COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Wei Zhang,Xinyue Ma,Rui Li,Wenzheng Yang,Qiao Li,Xiuyun Sun,Jiansheng Li,Jinyou Shen
Purification of various types of industrial wastewater containing chelated heavy metals (CHMs) remains a challenging task due to the easy dissolution, poor biodegradation and extremely high stability over a wide pH range. Compared with the common CHMs, the attention of Cr(III) complexes is greatly insufficient. Especially, Cr(III) of the wastewater is easily reoxidized and converted into Cr(VI) with high biotoxicity during the transferring process, so the treatment of Cr(III) complexes needs to be treated more strictly. Obviously, compared with previous advanced oxidation and replacement-coprecipitation technologies, adsorption method could directly remove Cr(III) complexes in one step, thus avoiding the accumulation of secondary toxic Cr(VI). Considering that ferrihydrite (Fh) materials are widely distributed on the nature, excellent adsorption performance, low cost, and environmentally friendly, this paper proposes a novel strategy that uses the common Fh as an efficient adsorbent to realize one-step elimination of typical EDTA-Cr(III) complexes without introducing secondary pollution. Batch experiment results illustrated that more than 93% of EDTA-Cr(III) was removed at pH = 3 or 6 (a final concentration of <1 mg/L EDTA-Cr(III) was detected in the residual solution within one hour). In particular, Fh retained good performance for the removal of EDTA-Cr(III) after desorption reactions in 2 g/L Na 2 SO 4 solution. A series of experiments and characterization results suggested that EDTA-Cr(III) was adsorbed on Fh materials mainly through electrostatic interactions and surface complexation. In general, this study also demonstrated Fh for the outstanding remediation of various Cr(III)-organic complexes from multicomponent environment.
研究领域:
环境科学
·
化学工程
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DOI
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2024
·
IF 2.2
Hao Zhang,Jiahong Wang,Peiling Han,Zhi Hu
Industrial wastewater often contains potentially toxic metals and it’s chelates, posing serious threats to human health and aquatic ecosystems, and adsorption is frequently used for the minimization of potentially toxic metals from water. In this study, citric acid modified MOF-808 (MOF-808-CA) was prepared by using citric acid to modify MOF-808 for the removal of Cr(III) and Cr(III)-EDTA from wastewater. MOF-808-CA with the BET surface area of 653.59 m2 g−1 and the pore volumes of 0.467 cm3 g−1 was successfully synthesized. The adsorption of Cr(III) and Cr(III)-EDTA by MOF-808-CA was 40.46 and 17.03 mg g−1 at pH 4.0 and 25°C, respectively. The adsorption isotherms and adsorption kinetics of Cr(III) and Cr(III)-EDTA were summarized using Langmuir-Freundlich isothermal adsorption model and the pseudo-second-order model. Even in high salinity wastewater (35,000 mg L−1), MOF-808-CA displayed a strong affinity for Cr(III) and Cr(III)-EDTA. The site energy (E*) values reduced with the increasing of adsorption capacities, and Cr(III) and Cr(III)-EDTA firstly dominated the high-energy adsorption sites before low-energy adsorption sites. The average site energies for the adsorption of Cr(III) and Cr(III)-EDTA by MOF-808-CA were 26.7 and 24 kJ mol−1, respectively, and the differences in the average site energies further illustrated the essential differences in their adsorption mechanisms. The adsorption by electrostatic adsorption and surface complexation were the main adsorption mechanisms for Cr(III) on MOF-808-CA, whereas hydrogen bonding and complexation were the main adsorption mechanisms for Cr(III)-EDTA on MOF-808-CA. The results showed that the MOF-808-CA adsorbent has a great potential for the removal of both Cr(III) and Cr(III)-EDTA from aqueous solutions.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2020
·
IF 3.333
Jiahong Wang,Min Mao,Saleem Atif,Yao Chen
The presence of widely used chelating agents such as ethylenediaminetetraacetic acid (EDTA) in aqueous solution increases the difficulty of heavy metal removal by the formation of heavy metal chelates. In this study, diethylenetriaminepentaacetic acid (DTPA)-chitosan functionalized magnetic silica (Fe 3 O 4 @SiO 2 /Cs-DTPA) was developed for the removal of Cr(III) and Cr(III)-EDTA. The obtained results from characterization confirmed that Fe 3 O 4 @SiO 2 /Cs-DTPA with the core-shell structure and superparamagnetic properties was synthesized. The maximum theoretical adsorption capacity of Cr(III) and Cr(III)-EDTA chelates on the adsorbents were 39.27 and 22.24 mg/g at 25 °C and pH 4.0, respectively. Adsorption equilibrium of Cr(III) and Cr(III)-EDTA on Fe 3 O 4 @SiO 2 /Cs-DTPA was achieved within 15 min, and the adsorption data fit the pseudo second-order model. The co-existing complex agents (EDTA) and cations (Na + , Ca 2+ , and Mg 2+ ) in the aqueous solution reduced Cr(III) adsorption by the competition with Cr(III) and Cr(III)-EDTA chelate for active groups of the adsorbent. The affinity of the Fe 3 O 4 @SiO 2 /Cs-DTPA for Cr(III) and Cr(III)-EDTA was excellent even at high salt and organic chelates concentration. The Cr(III) adsorption was attributed to surface complexation between Cr(III) and DTPA moieties of the adsorbent, while Cr(III)-EDTA as a whole was adsorbed on the adsorbent by the complexation and electrostatic interaction . Cr(III) saturated Fe 3 O 4 @SiO 2 /Cs-DTPA can be readily regenerated in acid solution and Cr(III) or Cr(III)-EDTA adsorption of regenerated adsorbent exhibits no obvious reduce.
研究领域:
环境科学
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材料科学
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化学工程
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DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Linqing Liang,Jiahong Wang,Yanxin Zhang
In this study, H 2 O 2 oxidized magnetic mesoporous carbon hollow microspheres (Fe 3 O 4 @void@C@H 2 O 2 ) with core-shell structure, high magnetic properties and abundant oxygen-containing functional groups was synthesized for removal of Cr(III)-EDTA and Cr(III) in high salinity wastewater. Fe 3 O 4 @void@C@H 2 O 2 was synthesized at optimum conditions of H 2 O 2 concentration of 20%, oxidation temperature of 40 °C and oxidation time of 4 h, and the determined adsorption amount of Cr(III)-EDTA and Cr(III) on the adsorbent was 9.72 and 10.53 mg g −1 at pH 4.0 and 25 °C, respectively. Adsorption behavior of Cr(III)-EDTA could be better described by Langmuir isotherm and Cr(III) adsorption followed Freundlich isotherm. Cr(III)-EDTA and Cr(III) adsorption on the adsorbent followed pseudo-second-order kinetics, and adsorption rate of Cr(III) adsorption on the adsorbent is higher than that of Cr(III)-EDTA. Fe 3 O 4 @void@C@H 2 O 2 showed strong affinity for Cr(III) and Cr(III)-EDTA even in high salinity water. Moreover, Fe 3 O 4 @void@C@H 2 O 2 exhibited the high stability in acid solution and Cr(III) saturated adsorbent can be easily regenerated in 0.1 mol L −1 HCl. Cr(III)-EDTA adsorption was described to the surface complexation between the oxygen-containing groups (such as hydroxyl, carbonyl and carboxyl groups) of the adsorbent and Cr(III) in Cr(III)-EDTA, and the hydrogen bonding between oxygen-containing groups of the adsorbent and EDTA of Cr(III)-EDTA, while Cr(III) adsorption on the adsorbent was surface complexation and ion exchange. The results highlighted that Fe 3 O 4 @void@C@H 2 O 2 have great potentials for adsorptive removal of Cr(III) and it's chelate from the high salinity wastewater.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Cuili Xing,Xinyi Yao,Kaiwei Zheng,Yang Liu,Yuankui Sun,Xiaohong Guan
Efficient removal of recalcitrant Cr(III)-organic complexes is always challenged by slow decomplexation process and the possible accumulation of highly toxic Cr(VI). Herein, a sulfidated zero-valent iron coupled ozonation strategy (S-ZVI/O 3 ) was proposed to achieve efficient decomplexation and simultaneous abatement of Cr(III)-EDTA without Cr(VI) accumulation. Results revealed that S-ZVI could catalyze O 3 to enhance removal of Cr(III)-EDTA and total organic carbon. Moreover, 88.3 % of total Cr was sequestrated by S-ZVI/O 3 and the corresponding kinetic constant was 3.1 times higher than that of ZVI/O 3 . Mechanistically, electron paramagnetic resonance and probing tests verified HO • was the dominant reactive oxidation species for decomplexation of Cr(III)-EDTA in both S-ZVI/O 3 and ZVI/O 3 . More attractively, it was found that structural Fe(II) was the major O 3 activator in S-ZVI/O 3 , whereas dissolved Fe 2+ accounted for O 3 catalyzation in ZVI/O 3 . The X-ray absorption spectroscopy analysis revealed that sulfidation treatment could enhance corrosion of ZVI with the formation of sufficient Fe(II) species. The in-situ formed Fe(II) could not only transform undesired Cr(VI) back to Cr(III) but also co-precipitate with Cr(III) to form solid Fe-Cr hydroxides. Besides Cr(III)-EDTA, S-ZVI/O 3 is also applicable to other EDTA complexed heavy metals. This work would provide a new method for the heavy metal complexes removal from water.
研究领域:
环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2023
·
IF 22.1
Minzi Liao,Shengxi Zhao,Kai Wei,Hongwei Sun,Lizhi Zhang
Cr(III)-organic complexes removal from wastewater is challenging to decompose the complexes without producing toxic Cr(VI). Herein we demonstrated that oxalated zero-valent iron (Ox-ZVI) could one-step decomplex 95.4% of Cr(III)-EDTA with 94.2% removal of total Cr and 60.5% removal of TOC without generating Cr(VI) at pH 6.0. Ox-ZVI with FeC 2 O 4 shell preferred to adsorb and activate O 2 to produce more reactive species than ZVI with iron oxide shell, while the generated 1 O 2 could selectively break the Cr-O and Cr-N bond to precisely decomplex Cr(III)-EDTA without producing Cr(VI). The released Cr(III) was in-situ precipitated on the surface of ZVI in Cr(OH) 3 form. Interestingly, •OH preferred the effective degradation of the released EDTA ligand to the oxidation of the chelated Cr(III) at pH 6.0. This study offers a green and facile method for the Cr(III)-organic complexes treatment, and also sheds light on the importance of reactive species adjustment for the precise pollutant control.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2020
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IF 3.232
Qiulan Li,Dezhi Yang,Yaling Yang
The study presents a spectrofluorimetric method for the determination of Cr(III) based on 2,3-diaminophenazine (DAP) as fluorescent nano sensor. With the peroxidase-mimicking activity of copper-doped carbon dots (Cu-CDs), colorless o -phenylenediamine (OPD) was oxidized to fluorescent DAP in the presence of H 2 O 2 via generation of hydroxyl radicals . The Cr(III) was found to decrease the fluorescent intensity of the Cu-CDs-mediated OPD oxidation system. Cr(VI) species were reduced to Cr(III) by employing 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate) (ABTS) as the reductant, and a novel spectrofluorimetric method for the highly sensitive detection of speciation Cr(VI) and Cr(III) was developed. The Cu-CDs nanozyme was prepared from ethylenediaminetetraacetic acid copper disodium salt (Na 2 [Cu (EDTA)]) by one-step pyrolysis method. Under optimal conditions, the fluorescence intensity of DAP is linearly proportional to the Cr(III) ion concentration in the range of 5 × 10 −6 to 1.5 × 10 −4 mol L −1 and the detection limit is 1.2 × 10 −7 mol L −1 . The method has a good anti-interference performance against some metal ions , such as, Hg 2+ , Co 2+ , Cu 2+ , Mg 2+ , Ba 2+ , K + , Mn 2+ , Ni 2+ , Al 3+ , and Fe 3+ . The proposed method was successfully applied in the determination of Cr(VI) and Cr(III) in water samples.
研究领域:
分析化学
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环境科学
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DOI
PubMed
高影响因子
Processes
·
2024
·Vol. 12
·期 5
·905
·
IF 2.8
Tianji Liu,Huawei Guo,Qing Yu,Yajun Wang,Huan Liu,Yanan Zeng,Yitong Wang,Chunyu Liu,Junguo Li
In this study,Chlorella pyrenoidosawas cultured with different concentrations of Cr(III) and Cr(VI), and the changes in biomass, lipid content, protein content and total sugar content ofChlorella pyrenoidosaunder different culture conditions were detected. The effects of Cr(III) and Cr(VI) on the intracellular antioxidant system and related key enzymes of lipid synthesis were analyzed. The results showed that appropriate Cr(III) and Cr(VI) concentrations could makeChlorella pyrenoidosaregulate the contents of SOD, POD, ASA, CAT and GSH in cells, improve the enzyme activity of ACC and promote lipid synthesis. The aim was to investigate the mechanism of lipid synthesis by analyzing the distribution of Cr(III) and Cr(VI) in algal cells. The lipid content ofChlorella pyrenoidosareached its highest level at 50.43 wt% and 38.00 wt% when both Cr(III) and Cr(VI) concentrations in the culture environment were 0.5 mg/L. These values were 1.37 and 1.03 times higher than the control group, respectively. The addition of appropriate Cr(III) and Cr(VI) concentrations can increase ME enzyme activity and decrease PEPC enzyme activity, shorten the biomass accumulation cycle and prolong the lipid synthesis cycle.
研究领域:
环境科学
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生物化学
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微生物学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Xiao Dan Sun,Zhangxin Duan,Jingjing Song,Hanxing Yang,Kai Yan,Zhenhua Tian,Dangge Gao,Jianzhong Ma
Carcinogen Cr(VI) is reduced efficiently into Cr(III) by a photocatalyst, but the produced Cr(III) is difficult to transfer from the photocatalytic active site. The “two birds with one stone” strategy is proposed to realize the in situ growth of ZnIn2S4 nanoplates on SBA-15 and the creation of separated active sites, in which ZnO loading on the porous SBA-15 nanorod was used as a zinc source. Obtained samples ZnIn2S4/SBA-15 (ZIS/SBA) showed the redshift of the absorption band and better separation of photoinduced carriers than pristine ZnIn2S4, due to its smaller size and S defect. All of the Cr(VI) was reduced to Cr(III) by the ZIS/SBA sample during the photocatalytic process, which was 2 times higher than pristine ZnIn2S4. Moreover, 92.8% of Cr(III) was adsorbed simultaneously during photocatalysis due to the electrostatic interaction from SBA-15. In addition, the ZIS/SBA sample showed good recycling stability after 5 times cycles, providing a new strategy for the in situ growth of ZnIn2S4 on the surface of porous materials and a novel way for the simultaneous removal of Cr(VI) and Cr(III) during photocatalysis.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Technology & Innovation
·
2025
·
IF 7.1
Yonglin Yang,Jiangyong He,Shuaige Shi,Long Yan,Jian Li,Xiaoyong Fan,Bi Chen,Guohui Dong,Hongrui Ma
There is a key issue about formation of highly toxic and easily dissoluble Cr(VI) during heat treatment of Cr-bearing solid waste, resulting in a prominent increase of environmental risk of incineration product. In this study, the effects of CaO and SiO 2 on formation and reduction of Cr(VI) were investigated during heating of Cr-bearing simulated sludge (Cr-SS) and Cr 2 O 3 , exploring Cr(III) oxidation mechanism. The findings indicates that doping CaO significantly promotes Cr(III) oxidation to Cr(VI), and chromium speciation vary with temperature. At 300℃, leaching amount of Cr(VI) in Cr-SS samples increases sharply to 9.3 % of total Cr. In contrast, no Cr(VI) was detected in Cr 2 O 3 samples. Above 300℃, oxidation rates of Cr(III) in different samples of Cr-SS and Cr 2 O 3 exhibit the same trend with temperature increasing. Above 1000℃, new Cr-containing crystalline phases were observed, like CaCr 2 O 4 and Ca 3 (CrO 4 ) 2 . The oxidation rate of Cr(III) is positively connected with the adding amount of CaO. Besides, doping SiO 2 to sludge prominently inhibits Cr(III) oxidation or facilitate Cr(VI) reduction at 600℃-1200℃, which is also confirmed by thermodynamic calculation, attributing to formation of Ca 5 Cr 2 SiO 12 and CaCr 2 O 4 . The number of holes in valence band will be changed through substitution of Cr(III) ions by cations of different valence states, thus facilitate or inhibit Cr(III) oxidation. The ions (III) can inhibit Cr(III) oxidation and promote Cr(VI) reduction. Introducing SiO 2 or Si-enriched materials to chromium-bearing wastes may be a promising alternative to solve the problem of highly toxic Cr(VI) formation during heat treatment.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 6
·3202-3208
·
IF 3.361
Wei-Qi Li,Duan Liu,Ji-Yan Qu,Jian-Hong Luo
In this work, an outstanding nanolayered tin phosphate with 15.0 Å interlayer spacing, Sn (HPO4)2·3H2O (SnP–H+), has been synthesized by conventional hydrothermal method and first used in the adsorptive removal of Cr(III) from aqueous solution. A number of factors such as contact time, initial concentration of Cr(III), temperature, pH, and ionic strength on adsorption were investigated by batch tests. Moreover, the isothermal adsorption characteristics and kinetic model of Cr(III) onto SnP–H+ were studied. The results showed that the adsorption of Cr(III) by SnP–H+ was in accordance with the Langmuir adsorption isotherm model and the pseudo-second-order kinetic model. The adsorption capacity of Cr(III) onto SnP–H+ at temperature 40.0 °C and pH 3.0 could reach 81.1 mg g−1. And the distribution coefficient Kd was 23.0 g L−1. Overall, experiments certified that SnP–H+ was an excellent adsorbent that can effectively remove Cr(III) from aqueous solution.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Linshan Zhang,Guozong Yue,Luming Yang,Deshun Huang
Ultra-thin MXene nanosheets (Nss) were facilely prepared via delaminating and intercalating the multi-layered MXene using tetramethylammonium hydroxide (TMAOH). Electron-rich characteristics, abundant surface active sites and the negative charges made MXene Nss having both good reduction ability and adsorption capacities, which would effectively remove anion Cr(VI) via reduction and remove cation Cr(III) via adsorption. Batch adsorption tests were carried out to study the pH impact, adsorption kinetics and isotherms. Upon adsorption, the well dispersed MXene Nss suspension was aggregated to form flocs and sediment at the bottom. The maximum Cr(VI) and Cr(III) removing capacities are calculated to be 554.9 mg/g at 318 K and 283 mg/g at 298 K, respectively. The mechanisms on Cr(VI)/Cr(III) adsorption were well studied employing SEM, TEM , XPS and FT-IR. In addition, the MXene Nss also showed good adsorption capacity towards other metal cations (such as Cu 2+ , Cd 2+ , and Pb 2+ ), manifesting that the current MXene Nss has the potential to be used as a general-purpose adsorbent.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）