JOURNAL OF HAZARDOUS MATERIALS
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2019
·
IF 7.65
Hongyang Wu,Wenjuan Wang,Yanfang Huang,Guihong Han,Shuzhen Yang,Shengpeng Su,Hafiza Sana,Weijun Peng,Yijun Cao,Jiongtian Liu
Toxic metal pollutants threaten water environment. It exists undesirably metal-ion concentration limits with conventional precipitation flotation. An enhanced precipitation flotation system focusing on efficient removal for bivalent metal-ions was researched. The system involved the addition of humics and Fe 3+ to generate and regulate the precipitates. The characteristics of precipitates were investigated by particle analysis, conditional stability constants and DLVO theory calculations, and SEM&TEM imaging. The results reveal that metal-ions chelate with humics at low metal-ion concentration, with generating the limited micro-size precipitates of <2.0 μm, fractal dimension of 1.60–1.80 and precipitate efficiency of <91.00%. By adding trivalent Fe 3+ , the macro-size precipitates are obtained with particle size of approximate 10.0 μm, fractal dimension of 1.50–1.60, and nearly-total flotation removal of precipitate. The chelating interaction of Fe 3+ with humics is the mainly regulating mechanism, which could enhance the conditional stability constants and the precipitate efficiency of metal-ions at low concentration. The desired precipitate particles are finally obtained by breaking the limitations of metal-ion concentration. Finally, the flotation removal of metal-ions from single or mixed solutions is respectively 99.10 ± 0.10% for Cu 2+ , 99.60 ± 0.10% for Pb 2+ , and 94.30 ± 0.30% for Zn 2+ . Therefore, the enhanced precipitation flotation process is an efficient purification approach for metal-containing wastewaters.
研究领域:
环境科学
·
化学工程
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产品关联
DOI
PubMed
高影响因子
Journal of Environmental Sciences
·
2023
·
IF 6.9
Rongping Chen,Chenghao Gan,Bingcai Cai,Ruxue Liu,Wenjie Xu,Weize Yin,Hongyi Li,Lei Yu,Qiang Yong
An eco-friendly adsorbent was prepared by reverse suspension crosslinking method to remove multiple pollutants from aqueous solution. Both raw materials, derived from humus (HS) and chitosan (CS), are biodegradable and low-cost natural biopolymers . After combining HS with CS, the adsorption capacity was significantly improved due to compensation effects between the two components. HS/CS exhibited the features of amphoteric adsorption through pH adjustment, enabling it to adsorb not only anionic pollutants (Methyl Orange (MO) and Cr(VI)), but also cationic ones (Methylene Blue (MB) and Pb(II)). The adsorption capacities were approximately 242 mg/g, 69 mg/g, 188 mg/g and 57 mg/g for MO, Cr(VI), MB and Pb(II), respectively. HS/CS showed a slight preference for MO in MO/Cr(VI) co-adsorption system, whereas strong selectivity for MB over Pb(II) in MB/Pb(II) system under acidic condition (pH<3.0). This selective behavior would allow for potential applications in separating MB/Pb(II) effluents and selectively recycling Pb(II) in acidic environment. The isothermal and kinetic adsorption behaviors followed Langmuir model and pseudo-second-order model, respectively. The density functional theory (DFT) confirmed that the interaction between metal ions and adsorbents was primarily attributed to chelation and electrostatic adsorption, owing to nitric and oxygenic functional groups. Whereas, the adsorption mechanisms for dyes were involved in electrostatic attraction, H-bond and π–π bond, due to available hydrogen, oxygen, nitrogen atoms and aromatic groups on the surface of adsorbent and adsorbates. The adsorbent could be efficiently regenerated and retained over 90% of its adsorption capacity after five cycles, which has a potential for practical applications in water treatment .
研究领域:
环境科学
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材料科学
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DOI
高影响因子
GREEN CHEMISTRY
·
2025
·
IF 9.2
Xianda Li,Zhongping Shao,Haozhe Shan,Li Liu
Cellulose utilization has been seriously hindered by the formation of humins, whereas humins structure remains challenging since unconverted cellulose and humins exist as solid mixture. In this work, we developed a novel strategy to extract humins from unconverted cellulose and disclosed the structural evolution process of cellulose-derived humins for the first time. The key intermediate of levoglucosan was successfully captured and identified, which significantly favors the formation of anhydro-sugars followed by polymerization due to the stability. By means of comprehensive HPLC-MS/MS, FT-IR, MALDI-TOF and SEM characterizations, it was proposed that multiple elementary reactions were involved in the formation of cellulose-derived humins, including cellulose depolymerization, etherification, esterification, aldol condensation, dehydration and thermal oxidation. In the early stage, cellulose depolymerization results in glucose and levoglucosan (LG), which undertake etherification to form the early humins via small molecule mechanism, accompanied by esterification and dehydration. In the later stage, gluco-oligosaccharides esp. with LG end from cellulose depolymerization undergo etherification via oligomer mechanism. Meanwhile, etherification of HMF and aldol condensation with LA take place prominently, together with dehydration and oxidation, resulting in the enhancement of C=C and C=O conjugation.
研究领域:
生物化学
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材料科学
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产品关联
DOI
高影响因子
Sustainability
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2020
·Vol. 12
·期 19
·7931
·
IF 2.576
Sanmei Li,Mingda Wu,Linghong Lu,Jiabao Zhu
Humin is the waste residue from the process of preparing humic acid, which accounts for a large proportion of the raw material (weathered coal humic acid). Its Cd(II) adsorption performance is far inferior to that of humic acid. How to regenerate humin is of great significance to the low-cost treatment of Cd(II) pollution in wastewater. In this study, humin was modified by hyperbranched polyethyleneimine to enhance the adsorption capacity for Cd(II). Fourier transform infrared spectroscopy and the X-ray photoelectron spectrometer showed that hyperbranched polyethyleneimine was grafted to the surface of humin. Flame atomic absorption spectroscopy showed that the saturated Cd(II) adsorption capacity of the modified humin was increased to 11.975 mg/g, which is about 5 times than that of humin and is also higher than that of humic acid. The adsorption kinetics, adsorption isotherm, and thermodynamic properties of humic acid, humin, and modified humin were also studied. This study may provide a foundation for research utilizing natural resources to reduce heavy metal pollution in the environment.Keywords:humin;hyperbranched polyethyleneimine;modification;adsorption;Cd(II)
研究领域:
环境科学
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材料科学
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DOI
高影响因子
MENDELEEV COMMUNICATIONS
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2019
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IF 2.01
Yuliya E. Tyutereva,Peter S. Sherin,Zizheng Liu,Victor F. Plyusnin,Ivan P. Pozdnyakov
Quantum yields of indirect UVC photodegradation of p -arsanilic acid (a widely used phenylarsonic feed additive) caused by the photolysis of humic substances were measured. The acquired results demonstrate that the efficiency of such decomposition of p -arsanilic acid is comparable with that of its direct UVC photolysis due to the participation of active intermediates generated during the photolysis of humic substances. These results could be important for understanding the fate of p -arsanilic acid during an UVC disinfection of wastewaters containing natural humic substances.
研究领域:
环境科学
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化学
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产品关联
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2019
·
IF 4.527
Guangfei Liu,Jiaqi Zhu,Ruofei Jin,Jiti Zhou,Zhanming Gao,Jing Wang
As an important fraction of humic substances , humin has been found capable of stimulating bioreduction reactions. However, whether humin could promote abiotic reduction and the effects of coexisting soluble humic substance and insoluble mineral remained unsolved. In this study, a humin sample was isolated from a paddy soil . Cyclic voltammetry, electron paramagnetic resonance, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses of the humin indicated the existence of redox-active quinone moieties and other oxygen-containing groups. The humin could be reduced by sulfide and its presence stimulated the abiotic reduction of acid red 27 (AR27) and four other azo dyes by sulfide. In the presence of 100–1000 mg/L intact humin, the sulfide-mediated AR27 reduction efficiency in 7 d was enhanced from 56.3% to 92.5%. The stimulating behavior of intact humin was observed for 100–300 mg/L AR27 and increased with the increase of sulfide concentration (1.2–3.0 mM). Much higher stimulating effects were found with the presence of humin pre-reduced by sulfide. Moreover, for sulfide-mediated AR27 reduction, the coexistence of humin (500 mg/L) and humic acid (10–30 mg/L) or Wyoming sodium-montmorillonite (SWy-2, 1–4 g/L) led to better promotion activities than the presence of single component. And synergistic promotion of sulfide-mediated AR27 reduction was observed with coexisting humin and SWy-2 due to enhanced Fe(II) production. These findings extended our understanding of the influence of humin on reductive transformation of pollutants in the environment.
研究领域:
环境科学
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土壤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
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2021
·
IF 9.642
Yanrong Chen,Yaoning Chen,Yuanping Li,Yihuan Liu,Hui Li,Hongjuan Jiang,Xinli Luo,Ping Tang,Li Chen,Haoqin Yan
The Fenton-like process was established by Fe 3 O 4 nanomaterials (NMs) and Phanerochaete chrysosporium or oxalate, and applied to the co-composting of rice straw and sediment to study its effect on the formation of humic substance and the bioavailability of Cd, Cu, and Pb. Results shown that the application of Fenton-like process significantly promoted the passivation of Cd and Cu, while not shown obvious enhancement for Pb. The decrease of exchangeable fraction Cd (EXC-Cd) and the humic acid (HA) content in pile B with Fe 3 O 4 NMs and oxalate were highest, which were 22.35% and 20.3 g/kg, respectively. Redundancy analyses (RDA) manifested that the Fenton-like process enhanced the influence of humus substance on the bioavailability of Cd, Cu, and Pb. Excitation-emission matrix (EEM) fluorescence spectra analysis suggested that Fenton-like process could obviously enhance the generation of humic substance. This research provides a new perspective and way for composting to remediate heavy metals pollution.
研究领域:
环境科学
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土壤学
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微生物学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 96
·93947-93955
·
IF 3.289
Bin Dong,Ying Xu,Danni Shen,Xiaohu Dai,Senming Lin
Reusing wastewater can enormously reduce environmental pollution and save water. One of the key obstacles to reuse is the scaling caused by calcium (Ca) ions and humic matter (HM). The interactions among HM, Ca ions and cation-exchange resins (CERs) during the water softening process were explored via lab-scale and pilot-scale tests. Surface topography, pore structure, and surface molecular structure of the CERs were determined using an atomic-force microscope, an automatic mercury porosimeter, a laser-Raman spectrum and X-ray photoelectron spectroscopy, respectively. The surface charge of CERs was assessed by measuring zeta potential. Experimental results showed that HM can react with Ca-ions to form HM–Ca+ and Ca ions can act as a bridge for HM and CER, suggesting that Ca ions and HM can be simultaneously removed by CERs. Kinetic analyses indicate that a pseudo-first order equation was able to accurately describe the overall adsorption kinetics and diffusion of Ca ions through a liquid film of CER was the rate-determining step for the overall adsorption process. Further investigation revealed that during the first 60 minutes of adsorption, the effect of HM on the CER adsorption kinetics can be described well by pseudo-first and pseudo-second order equations. This indicates that diffusions of Ca ions, HM, and HM–Ca+ and their interactions were equivalent for controlling the initial stage of adsorption. In addition, 99% of Ca ions and 30–60% of HM in wastewater were removed in the pilot-scale test, suggesting that CERs have significant potential to remove Ca ions and HM simultaneously in wastewater.
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
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2023
·
IF 9.8
Bo Gong,Wei Chen,Patrick H.-L. Sit,Xian-Wei Liu,Chen Qian
Dissolved organic matter (DOM) is ubiquitous in aqueous environments and is composed of different components that play different but important roles in the migration and the fate of pollutants , emergence of the disinfect byproduct, thus requiring quantitative characterization. However, until now, simultaneous quantification of the main contents in DOM, i.e., saccharides, proteins, and humic substances , has been difficult, impeding us from understanding and predicting the environmental behaviors of typical pollutants. In this work, a fluorescence approach based on the excitation emission matrix (EEM), combined with a new algorithm, denoted matrix reconstruction coupled with prior linear decomposition (MR-PLD), was developed to quantify multiple DOM simultaneously. First, a set of simulated water samples consisting of glucose, tryptones, and humic acid (HA) were analyzed using MR-PLD to validate the feasibility of the method. The DOM components could be reliably determined with a higher accuracy than parallel factor analysis (PARAFAC) and Parallel Factor Framework-Linear Regression (PFFLR), also with a more convenient procedure than conventional PLD. Second, both actual simulated and experimental methods were performed to test the anti-interference performance of MR-PLD, indicating that the quantification of DOM would not be significantly impacted by other fluorophores. Finally, several actual water samples from natural waters and wastewater treatment plants were also analyzed to confirm the robustness of this method in actual aqueous environments. This study provides a new approach to characterize DOM with EEM, contributing to its convenient concentration monitoring and the further exploration of the environmental impacts.
研究领域:
环境科学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Chen Zhong,He Zhao,Qingzhen Han,Hongbin Cao,Feng Duan,Junyi Shen,Yongbing Xie,Wanqian Guo,Shanshan Sun
As an important raw material and intermediate of widely used antibiotics cefazolin and cefazedone, 2-mecapto-5-methyl-1,3,4-thiadizaole (MMTD) in antibiotic wastewater is hardly decyclized during wastewater treatment, posing great risk to the environment. This work proposed a green “coupling-oxidation” process to enhance ring-opening of MMTD during antibiotic wastewater treatment. In particular, the significant role of humic substances (HS) as pre-coupling reagent was emphasized. Real HS and different model HS, especially quinones, not only efficiently pre-coupled MMTD (>95%) but also promoted the MMTD removal by MnO 2 (from 72.4% to 92.4%). Mass spectrometric analysis indicated that MMTD pre-coupled to HS would be oxidized with ring opening to environmental-friendly sulfonated HS, while direct oxidation of MMTD produced MMTD dimers or sulfonated MMTD that would not undergo ring opening. Theoretical calculations indicated that pre-coupling to HS enabled the ring-opening oxidation by increasing the nucleophilicity and decreasing ring-opening barrier of thiadiazole. Based on the density function theory (DFT), the global nucleophilicity index (Nu) followed the trend of HS-MMTD > MMTD dimer > sulfonated MMTD, while the ring-opening barrier followed the trend of HS-MMTD (274 kJ/mol) < first ring of MMTD dimers (286 kJ/mol) < MMTD (338 kJ/mol). Theoretical calculations further confirmed that the cross-coupled HS-MMTD intermediate was more likely to be decyclized than intermediates from direct oxidation. Moreover, nitrogen, acetaldehyde group, sulfate and CO 2 were the products of thiadiazole ring degradation. Pre-coupling of MMTD with HS provides a new idea and strategy in developing a green and sustainable scheme for wastewater treatment.
研究领域:
环境科学
·
化学工程
·
废水处理
·
理论化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Chemical Engineering Journal Advances
·
2025
·
IF 7.1
Wuxin Hou,Jizhuang Zuo,Yongle Gao,Yao Wang,Li Liu
The generation of humins by-products in biorefinery is often unavoidable. We here report the valorization of chitosan-derived humins for removal of heavy metal ions to enhance the atomic economy of the biomass conversion. Chitosan-derived humins were synthesized by catalysis of oxalic acid (OA), whereby the adsorption performance for Cd(II), Cr(III) and Cr(VI) was explored. The adsorption data were well fitted by the pseudo-second-order kinetic model, complemented by the Freundlich and Temkin isotherm models, revealing maximum adsorption capacities of humins for heavy metal ions as follows: 358.7 mg/g for Cr(VI), 152.6 mg/g for Cd(II), and 40.2 mg/g for Cr(III). The mechanistic studies revealed that the adsorption of Cd(II) and Cr(III) by humins mainly occurs through ion exchange (carboxyl groups) and surface complexation (hydroxyl, carbonyl, and amino groups). In comparison, the adsorption of Cr(VI) by humins involves electrostatic attraction, alongside ion exchange and surface complexation. After carbonization and activation, the specific surface area increased markedly, however the adsorption capacity decreased owing to reduced oxygen- and nitrogen-containing functional groups. Competitive adsorption studies, industrial wastewater experiments, and cyclic adsorption tests demonstrate that humins exhibit remarkable adsorption performance even in complex environments. This work highlights that chitosan-derived humins are promising adsorbents for the remediation of heavy metal ions.
研究领域:
环境化学
·
生物质转化
·
吸附科学
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污染修复
·
材料化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2022
·
IF 8.91
Zhixing Xiao,Lizhuang Yang,Chuang Chen,Dan Chen,Xue Zhou
Redox reactions between humic substances and Fe(III) compounds play a critical role in the biogeochemical cycle of pollutants. Most humic substances in soils and sediments are in a solid form (i.e. humin (HM)). In order to assess the contribution of electron shuttling via HM within the electron transfer network in natural environments and to predict environmental fate of pollutants associated with iron oxides , it is necessary to understand the electron transfer processes from HM to the environmentally relevant Fe(III) minerals, and to examine the redox reversibility of HM. The results of this study demonstrated that non-reduced HMs could only donate electrons to dissolved ferric citrate and poorly crystalline ferrihydrite , but reduced HMs could also reduce hematite and magnetite that had high crystallinity . The degree of reduction depended on the difference in redox potential and the crystallinity of the Fe(III) compounds. The electron-accepting capacities of different HMs correlated well with their organic carbon content, and quinones and Fe-bound organic component were important electron-accepting groups in HMs. Furthermore, the redox reversibility experiments demonstrated that HMs could maintain stable electron transfer capacities over three reduction-oxidation cycles, indicating that the HM could be an environmentally sustainable electron shuttle. Our results suggest that (1) HM may play an unrecognized and important role in biogeochemical cycles of pollutants in Fe(III) mineral-rich environments; (2) electron shuttling through HM to ferric citrate and ferrihydrite can occur even in the presence of O 2 ; and (3) HM would be a promising material for environmental remediation.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）