1
|
Liu Y, Xie S, Sun Y, Ma L, Lin Z, Grathwohl P, Lohmann R. In-situ and ex-situ measurement of hydrophobic organic contaminants in soil air based on passive sampling: PAH exchange kinetics, non-equilibrium correction and comparison with traditional estimations. JOURNAL OF HAZARDOUS MATERIALS 2021; 410:124646. [PMID: 33250309 DOI: 10.1016/j.jhazmat.2020.124646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/14/2020] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
It is a great challenge to accurately estimate chemical activity of hydrophobic organic contaminants in field soils. Ex-situ and in-situ determinations were developed for this purpose based on low-density polyethylene (LDPE) passive sampling and non-equilibrium correction by release of performance reference compounds (PRCs) previously spiked to the samplers. This work investigated kinetic processes of target contaminants' uptake into and PRCs' release from the sampler in an ex-situ soil suspension incubated for 100 days. A close agreement of kinetic parameters for pyrene's (target) uptake into and deuterated pyrene's (PRC) release from LDPE indicated their similar exchange kinetics. Three kinetic models were developed to correct uptake of target compounds in non-equilibrium conditions via release processes of PRCs. The second-order kinetic model was recommended for ex-situ measurements. The PRC-based non-equilibrium corrections were further applied to in-situ static passive sampling from several weeks to months in a PAH-contaminated field site. Two-weeks' deployments were sufficient for quantifying lighter PAHs (logKOA < 8.0), but not recommended to accurately estimate heavier PAHs (logKOA > 9.0), even if over four months. Concentration estimates from the in-situ and ex-situ passive samplings were comparable in order of magnitude with traditional estimation from equilibrium partitioning models considering both organic and black carbon fractions.
Collapse
Affiliation(s)
- Ying Liu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; China Meteorological Administration Key Laboratory of Cities' Mitigation and Adaptation to Climate Change (Shanghai Meteorological Bureau), IESD, Tongji University, Shanghai 200092, China.
| | - Shuya Xie
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Center for Applied Geoscience, University of Tübingen, Hölderlinstrasse 12, Tübingen 72074, Germany
| | - Yajie Sun
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Limin Ma
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Zhifen Lin
- Shanghai Key Lab of Chemical Assessment and Sustainability, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Peter Grathwohl
- Center for Applied Geoscience, University of Tübingen, Hölderlinstrasse 12, Tübingen 72074, Germany
| | - Rainer Lohmann
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882-1197, United States
| |
Collapse
|
2
|
Ahkola H, Lindholm-Lehto P, Perkola N, Välitalo P, Meriläinen P, Mäenpää K, Stelzer JAA, Heiskanen I, Järvistö J, Nuutinen J, Leppänen MT. A preliminary study on the ecotoxic potency of wastewater treatment plant sludge combining passive sampling and bioassays. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 758:143700. [PMID: 33257078 DOI: 10.1016/j.scitotenv.2020.143700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/28/2020] [Accepted: 11/06/2020] [Indexed: 06/12/2023]
Abstract
Sewage sludge is an inevitable byproduct produced in wastewater treatment. Reusing nutrient-rich sludge will diminish the amount of waste ending in soil dumping areas and will promote circular economy. However, during sewage treatment process, several potentially harmful organic chemicals are retained in sludge, but proving the safety of processed sludge will promote its more extensive use in agriculture and landscaping. Environmental risk assessment of sludge requires new methods of characterizing its suitability for various circular economy applications. Bioavailable and bioaccessible fractions are key variables indicating leaching, transport, and bioaccumulation capacity. Also, sludge treatments have a significant effect on chemical status and resulting environmental risks. In this study, the concentrations of polyaromatic hydrocarbons (PAHs), triclosan (TCS), triclocarban (TCC), methyl triclosan (mTCS), and selected active pharmaceutical ingredients (APIs) were determined in different sludge treatments and fractions. Passive samplers were used to characterize the bioavailable and bioaccessible fractions, and the sampler extracts along the sludge and filtrate samples were utilized in the bioassays. The TCS and PAH concentrations did not decrease as the sludge was digested, but the contents diminished after composting. Also, mTCS concentration decreased after composting. The API concentrations were lower in digested sludge than in secondary sludge. Digested sludge was toxic for Aliivibrio fischeri, but after composting, toxicity was not observed. However, for Daphnia magna, passive sampler extracts of all sludge treatments were either acutely (immobility) or chronically (reproduction) toxic. Secondary and digested sludge sampler extracts were cytotoxic, and secondary sludge extract was also genotoxic. The measured chemical concentration levels did not explain the toxicity of the samples based on the reported toxicity thresholds. Bioassays and sampler extracts detecting bioavailable and bioaccessible contaminants in sludge are complementing tools for chemical analyses. Harmonization of these methodswill help establish scientifically sound regulative thresholds for the use of sludge in circular economy applications.
Collapse
Affiliation(s)
- Heidi Ahkola
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland.
| | - Petra Lindholm-Lehto
- Aquatic Production Systems, Natural Resources Institute Finland (Luke), Survontie 9A, FI-40500 Jyväskylä, Finland; University of Jyväskylä, FI-40500 Jyväskylä, Finland
| | - Noora Perkola
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland
| | - Pia Välitalo
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland; Aalto University, Tietotie 1E, FI-02150 Espoo, Finland
| | - Päivi Meriläinen
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland; Finnish Institute for Health and Welfare, P.O.Box 95, FI-70701 Kuopio, Finland
| | - Kimmo Mäenpää
- University of Eastern Finland, Yliopistokatu 2, P.O.Box 111, FI-80101 Joensuu, Finland
| | - Julio Alberto Alegre Stelzer
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland; University of Geneva, CH-1211 Geneva, Switzerland
| | - Ilse Heiskanen
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland
| | - Johanna Järvistö
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland
| | - Jari Nuutinen
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland
| | - Matti T Leppänen
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland
| |
Collapse
|
3
|
Posada-Baquero R, Jiménez-Volkerink SN, García JL, Vila J, Cantos M, Grifoll M, Ortega-Calvo JJ. Rhizosphere-enhanced biosurfactant action on slowly desorbing PAHs in contaminated soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137608. [PMID: 32143055 DOI: 10.1016/j.scitotenv.2020.137608] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 02/22/2020] [Accepted: 02/26/2020] [Indexed: 04/15/2023]
Abstract
We studied how sunflower plants affect rhamnolipid biosurfactant mobilization of slowly desorbing fractions of polycyclic aromatic hydrocarbons (PAHs) in soil from a creosote-contaminated site. Desorption kinetics of 13 individual PAHs revealed that the soil contained initially up to 50% slowly desorbing fractions. A rhamnolipid biosurfactant was applied to the soil at the completion of the sunflower cycle (75 days in greenhouse conditions). After this period, the PAHs that remained in the soil were mainly present in a slowly desorbing form as a result of the efficient biodegradation of fast-desorbing PAHs by native microbial populations. The rhamnolipid enhanced the bioavailable fraction of the remaining PAHs by up to 30%, as evidenced by a standardized desorption extraction with Tenax, but the enhancement occurred with only planted soils. The enhanced bioavailability did not decrease residual PAH concentrations under greenhouse conditions, possibly due to ecophysiological limitations in the biodegradation process that were independent of the bioavailability. However, biodegradation was enhanced during slurry treatment of greenhouse planted soils that received the biosurfactant. The addition of rhamnolipids caused a dramatic shift in the soil bacterial community structure, which was magnified in the presence of sunflower plants. The stimulated groups were identified as fast-growing and catabolically versatile bacteria. This new rhizosphere microbial biomass possibly interacted with the biosurfactant to facilitate intra-aggregate diffusion of PAHs, thus enhancing the kinetics of slow desorption. Our results show that the usually limited biosurfactant efficiency with contaminated field soils can be significantly enhanced by integrating the sunflower ontogenetic cycle into the bioremediation design.
Collapse
Affiliation(s)
- Rosa Posada-Baquero
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), Avenida Reina Mercedes, 10, Seville 41012, Spain
| | - Sara Nienke Jiménez-Volkerink
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Diagonal 643, Barcelona 08028, Spain
| | - José Luis García
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), Avenida Reina Mercedes, 10, Seville 41012, Spain
| | - Joaquim Vila
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Diagonal 643, Barcelona 08028, Spain
| | - Manuel Cantos
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), Avenida Reina Mercedes, 10, Seville 41012, Spain
| | - Magdalena Grifoll
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Diagonal 643, Barcelona 08028, Spain
| | - Jose Julio Ortega-Calvo
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), Avenida Reina Mercedes, 10, Seville 41012, Spain.
| |
Collapse
|
4
|
Portet-Koltalo F, Gardes T, Debret M, Copard Y, Marcotte S, Morin C, Laperdrix Q. Bioaccessibility of polycyclic aromatic compounds (PAHs, PCBs) and trace elements: Influencing factors and determination in a river sediment core. JOURNAL OF HAZARDOUS MATERIALS 2020; 384:121499. [PMID: 31685316 DOI: 10.1016/j.jhazmat.2019.121499] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 10/16/2019] [Accepted: 10/17/2019] [Indexed: 06/10/2023]
Abstract
Organic matter (OM), clays, sand or time are factors possibly influencing the bioaccessibility of polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs) from sediments. An experimental design was performed to monitor and quantify this process. The bioaccessible fraction, linked to the rapidly-desorbing fraction (Frap) of contaminants, was assessed through a non-exhaustive extraction using a carboxymethyl-β-cyclodextrin polymer. OM content was the most influential factor as regards Frap. Clay percentage was a slightly influential factor for PAHs while the interaction sand × OM was a slightly influential factor for PCBs. Frap was also determined in a sediment core collected from Martot's Pond (France). The higher the PAH/PCB concentration in this sediment, the higher the bioaccessible fraction. The relationship between a lower bioaccessibility and a higher number of PAHs cycles or PCB chlorines was linear. OM content impacted on Frap only for PAHs. Sequential extractions of some trace elements were also performed to evaluate their mobility. Cu, Cr, Pb, Ni were the less bioaccessible. A great part of As, Cd and Zn was found in the most bioaccessible sediment fractions. The 40-65 cm section might be considered as the most negatively impacting on the aquatic fauna, due to Cd and Zn high bioaccessible concentrations.
Collapse
Affiliation(s)
- F Portet-Koltalo
- Normandie University, UNIROUEN, COBRA Laboratory UMR CNRS 6014, 55 rue Saint Germain, 27000 Evreux, France.
| | - T Gardes
- Normandie University, UNIROUEN, COBRA Laboratory UMR CNRS 6014, 55 rue Saint Germain, 27000 Evreux, France; Normandie University, UNIROUEN, M2C Laboratory UMR 6143, FR CNRS 3730 SCALE, Bâtiment Blondel, Place Emile Blondel, 76821 Mont Saint Aignan Cedex, France.
| | - M Debret
- Normandie University, UNIROUEN, M2C Laboratory UMR 6143, FR CNRS 3730 SCALE, Bâtiment Blondel, Place Emile Blondel, 76821 Mont Saint Aignan Cedex, France.
| | - Y Copard
- Normandie University, UNIROUEN, M2C Laboratory UMR 6143, FR CNRS 3730 SCALE, Bâtiment Blondel, Place Emile Blondel, 76821 Mont Saint Aignan Cedex, France.
| | - S Marcotte
- Normandie University, UNIROUEN, COBRA Laboratory UMR CNRS 6014, 55 rue Saint Germain, 27000 Evreux, France.
| | - C Morin
- Normandie University, UNIROUEN, COBRA Laboratory UMR CNRS 6014, 55 rue Saint Germain, 27000 Evreux, France.
| | - Q Laperdrix
- Normandie University, UNIROUEN, COBRA Laboratory UMR CNRS 6014, 55 rue Saint Germain, 27000 Evreux, France.
| |
Collapse
|
5
|
Cocovi-Solberg DJ, Kellner A, Schmidt SN, Loibner AP, Miró M, Mayer P. Membrane Enhanced Bioaccessibility Extraction (MEBE) of hydrophobic soil pollutants - Using a semipermeable membrane for separating desorption medium and acceptor solvent. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 257:113470. [PMID: 31706770 DOI: 10.1016/j.envpol.2019.113470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/05/2019] [Accepted: 10/21/2019] [Indexed: 06/10/2023]
Abstract
Bioaccessibility extractions are increasingly applied to measure the fraction of pollutants in soil, sediment and biochar, which can be released under environmentally or physiologically relevant conditions. However, the bioaccessibility of hydrophobic organic chemicals (HOCs) can be markedly underestimated when the sink capacity of the extraction medium is insufficient. Here, a novel method called "Membrane Enhanced Bioaccessibility Extraction" (MEBE) applies a semipermeable membrane to physically separate an aqueous desorption medium that sets the desorption conditions from an organic medium that serves as acceptor phase and infinite sink. The specific MEBE method combines HOC (1) desorption into a 2-hydroxypropyl-β-cyclodextrin solution, (2) transfer through a low-density polyethylene (LDPE) membrane and (3) release into ethanol, serving as analytical acceptor phase. The surface to volume ratio within the LDPE membrane is maximized for rapid depletion of desorbed molecules, and the capacity ratio between the acceptor phase and the environmental sample is maximized to achieve infinite sink conditions. Several experiments were conducted for developing, optimizing and pre-testing the method, which was then applied to four soils polluted with polycyclic aromatic hydrocarbons. MEBE minimized sample preparation and yielded a solvent extract readily analyzable by HPLC. This study focused on the proof-of-principle testing of the MEBE concept, which now can be extended and applied to other samples and desorption media.
Collapse
Affiliation(s)
- David J Cocovi-Solberg
- DTU Environment, Technical University of Denmark, Bygningstorvet B115, DK-2800, Kgs. Lyngby, Denmark; FI-TRACE group, Department of Chemistry, University of the Balearic Islands, Carretera de Valldemossa, Km 7.5, E-07122, Palma de Mallorca, Spain.
| | - Astrid Kellner
- DTU Environment, Technical University of Denmark, Bygningstorvet B115, DK-2800, Kgs. Lyngby, Denmark; BOKU, University of Natural Resources and Life Sciences Vienna, Dept. IFA-Tulln, Konrad Lorenz Strasse 20, A-3430, Tulln, Austria.
| | - Stine N Schmidt
- DTU Environment, Technical University of Denmark, Bygningstorvet B115, DK-2800, Kgs. Lyngby, Denmark.
| | - Andreas P Loibner
- BOKU, University of Natural Resources and Life Sciences Vienna, Dept. IFA-Tulln, Konrad Lorenz Strasse 20, A-3430, Tulln, Austria.
| | - Manuel Miró
- FI-TRACE group, Department of Chemistry, University of the Balearic Islands, Carretera de Valldemossa, Km 7.5, E-07122, Palma de Mallorca, Spain.
| | - Philipp Mayer
- DTU Environment, Technical University of Denmark, Bygningstorvet B115, DK-2800, Kgs. Lyngby, Denmark.
| |
Collapse
|
6
|
Hilber I, Arrigo Y, Zuber M, Bucheli TD. Desorption Resistance of Polycyclic Aromatic Hydrocarbons in Biochars Incubated in Cow Ruminal Liquid in Vitro and in Vivo. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:13695-13703. [PMID: 31682112 DOI: 10.1021/acs.est.9b04340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Biochar is a new, promising, and sustainable feed additive alternative in agricultural production, which may, however, contain a considerable amount of polycyclic aromatic hydrocarbons (PAHs). As a measure of their bioaccessibility to ruminants, we quantified PAH concentrations in biochars before and after three different incubation experiments. Specifically, the biochars were subjected to (1) an aqueous cyclodextrin suspension with a contaminant trap as (infinite) sink, (2) an in vitro experiment with cow ruminal liquid and a contaminant trap, and (3) an in vivo experiment within cow rumen. Three different biochars were used that contained 13-407 mg/kgdw of the sum of 16 U.S. EPA PAHs before the exposure. While experiment (1) resulted in no or minimal bioaccessibility (desorption resistance) of the PAHs expressed by their largely unaltered concentrations, experiments (2) and (3) caused concentration reductions on average by 35 and 56%, respectively, presumably mainly due to the presence of the ruminal fluid in (2) and (3), and the extended sorption capacity in (3). Thus, simple and "abiotic" passive sampling methods may not capture all processes contributing to bioaccessibility in complex biological systems. A comparison with average daily PAH intake of ruminants suggests that quality-controlled biochar containing <10 mg/kgdw PAHs will not pose an increased risk when applied as a feed additive.
Collapse
Affiliation(s)
- Isabel Hilber
- Agroscope, Research Group Environmental Analytics , 8046 Zurich , Switzerland
| | - Yves Arrigo
- Agroscope, Research Group Ruminants , 1725 Posieux , Switzerland
| | - Martin Zuber
- Agroscope, Research Group Environmental Analytics , 8046 Zurich , Switzerland
| | - Thomas D Bucheli
- Agroscope, Research Group Environmental Analytics , 8046 Zurich , Switzerland
| |
Collapse
|
7
|
Hu Q, Liu S, Liu Y, Fang X, Xu J, Chen X, Zhu F, Ouyang G. Development of an on–site detection approach for rapid and highly sensitive determination of persistent organic pollutants in real aquatic environment. Anal Chim Acta 2019; 1050:88-94. [DOI: 10.1016/j.aca.2018.11.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/25/2018] [Accepted: 11/05/2018] [Indexed: 12/29/2022]
|
8
|
Bartolomé N, Hilber I, Schulin R, Mayer P, Witt G, Reininghaus M, Bucheli TD. Comparison of freely dissolved concentrations of PAHs in contaminated pot soils under saturated and unsaturated water conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 644:835-843. [PMID: 30743881 DOI: 10.1016/j.scitotenv.2018.06.359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/28/2018] [Accepted: 06/28/2018] [Indexed: 06/09/2023]
Abstract
Passive sampling (PS, equally used for passive sampler) methods have successfully been applied in situ to quantify the bioavailability of hydrophobic organic compounds in air, water and sediments. However, very little is known on the applicability of PS in unsaturated soils. Here, we present the results of a greenhouse experiment in which we applied in situ PS methods in pots. Low density polyethylene (LDPE) and polydimethylsiloxane (PDMS) fibres with a newly developed PS holder were used to analyse freely dissolved polycyclic aromatic hydrocarbon (PAH) concentrations (Cfree) in a skeet shooting range soil and an uncontaminated control soil under water saturated and unsaturated conditions for up to nine months. A short exposure time of three months was not sufficient for the PDMS samplers to reach distribution equilibrium with the surrounding soil. Under saturated water conditions, the in situ results agreed well with measurements obtained from the conventional ex situ soil suspension method. They were in accordance with similar comparisons made in previous studies on sediments, as well as with model predictions. However, for unsaturated water conditions, the results differed considerably from the ex situ Cfree values, in particular for the light molecular weight (LMW) PAHs such as phenanthrene, fluoranthene, and pyrene. The results of the two in situ PS methods were in good agreement with each other under both soil water conditions, indicating that dissipation mechanisms, such as degradation or volatilization, led to a substantial decrease in Cfree under unsaturated conditions, especially for the LMW PAHs (log10KOW < 5.85) over a period of six months or more. Thus, in their current state of development, in situ PS methods can be used in soils under water-saturated conditions. However, an adequate method to correct for non-equilibrium conditions needs to be developed before they can be applied to unsaturated conditions, mainly for LMW PAHs.
Collapse
Affiliation(s)
- Nora Bartolomé
- Agroscope, Environmental Analytics, Reckenholzstrasse 191, 8046 Zurich, Switzerland; Department of Environmental Systems Sciences, ETH Zurich, Universitätsstrasse 16, 8092 Zurich, Switzerland
| | - Isabel Hilber
- Agroscope, Environmental Analytics, Reckenholzstrasse 191, 8046 Zurich, Switzerland
| | - Rainer Schulin
- Department of Environmental Systems Sciences, ETH Zurich, Universitätsstrasse 16, 8092 Zurich, Switzerland
| | - Philipp Mayer
- Technical University of Denmark, 2800, Kongens, Lyngby, Denmark
| | - Gesine Witt
- University of Applied Science Hamburg, D-21033 Hamburg, Germany
| | | | - Thomas D Bucheli
- Agroscope, Environmental Analytics, Reckenholzstrasse 191, 8046 Zurich, Switzerland.
| |
Collapse
|
9
|
Sjoeholm KK, Schmidt SN, Jahnke A, Svensmark B, Mayer P. Equilibrium sampling reveals increasing thermodynamic potential of polycyclic aromatic hydrocarbons during sewage sludge digestion. CHEMOSPHERE 2018; 207:421-429. [PMID: 29807341 DOI: 10.1016/j.chemosphere.2018.05.104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 05/07/2018] [Accepted: 05/18/2018] [Indexed: 06/08/2023]
Abstract
The reuse of digested sludge from wastewater treatment plants (WWTPs) as soil fertilizer poses a risk for contamination of soil and water environments. The present study provides a new approach for investigating the exposure of hydrophobic organic chemicals in sewage sludge. The methodology of equilibrium sampling with multiple thicknesses of silicone was successfully validated and applied to complex sludge matrices. Polycyclic aromatic hydrocarbon (PAH) concentrations in silicone (Csilicone) were determined and compared across four WWTPs. Activity ratios (ARs), defined as Csilicone at equilibrium with digested sludge (final product) over Csilicone at equilibrium with secondary sludge (intermediate product), were in the range 0.85-20 with all except one AR>1. These ARs thus revealed increased thermodynamic potential of both parent and alkylated PAHs in digested sludge compared with secondary sludge, and thereby higher exposure of PAHs in sludge after digestion than before digestion. This observation can be explained by the concept of "solvent depletion" as organic matter decreased by a factor of 1.3 during digestion, resulting in reduced sorptive capacity and increased freely dissolved concentrations (Cfree). The PAHs with logKow > 6 had ARs close to 1.3, whereas PAHs with logKow < 6 showed higher ARs than the organic matter decrease factor of 1.3. Cfree in digested sludge were higher than reported in rural soil and generally consistent with levels reported for Baltic Sea sediment.
Collapse
Affiliation(s)
- Karina K Sjoeholm
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet B115, DK-2800, Kgs, Lyngby, Denmark; Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg, Denmark.
| | - Stine N Schmidt
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet B115, DK-2800, Kgs, Lyngby, Denmark; Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg, Denmark.
| | - Annika Jahnke
- Department of Cell Toxicology, Helmholtz Center for Environmental Research GmbH - UFZ, Permoserstraβe 15, DE-04318, Leipzig, Germany.
| | - Bo Svensmark
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg, Denmark.
| | - Philipp Mayer
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet B115, DK-2800, Kgs, Lyngby, Denmark.
| |
Collapse
|