Adsorption of heavy metals by Lycium barbarum branch-based adsorbents: raw, fungal modification, and biochar

Abstract

The present study reports on the adsorptive removal of heavy metals (Cr3+, Cd2+, and Cu2+) from water by a series of Lycium barbarum branch-based adsorbents: Lycium barbarum branch (denoted as LB), fungal fermented LB (FLB), LB biochar (LBB), FLB biochar (FLBB), alkaline modified LBB (ALBB), and alkaline modified FLBB (AFLBB). The six adsorbents were characterized in terms of FTIR, SEM, surface area and pore size as well as Zeta potential. Adsorptive potential of these adsorbents was tested under varying conditions – pH, contact time, initial concentration, and temperature. Adsorption results were well fitted with Langmuir, Freundlich, and Temkin models. The maximum adsorption capacity (qm) was calculated to be 6.29 mg/g for Cr3+ by FLB, 11.53 mg/g for Cd2+ by LB, and 7.27 mg/g for Cu2+ by LB. Pseudo-second-order kinetic equation better described the adsorption process. Based on the thermodynamics parameters, the adsorption of heavy metals was endothermic but not spontaneous for biochars. The experimental results offer a new way for recycling and reutilizing LB in wastewater treatment.

Valorization of sugarcane bagasse for sugar extraction and residue as an adsorbent for pollutant removal

“…It was clear that the latter model better fitted the adsorption process in all the investigated cases (R 2 > 0.999), implying that the enzymatic hydrolysis of SCB did not alter the adsorption kinetic feature. Moreover, the results also suggested that chemical interactions occurred between SCB or SCBE and pollutants via the exchange/sharing of electrons, where strong covalent bonds were formed (Han et al, 2010;Ezeonuegbu et al, 2021;Guan et al, 2022). Furthermore, the calculated q e (cal) values and q e (exp) obtained from experiment are very similar: 24.33 vs. 24.34 mg/g for MB by SCB, 24.57 vs. 24.63 mg/g for MB by SCBE, 4.17 vs. 4.14 mg/g for Cu 2+ by SCB, and 2.59 vs. 2.58 mg/g for Cu 2+ by SCBE.…”

Pb (II) Recovery by Trout Bones: Adsorption, Desorption and Kinetic Study

“…There are many heavy metal adsorption studies in the literature, especially with adsorbents obtained from natural sources such as agricultural wastes and their modified forms (Dubey & Gopal, 2007;Bansal et al, 2009;Qiao et al, 2019;Yu et al, 2022), wheat straw (Khan et al, 2021), biochar (Q. Wang et al, 2018;Guan et al, 2022), clay (Xie et al, 2018), tea plant waste (Ibrehem, 2019).…”