ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 45
·68680-68691
·
IF 5.19
Guo Lin-yu,He Xian,Hong Zhi-neng,Xu Ren-Kou
Lead (Pb) is one of the top metal pollutants worldwide, and its distribution between liquid and solid phases of soils is strongly controlled by its adsorption on minerals, organic matter, and their composites. This paper presented the effect of fulvic acid (FA) coexistence on the distribution of Pb(II) at the solid–liquid interface of four minerals, which provided reference for how to use humic substances to remove toxic Pb(II) in soils. The free Pb 2+ of suspensions, measured by Pb ion selective electrode, was used to characterize the complexation of FA with Pb 2+ at various pH. The adsorption isotherms of Pb(II) by montmorillonite, kaolinite, goethite, and gibbsite with and without FA were studied with batch experiments. Results indicated that the free Pb 2+ decreased and complexed Pb(II) increased with the increase of FA concentration in Pb(II)-FA solutions, whether the initial concentration of Pb(II) was 0.1 or 1 mM. Pb 2+ hydrolysis was low and the free Pb 2+ concentration in pure lead solution without FA was generally unchanged with increasing solution pH at pH < 6.0. But free Pb 2+ decreased with the increase of pH in the presence of FA, suggesting that the complexation ability of FA with Pb 2+ increased with the increase of solution pH. The adsorption of Pb(II) by the minerals without FA followed the order: montmorillonite > kaolinite ≈ goethite > gibbsite at pH5.0. The Pb(II) adsorption by montmorillonite and kaolinite significantly enhanced with 1 g/L FA, while significantly inhibited with 3 g/L FA at low initial Pb(II) concentration. However, the effect of FA on Pb(II) adsorption by montmorillonite was greater than that of kaolinite, which was mainly related to the crystal layer structure, adsorption area, and cation exchange capacity of the minerals. The Pb(II) adsorption by goethite and gibbsite was significantly enhanced by the addition of both 1 g/L and 3 g/L FA, and the enhancement was more evident in goethite system. The effect of FA on the distribution of Pb(II) between solid and liquid phases of the minerals was determined by the factors such as the initial concentration ratio of FA to Pb(II), the adsorption capacity of minerals for FA, and the number of soluble complexes of FA with Pb 2+ . Therefore, the distribution of FA between solid and liquid of four minerals affected the distribution of Pb(II) between solid and liquid phases of the minerals greatly. The results can provide an important reference for understanding the distribution of Pb(II) and the dynamics and mobility of active components in polluted soils.
研究领域:
环境科学
·
土壤学
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产品关联
DOI
PubMed
高影响因子
Environmental Technology & Innovation
·
2025
·
IF 7.1
Changsheng Jin,Yin Gao,Jingjing Lu,Yuxi Liu,Baowei Hu
Soils contain abundant organic matter (OM) and Mn(oxyhydr)oxides (MnOs) composites, which primarily control the geochemical behavior of Cd. However, the impact of manganese phase transformation on the retention and availability of Cd remains unclear. Here, four organo-mineral composites were synthesized using birnessite (δ-Mn Ⅳ O 2 ), β-Mn Ⅲ,Ⅳ O 2 , γ-Mn Ⅲ OOH, and Mn Ⅱ,Ⅲ 3 O 4 with fulvic acid (FA), during adsorption to preformed MnOs with 5 wt% organic carbon loadings. The performance and underlying Cd(II) adsorption mechanism by resulting FA-MnO composites were explored. Results showed that δ-MnO 2 transformation decreases Cd(II) adsorption capacity by 23.02–45.44 % on the resulting FA-MnOs. This reduction was attributed to increased aggregation of MnO particles and competition from generated Mn(II/III) for available vacancy sites. Cd undergoes redistribution within the FA-MnOs during the transformation of δ-MnO 2 . The amount of Cd associated with MnOs decreases by 9.46–37.08 %, while OM bound-Cd increases by 2.82–10.49 %. FAδ-MnO 2 predominantly interacted with Cd(II) through tetravalent manganese, forming stable coordination or chemical bonds. In contrast, FAγ-MnOOH and FA-Mn 3 O 4 primarily interacted with Cd(II) through divalent manganese via electrostatic attraction and ion exchange, resulting in weaker binding stability. These findings provide new insights into the roles of manganese transformation in the geochemical cycling of Cd in soils.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2024
·Vol. 31
·期 39
·52582-52595
·
IF 0
Zhou Hao,Dang Yan,Chen Xinyu,Ivanets Andrei,Ratko Alexander A.,Kouznetsova Tatyana,Liu Yongqi,Yang Bo,Zhang Xulong,Sun Yiwei,He Xiaoyan,Ren Yanjie,Su Xintai
Due to industrialization, soil heavy metal pollution is a growing concern, with humic substances (HS) playing a pivotal role in soil passivation. To address the long duration of the compost humification problem, coal fly ash (CFA) in situ catalyzes the rapid pyrolysis of the cotton stalk (CS) to produce HS to address Cd passivation. Results indicate that the highest yield of humic acid (HA) (8.42%) and fulvic acid (FA) (1.36%) is obtained when the CS to CFA mass ratio is 1:0.5, at 275 ℃ for 120 min. Further study reveals that CFA catalysis CS humification, through the creation of alkaline pyrolysis conditions, Fe 2 O 3 can stimulate the protein and the decomposition of hemicellulose in CS, and then, through the Maillard and Sugar-amine condensation reaction synthesis HA and FA. Applying HS-CS&CFA in Cd-contaminated soil demonstrates a 26.69% reduction in exchangeable Cd within 30 days by chemical complexation. Excellent maize growth effects and environmental benefits of HS products are the prerequisites for subsequent engineering applications. Similar industrial solid wastes, such as steel slag and red mud, rich in Fe 2 O 3 , can be explored to identify their catalytic humification effect. It could provide a novel and effective way for industrial solid wastes to be recycled for biomass humification and widely applied in remediating Cd-contaminated agricultural soil.
研究领域:
环境科学
·
土壤修复
✓ 已验证
产品关联
DOI
PubMed
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Junyu Tao,Yincheng Wang,Yingying Yu,Yongjie Hu,Chen Chen,Ning Li,Beibei Yan,Zhanjun Cheng,Guanyi Chen
Fulvic acid (FA), a widely existed contaminant in organic wastewater, also represents a significant chemical asset. Recovery using activated carbon (AC) faces limitations due to FA’s high solubility, and the concomitant recovery of other contaminants undermines the value of the recovered FA. In this study, by carefully designed experiments, we have demonstrated that introducing a gaseous CO 2 flow can selectively enhance the FA recovery capacity of AC at room temperature. Extensive experiments and characterizations were conducted to validate the enhancing capability, explain its working mechanism, and optimize the recovery performance for FA. Results showed that the optimal conditions for FA recovery were found to be an FA concentration of 2 g/L, an AC dosage of 1 g, and a CO 2 flow rate of 0.1 L/min. Compared with the sole AC recovery system, the AC + CO 2 system significantly increased FA recovery capacity from 28.7 mg FA /g AC to 98.9 mg FA /g AC with negligible enrichment of other pollutants. The adsorption process in the AC + CO 2 system followed a pseudo-second-order kinetic model, indicating a predominance of chemical adsorption mechanism. Further experiments were designed to figure out the recovery-enhancing mechanism in respects to gas flow disturbance, pH, and ion species. It was found that the existence of HCO 3 – played an important role in recovery enhancement of AC. Furthermore, the enhancing effect could work for different kinds of AC but only work for FA recovery. The discoveries are promising to develop an effective and economic FA recovery technique in aqueous systems.
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
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 45
·64503-64515
·
IF 4.223
Dong
Youming,Gao Minling,Qiu Weiwen,Song Zhengguo
The large-scale use of polytetrafluoroethylene has resulted in ever-increasing amounts of polytetrafluoroethylene (PTFE) microplastic particles entering the environment. Given that the environment is polluted with arsenic (As(III)), and that the environment contains significant levels of humic acid (HA) and fulvic acid (FA), how PTFE and As(III) in water interacting in the presence of HA and FA needs to be urgently investigated. The results showed that As(III) was adsorbed by PTFE in the presence of HA and FA more markedly than the absence of them Adsorption equilibrium was reached at approximately 960 min and the adsorption isotherms were found to be best fitted by the Toth model. An increase in temperature was found to destroy hydrogen bonds, resulting in inhibited, non-spontaneous adsorption; a higher pH inhibited adsorption in the range 3–7. Computational and mechanistic studies revealed that PTFE formed π complexes with HA units, which increased the number of oxygen-containing functional groups on its surface. The surface of the PTFE-HA π complex was mostly negatively charged; however, the hydrogen atoms of the hydroxyl and carboxylic acid groups exhibited large positive potentials that enabled the adsorption of As(III). When the oxygen atom on As was close to the oxygen-containing functional group on PTFE-HA, the more electronegative oxygen atom forms a special intermolecular interaction in the form of O–H···O through the medium of hydrogen, which makes As adsorb on the surface of PTFE. Pore filling, hydrogen bonding, and covalent bonding are the main ways in which PTFE adsorbs As(III) in the presence of HA and FA. PTFE also adsorbed more As(III) in the presence of HA than in the presence of FA.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Jiajun Wen,Zhongwu Li,Changsheng Jin,Jia Chen,Changqing Cai
Dissolved organic matter (DOM) or iron/manganese (hydro)oxides were important factors in the migration of Cd in sediments of wetlands. DOM and Fe oxides simultaneously affect the longitudinal and transverse migration of Cd in wetlands sediments of plants was still unclear. In this study, a 14-day rhizobox experiment was conducted and the result showed that the rhizosphere effect of Cd migration was only limited to the upper layer of sediments (− 2 to − 4 cm). Fe with fulvic acid (FA) simultaneously existed can precipitate Cd(II) from supernatant to sediments downward. Fe oxides at sediment concentration could effectively prevent Cd(II) from migrating to root surface (0.21 vs 0.02 at%). While Fe oxides with FA together at sediment concentration could effectively promoted the migration of Cd(II) to root surface (0.07 vs 0.08 at%). The formation of organo-metallic complexes of Fe in the presence of FA profoundly proved this finding (increased by ~33.0%). And the polysaccharides and aromatics in organic matter were the chief functional groups participating in the incorporation of Cd and Fe oxides. The findings reveal the migration rules of Cd(II) in sediments by FA and Fe oxides and give an insight into the mechanisms of Cd(II) migration to the root surface around wetland plants.
研究领域:
环境科学
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植物学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yihao Li,Hongmei Tang,Xiangqin Peng,Shiyang Tao,Jie Ding,Meiqing Chen,Pingxiao Wu,Nengwu Zhu
The dynamic interactions among iron (Fe) oxides and organic matter (OM) play vital roles in controlling the geochemical cycling of carbon (C) and toxic trace metals. Although the effects of OM on the Fe oxides transformation, and dynamic with toxic trace metals have been studied previously, it is still poor to understand the mechanistic and quantitative on the C sequestration during the Fe(III) mineralization process, and kinetics with hydrated Cu(II) in the acid drainage. In this study, Mössbauer spectroscopy, X-ray absorption spectroscopy (XAS), high resolution transmission electron microscopy (HRTEM), and density functional theory (DFT) were used to elucidate the underlying mechanism for the fine structure of iron minerals, fulvic acid (FA) sequestration and hydrated Cu(II) coordination on Fe oxides. FA dosages played an essential role in the formation of Fe oxides, which can inhibit the formation of Fe-O octahedrons and benefit to the Fe-O tetrahedron. FA molecules were mainly sequestrated on the surfaces of Fe oxides and van der Waals forces were the main interaction between FA and Fe oxides. The hydrated Cu(II) oxides mainly distributed on the surface of iron oxides as divalent oxidation states, and feasible coordinated with phenolic hydroxyl group of FA and Fe oxides. The knowledge of the dynamic coupling between Fe oxide transformation under the effect of FA and the fate of hydrated Cu(II) on Fe oxides provided the basis for predicting the geochemical process of Fe, C and toxic trace metals.
研究领域:
环境科学
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地球化学
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Qi Li,Xijuan Chen,Xin Chen,Yan Jin,Jie Zhuang
Mobile e ngineered nanoparticles have the potential for removing a variety of pollutants from contaminated soils. In this study, elution of soil cadmium (Cd) by nano hydroxyapatite (nHAP) suspension was investigated at different concentrations of fulvic acid (FA). The nHAP nanofluid (500 mg L −1 ) increased the elution rate of soil Cd by ∼4.34 times (from 0.64% to 2.78%) compared with nHAP-free background solution due to a ∼2 order of magnitude larger adsorption capacity of Cd on nHAP than on the experimental loamy soil. FA played an indispensable role in the efficient removal of Cd by nHAP from the soil. The elution rate of soil Cd increased from 2.78% to 3.31%, 4.37%, 5.45%, and 8.46% after adding 20, 100, 200, and 500 mg L −1 of FA to the nHAP nanofluid (500 mg L −1 ), respectively. This linear facilitation (i.e., addition of each 100 mg L −1 of FA increased Cd elution by ∼1%) is attributed to FA-enhanced nHAP mobility and FA-strengthened Cd transfer from soil to nHAP. This study suggests that flushing with the environment-friendly, cost-effective, and FA-containing nHAP nanofluid can effectively remove Cd from soil, given that leachate could be collected by subsurface drainage tiles.
研究领域:
环境科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL GEOLOGY
·
2017
·
IF 3.347
Yingying Xie,Guining Lu,Han Ye,Chengfang Yang,Di Xia,Xiaoyun Yi,John Reinfelder,Zhi Dang
The cycling of Fe and Cr is intimately linked to the fate of schwertmannite in acid mine drainage (AMD) and acid sulfate soil (ASS) environments. Dissolved organic matter (DOM) can affect the stability of minerals and speciation, mobility and toxicity of heavy metals via redox reactions and complexation. However, knowledge about the fate of Fe and Cr upon reduction and complexation of CrO 4 2 − -substituted schwertmannite by fulvic acid (FA) is poorly understood. In this study, experiments were devised to investigate the interaction between FA and schwertmannite, with major degeneration of the schwertmannite structure as well as the formation of secondary minerals. For CrO 4 2 − -substituted schwertmannite, results indicated that the concentrations of total Fe and Cr in the solution were determined to be the maximum values at 360 h and 96 h, and then decreasing over the reaction time when FA was 10 mg/L at pH of 6.5. The characterization on the solid phase by X-ray diffraction, scanning electron microscopy and X-ray photo electron spectroscopy technologies revealed that goethite was the dominant newly secondary mineral phases which played a vital role in controlling the fate and transport of Fe and Cr. The possible mechanism was proposed to be synergistic effect including ligand-promoted and reduction. This study provides new insights into the understanding of trace element behavior in environments affected by DOM and also has guiding significance for Cr-contaminant remediation.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Xu Qiao,Yuhan Xia,Xuhan Su,Bingkun Wang,Guang Chen,Huan Chen
Fulvic acid (FA) is an organic substance that is widely used in the field of wastewater treatment , and improving its recycling capacity is a current research hotspot. In this study, a porous carbon material was prepared using FA (PCFA). Brilliant green (BG) and sulfadiazine sodium salt (SDZ) were selected as the model pollutants to study the adsorption mechanism and performance of PCFA. The maximum adsorption capacities of PCFA toward BG and SDZ at pH values of 9 and 3 were 2250 and 941 mg g −1 , respectively. After five cycles, PCFA retained 63% and 56% of its initial adsorption capacity toward BG and SDZ, respectively. Experimental results showed the excellent adsorption capacity and cycling stability of PCFA, confirming its role as an efficient adsorbent. The findings of this study show an improvement in the recycling capacity of FA and provide a new approach for exploring the applications of FA.
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
Micromachines
·
2022
·Vol. 13
·期 7
·1057
·
IF 3.523
Yuanhui Wu,Meizhi Yang,Dan Long,Fanian Yang,Suxing Luo
Natural organic matters (NOMs) are ubiquitous in the environment, but few systematic studies have examined the influence of NOMs on the sorption ability of magnetic sludge biochar. In this study, magnetic sludge biochar was synthesized, characterized, and used as a sorbent to remove tetracycline (TC) from aqueous solutions. The effects of pH, humic acid (HA), and fulvic acid (FA) on TC adsorption by magnetic sludge biochar were studied using batch experiments. Adding HA and FA can alter the adsorption behavior of TC, except for its pH dependency. The results of this study show that relatively low concentrations of dissolved HA (≤8 ppm) and FA (≤5 ppm) promote the adsorption capacity of TC, but higher concentrations compete against TC for sorption sites on the surface of magnetic sludge biochar. The results of this study promote a better understanding of the application of magnetic sludge biochar in real antibiotic wastewater.Keywords:adsorption;fulvic acid;humic acid;magnetic sludge biochar;tetracycline
研究领域:
环境科学
·
污染控制
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2016
·Vol. 100
·期 12
·5607-5618
·
IF 3.376
Li Mu,Su Yinglong,Chen Yinguang,Wan Rui,Zheng Xiong,Liu Kun
The heterotrophic denitrification requires the participation of electrons which are derived from direct electron donor (usually nicotinamide adenine dinucleotide (NADH)), and the electrons are transferred via electron transport system in denitrifiers and then consumed by denitrifying enzymes. Despite the reported electron transfer ability of humic substances (HS), the influences of fulvic acid (FA), an ubiquitous major component of HS, on promoting NADH generation, electron transfer, and consumption in denitrification process have never been reported. The presence of FA, compared with the control, was found not only significantly improved the total nitrogen (TN) removal efficiency (99.9 % versus 74.8 %) but remarkably reduced the nitrite accumulation (0.2 against 43.8 mg/L) and N 2 O emission (0.003 against 0.240 mg nitrogen/mg TN removed). The mechanisms study showed that FA increased the metabolism of carbon source via glycolysis and tricarboxylic acid (TCA) cycle pathways to produce more available NADH. FA also facilitated the electron transfer activities from NADH to denitrifying enzymes via complex I and complex III in electron transport system, which improved the reduction of nitrate and accelerated the transformations of nitrite and N 2 O, and lower nitrite and N 2 O accumulations were therefore observed. In addition, the consumption of electrons in denitrification was enhanced due to FA stimulating the synthesis and the catalytic activity of key denitrifying enzymes, especially nitrite reductase and N 2 O reductase. It will provide an important new insight into the potential effect of FA on microbial denitrification metabolism process and even nitrogen cycle in nature niches.
研究领域:
环境科学
·
微生物学
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生物地球化学
✓ 已验证
DOI
PubMed
高影响因子
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