WATER RESEARCH
·
2021
·
IF 11.236
Shuai Wang,Kai Zheng,Heping Li,Xiaonan Feng,Luying Wang,Qingyou Liu
Arsenopyrite is a common metal sulfide mineral and weathers readily in the open environment, releases As, and pollutes the surrounding environment. Humic acid (HA) is ubiquitous in soils, sediments and waters, and contains various functional groups and complex with arsenic, iron and other metal ions that affect the weathering behavior of arsenopyrite. Because As, iron, and HA are redox-active compounds, electrochemical techniques, including polarization curves, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV), were used to fundamentally investigate the weathering process and mechanism of arsenopyrite over a wide range of environmental relevant conditions. Polarization curves showed higher HA concentrations (0-1000 mg•L −1 ), higher temperatures (5-35°C) or acidities (pH 1.0-7.0) promoted arsenopyrite weathering; there was a linear relationship between the corrosion current density ( i corr ), temperature (T) and acidity (pH): i corr = -3691.2/ T + 13.942 and i corr = -0.2445pH + 2.2125, respectively. Arsenopyrite weathering readily occurred in the presence of HA as confirmed by its activation energy of 24.1 kJ•mol −1 , and EIS measurements confirmed that the kinetics were controlled by surface reaction as confirmed by decreased double layer resistance. CV and surface characterization (FTIR and XPS) showed that arsenopyrite initially oxidized to S 0 , As(III) and Fe 2+ , then S 0 and Fe 2+ were ultimately converted into SO 4 2− and Fe 3+ , while As(III) oxidized to As(V). Furthermore, the carboxyl (–COOH) and phenolic (–OH) of HA could bind with As(III)/(V) and Fe 3+ via a ligand exchange mechanism forming As(III)/(V)-HA and As(III)/(V)-Fe-HA complexes that hinders the formation of FeAsO 4 and decreases the bioavailability of As. Findings gained from this study are valuable for the understanding of the fate and transport of As in acidic conditions, and have powerful implications for the remediation and management of As-bearing sites affected by mining activities.
研究领域:
环境科学
·
地球化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Han Linting,Chen Kun,Dong Huaping,Li Jianfa,Li Yimin
The abuse and improper disposal of antibiotics including metronidazole (MNZ) result in serious contamination in aquatic environments. In this study, pyrite, which was not reactive for MNZ removal, was simply mixed with zero valent iron (ZVI) to efficiently remove MNZ in anaerobic aqueous solutions. A dual ZVI/pyrite system consisting of ZVI (1.0 g/L) and pyrite (4.0 g/L) removed MNZ completely in 360 min within a broad pH 0 range (5.0–9.0), and it still maintained a high removal efficiency (~80%) even at a high pH 0 of 10.0. By contrast, single ZVI (1.0 g/L) showed much lower efficiency (4.8%–22.0%) within the same pH 0 range (5.0–10.0). On investigating the mechanism of MNZ removal, the cooperation between ZVI and pyrite enhanced the surface corrosion of ZVI and facilitated the redox cycle of Fe(III)/Fe(II) to generate more sorbed Fe(II), which was a dominant reactive species for MNZ removal. Pyrite also activated the ZVI surface to form FeS@Fe in situ , accelerating the electron transfer from Fe 0 core to the surface-enriched MNZ, and stimulated the formation of green rust sulfate on the ZVI surface to further promote MNZ removal. LC-MS analysis confirmed ZVI/pyrite reductively transformed MNZ into readily biodegradable products by denitration and cleavage of hydroxyethyl.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACTA OCEANOLOGICA SINICA
·
2014
·Vol. 33
·期 9
·100-108
·
IF 0.684
Kang Xuming,Liu Sumei,Zhang Guoling
Cold diffusion methods are used to separate and quantify the three reduced inorganic sulfur species into acid volatile sulfide (AVS), pyrite-S and element sulfur (ES) in the sediments of the Yellow and East China Seas. The results show that up to 25.02 μmol/g of AVS, 113.1 μmol/g of pyrite-S and 44.4 μmol/g of ES are observed in the sediments of the Yellow Sea and East China Sea. Pyrite-S is the predominant sulfide mineral in the sediments, while the concentration of AVS is quite low at most stations in the study area. The amounts and reactivity of organic matter are the primary limited factor for the sulfide formation, while an iron limitation and a sulfate limitation are not observed in the sediments of the Yellow Sea and East China Sea. The irregular profiles of the three reduced inorganic sulfur species also reflected the comprehensive influence of sediment composition and sedimentation rates.
研究领域:
海洋学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2025
·Vol. 30
·期 11
·2412
·
IF 4.6
Minyi Zhu,Minhui Ma,Shuo Chen,Rongfang Yuan,Shaona Wang
Pollution caused by N and P is a significant contributor to water eutrophication. While traditional biological treatment processes can remove some N and P elements from water, the effluent quality often fails to meet the stringent requirements of sensitive areas. The autotrophic denitrification’s simultaneous nitrogen and phosphorus removal pro-cess, known for its low operating cost and minimal sludge production, has garnered considerable attention from researchers. In this study, natural pyrite was used for the removal of nitrogen and phosphorus in a denitrification system, and the underlying mechanisms were elucidated. The results indicate that the N and P removal efficiency was influenced by empty bed contact time (EBCT) and the pH value. The highest NO 3 − -N removal rate of 90.24% was achieved at an EBCT of 8 h, while the PO 4 3− -P removal rate reached 81.58% at an EBCT of 12 h. The addition of a carbon source enhanced the synergistic autotrophic/heterotrophic denitrification, significantly improving phosphorus removal with an increasing C/N ratio. Microbial characteristics analysis revealed that, at the phylum level, Chlorobiota , Bacteroidota , and Chloroflexota played a crucial role in heterotrophic autotrophic denitrification. At the genus level, Thauera , Aridibacter , and Gemmatimonas were key players in heterotrophic denitrification, while Thiobacillus , Rhodoplanes , and Geobacter were associated with autotrophic denitrification.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Bio
·
2023
·
IF 8.2
Changcan Shi,Yinting Yu,Hongjuan Wu,Huanjin Liu,Mengyu Guo,Wenxin Wang,Dan Wang,Chenxu Wei,Hao Zhai,Guojun Yan,Zhipeng Chen,Ting Cai,Weidong Li
A coordinated interaction between osteogenesis and the osteoimmune microenvironment plays a vital role in regulating bone healing. However, disturbances in the pro- and anti-inflammatory balance hinder the therapeutic advantages of biomaterials. In this study, a novel composite hydrogel was successfully fabricated using graphene oxide (GO)-loaded processed pyritum (PP) in combination with poly(ethylene glycol) diacrylate (PEGDA) and carboxymethyl chitosan (CMC). Subsequently, the immunomodulatory effects and bone regenerative potential of PP/GO@PEGDA/CMC were investigated. The results demonstrated that the PP/GO@PEGDA/CMC hydrogel possessed excellent mechanical properties, swelling capacity, and stability. Moreover, PP/GO@PEGDA/CMC prominently promoted M2 polarization and increased the levels of anti-inflammatory factors (interleukin (IL)-4, IL-10, and transforming growth factor-β). These beneficial effects facilitated the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells in vitro. Additionally, the in vivo results further verified that the implantation of PP/GO@PEGDA/CMC markedly reduced local inflammation while enhancing bone regeneration at 8 weeks post-implantation. Therefore, the results of this study provide potential therapeutic strategies for bone tissue repair and regeneration by modulating the immune microenvironment.
研究领域:
材料科学
·
生物材料
·
组织工程
·
免疫学
·
骨再生
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）