Investigation of the Adsorption Process of Chromium (VI) Ions from Petrochemical Wastewater Using Nanomagnetic Carbon Materials

Abstract

Magnetic mesoporous carbon (MMC) and magnetic activated carbon (MAC) are good functionalized carbon materials to use when applying environmental techniques. In this work, a series of efficient magnetic composite adsorbents containing Fe3O4 and carbon were prepared successfully and used for the adsorption of Cr(VI) ions in petrochemical wastewater. The morphology and structure of these magnetic adsorbents were characterized with FTIR, TG, XRD, VSM, BET, and SEM technologies. The effect of different factors, such as pH, adsorption time, initial Cr(VI) ions’ concentration, Fe3O4 loading, and adsorption time, on the adsorption behavior were discussed. The results showed that the 8%Fe3O4@MMC adsorbent exhibited a high removal rate, reutilization, and large adsorption capacity. The corresponding adsorption capacity and removal rate could reach 132.80 mg·g−1 and 99.60% when the pH value, adsorption time, and initial Cr(VI) ions’ concentration were 2, 180 min, and 80 mg·L−1 at 298 K. Four kinds of adsorption isotherm models were used for fitting the experimental data by the 8%Fe3O4@MMC adsorbent at different temperatures in detail, and a kinetic model and thermodynamic analysis also were performed carefully. The reutilization performance was investigated, and the Fe3O4@MMC adsorbent exhibited greater advantage in the adsorption of Cr(VI) ions. These good performances can be attributed to a unique uniform pore structure, different crystalline phases of Fe3O4 particles, and adsorption potential rule. Hence, the 8%Fe3O4@MMC adsorbent can be used in industrial petrochemical wastewater treatment.

Yeast—As Bioremediator of Silver-Containing Synthetic Effluents

“…Increasing of the silver ion concentration in experimental solutions from 10 to 100 mg/L resulted in the increase of S. cerevisiae biomass sorption capacity from 1.3 to 10 mg/g in the Ag(I) system, from 1.1 to 9.5 mg/g in the Ag(I)/Cu(II) system, and from 0.94 to 9.3 mg/g in the Ag(I)/Cu(II)/Ni(II)/Zn(II) system ( Figure 8 ). At low metal ion concentrations in solution, their high sorption is explained by the large number of active sites on the surface of the adsorbent, while at high metal concentrations the efficiency of sorption decrease is due to occupation of binding sites [ 25 ]. However, as it can be seen from the experimental data presented in Figure 8 , S. cerevisiae biomass maintained high sorption capacity toward silver ions even at high metal ion concentrations in solution.…”

“…Biosorption is based on physico-chemical interactions between the metal ion and the functional groups present on the cell surface [ 10 ]. Many studies in the literature suggest the use of algae, bacteria, filamentous fungi, and yeast as biosorbents for metal ion removal from wastewater and batch systems [ 16 , 18 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ].…”

Adsorption of Cr(Ⅵ) polluted water by Fe3O4@SiO2-APTMS nanocomposites prepared in the presence of ultrasonic irradiation for sustainable water resources utilization

“…There was competitive adsorption with Cr 2 O 7 2- , which would reduce the adsorption amount of Cr(Ⅵ) by Fe 3 O 4 @SiO 2 -APTMS. Similarly, when the pH value decreased, the —NH 2 /—SiO 3 2 - that APTMS brings to the solution became neutral or positive ions, which reduced the competitive adsorption of anions and enhanced the adsorption capacity [47] . From the above, it could be seen that the adsorption of Cr(Ⅵ) by Fe 3 O 4 @SiO 2 -APTMS was mainly electrostatic adsorption, and the adsorption effect was better when the initial pH value was 1.…”

Removal of Cr(VI) from Wastewater Using Acrylonitrile Grafted Cellulose Extracted from Sugarcane Bagasse

“…Cr(VI) solutions of 100, 200, 300 and 400 ppm were taken in different flasks containing GSB and the adsorption was checked from 10 min to 180 min. The value of q max at specific time (qt) and equilibrium time (q e ), and K 2 (gmg −1 min −1 ) were calculated (t/q t ) vs. t plot [64].…”