| 1. |
- Knutsson, Jesper, 1973
(författare)
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Passive sampling for monitoring of inorganic pollutants in water
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As new environmental management policies for watersheds are implemented, there has been a growing interest for new monitoring alternatives. Traditionally grab sampling has been the method of choice for monitoring purposes, but may not be adequate or economically viable, to meet the requirements of the new policies. Passive samplers for monitoring of aquatic pollutants have been described in the literature for almost three decades, but they are only beginning to gain acceptance outside the scientific research community. The potential advantages of passive samplers over other sampling and measurement strategies include the ability to integrate pollutant levels over extended sampling periods (up to several weeks), as well as inherent speciation capabilities, allowing for critical in situ speciation of metals. Passive samplers are relatively low-cost and do not require secure locations or additional infrastructure, making them ideal devices for certain monitoring tasks.The research presented in this thesis aims at further developing passive sampling for aquatic monitoring. This research includes field trials, the development of a novel application for nutrient monitoring in waste water treatment plant effluents and the identification of scenarios for which passive samplers can be used. An analysis of measurement uncertainties associated with passive samplers is also presented.
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| 2. |
- Arpadjan, S., et al.
(författare)
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Speciation analysis of thallium in water samples after separation/ preconcentration with the EmporeTM chelating disk
- 2011
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Ingår i: International Journal of Environmental Analytical Chemistry. - : Informa UK Limited. - 0306-7319 .- 1029-0397. ; 91:11, s. 1088-1099
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Tidskriftsartikel (refereegranskat)abstract
- A simple, reliable and novel solid phase extraction procedure using the Empore chelating disk has been developed for determination of Tl(I) and Tl(III) in environmental water samples by electrothermal atomic absorption spectrometry (ETAAS). The influence of humic acids on separation/preconcentration of thallium species with the Empore chelating disk is investigated. The preconcentration factor and detection limit are 500 and 5 ng L-1, respectively. The recoveries are in the range 93-103% for mineral, pond, sea, snowmelt, waste waters at 28-500 ng L-1 Tl and in the range 82-112% for river waters at 18-28 ng L-1 Tl.
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| 3. |
- Knutsson, Jesper, 1973, et al.
(författare)
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Performance of a passive sampler for the determination of time averaged concentrations of nitrate and phosphate in water
- 2013
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Ingår i: Environmental Sciences: Processes and Impacts. - 2050-7895 .- 2050-7887. ; 15:5, s. 955-962
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Tidskriftsartikel (refereegranskat)abstract
- A passive sampler device for the kinetic accumulation of nitrate (NO3-) and phosphate (HPO42-) in water was developed and calibrated. The sampler incorporates an ion-exchange disk as the receiving phase and selectively collects nitrate and phosphate at sampling rates of 197 +/- 43 and 75 +/- 12 mL per day, respectively. Minimum exposure times under nutrient rich and nutrient poor conditions were estimated to be 3 and 27 days respectively for phosphate and 1 and 7 days respectively for nitrate. The influence of the environmental variables pH (5-9), temperature (7-21 [degree]C) and turbulence (50-400 rpm) on sampling rates was investigated. Temperature was found to have a significant influence on uptake rates for both anions, while pH influenced phosphate only. Water turbulence did not influence the uptake rates under the studied conditions. A series of field studies was conducted at a municipal wastewater treatment plant. Results for the passive sampler were lower than concentrations obtained using conventional measurement methods, due to methodological differences, and biofouling was found to affect the results for sampling periods over 3 days. This study shows that passive sampling can be used to monitor nitrate and phosphate concentrations in aqueous media. The approach provides an interesting alternative to grab sampling as it yields time-averaged concentrations of the analytes.
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| 4. |
- Arpadjan, Sonja, et al.
(författare)
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Preconcentration Methods for Determination of Thallium in Natural Waters
- 2008
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Ingår i: Eurasian Journal of Analytical Chemistry. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Two preconcentration procedures for electrothermal atomic absorption (ETAAS) determination of thallium in mineral, spring, tap, river, underground and sea water were developed and compared: (i) Column solid phase extraction with new sandwich type disposable sorbent columns (
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| 5. |
- Knutsson, Jesper, 1973, et al.
(författare)
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Estimation of Measurement Uncertainties for the DGT Passive Sampler Used for Determination of Copper in Water
- 2014
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Ingår i: International Journal of Analytical Chemistry. - : Hindawi Limited. - 1687-8779 .- 1687-8760. ; 2014, s. 7-
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Tidskriftsartikel (refereegranskat)abstract
- Diffusion-based passive samplers are increasingly used for water quality monitoring. While the overall method robustness and reproducibility for passive samplers in water are widely reported, there has been a lack of a detailed description of uncertainty sources. In this paper an uncertainty budget for the determination of fully labile Cu in water using a DGT passive sampler is presented. Uncertainty from the estimation of effective cross-sectional diffusion area and the instrumental determination of accumulated mass of analyte are the most significant sources of uncertainty, while uncertainties from contamination and the estimation of diffusion coefficient are negligible. The results presented highlight issues with passive samplers which are important to address if overall method uncertainty is to be reduced and effective strategies to reduce overall method uncertainty are presented.
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| 6. |
- Knutsson, Jesper, 1973, et al.
(författare)
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Evaluation of a passive sampler for the speciation of metals in urban runoff water
- 2013
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Ingår i: Environmental Sciences: Processes and Impacts. - : Royal Society of Chemistry (RSC). - 2050-7895 .- 2050-7887. ; 15:12, s. 2233-2239
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Tidskriftsartikel (refereegranskat)abstract
- Metals in urban runoff water need to be monitored in order to estimate fluxes and assess their impact on the aquatic environment. Passive sampling is a useful and reliable emerging tool for measuring time averaged concentrations of metals in water bodies. This paper describes the deployment of a passive sampler to measure Cu, Ni and Zn in an urban runoff water treatment facility. The concentrations derived from the passive samplers are compared to concentrations obtained from an automated water sampler which provides pooled spot water samples and to model predictions from the visualMINTEQ computer speciation code. Results show that visualMINTEQ predictions partly describe the metal speciation in non-equilibrium systems. In addition we conclude that passive samplers are useful for monitoring and characterization of metal speciation under chemodynamic conditions. © 2013 The Royal Society of Chemistry.
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| 7. |
- Mills, Graham A., et al.
(författare)
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Monitoring heavy metals using passive samplers
- 2009
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Ingår i: Rapid chemical and biological techniques for water monitoring. - Chichester, UK : John Wiley & Sons, Ltd. - 9780470058114 ; , s. 243-262
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Rapid Chemical and Biological Techniques for Water Monitoring presents in one volume the broad spectrum of monitoring tools, both available and under development, and provides an assessment of their potential for underpinning environmental management and legislation. The book explores screening methods in the context of water policies; chemical methods; biological methods; potential use of screening methods; quality assurance and validation methods; integration of screening methods in water monitoring strategies. The text provides a timely source of information for post-graduates, researchers, and professionals involved in water management at all levels.
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| 8. |
- Vrana, Branislav, et al.
(författare)
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Performance optimization of a passive sampler for monitoring hydrophobic organic pollutants in water
- 2005
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Ingår i: Journal of Environmental Monitoring. - : Royal Society of Chemistry (RSC). - 1464-0333 .- 1464-0325. ; 7:6, s. 612-620
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Tidskriftsartikel (refereegranskat)abstract
- The performance of an integrative passive sampler that consists of a C18 Empore disk sorbent receiving phase fitted with low d. polyethylene membrane was optimized for the measurement of time-weighted av. concns. of hydrophobic micropollutants in water. A substantial improvement of sampling characteristics including the rate of sampling and the sampling precision was achieved by decreasing the internal sampler resistance to mass transfer of hydrophobic org. chems. This was achieved by adding a small vol. of n-octanol, a solvent with high permeability (soly. * diffusivity) for target analytes, to the interstial space between the receiving sorbent phase and the polyethylene diffusion-limiting membrane. [on SciFinder (R)]
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