Removal of Cr(VI) from aqueous solution by rice husk derived magnetic sorbents

Fan, Yuan; Yang, Ruijin; Lei, Zhimin; Liu, Na; Lv, Jia-Liang; Zhai, Shangru; Zhai, Bin; Wang, Lei

doi:10.1007/s11814-015-0248-y

Cited by 26 publications

(31 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…12 Up to now, a variety of adsorbents, such as graphene, 13 biomass, 14 activated carbon, 3 mineral, 15,16 etc., have been developed to dispose Cr(VI). Amongst them, using low-cost biomass as adsorbent to remove Cr(VI) has received great attention, such as rice husk, 17 cellulose, 18 lignin, 19 sodium alginate 20 and chitosan. 21 Among these materials, cellulose has received increasing attentions owing to its properties which contain inexpensive, abundant, non-toxic, low weight, renewable and biodegradable.…”

Section: Introductionmentioning

confidence: 99%

Polyethylenimine-functionalized cellulose aerogel beads for efficient dynamic removal of chromium(vi) from aqueous solution

et al. 2017

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

Polyethylenimine-functionalized cellulose aerogel beads for efficient dynamic removal of chromium(vi) from aqueous solution

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The diffraction at 44.7° was attributed to the (100) plane of cubic Fe. 19 These iron oxides may play a key role in the Cr(VI) adsorption. The observed minerals in XRD, such as quartz, calcite, and magnetite, were in agreement with the presence of Si–O–Si, C–O, and Fe–O in the corresponding FTIR spectra, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, it may be suggested that the high-efficiency removal of Cr(VI) was possibly completed in the following steps. 10 , 19 , 28 In the first step, the pre-modified biochars presented a positive nature due to the abundance of hydroxyl and carboxyl acid groups on surface; then, negatively charged Cr(VI) was adsorbed onto the Fe pre-modified surface via electrostatic attraction, especially 1BC-Fe@B500 and 5 BC-Fe@B500. Second, the Cr (VI) anions attached to the surface were transformed to Cr(III) due to abundant electron donors (Fe–O observed from FTIR analysis and iron oxides and cubic iron observed in XRD and XPS patterns) on the surface of magnetic biochars.…”

Section: Resultsmentioning

confidence: 99%

“… 3 , 6 Then, the mixture was shaken at 150 rpm for 12 h. After adsorption, the mixture was filtered and the concentrations of Cr(VI) in the filtrate were measured according to the PRC National Standard (GB/T 7467–1987) using an ultraviolet–visible light spectrophotometer (UV756, China) at a wavelength of 540 nm with a colorimetric method using 1,5-diphenylcarbazide. 2 , 19 , 31 The equations of adsorption capacity q e (mg/g) and the removal efficiency (% R ) are shown in Section S-III of the Supporting Information .…”

Section: Methodsmentioning

confidence: 99%

“… 11 The pH values in solutions play a key role in Cr(VI) removal by influencing the existing form of chromium. 19 The reason may be that electrostatic interactions are prominent for the removal of anionic metals at lower pH, whereas a higher pH is suitable for removal of cationic metals by electrostatic interactions. 5 However, the wide range of pH values in Fe-modified biochars can be due to (1) the different methods for synthesis of Fe-modified biochar, (2) the various raw materials used for Fe-modified biochar, and (3) the different physicochemical properties of Fe-modified biochar.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Influence of Synthesis Methods on the High-Efficiency Removal of Cr(VI) from Aqueous Solution by Fe-Modified Magnetic Biochars

Jian

Feng

et al. 2020

ACS Omega

View full text Add to dashboard Cite

Fe-modified biochars have been widely used in removal of Cr(VI) from water due to the resulting modified surface functional groups and magnetization property. However, few studies have synthetically investigated modification methods and synthesis parameters on the improvement of the removal efficiency of Cr(VI) by Fe-modified biochars. Herein, 10 types of corn straw-based magnetic biochars were produced using pre-modification and post-modification methods with various modifier ratios, and the highest heating temperature (HHT). Cr(VI) removal results suggest that the removal efficiency of pre-modified biochars ranged from 50.7 to 98.6%, which was much higher than that of post-modified (6.6–21.6%) and unmodified biochars (0.4–7.6%). The effect of synthesis methods on Cr(VI) adsorption was in the following order: Fe-modification method > modifier ratio > HHT. The adsorption kinetics and isotherm results of three types of pre-modified biochars were well fitted with the pseudo-second-order model (R 2 > 0.99) and the Langmuir adsorption model (R 2 > 0.99), respectively, indicating the surface homogeneity of the pre-modified biochars and unilayer chemisorptions of Cr(VI). Characterization results show that iron oxides or zerovalent iron particles were successfully deposited onto the surface of biochars and magnetism was introduced. A good Pearson correlation (r = −0.9694) between the removal efficiency and pH value in modified biochar suggests that the lower pH value may offer more positive charges and promote electrostatic attraction. Therefore, the dominant mechanism for enhanced Cr(VI) adsorption on pre-modified biochar was electrostatic attraction, resulting from its distinguished acidity nature. Our findings provide new insights into the high-efficiency removal of Cr(VI) onto Fe-modified magnetic biochars and will benefit future design of more efficient magnetic biochars.

show abstract

Synergistic and inhibitory reduction of Cr(VI) by montmorillonite, citric acid, and Mn(II)

2017

View full text Add to dashboard Cite

Removal of Cr(VI) from aqueous solution by rice husk derived magnetic sorbents

Cited by 26 publications

References 57 publications

Polyethylenimine-functionalized cellulose aerogel beads for efficient dynamic removal of chromium(vi) from aqueous solution

Polyethylenimine-functionalized cellulose aerogel beads for efficient dynamic removal of chromium(vi) from aqueous solution

Influence of Synthesis Methods on the High-Efficiency Removal of Cr(VI) from Aqueous Solution by Fe-Modified Magnetic Biochars

Synergistic and inhibitory reduction of Cr(VI) by montmorillonite, citric acid, and Mn(II)

Contact Info

Product

Resources

About