Simultaneous adsorption of As(III) and Cd(II) by ferrihydrite-modified biochar in aqueous solution and their mutual effects

Abstract

A simply synthetic ferrihydrite-modified biochar (Fh@BC) was applied to simultaneously remove As(III) and Cd(II) from the aqueous solution, and then to explore the mutual effects between As(III) and Cd(II) and the corresponding mechanisms. The Langmuir maximum adsorption capacities of As(III) and Cd(II) in the single adsorbate solution were 18.38 and 18.18 mg g−1, respectively. It demonstrated that Fh@BC was a potential absorbent material for simultaneous removal of As(III) and Cd(II) in aqueous solution. According to the XRF, SEM–EDS, FTIR, XRD, and XPS analysis, the mechanisms of simultaneous removal of As(III) and Cd(II) by Fh@BC could be attributable to the cation exchange, complexation with R-OH and Fe-OH, and oxidation. Moreover, the mutual effect experiment indicated that Cd(II) and As(III) adsorption on Fh@BC in the binary solution exhibited competition, facilitation and synergy, depending on their ratios and added sequences. The mechanisms of facilitation and synergy between Cd(II) and As(III) might include the electrostatic interaction and the formation of both type A or type B ternary surface complexes on the Fh@BC.

Enhanced Adsorption of Cd on Iron–Organic Associations Formed by Laccase-Mediated Modification: Implications for the Immobilization of Cadmium in Paddy Soil

“…The high-resolution spectra of Fe2p3 showed that Fe had three sets of double peaks in all four minerals, and no new peaks appeared or changes in binding energy occurred before and after the adsorption of Cd, demonstrating that the morphology of the adsorbent did not change during the adsorption process. The proportion of the Fe2p3 peak area in FH and Fe-OM did not change significantly before and after Cd adsorption, suggesting that the adsorption of Cd by these four adsorbents does not depend on Fe, which is consistent with the conclusion obtained by Tian et al [ 74 ] in studying the adsorption of Cd on the complex of pyrite and biochar.…”

Elevated Adsorption of Lead and Arsenic over Silver Nanoparticles Deposited on Poly(amidoamine) Grafted Carbon Nanotubes

“…In this context, several adsorbents have been developed and tested for their efficiency in removing different pollutants [ 6 , 12 , 29 ]. The dynamic adsorbents are based on activated carbon [ 30 ], activated alumina [ 31 ], inorganic minerals [ 32 ], biomass adsorbents [ 33 , 34 , 35 , 36 , 37 , 38 ], polymer [ 39 , 40 , 41 ], carbon nanotubes (CNTs) [ 42 , 43 , 44 ] graphene oxide [ 45 , 46 ], metal-organic frameworks [ 47 ], microplastics [ 48 ] and more. Among these, CNTs based adsorbents are particularly interesting because their unique physical and chemical properties are relevantly suitable for adsorption [ 42 , 43 , 44 ].…”

Removal of heavy metals from binary and multicomponent adsorption systems using various adsorbents – a systematic review

“…Ferrihydrite-modified biochar (Fh@BC) was utilized for the simultaneous decontamination of As( iii ) and Cd( ii ) ions from binary-metal aqueous systems as well as determine the mechanism of the sorption process. 95 The Langmuir model best correlated with equilibrium sorption data with optimum sorption rates of 18.38 and 18.18 mg g −1 for As( iii ) and Cd( ii ), respectively. The mechanisms of the simultaneous elimination of As( iii ) and Cd( ii ) by Fh@BC were due to cation exchange, complexation, and oxidation.…”