| 1. |
- Andersen, Henrik Rasmus, et al.
(författare)
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Estrogenic personal care products in a greywater reuse system
- 2007
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 56:12, s. 45-49
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Tidskriftsartikel (refereegranskat)abstract
- The occurrence and fate of parabens in a greywater system was assessed. The potential for removal of residual paraben concentrations in effluent greywater with chlorine dioxide was also investigated. The influent to the greywater plant was characterised by considerable variation, with concentrations from below the detection limit to 40 μg/L and the five commonly used parabens in consumer products were frequently detected. After the biological treatment only two paraben were detected with concentration from 65–120 ng/L. Chlorine dioxide treatment of the biologically treated effluent with dosages down to 0.75 mg/L resulted in more than 97% reduction of all parabens. Formation of the by-product chloroform was insignificant from the chlorine dioxide treatment.
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| 2. |
- Augulyte, Lijana, 1978-
(författare)
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Use and Development of Diffusive Samplers to Analyse the Fate of Polycyclic Aromatic Compounds, Polychlorinated Biphenyls and Pharmaceuticals in Wastewater Treatment Processes
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The efficiency of wastewater treatment systems is commonly measured by the reductions of parameters such as biological oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solids (TSS) and/or reductions in levels of selected macro compounds (e.g. long-chained hydrocarbons and inorganic compounds). Less attention has generally been paid to micropollutants with high potential toxic effects, such as polycyclic aromatic compounds (PACs), including unsubstituted and alkylated polycyclic aromatic hydrocarbons (PAHs) and dibenzothiophenes, polychlorinated biphenyls (PCBs), human pharmaceuticals and by-products formed during the treatment process. These organic micropollutants occur in wastewaters at trace and ultra-trace levels, therefore their detection requires advanced, costly analyses and large sample volumes. Furthermore, concentrations of micropollutants can fluctuate widely both diurnally and between days. Thus, in order to understand the fate of micropollutants in wastewaters there is a need to develop sampling techniques that allow representative samples to be readily collected. In the work underlying this thesis two types of diffusive passive samplers, semipermeable membrane devices (SPMDs) and polar organic chemical integrative samplers (POCISs), were used to monitor non-polar and polar organic micropollutants in wastewaters subjected to various treatment processes. The pollutants sequestered in these samplers represent micropollutants in the dissolved phase that are available for aquatic organisms. Further, since they collect pollutants in an integrative manner, i.e. they sample continuously during the selected exposure time (usually approx. one to ca. three weeks), the results provide time-weighted average (TWA) concentrations. In addition, the effects of various environmental factors on the uptake of analyzed micropollutants in POCISs and SPMDs were investigated using laboratory calibration and in situ calibration with performance reference compounds (PRCs). The results confirm that SPMDs are good sampling tools for investigating the efficacy of wastewater treatment processes for removing non-polar PACs and PCBs, and the effects of varying the process settings. In addition, analyses of process streams in municipal sewage treatment plants demonstrated that conventional sewage treatment processes are not optimized for removing dissolved four-ringed PAHs, some of the five-ringed PAHs, and tri- to hexa-chlorinated biphenyls. The removal of bioavailable PACs was enhanced by adding sorbents with high sorption capacities to the sludge used in the activated sludge treatment step, and a biologically activated carbon system was designed that robustly removed bioavailable PACs, with removal efficiencies of 96.9-99.7 percent across the tested ranges of five varied process parameters. In situ SPMD calibration data acquired show that uptake of PACs, described by SPMD sampling rates (Rs), were four to eight times higher than published laboratory calibrated Rs values, mainly due to strong (bio)fouling and turbulence effects. In addition, the laboratory calibration study demonstrated that temperature affects the POCIS uptake of pharmaceuticals. The uptake of four pharmaceuticals was higher, by 10-56 percent, at 18 °C compared to 5 °C. For two of the pharmaceuticals our data indicate that the uptake was lower by 18-25 percent at 18 °C. Our results also indicate that uptake of the studied pharmaceuticals was in the linear phase throughout the 35 day exposure period at both temperatures. Finally, calibration studies enabled aqueous concentrations of micropollutants to be more accurately estimated from amounts collected in the passive samplers.
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| 3. |
- Baun, Anders, et al.
(författare)
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A methodology for ranking and hazard identification of xenobiotic organic compounds in urban stormwater
- 2006
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 370:1, s. 29-38
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Tidskriftsartikel (refereegranskat)abstract
- The paper presents a novel methodology (RICH, Ranking and Identification of Chemical Hazards) for ranking and identification ofxenobiotic organic compounds of environmental concern in stormwater discharged to surface water. The RICHmethod is illustrated as afunnel fitted with different filters that sort out problematic and hazardous compounds based on inherent physico-chemical and biologicalproperties. The outcomes of the RICH procedure are separate lists for both water phase and solid phase associated compounds. Theselists comprise: a justified list of compounds which can be disregarded in hazard/risk assessments, a justified list of stormwater prioritypollutants which must be included in hazard/risk assessments, and a list of compounds which may be present in discharged stormwater,but cannot be evaluated due to lack of data. The procedure was applied to 233 xenobiotic organic chemicals (XOCs) of relevance forstormwater. Of these 233 compounds, 121 compounds were found to be priority pollutants with regard to solids phases (i.e. suspendedsolids, soil, or sediments) when stormwater is discharged to surface water and 56 compounds were found to be priority pollutants withregard to the water phase. For 11% of the potential stormwater priority pollutants the screening procedure could not be carried out due tolack of data on basic physico-chemical properties and/or data on bioaccumulation, resistance to biodegradation, and ecotoxicity. Thetiered approach applied in the RICH procedure and the focus on the phases relevant for monitoring or risk assessment in the aquaticenvironment refines the list of “compounds of concern” when compared to the outcome of existing classification schemes. In this paperthe RICH procedure is focused on effects in the aquatic environment exemplified with xenobiotic organic compounds (XOCs) found inurban stormwater, but it may be transferred to other environmental compartments and problems. Thus, the RICH procedure can be usedas a stand-alone tool for selection of potential priority pollutants or it can be integrated in larger priority setting frameworks.
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| 4. |
- Bergdahl, Björn, et al.
(författare)
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In the Forefront of Development:The New Undergraduate Medical Curriculu
- 2006. - 1
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Ingår i: Celebrating the Past by Expanding the Future: The Faculty of Health Science, Linköping University 1986–2006. - Linköping : Linköping University Electronic Press. - 9185643076 ; , s. 98-102
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Dahlman, Joakim, 1974-, et al.
(författare)
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Could sound be used as a strategy for reducing symptoms of perceived motion sickness?
- 2008
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Ingår i: Journal of NeuroEngineering and Rehabilitation. - : Springer Science and Business Media LLC. - 1743-0003. ; 5:35
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Tidskriftsartikel (refereegranskat)abstract
- Background: Working while exposed to motions, physically and psychologically affects a person. Traditionally, motion sickness symptom reduction has implied use of medication, which can lead to detrimental effects on performance. Non-pharmaceutical strategies, in turn, often require cognitive and perceptual attention. Hence, for people working in high demand environments where it is impossible to reallocate focus of attention, other strategies are called upon. The aim of the study was to investigate possible impact of a mitigation strategy on perceived motion sickness and psychophysiological responses, based on an artificial sound horizon compared with a non-positioned sound source.Method: Twenty-three healthy subjects were seated on a motion platform in an artificial sound horizon or in non-positioned sound, in random order with one week interval between the trials. Perceived motion sickness (Mal), maximum duration of exposure (ST), skin conductance, blood volume pulse, temperature, respiration rate, eye movements and heart rate were measured continuously throughout the trials.Results: Mal scores increased over time in both sound conditions, but the artificial sound horizon, applied as a mitigation strategy for perceived motion sickness, showed no significant effect on Mal scores or ST. The number of fixations increased with time in the non-positioned sound condition. Moreover, fixation time was longer in the nonpositioned sound condition compared with sound horizon, indicating that the subjects used more time to fixate and, hence, assumingly made fewer saccades.Conclusion: A subliminally presented artificial sound horizon did not significantly affect perceived motion sickness, psychophysiological variables or the time the subjects endured the motion sickness triggering stimuli. The number of fixations and fixation times increased over time in the non-positioned sound condition.
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| 6. |
- Dahlman, Joakim, 1974-, et al.
(författare)
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Performance and Autonomic Responses during Motion Sickness
- 2009
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Ingår i: Human Factors. - : SAGE Publications. - 0018-7208 .- 1547-8181. ; 51:1, s. 56-66
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of the study was to investigate how motion sickness, triggered by an optokinetic drum, affects short term memory performance and to explore autonomic responses to perceived motion sickness. Background: Previous research has found motion sickness to decrease performance, but it is not known how short term memory in particular is affected. Method: Thirty-eight healthy participants performed a listening span test while seated in a rotating optokinetic drum. Measurements of motion sickness, performance, heart rate, skin conductance, blood volume pulse, and pupil size were performed simultaneously throughout the experiment. Results: A total of 16 participants terminated the trial due to severe nausea, while the other 22 endured the full 25 minutes. Perceived motion sickness increased over time in both groups, but less among those who endured the trial. Short term memory performance decreased towards the end for those who terminated, while it increased for the other group. Results from the measured autonomic responses were ambiguous. Conclusion: The present study concludes that performance, measured as short term memory, declines as perceived motion sickness progresses. Application: This research has potential implications for command and control personnel in risk of developing motion sickness.
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| 7. |
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| 8. |
- Eriksson, Eva, 1973-, et al.
(författare)
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Chemical hazard identification and assessment tool for evaluation of stormwater priority pollutants
- 2005
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Ingår i: Water Science and Technology. - 0273-1223 .- 1996-9732. ; 51:2, s. 47-55
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Tidskriftsartikel (refereegranskat)abstract
- Assessment of chemical hazards is a critical issue, which have to be dealt with when evaluating different strategies for sustainable handling of stormwater. In the present study, a methodology for identifying the most critical and representative chemical pollutants was developed. A list of selected stormwater priority pollutants (SSPP-list) is the out-put from the procedure. Two different strategies for handling of stormwater were considered; discharge into a surface water recipient and infiltration. However, the same methodology can be used for other types of wastewater and other strategies for handling and treatment. A literature survey revealed that at least 656 xenobiotic organic compounds (XOCs) could be present in stormwater. In the next step, 233 XOCs were evaluated with respect to the potential for being hazardous towards either aquatic living organisms or humans, or causing technical or aesthetical problems. 121 XOCs were found have at least one of these negative effects, while 26 XOCs could not be assessed due to the lack of data. The hazard assessment showed that 40 XOCs had a PEC/PNEC ratio above one., e.g. they should be considered as priority pollutants. The final step is the expert judgement, which resulted in a final SSPP-list containing 16 selected priority pollutants.
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| 9. |
- Eriksson, Eva, 1973-, et al.
(författare)
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Greywater pollution variability and loadings
- 2009
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Ingår i: Ecological Engineering. - : Elsevier BV. - 0925-8574 .- 1872-6992. ; 35:5, s. 661-669
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Tidskriftsartikel (refereegranskat)abstract
- Small on-site greywater treatment and reuse plants are susceptible to high short-term variation in flow and pollutant concentrations. As demonstrated in this study of a bathroom greywater plant in Copenhagen, Denmark, the flow ranges from no-flow periods to high-flow periods reaching 34 l min−1. Concentrations of both macro- and micro-pollutants (organic matter and parabens) were found to range by several orders of magnitude in the influent, based on sampling every 20 min. Paraben degradation was proven to occur in the rotating biological contactor (RBC), while the remnant organic matter in the effluent was proved not to be readily degradable. Ammonium content, presumably from urine contamination, was found to undergo nitrification in the RBC. Mass flow (daily loads) for individual substances was calculated for several pollutants. Macropollutants were found to be generated in low numbers of grams per person per day, whereas the paraben loadings were below 1 mg per person per day. These data are highly relevant for comparing decentralised treatment options with existing end-of-pipe treatments, for feeding into risk assessments and for design purposes.
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| 10. |
- Eriksson, Eva, 1973-, et al.
(författare)
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Phytotoxicity of grey wastewater evaluated by toxicity tests
- 2006
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Ingår i: Urban Water Journal. - : Informa UK Limited. - 1573-062X .- 1744-9006. ; 3:1, s. 13-20
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Tidskriftsartikel (refereegranskat)abstract
- An algal growth inhibition test and a short-term acute assay for willows were used in order to evaluate the phytotoxicity of grey wastewater from different sources. Bathroom grey wastewaters were toxic towards algae (EC10 = 36 – 375 mL/L), whereas kitchen and laundry wastewaters were found to be toxic to both organisms (EC10 = 55 – 198 mL/L). The investigation showed that untreated grey wastewater could pose an environmental hazard if discharged into small-size receiving waters. Discharge to willow evaporation beds is problematic and toxic effects may be encountered, but, compared to direct discharge to surface water, the risks of toxic effects are much less pronounced.
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