Magnetic supported activated carbon obtained from walnut shells for bisphenol-a uptake from aqueous solution

Abstract

This work investigated the usability of activated carbon walnut shell (ACWS) and magnetic activated carbon walnut shell (MACWS) for Bisphenol-A (BPA) elimination from aqueous solution. Fourier-transform infrared (FT-IR) and X-ray diffraction (XRD) were used to study the chemistry of the adsorbents. Batch sorption studies at different temperatures, contact time, adsorbent dosage, pH and varied Bisphenol-A concentrations were performed, while pseudo-first-order and pseudo-second-order kinetics models were deployed to investigate the kinetic data. Equilibrium parameters were computed using the Dubinin–Radushkevich, Freundlich, Temkin and Langmuir isotherms, while Box–Behnken design was used to optimize the adsorption factors. FT-IR report showed the existence of O–H, C=O, C–O and C=C stretches in both adsorbents and Fe–O in MACWS, while XRD revealed an amorphous morphology. BPA removal by ACWS and MACWS with correlation coefficient (R2) > 0.9 showed that the pseudo-first-order kinetic model was the most appropriate for explaining the kinetic data. Judging from the values of the maximum adsorption capacity (115.85 and 166.67 mg/g for ACWS and MACWS, respectively), it can be inferred that the Langmuir isotherm best describes the equilibrium results. Thermodynamic investigation showed the process of Bisphenol-A uptake to be spontaneous and endothermic with entropy change (∆So) values of 0.033 and 0.039 kJ/mol for ACWS and MACWS, respectively. The data obtained from the kinetics, isotherm and equilibrium studies revealed that ACWS and MACWS adsorbents were effective for the treatment of Bisphenol-A.

Research progress of methods for degradation of Bisphenol A

“…Activated carbons prepared from argan nut shell by phosphoric acid also show great potential in BPA adsorption(93%)(Zbair et al 2018). As demonstrated byUzosike et al, they found the adsorption capacity of BPA on activated carbon derived from walnut shell and magnetic activated carbon derived from a walnut shell were 115.85 mg/g and 166.67 mg/g, respectively(Uzosike et al 2022). Likewise, in a study byWang and Zhang et al, magnetic biochar was prepared with excellent reusability (Wang and Zhang 2020).…”

Nano round polycrystalline adsorbent of chicken bones origin for Congo red dye adsorption

“…Effluents discharged from industry into the aquatic environment are among the chief causes of the deterioration of water quality 1 – 4 . Rapid increase in industrialization leading to urbanization had led to the released of huge quantities of wastewater into the environment, causing pollution 5 , 6 . The textile industry as well as its dye-containing wastewaters is the major sources of organic pollutants.…”

“…The textile industry as well as its dye-containing wastewaters is the major sources of organic pollutants. Report has it that up to 25% of textile dyes during dyeing process is lost, while about 2–20% is released into the environmental as aqueous effluents 6 , 7 . Discharge of effluents containing dyes into water body is detrimental due to their colours which prevent the flow of oxygen directly into water 3 – 5 .…”

“…Recently, many techniques such as photo-catalytic degradation, filtration, and adsorption have been deployed in remediating dyes from contaminated sites 7 – 11 . Among these techniques, adsorption is popularly considered to be the most appropriate method as a result of its high efficacy and efficiency, very easy to operate, eco-friendly and very cheap to practice 6 , 7 . The commonly used adsorbent in the adsorption process is activated carbon but its application is restricted as a result of its high cost of production and purity particularly to the common man.…”

“…To this end, several materials have been reported for Congo red uptake and some of them are FexCo 3 -xO 4 nanoparticles 6 , soybean curd xerogels 10 , graphene oxide 11 , rice husk 12 , coffee waste 13 , tunics of the corm of the saffron 14 , cadmium(II) metal–organic frameworks 15 , magnesium aluminium layered double hydroxide 16 , guava leaf-based activated carbon 17 , pine bark 18 , and industrial waste 19 have been developed. Attallah et al 20 used metal hydroxide sludge (MHS) obtained from hot dipping galvanizing plant as adsorbent for removal of CR, Maximum uptake capacity of 40 mg g −1 was attained at solution pH of 6.0, Kumar et al 21 studied the use of starch/AlOOH/FeS 2 nanocomposite as excellent adsorbent for the removal of CR from an aqueous solution.…”