Bio-Stimulated Adsorption of Cr(VI) from Aqueous Solution by Groundnut Shell Activated Carbon@Al Embedded Material

Abstract

In this study, a low-cost bioadsorbent aluminum metal blended with groundnut shell activated carbon material (Al-GNSC) was used for Cr(VI) adsorption from aqueous solutions. Al-GNSC was prepared and characterized using Fourier transform infrared spectrometer (FT-IR), scanning electron microscopic (SEM) and X-ray diffraction (XRD) to determine its surface morphology. Batch studies were performed and the optimum conditions for maximum Cr(VI) removal (of 94.2%) were found at pH 4.0, initial concentration 100 mg/L, adsorbent dosage 8 g/L of Cr(VI) solution, and time of contact 50 min. Moreover, the Langmuir isotherm model (maximum adsorption capacity of 13.458 mg/g) was the best fit and favored the mono-layered Cr(VI) adsorption. The kinetic studies reveal that the pseudo-second-order model was the best fit and favored chemisorption as the rate-limiting step. The desorption study revealed that Cr(VI) leached with sodium hydroxide solution acted as a regenerating agent. It is proved that Al-GNSC removes the Cr(VI) content in groundwater samples. The methodology developed using the Al-GNSC adsorbent as an alternative for the adsorption of Cr(VI) ions is remarkably successful in this study.

Removal of CrO42–, a Nonradioactive Surrogate of 99TcO4–, Using LDH–Mo3S13 Nanosheets

“…The experimentally obtained Cr 6+ sorption isotherm data are fitted with the Langmuir model which yielded R 2 ∼ 0.98 (Figure D). The Langmuir constant, b , was obtained as 0.005(2) L/mg and is comparable to other Cr 6+ adsorbents …”

“…The Langmuir constant, b, was obtained as 0.005(2) L/ mg and is comparable to other Cr 6+ adsorbents. 53 To determine the effectiveness of LDH−Mo 3 S 13 for Cr 6+ removal in the presence of highly competitive ions in purified and naturally contaminated water, we investigated Cr 6+ removal efficiency from tap water and Mississippi River water (collected from Vidalia, Louisiana) by spiking them with 1000 ppb of Cr 6+ (CrO 4 2− ) (Figures 2E and 2F, Table S7). This study showed that despite the presence of numerous ions, such as Ca 2+ , Mg 2+ , Na + , K + , HCO 3 − , SO 4 2− , and Cl − , and other organic or inorganic constituents, LDH−Mo 3 S 13 can remove ≥99.6% of Cr 6+ .…”

Facilitated Adsorption of Mercury(II) and Chromium(VI) Ions over Functionalized Carbon Nanotubes

“…In general, the Hg(II) and Cr(VI) adsorption over CNTs–PLA–Pd occurred through monolayer molecular covering and chemisorption together [ 74 ]. The maximum adsorption capacity (q m ) of CNTs–PLA–Pd estimated for Hg(II) and Cr(VI) adsorption was compared to the reported values for different adsorbents and presented in Table 3 and Table 4 , respectively [ 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 ]. The stability of CNTs–PLA–Pd was estimated by recovering and applying it in three subsequent cycles of adsorption of Hg(II).…”

Removal of Toxic Hexavalent Chromium from Wastewater by Activated Carbon Generated from Liming Pelt Trimming with Tannin

“…Where, Ci and Cf (mg/L) are the initial and the equilibrium concentration, V(L) is volume of the used solution, and the amount of dry adsorbent used is m (g) (Vaddi et al 2022).…”