Advanced kinetic model of the Cr(VI) removal by biomaterials at various pHs and temperatures

Park, Donghee; Yun, Yeoung‐Sang; Lee, Hae Woo; Park, Jong

doi:10.1016/j.biortech.2007.02.025

Cited by 92 publications

(39 citation statements)

References 26 publications

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“…Inside the pores, there are many kinds of phenol, hydroxyl, and amino groups, which serve as the active adsorption sites for the solid phase microextractant of dichromate [7]. The microextraction kinetics can be obtained from the potentialtime curve in the time interval of 300-400 s (curve 1 in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…[7,21]. These reactions cannot be extracted effectively, and are responsible for the decrease of open circuit potential in this pH region.…”

Section: δE / V (Vssce)mentioning

confidence: 97%

“…Recently, the transformation from Cr(VI) to Cr(III) with low-cost natural biomaterials has been investigated [3][4][5]. Among the many natural biomaterials, pine needles were reported as a powerful natural biomaterial with microporous structure of resin ducts containing reduction groups, such as phenol, hydroxyl, amino, and terpenoid [6,7]. The adsorption of Cr(VI) and transformation from Cr(VI) to Cr(III) by pine needles has been reported as several hundreds times higher than other natural biomaterials, so it was considered as a good biomaterial in the effective removal of Cr(VI) pollutants in the aqueous solutions [8].…”

Section: Introductionmentioning

confidence: 99%

“…Even though, in our studies, the natural pine needle powder has shown two functions including adsorption and transformation of Cr(VI)-Cr(III) [6,7] only the adsorption of the Cr(VI) function can be found and monitored in the carbon paste electrode case. The second function of the transformation from Cr(VI) to Cr(III) can be monitored with spectrophotometry.…”

Section: Introductionmentioning

confidence: 99%

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Solid phase microextraction and determination of dichromate in aqueous solution based on pine needle powder-modified carbon paste electrode by potentiometry

et al. 2013

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Pine needle is a low-cost natural biopolymer, and Cr 2 O 7 2-is a poisonous anions in the environment. In the present paper, pine needle powder was used as a solid phase microextractant in the modification of carbon paste electrode for extraction and determination of Cr 2 O 7 2-anions. The extraction process was monitored by an open circuit potential method, and an apparent first-order rate constant of 0.06474 s -1 was obtained from a Richard model. The extraction isothermal curve follows a logarithm adsorption model with a adsorption equilibrium constant of 5.95. Under the optimal conditions, the concentration of K 2 Cr 2 O 7 in river water of Shenyang Normal University campus was determined by the potentiometric method in the concentration range of 1.0 9 10 -6 -1.0 9 10 -2 M with a detection limit of 1.0 9 10 -7 M (the signal to noise Ratio was 3:1), relative standard deviation of 3.44 %, and standard addition recovery in the range of 94.70-103.5 %. The large amounts of common existing ions such as Cr 3? , Cu 2? , and SO 4 2-showed no interference with the molar ratio up to 100:1, but CrO 4 2-, Pb 2? ions showed a great interference in the detection of Cr 2 O 7 2-due to the transformation from CrO 4 2-to Cr 2 O 7 2-and precipitations of PbCrO 4 and PbCr 2 O 7 , respectively.

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Section: Resultsmentioning

confidence: 99%

“…[7,21]. These reactions cannot be extracted effectively, and are responsible for the decrease of open circuit potential in this pH region.…”

Section: δE / V (Vssce)mentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Solid phase microextraction and determination of dichromate in aqueous solution based on pine needle powder-modified carbon paste electrode by potentiometry

et al. 2013

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“…Studies on Cr(VI) removal mechanisms using various biosorbents in batch systems under acidic conditions have been conducted (Reddad et al, 2003;Park et al, 2005a;Park et al, 2005b;Xu et al, 2007;Park et al, 2008;Wang et al, 2009). The mechanisms proposed by these researchers were similar and generally involve the adsorption of the anionic Cr(VI) on protonated adsorption sites, followed by the reduction to Cr(III) by electrons donated by adjacent functional groups.…”

Section: Introductionmentioning

confidence: 99%

Removal and transformation of hexavalent chromium in sequencing batch reactor

Loo¹,

Leong²,

Lim³

2012

WSA

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The objectives of this study are to evaluate the efficiency of removal of hexavalent chromium (Cr(VI)) in a sequencing batch reactor (SBR) and to ascertain the fate of Cr(VI) in the treatment process. An SBR was operated with the FILL, REACT, SETTLE, DRAW and IDLE periods in the time ratio of 2:12:2:1.5:6.5 for a cycle time of 24 h. The study was divided into 5 phases with the addition of 0.5, 2.0, 3.0 and 5.0 mg/ℓ of Cr(VI) in Phases II, III, IV and V for a duration of 46, 75, 43 and 16 operational cycles, respectively. The Cr(VI) removal efficiencies for SBR were found to be 79.8, 88.4 and 99.8% in Phases III, IV and V, respectively. The results revealed that Cr(VI) removal efficiency improved with acclimated activated sludge. Determination of Cr in the suspended sludge showed that around 95% of the Cr species were Cr(III). Determination of Cr concentration profiles during the FILL and REACT periods showed that the predominant species was Cr(III) as Cr(VI) was bio-reduced. The proposed Cr(VI) removal mechanism involves bioreduction to Cr(III) which was subsequently precipitated and adsorbed by activated sludge. Precipitation rather than sorption is envisaged to be the main path of removal of Cr(III) from the solution.

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Amino‐Functionalized Multilayer Core–Shell Mesoporous Organosilica Nanospheres for Cr(VI) Removal

Lai

Sun

Hou

et al. 2018

Adv Materials Inter

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Developing low-cost and highly efficient adsorbents for the removal of toxic heavy metal ions has been the subject of intensive research with the increasingly stringent water pollution control standards. In this paper, three types of amino-functionalized multi-layer core-shell mesoporous organosilica nanospheres (MCMONs) have been synthesized using an indirect co-condensation method for Cr(VI) removal applications. Results show that amino groups have been successfully immobilized on the nanospheres and these amino-functionalized MCMONs exhibit unique organic-inorganic multi-layer core-shell structures . When used as adsorbent for Cr(VI) removal, our N-(3-trimethoxysilylpropyl)diethylenetriamine functionalized MCMONs exhibits an maximum adsorption capacity of 279.92 mg/g at initial Cr(VI) concentration of 150 mg/L. This is about 20% greater than the highest Cr(VI) adsorption capacity previously reported for other core-shell silica-based adsorbents, demonstrating the great potential of our MCMONs in Cr(VI) removal applications.

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Advanced kinetic model of the Cr(VI) removal by biomaterials at various pHs and temperatures

Cited by 92 publications

References 26 publications

Solid phase microextraction and determination of dichromate in aqueous solution based on pine needle powder-modified carbon paste electrode by potentiometry

Solid phase microextraction and determination of dichromate in aqueous solution based on pine needle powder-modified carbon paste electrode by potentiometry

Removal and transformation of hexavalent chromium in sequencing batch reactor

Amino‐Functionalized Multilayer Core–Shell Mesoporous Organosilica Nanospheres for Cr(VI) Removal

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