Abstract
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. The 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. The 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.
Highlights
Anthropogenic activities, i.e., leather, mining, textile, electroplating, battery, and pesticide processing/production as well as ewaste dumping are thought to be the dominant contributors for heavy metals in wastewater (Song & Li 2015)
The alkaline modified biochars were separated from solution and washed with deionized water to neutral and oven-dried at 80 °C, and the obtained solids were named as alkaline modified LBB (ALBB) and alkaline modified FLBB (AFLBB), respectively
An increasing trend was observed for total pore volume with the order of Lycium barbarum branch (LB), fermented LB (FLB), LB biochar (LBB), FLB biochar (FLBB), ALBB, AFLBB
Summary
Anthropogenic activities, i.e., leather, mining, textile, electroplating, battery, and pesticide processing/production as well as ewaste dumping are thought to be the dominant contributors for heavy metals in wastewater (Song & Li 2015). Awareness in environmental protection has been increasingly reinforced worldwide, high concentrations of heavy metals can be still detected in natural waters. Heavy metals normally enter into water as ions, which jeopardize aquatic lives and through food chains build up in human bodies, causing organ failure and even cancer (Balali-Mood et al 2021). Fewer research has been conducted towards Cr3þ due to its low toxicity, which, could be enhanced by 100-fold when oxidized into Cr6þ in environment, posing great threat to environmental ecology and human health (Jin et al 2020). Even though at low concentration Cu2þ could foster the formation of red blood cells and maintaining nervous system and immune functions, the overdose, could do great harm to human body by damaging kidney, brain, nervous and blood system (Vardhan et al 2019)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
