Simultaneous removal of Cd(II) and Sb(V) by Fe–Mn binary oxide: Positive effects of Cd(II) on Sb(V) adsorption

Abstract

h i g h l i g h t s• Fe-Mn binary oxide achieves the simultaneous removal of Cd(II) and Sb(V).• Cd(II) at above 0.25 mmol/L improves Sb(V) adsorption onto FMBO.• Cd(II) improves more significant Sb(V) adsorption than Ca 2+ and Mn 2+ .• Sb(V) adsorption decreases whereas Cd(II) adsorption increases with elevated pH.• The increased -potential and The coexistence of cadmium ion (Cd(II)) and antimonate (Sb(V)) creates the need for their simultaneous removal. This study aims to investigate the effects of positively-charged Cd(II) on the removal of negative Sb(V) ions by Fe-Mn binary oxide (FMBO) and associated mechanisms. The maximum Sb(V) adsorption density (Q max,Sb(V) ) increased from 1.02 to 1.32 and 2.01 mmol/g in the presence of Cd(II) at 0.25 and 0.50 mmol/L. Cd 2+ exhibited a more significant positive effect than both calcium ion (Ca 2+ ) and manganese ion (Mn 2+ ). Cd 2+ showed higher affinity towards FMBO and increased its -potential more significantly compared to Ca 2+ and Mn 2+ . The simultaneous adsorption of Sb(V) and Cd(II) onto FMBO can be achieved over a wide initial pH (pH i ) range from 2 to 9, and Q Sb(V) decreases whereas Q Cd(II) increases with elevated pH i . Their combined values, as expressed by Q Sb(V)+Cd(II) , amount to about 2 mmol/g and vary slightly in the pH i range 4-9. FTIR and XPS spectra indicate the significant synergistic effect of Cd(II) on Sb(V) adsorption onto FMBO, and that little chemical valence transformation occurs. These results may be valuable for the treatment of wastewater with coexisting heavy metals such as Cd(II) and Sb(V).

An Effective Method to Remove Antimony in Water by Using Iron-Based Coagulants

“…Peaks near 646 cm −1 were assigned to the Fe-OH bonds of precipitates, and the small shift of those bands was attributed to the adsorption of Sb(III) and Sb(V) [33]. The small peaks at 590 and 487 cm −1 of HFO-Sb(V), which were observed for the precipitates produced by coagulation of Sb(V) with PFS and FC, were due to the symmetric stretching and bending vibrations of Sb(V)-O bonds, respectively [32]. In addition, the Sb(V)-O bonds did not appear in the spectrum of precipitates produced by the coagulation of Sb(III), which indicates that no oxidation of Sb(III) appeared on the surface of iron hydrolytic precipitates.…”

“…The spectral bands that appeared at around 3509 and 1641 cm −1 were attributed to the stretching and bending vibrations of -OH groups, respectively, for the adsorption of water on the surface of precipitates [31]. Peaks at 1402 cm −1 were ascribed to the bending vibrations of -OH groups connected to Sb and iron [32]. Peaks near 646 cm −1 were assigned to the Fe-OH bonds of precipitates, and the small shift of those bands was attributed to the adsorption of Sb(III) and Sb(V) [33].…”

“Nanotraps” in porous electrospun fibers for effective removal of lead(ii) in water

“…[4][5][6][7][8] Precisely, adsorption is considered to be the most effectual method owing to its low cost, good performance, and troublefree operation, and its ability to use a variety of materials as an adsorbent. [9][10][11][12][13] Although nanoparticles play an active role in removing these metal ions, their practical applicability in waste water treatment is limited due to the need for additional separation procedures to recycle them from water. [14][15][16][17] In order to evade these issues, supported matrices have been introduced, due to which electrospun bers have emerged as a successful family of sorbents for removing heavy metal ions in the recent past.…”

A microscopic and spectroscopic study of rapid antimonite sequestration by a poorly crystalline phyllomanganate: differences from passivated arsenite oxidation

“…As shown in Fig. 4a, several of the typical absorption bands for pristine d-MnO 2 that were observed in the absorption band at 1624 cm À1 were ascribed to the hydroxyl (-OH) groups of the physically adsorbed water molecules, 46 and two broad features at 520 and 460 cm À1 were assigned to the Mn-O lattice vibration of the Mn oxides. 47 The changes in the bond positions of d-MnO 2 in the FTIR spectra were insignicant during its reaction with various concentrations of As(III) (Fig.…”