SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Haidong Li,Han Song,Yuankun Yang,Haitao Wang,Beibei Fan,Juncheng Zheng,Weiguo Tu,Xuemei Luo,Shu Chen
Efficient and economical reduction and elimination of co-pollution of vanadium (V) and chromium (Cr) from water sources is a major challenge. In this study, sulphate green rust (GR SO4 ) was successfully prepared by co-precipitation method and used for the removal of V(V) and Cr(VI). The findings from batch adsorption experiments indicated that the adsorption capacity of GR SO4 for V(V) and Cr(VI) individually was 30.66 mg⋅g −1 and 39.48 mg⋅g −1 , respectively, with equilibrium reached in 25 min and 10 min. Intriguingly, in a binary system with both V(V) and Cr(VI) present, the time to reach adsorption equilibrium for V(V) removal by GR SO4 was 30 % shorter comparison to the single system under identical conditions. By analyzing the surface characteristics, crystal structure and elemental valence changes of GR SO4 minerals before and after the reaction, it can be obtained that: i) Direct adsorption mainly drives the removal of V(V) by GR SO4 , whereas the removal of Cr(VI) is preceded by reduction and followed by adsorption. ii) In a binary coexistence system, the formation of Fe(III)-Cr(III) oxide (GR-Cr(III)) during the removal of Cr(VI) by GR SO4 formed during the removal of Cr(VI) by GR SO4 creates additional adsorption sites for V(V), which shortens the equilibrium time of the V(V) removal reaction by GR SO4 and reduces the amount of V(V) leached. These findings are of great practical significance for understanding the mechanism and practical application of GR SO4 in the synergistic removal of V(V) and Cr(VI) heavy metals and provide valuable insights into their geophysical-chemical cycling.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2023
·
IF 5.6
Fang Wang,Pingxiao Wu,Meiqing Chen,Jiayan Wu,Leiye Sun,Zhongbo Shang,Nengwu Zhu
Green rust (GR), as one of mixed-valent iron [Fe(II)-Fe(III)] minerals, has received a significant attention in recent years because it is an intrinsic and essential part of biogeochemical cycling of heavy metals and DOM . The transformation of GR is a key factor in altering the environmental behavior of heavy metals, and therefore, prediction of such transformation is critical for managing environmental quality. DOM and heavy metals are recognized to have a significant impact on iron oxide transformation. However, detailed information on these phenomena and mechanisms are still limited. In this study, Cr(VI) and oxalic acid (OA) widely distributed in the natural environment were selected representatives of heavy metals and DOM. The mechanism of their influence on GR transformation and their environmental significance were clarified. GR transformed to feroxyhyte under the impact of Cr(VI) and OA, and feroxyhyte did not transform to more crystalline iron oxides after 7 days. However, OA enhanced Fe dissolution and Cr(VI) reduction while weakening the immobilization of Cr on GR. SEM results demonstrated that OA addition resulted in the collapse of the feroxyhyte structure. SEM-EDS data indicated that Cr and OA were adsorbed on GR, suggesting that this can be an essential pathway for C and Cr sequestration during GR transformation. This study reveals Cr(VI) not only favors the formation of feroxyhyte, but also stabilizes the mineral to prevent transformation and meanwhile indicates the mechanisms of organic matter interactions with iron oxide and the environmental behavior of C and Cr during the iron oxide transformation processes.
研究领域:
环境科学
·
地球化学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2025
·
IF 12.4
Xian Zhao,Jia-Yi Wang,Yu-Qian Wang,Chen-Hao Cui,Xin Yan,Wei Dai,An-Ran Zhang,Zhen-Ying Zhang,Ding-Ding Tang,Yan Zhou,Qiong Qin,Ji-Wei Pang,Lu-Yan Zhang,Nan-Qi Ren,Jie Ding,Shan-Shan Yang
s Green rust (GR), a reductive iron-based mineral pivotal in soil and groundwater remediation, remains unexplored for wastewater treatment. This study reveals that high-pH-Fe(II) coagulation enables in-situ generation of stabilized GR, thereby enhancing the coagulation efficiency (> 90 % removal for diverse dyes). The formation mechanism includes three sequential stages: Initially, alkaline conditions facilitate abundant Fe(OH) 2 ; Subsequently, partial oxidation of Fe(II) by oxidants produces anoxic zones, where Fe(II)/Fe(III) co-precipitation initiates GR crystallization; Simultaneously, multivalent anions intercalate into GR interlayers, further enhancing GR stability through strong electrostatic interactions. GR-enhanced-Fe(II) coagulation demonstrates dual dyes removal mechanisms: direct reductive degradation of electrophilic moieties (e.g., azo bond) and adsorption-coprecipitation of macromolecules. Based on the mechanism insights, it is found that GR-enhanced-Fe(II) coagulation achieves unparalleled removal of both anionic and cationic dyes (nearly 100 % decolorization for 50 mg/L dye solutions) under anoxic conditions. HPLC-MS and DFT confirm GR-driven reductive cleavage of Reactive Red 2 into low-molecular-weight byproducts. Pilot and full-scale trials at a dyeing wastewater treatment plant concluded that GR-enhanced-Fe(II) coagulation achieves 53.5 % COD removal, outperforming conventional Fe(II) processes (46.5 %) under actual hydraulic and pollutant load fluctuations. This work expands coagulation theory and offers a cost-effective strategy for wastewater treatment, adaptable to diverse effluents while retaining operational simplicity.
研究领域:
环境科学
·
水处理技术
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 33
·19247-19253
·
IF 3.119
Ying Han,Junkai Huang,Hongyuan Liu,Yue Wu,Zhao Wu,Kemin Zhang,Qingjie Lu
The reduction of p-chloronitrobenzene (p-CNB) by sulfate green rust (GRSO4) was systematically studied. The results revealed that GRSO4 has a good removal effect on p-CNB. The removal efficiencies of p-CNB by GRSO4 improved with the increase of the pH value. The removal efficiencies in the presence of ions were better than that of GRSO4 alone, while natural organic matter (NOM) could adsorb p-CNB, which competed with GRSO4. The reductions of p-CNB by GRSO4 under different conditions followed pseudo-first-order reaction kinetics except for the reactions in the presence of NOM. p-CNB was converted into p-chloroaniline (p-CAN), which produced p-nitrosochlorobenzene and p-chlorophenylhydroxylamine as the intermediate products. The results of the X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed GRSO4 was gradually transformed into goethite. Fe(II) in the GRSO4 structure was the main electron donor involved in the reaction.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）