1
|
Liu K, Li F, Cui J, Yang S, Fang L. Simultaneous removal of Cd(II) and As(III) by graphene-like biochar-supported zero-valent iron from irrigation waters under aerobic conditions: Synergistic effects and mechanisms. JOURNAL OF HAZARDOUS MATERIALS 2020; 395:122623. [PMID: 32353819 DOI: 10.1016/j.jhazmat.2020.122623] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/06/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Irrigation water is commonly contaminated with cadmium and arsenic near mining regions, which significantly contributes to excessive heavy metals in rice grains. Herein, we have developed a novel graphene-like biochar (GB)-supported nanoscale zero-valent iron (nZVI) and the underlying mechanisms of synergistic effects between GB and nZVI for the simultaneous removal of Cd(II) and As(III) under aerobic conditions. The results show that GB/nZVI has a high removal capacity of 363 mg/g (nZVI) for As(III) at pH 4 and 92.8 mg/g (nZVI) for Cd(II) at pH 7. These values are significantly higher than GB and nZVI (1.7 times for Cd(II); 1.4 times for As(III)) alone, suggesting strong synergistic effects between GB and nZVI. GB promotes nZVI oxidation to form iron oxyhydroxides and causing 35 % of As(III) converting to As(V). Importantly, As(III) significantly enhance Cd(II) removal by GB/nZVI (i.e., 131.8 mg/g as nZVI). Coexisting ions such as phosphate and humic acid have a stronger inhibitory effect on the simultaneous removal of Cd(II) and As(III). Our results indicate that oxidation and surface complexation are the dominant mechanisms and electrostatic binding exists for As(III) removal, while surface complexation predominates for Cd(II) removal. These findings provide insight into developing an effective solution for removing Cd(II)/As(III) from irrigation waters.
Collapse
Affiliation(s)
- Kai Liu
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou, 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou, 510650, China; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fangbai Li
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou, 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou, 510650, China
| | - Jianghu Cui
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou, 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou, 510650, China
| | - Shiyun Yang
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou, 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou, 510650, China; College of Agriculture, Guizhou University, Guiyang, 50025, China
| | - Liping Fang
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou, 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou, 510650, China.
| |
Collapse
|
2
|
Xu M, Barbosa da Silva E, Gao P, Liao R, Wu J, Ma J, Yang G, Zhang X, Xiao Y, Long L. Biochar impact on chromium accumulation by rice through Fe microbial-induced redox transformation. JOURNAL OF HAZARDOUS MATERIALS 2020; 388:121807. [PMID: 31831288 DOI: 10.1016/j.jhazmat.2019.121807] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 10/20/2019] [Accepted: 11/30/2019] [Indexed: 06/10/2023]
Abstract
Iron (Fe) dissimilatory reduction might impact chromium (Cr) mobility in the rice rhizosphere, but it is poorly understood. We assessed rhizosphere microbes' role in Cr immobilization and bioavailability by conducting the pot experiment to test different biochar sources (PMB - pig manure and PSB - pine sawdust) and phosphorus (P) levels impact on Cr mobility. Results showed that PMB application increased root biomass (23-65 %) and decreased root Cr concentration (46-74 %) regardless P treatment. However, P addition reduced root and shoot biomass in control and PMB treatments by 33-43 % and 25-26 %. Therefore, low P input is recommended in Cr-contaminated soil. Moreover, Geobacter was the key microbial groups which may be involved in promoting Cr release by increasing Fe dissolution. Finally, Geobacter and Fe dissimilatory reduction play a central role in Cr translocation and they should be considered in strategies to reduce rice Cr uptake by biochar application.
Collapse
Affiliation(s)
- Min Xu
- College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China
| | - Evandro Barbosa da Silva
- Research Center for Soil Contamination & Environment Remediation, Southwest Forestry University, Yunnan 650224, China; Innovative Technical Solutions, Gainesville, FL 32607, USA
| | - Peng Gao
- Soil and Water Sciences Department, University of Florida, Gainesville, FL 32611, USA
| | - Ruiting Liao
- College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China
| | - Jun Wu
- College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China.
| | - Jing Ma
- College of Water Conservancy and Hydropower Engineering, Sichuan Agricultural University, Yaan 625014, China
| | - Gang Yang
- College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China
| | - Xiaohong Zhang
- College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China
| | - Yinlong Xiao
- College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China
| | - Lulu Long
- College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, China
| |
Collapse
|
3
|
Awad AM, Shaikh SM, Jalab R, Gulied MH, Nasser MS, Benamor A, Adham S. Adsorption of organic pollutants by natural and modified clays: A comprehensive review. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2019.115719] [Citation(s) in RCA: 241] [Impact Index Per Article: 48.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
4
|
Rechberger MV, Kloss S, Wang SL, Lehmann J, Rennhofer H, Ottner F, Wriessnig K, Daudin G, Lichtenegger H, Soja G, Zehetner F. Enhanced Cu and Cd sorption after soil aging of woodchip-derived biochar: What were the driving factors? CHEMOSPHERE 2019; 216:463-471. [PMID: 30384316 DOI: 10.1016/j.chemosphere.2018.10.094] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 10/12/2018] [Accepted: 10/15/2018] [Indexed: 06/08/2023]
Abstract
Biochar (BC) is increasingly tested as a soil amendment for immobilization of heavy metals (HMs) and other pollutants. In our study, an acidic soil amended with wood chip-derived BC showed strongly enhanced Cu and Cd sorption after 15 months of aging under greenhouse conditions. X-ray absorption near edge structure suggested formation of Cu(OH)2 and CuCO3 and upon aging increasingly Cu sorption to the BC organic phase (from 9.2% to 40.7%) as main binding mechanisms of Cu on the BCs. In contrast, Cd was predominantly bound as CdCO3 on the BCs even after 15 months (82.7%). We found indications by mid-infrared spectroscopy that the formation of organic functional groups plays a role for increased HM sorption on aged BCs. Yet, our data suggest that the accessibility of BC's pore network and reactive surfaces is likely to be the overriding factor responsible for aging-related changes in HM sorption capacity, rather than direct interactions of HMs with oxidized functional groups. We observed highly weathered BC surface structures with scanning electron microscopy along with strongly increased wettability of the BCs after 15 months of soil aging as indicated by a decrease of water contact angles (from 62.4° to 4.2°).
Collapse
Affiliation(s)
- Maria V Rechberger
- Institute of Soil Research, University of Natural Resources and Life Sciences, Peter-Jordan-Str. 82, 1190, Vienna, Austria; AIT Austrian Institute of Technology GmbH, Energy Department, Environmental Resources & Technologies, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Stefanie Kloss
- Institute of Soil Research, University of Natural Resources and Life Sciences, Peter-Jordan-Str. 82, 1190, Vienna, Austria
| | - Shan-Li Wang
- Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan
| | - Johannes Lehmann
- Soil and Crop Sciences, Cornell University, Ithaca, NY 14853, United States
| | - Harald Rennhofer
- Institute of Physics and Material Sciences, University of Natural Resources and Life Sciences, Peter-Jordan-Str. 82, 1190, Vienna, Austria
| | - Franz Ottner
- Institute of Applied Geology, University of Natural Resources and Life Sciences, Peter-Jordan-Str. 82, 1190, Vienna, Austria
| | - Karin Wriessnig
- Institute of Applied Geology, University of Natural Resources and Life Sciences, Peter-Jordan-Str. 82, 1190, Vienna, Austria
| | - Gabrielle Daudin
- Eco&Sols, Univ Montpellier, CIRAD, INRA, IRD, Montpellier SupAgro, Place Viala, 34060, Montpellier, France
| | - Helga Lichtenegger
- Institute of Physics and Material Sciences, University of Natural Resources and Life Sciences, Peter-Jordan-Str. 82, 1190, Vienna, Austria
| | - Gerhard Soja
- AIT Austrian Institute of Technology GmbH, Energy Department, Environmental Resources & Technologies, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria; Institute for Chemical and Energy Engineering, University of Natural Resources and Life Sciences, Muthgasse 107, 1190 Vienna, Austria
| | - Franz Zehetner
- Institute of Soil Research, University of Natural Resources and Life Sciences, Peter-Jordan-Str. 82, 1190, Vienna, Austria.
| |
Collapse
|
5
|
Fang L, Xu C, Li J, Borggaard OK, Wang D. The importance of environmental factors and matrices in the adsorption, desorption, and toxicity of butyltins: a review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:9159-9173. [PMID: 28160180 DOI: 10.1007/s11356-017-8449-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Accepted: 01/11/2017] [Indexed: 06/06/2023]
Abstract
Butyltins (BTs) are considered as a group of the most important organometallic compounds in industry and agriculture. Due to their widespread use, large amounts of BTs including tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) have entered into the environment, and subsequently causing detrimental effects on humans and aquatic organisms. This work provides a critical review of recent studies on the adsorption, desorption, bioaccumulation, and toxicity of BTs that can notably influence the distribution of BTs in the environment. Influence of environmental factors (e.g., pH and salinity) and adsorbents in the matrices (e.g., minerals, organic carbons, and quartz) on the adsorption, desorption, and toxicity of BTs is particularly addressed.
Collapse
Affiliation(s)
- Liping Fang
- Department of Chemistry, Faculty of Material Sciences and Chemistry, China University of Geosciences, Wuhan, 430074, China.
| | - Cuihong Xu
- Department of Chemistry, Faculty of Material Sciences and Chemistry, China University of Geosciences, Wuhan, 430074, China
| | - Ji Li
- Department of Chemistry, Faculty of Material Sciences and Chemistry, China University of Geosciences, Wuhan, 430074, China.
| | - Ole K Borggaard
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark
| | - Dongsheng Wang
- Department of Chemistry, Faculty of Material Sciences and Chemistry, China University of Geosciences, Wuhan, 430074, China
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| |
Collapse
|
6
|
Sabah A, Bancon-Montigny C, Rodier C, Marchand P, Delpoux S, Ijjaali M, Tournoud MG. Occurrence and removal of butyltin compounds in a waste stabilisation pond of a domestic waste water treatment plant of a rural French town. CHEMOSPHERE 2016; 144:2497-2506. [PMID: 26624956 DOI: 10.1016/j.chemosphere.2015.11.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 10/07/2015] [Accepted: 11/02/2015] [Indexed: 06/05/2023]
Abstract
The aim of this study was to investigate the fate and behaviour of butyltin pollutants, including monobutyltin (MBT), dibutylin (DBT), and tributyltin (TBT), in waste stabilisation ponds (WSP). The study was conducted as part of a baseline survey and included five sampling campaigns comprising bottom sludge and the water column from each pond from a typical WSP in France. Butyltins were detected in all raw wastewater and effluents, reflecting their widespread use. Our results revealed high affinity between butyltins and particulate matter and high accumulation of butyltins in the sludge taken from anaerobic ponds. The dissolved butyltins in the influent ranged from 21.5 to 28.1 ng(Sn).L(-1) and in the effluent, from 8.8 to 29.3 ng(Sn).L(-1). The butyltin concentrations in the sludge ranged from 45.1 to 164 and 3.6-8.1 ng(Sn).g(-1) respectively in the first and last ponds. Our results showed an average treatment efficiency of 71% for MBT, 47% for DBT, 55% for TBT. Laboratory sorption experiments enabled the calculation of a distribution coefficient (Kd = 75,000 L.kg-1) between TBT and particulate matter from the WSPs. The Kd explained the accumulation and persistence of the TBT in the sludge after settling of particulate matter. The continuous supply of contaminated raw wastewater and the sorption-desorption processes in the ponds led to incomplete bio- and photolytic degradation and to the persistence of butyltins in dissolved and particulate matrices throughout the survey period. It is thus recommended to use shallow ponds and to pay particular attention when sludge is used for soil amendment.
Collapse
Affiliation(s)
- A Sabah
- Laboratoire HydroSciences UMR 5569, CNRS, Université de Montpellier, IRD, Place Eugène Bataillon, CC MSE, 34095 Montpellier cedex 5, France; Faculté des Sciences et Techniques de Fès, Université Sidi Mohamed Ben Abdellah, Route d'Imouzzer, BP 2202, 30000 Fès, Morocco
| | - C Bancon-Montigny
- Laboratoire HydroSciences UMR 5569, CNRS, Université de Montpellier, IRD, Place Eugène Bataillon, CC MSE, 34095 Montpellier cedex 5, France.
| | - C Rodier
- Laboratoire HydroSciences UMR 5569, CNRS, Université de Montpellier, IRD, Place Eugène Bataillon, CC MSE, 34095 Montpellier cedex 5, France
| | - P Marchand
- Laboratoire HydroSciences UMR 5569, CNRS, Université de Montpellier, IRD, Place Eugène Bataillon, CC MSE, 34095 Montpellier cedex 5, France
| | - S Delpoux
- Laboratoire HydroSciences UMR 5569, CNRS, Université de Montpellier, IRD, Place Eugène Bataillon, CC MSE, 34095 Montpellier cedex 5, France
| | - M Ijjaali
- Faculté des Sciences et Techniques de Fès, Université Sidi Mohamed Ben Abdellah, Route d'Imouzzer, BP 2202, 30000 Fès, Morocco
| | - M-G Tournoud
- Laboratoire HydroSciences UMR 5569, CNRS, Université de Montpellier, IRD, Place Eugène Bataillon, CC MSE, 34095 Montpellier cedex 5, France
| |
Collapse
|
7
|
Li T, She Y, Wang M, Liu G, Yu H, Wang J, Wang S, Jin F, Jin M, Shao H. Simultaneous determination of four organotins in food packaging by high-performance liquid chromatography–tandem mass spectrometry. Food Chem 2015; 181:347-53. [DOI: 10.1016/j.foodchem.2015.02.115] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 02/02/2015] [Accepted: 02/22/2015] [Indexed: 11/30/2022]
|
8
|
Comparative study of tributyltin adsorption onto mesoporous silica functionalized with calix[4]arene, p-tert-butylcalix[4]arene and p-sulfonatocalix[4]arene. Molecules 2014; 19:4524-47. [PMID: 24727422 PMCID: PMC6271541 DOI: 10.3390/molecules19044524] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 04/03/2014] [Accepted: 04/04/2014] [Indexed: 11/25/2022] Open
Abstract
The adsorption of tributyltin (TBT), onto three mesoporous silica adsorbents functionalized with calix[4]arene, p-tert-butylcalix[4]arene and p-sulfonatocalix[4]arene (MCM-TDI-C4, MCM-TDI-PC4 and MCM-TDI-C4S, respectively) has been compared. Batch adsorption experiments were carried out and the effect of contact time, initial TBT concentration, pH and temperature were studied. The Koble–Corrigan isotherm was the most suitable for data fitting. Based on a Langmuir isotherm model, the maximum adsorption capacities were 12.1212, 16.4204 and 7.5757 mg/g for MCM-TDI-C4, MCM-TDI-PC4 and MCM-TDI-C4S, respectively. The larger uptake and stronger affinity of MCM-TDI-PC4 than MCM-TDI-C4 and MCM-TDI-C4S probably results from van der Waals interactions and the pore size distribution of MCM-TDI-PC4. Gibbs free energies for the three adsorption processes of TBT presented a negative value, reflecting that TBT/surface interactions are thermodynamic favorable and spontaneous. The interaction processes were accompanied by an increase of entropy value for MCM-TDI-C4 and MCM-TDI-C4S (43.7192 and 120.7609 J/mol K, respectively) and a decrease for MCM-TDI-PC4 (−37.4704 J/mol K). It is obviously observed that MCM-TDI-PC4 spontaneously adsorbs TBT driven mainly by enthalpy change, while MCM-TDI-C4 and MCM-TDI-C4S do so driven mainly by entropy changes.
Collapse
|
9
|
Ayanda OS, Fatoki OS, Adekola FA, Ximba BJ. Utilization of nSiO2, fly ash, and nSiO 2/fly ash composite for the remediation of triphenyltin (TPT) from contaminated seawater. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2013; 20:8172-8181. [PMID: 23649603 DOI: 10.1007/s11356-013-1775-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Accepted: 04/24/2013] [Indexed: 06/02/2023]
Abstract
The removal of triphenyltin chloride from contaminated simulated seawater with adsorption method was discussed. The adsorbents used are fly ash, nSiO2, and nSiO2/fly ash composite. The results showed that the adsorption of the adsorbents increases with increase in the adsorbent dose, contact time, pH, stirring speed, initial TPT concentration, and decreased with increase in temperature. The adsorption fitted well with the Freundlich isotherm, showing that the adsorbent and TPT combined with function groups and the adsorption kinetics followed the pseudo-second-order kinetic model. The thermodynamic parameters were also evaluated. Optimal conditions for the adsorption of TPT from simulated seawater were applied to TPT removal from natural seawater. A higher removal efficiency of TPT (>99%) was obtained for the nSiO2/fly ash composite but not for fly ash and nSiO2.
Collapse
Affiliation(s)
- Olushola S Ayanda
- Department of Chemistry, Faculty of Applied Sciences, Cape Peninsula University of Technology, P.O. Box 1906, Bellville, South Africa,
| | | | | | | |
Collapse
|
10
|
Ayanda OS, Fatoki OS, Adekola FA, Ximba BJ. Kinetics and equilibrium models for the sorption of tributyltin to nZnO, activated carbon and nZnO/activated carbon composite in artificial seawater. MARINE POLLUTION BULLETIN 2013; 72:222-230. [PMID: 23643341 DOI: 10.1016/j.marpolbul.2013.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 03/13/2013] [Accepted: 04/01/2013] [Indexed: 06/02/2023]
Abstract
The removal of tributyltin (TBT) from artificial seawater using nZnO, activated carbon and nZnO/activated carbon composite was systematically studied. The equilibrium and kinetics of adsorption were investigated in a batch adsorption system. Equilibrium adsorption data were analyzed using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) isotherm models. Pseudo first- and second-order, Elovich, fractional power and intraparticle diffusion models were applied to test the kinetic data. Thermodynamic parameters such as ΔG°, ΔS° and ΔH° were also calculated to understand the mechanisms of adsorption. Optimal conditions for the adsorption of TBT from artificial seawater were then applied to TBT removal from natural seawater. A higher removal efficiency of TBT (>99%) was obtained for the nZnO/activated carbon composite material and for activated carbon but not for nZnO.
Collapse
Affiliation(s)
- Olushola S Ayanda
- Department of Chemistry, Faculty of Applied Sciences, Cape Peninsula University of Technology, P.O. Box 1906, Bellville, South Africa.
| | | | | | | |
Collapse
|
11
|
Fang L, Borggaard OK, Christensen JH, Holm PE, Hansen HCB. Adsorption of mono- and di-butyltin by a wheat charcoal: pH effects and modeling. CHEMOSPHERE 2012; 89:863-8. [PMID: 22664389 DOI: 10.1016/j.chemosphere.2012.05.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 05/03/2012] [Accepted: 05/07/2012] [Indexed: 05/25/2023]
Abstract
Understanding adsorption processes of butyltins (BTs) such as monobutyltin (MBT) and dibutyltin (DBT) by black carbons is important for the evaluation of BT exposure risks to organisms and humans. However, relevant knowledge is scarce. In this study, the acidity constants pK(a,1)=2.3, pK(a,2)=3.5 and pK(a,3)=5.9 for MBT and pK(a,1)=3.0 and pK(a,2)=5.1 for DBT are estimated via potentiometric titration. Additionally, adsorption isotherms of BTs to a wheat charcoal were determined. The adsorption behavior was observed to be pH-dependent due to BT speciation and the pH-dependent surface charge of the charcoal. MBT adsorption to the charcoal decreases with increasing pH from 4 to 8, while the highest adsorption occurs at pH 6 for DBT. Adsorption of the BTs is successfully described in the pH range of 3-10 by using a newly developed pH-dependent Dual Langmuir model. The model has the potential to predict the interaction of BT species with charcoal, which can contribute to the risk assessments of BTs in the environment.
Collapse
Affiliation(s)
- Liping Fang
- Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, Denmark.
| | | | | | | | | |
Collapse
|
12
|
Fang L, Borggaard OK, Holm PE, Hansen HCB, Cedergreen N. Toxicity and uptake of TRI- and dibutyltin in Daphnia magna in the absence and presence of nano-charcoal. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2011; 30:2553-2561. [PMID: 21858855 DOI: 10.1002/etc.649] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 05/17/2011] [Accepted: 07/26/2011] [Indexed: 05/31/2023]
Abstract
Butyltins (BTs), such as tributyltin (TBT) and dibutyltin (DBT), are toxic to aquatic organisms, but the presence of the strong adsorbent, black carbon (BC), can markedly influence BT toxicity and uptake in organisms. In the present study, the acute toxicity and uptake of TBT and DBT in the crustacean, Daphnia magna, were investigated with and without addition of nano-charcoal at different pHs and water hardnesses. The results showed that the toxicity of TBT and DBT increased by lowering the pH from 8 to 6. This reflects a relatively higher toxicity of cationic BT species than of the neutral species. At pH 6, by enhancing the water hardness of the media from 0.6 to 2.5 mM, the toxicity of TBT and DBT consistently decreased due to competitive binding of bivalent cations (Mg²⁺, Ca²⁺) to biotic ligands of D. magna. Furthermore, the toxicity of TBT to D. magna significantly decreased in the presence of nano-charcoal compared with experiments without nano-charcoal at pH 6 and 8, while no significant decrease in toxicity of DBT was observed in the presence of nano-charcoal. This can be attributed to the insignificant decrease of free DBT concentration in the presence of nano-charcoal compared with that for TBT. Conversely, it was observed that more TBT and DBT were taken up in D. magna in the presence of nano-charcoal due to the uptake of TBT or DBT associated with nano-charcoal by Daphnia in gut systems, as seen by light microscopy. This indicated that only free nonadsorbed BTs were toxic to D. magna, at least during short periods of exposure.
Collapse
Affiliation(s)
- Liping Fang
- Department of Basic Sciences and Environment, University of Copenhagen, Copenhagen, Denmark.
| | | | | | | | | |
Collapse
|