Removal of Ni(II) from aqueous solutions using activated carbon with manganese formate hydrate in-situ modification

Adsorption of Hg(II) in an Aqueous Solution by Activated Carbon Prepared from Rice Husk Using KOH Activation

“…To determine the possible adsorption mechanism more accurately, the C 1s, O 1s, and Hg 4f spectra were further measured after adsorption of mercury ions. The C 1s spectrum of RHAC after adsorption consisted of three fitting peaks, including C–C, C–O, and CO, centered on the binding energies of 284.2, 285.6, and 288.6 eV, respectively, in Figure d . Moreover, the O 1s spectrum of RHAC after adsorption (Figure e) was also composed of three fitting peaks of CO, H–O, and C–O at 530.2, 531.9, and 533.3 eV, respectively .…”

“…The C 1s spectrum of RHAC after adsorption consisted of three fitting peaks, including C−C, C−O, and CO, centered on the binding energies of 284.2, 285.6, and 288.6 eV, respectively, in Figure 2d. 50 Moreover, the O 1s spectrum of RHAC after adsorption (Figure 2e) was also composed of three fitting peaks of CO, 51 It could be found that C and O had a certain chemical shift after the adsorption of mercury ions, indicating that they were all involved in the adsorption process. Two peaks at 100.8 and 104.8 eV are shown in Figure 2f, which may be attributed to the presence of Hg 4f 7/2 and 4f 5/2 .…”

Evaluation of Removal Efficiency of Ni(II) and 2,4-DCP Using in Situ Nitrogen-Doped Biochar Modified with Aquatic Animal Waste

“…Ni­(II) can potentially exist as the species of Ni 2+ (pH < 8), Ni­(OH) + , Ni­(OH) 2 0 , Ni­(OH) 3 – , and Ni­(OH) 4 2– , depending on the pH value …”

“…Ni(II) can potentially exist as the species of Ni 2+ (pH < 8), Ni(OH) + , Ni(OH) 2 0 , Ni(OH) 3 − , and Ni(OH) 4 2− , depending on the pH value. 35 The solution pH is one of the most important parameters influencing the adsorption process, as pH not only affects the adsorbent surface charge, functionalities, and adsorption site but also the ionization degree and the existing form of pollutants. When the pH value of the solution was lower than pK a , most of the adsorption sites on the surface of BCs were protonated and exhibited positive charges.…”

Performance and modeling of Ni(II) adsorption from low concentrated wastewater on carbon microspheres prepared from tangerine peels by FeCl3-assisted hydrothermal carbonization

“…The concentration of nickel may range from 0.5 mg L − 1 to 192 mg L − 1 in wastewater effluents [53]. Adsorption on several carbon-based adsorbents [80,95,96] has resulted in efficient processes for the removal of Ni. However, many studies report high uptake capacities, since the removal of Ni from waste waters is normally studied considering high loads of the heavy metal (> 50 mg L − 1 ) [24,53,59].…”