Abstract
In this study, activated carbon (AC) was prepared from agro-waste betel nut husks (BNH) through the chemical activation method. Different characterization techniques described the physicochemical nature of betel nut husks activated carbon (BNH-AC) through Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), and pH point of zero charge. Later, the produced AC was used for methylene blue (MB) adsorption via numerous batch experimental parameters: initial concentrations of MB dye (25-250 mg/L), contact time (0.5-24 hours) and initial pH (2-12). Dye adsorption isotherms were also assessed at three temperatures where the maximum adsorption capacity (381.6 mg/g) was found at 30 °C. The adsorption equilibrium data were best suited to the non-linear form of the Freundlich isotherm model. Additionally, non-linear pseudo-second-order kinetic model was better fitted with the experimental value as well. Steady motion of solute particles from the boundary layer to the BNH-AC's surface was the possible reaction dynamics concerning MB adsorption. Thermodynamic study revealed that the adsorption process was spontaneous and exothermic in nature. Saline water emerged as an efficient eluent for the desorption of adsorbed dye on AC. Therefore, the BNH-AC is a very promising and cost-effective adsorbent for MB dye treatment and has high adsorption capacity.
Highlights
Synthetic dyes, of which 800,000 tons are manufactured every year globally, are soluble in water, readily absorbed and are versatile colors in nature compared to natural dyes (Jamee & Siddique )
Volatile matter of betel nut husks (BNH)-activated carbon (AC) has a lower value compared to the raw BNH
The carbon content discloses the higher value in the case of betel nut husks activated carbon (BNH-AC) (Table 1)
Summary
Of which 800,000 tons are manufactured every year globally, are soluble in water, readily absorbed and are versatile colors in nature compared to natural dyes (Jamee & Siddique ). Despite having complex molecular structures and toxic characteristics, these dyes are increasingly used in chemicals, foods, textiles, paper, and the pharmaceutical industries, resulting in serious outcomes for human health and the environment (Islam et al a; Baumer et al ). The overall quality of the receiving water is greatly damaged and has serious implications for human survival (Islam et al ). The adsorption method is considerably effective due to the feasibility and applicability of low-priced sorbents (Oyekanmi et al ). It has great potential in significantly reducing such environmental problems, increasing productivity and helping to remediate the environment (Hoque & Clarke ). Several low-cost adsorbents, such as agricultural wastes, industrial solid wastes, biomass, clays minerals and zeolites, are usually utilized for MB removal (Rafatullah et al )
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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
