomasses in the Department of Bolivar (Colombia), derived from agro-industrial activities. The materials were characterized by ultimate and proximate analysis, Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller analysis (BET), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS) in order to determine the physicochemical properties of bioadsorbents. The adsorption tests were carried out in batch mode, keeping the initial metal concentration at 100 ppm, temperature at 30 °C, particle size at 1 mm, and solution pH at 6. The experimental results were adjusted to kinetic and isotherm models to determine the adsorption mechanism. The remaining concentration of Pb(II) in solution was measured by atomic absorption at 217 nm. The functional groups identified in FTIR spectra are characteristic of lignocellulosic materials. A high surface area was found for all biomaterials with the exception of yam peels. A low pore volume and size, related to the mesoporous structure of these materials, make these bioadsorbents a suitable alternative for liquid phase adsorption, since they facilitate the diffusion of Pb(II) ions onto the adsorbent structure. Both FTIR and EDS techniques confirmed ion precipitation onto adsorbent materials after the adsorption process. The adsorption tests reported efficiency values above 80% for YP, BP, and CP, indicating a good uptake of Pb(II) ions from aqueous solution. The results reported that Freundlich isotherm and pseudo-second order best fit experimental data, suggesting that the adsorption process is governed by chemical reactions and multilayer uptake. The future prospective of this work lies in the identification of alternatives to reuse Pb(II)-contaminated biomasses after heavy metal adsorption, such as material immobilization.

Adsorption in a binary system of Pb (II) and Ni (II) using lemon peels

“…The surface of the biomaterial is irregular, and porous allowing a better heterogeneous biosorption due to the large interface ( Figure 2a); moreover, it presents small white spots which are caused by the presence of Calcium, Aluminium and Potassium in its structure ( Figure 3a). The SEM micrographs after adsorption (Figures 2b and 2c), show Pb(II) and Ni(II) agglomerations on their surface, which can be attributed to the formation of chelates in the samples [7], [28]. This fact is confirmed in the EDS analysis after metal removal, Figures 3b and 3c, which show the appearance of the characteristic high-intensity peaks for Pb and Ni at 1.7 and 0.8 keV, respectively.…”

“…This event was due to the mechanisms that appear during the adsorption process of metals on bioadsorbents, which include ion exchange, microprecipitation, complexation and coordination, due to the presence of functional groups on the surface of the adsorbent [29], [30]. Figure 3a revealed that carbon and oxygen contribute more to the elemental composition of the biomass, which is attributed to the organic nature of the lignocellulosic residues [27], and its ability to capture cations by electrostatic forces [28], [31]. The presence of both heavy metals on the adsorption surface was evidenced with a mass percentage of 0.26 and 0.11%, respectively.…”

Efficient photocatalytic degradation of dyes using photo-deposited Ag nanoparticles on ZnO structures: simple morphological control of ZnO

“…N 2 adsorption/desorption isotherms of the as-prepared ZnO materials exhibited a typical type IV pattern for ZnOsf, ZnOw, ZnOr, ZnOf, indicative of mesoporous characteristics 59 and typical type III pattern for ZnOu indicating a microporous material. 59,60 The BET surface areas of various ZnO types were in the following order: ZnOsf (13.45 m 2 g À1 ) > ZnOw (10.46 m 2 g À1 ) > ZnOr (3.44 m 2 g À1 ) > ZnOf (1.59 m 2 g À1 ) > ZnOu (0.93 m 2 g À1 ).…”

Elimination of Cadmium (II) in aqueaous solution using corn cob (Zea mays) in batch system: adsorption kinetics and equilibrium

“…In the spectrum, the C=O and C-O stretching in the bands around 1600 cm −1 is observed, which indicates the vibration of the carboxyl groups belonging to pectin, hemicellulose and lignin in corn cob and reported in the previous characterization of the material . The vibration of the OH groups and secondary amines between 3200 and 3600 cm −1 corresponding to the hydroxyl of the ligno-cellulosic molecules (Tejada-tovar et al, 2019). The peak observed around 2900 cm −1 can be attributed to the C-H vibrations of methyl, methylene and methoxy groups.…”