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- Andersson Ersman, Peter, et al.
(författare)
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Screen printed digital circuits based on vertical organicelectrochemical transistors
- 2017
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Ingår i: Flexible and Printed Electronics. - : IOP Publishing. - 2058-8585. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Vertical organic electrochemical transistors (OECTs) have been manufactured solely using screenprinting. The OECTs are based on PEDOT:PSS (poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonic acid)), which defines the active material for both the transistor channel and the gateelectrode. The resulting vertical OECT devices and circuits exhibit low-voltage operation, relativelyfast switching, small footprint and high manufacturing yield; the last three parameters are explainedby the reliance of the transistor configuration on a robust structure in which the electrolyte verticallybridges the bottom channel and the top gate electrode. Two different architectures of the verticalOECT have been manufactured, characterized and evaluated in parallel throughout this report. Inaddition to the experimental work, SPICE models enabling simulations of standalone OECTs andOECT-based circuits have been developed. Our findings may pave the way for fully integrated, lowvoltageoperating and printed signal processing systems integrated with e.g. printed batteries, solarcells, sensors and communication interfaces. Such technology can then serve a low-cost basetechnology for the internet of things, smart packaging and home diagnostics applications.
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| 3. |
- Eveborn, David
(författare)
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Bed filters for phosphorus removal in on-site wastewater treatment : Removal mechanisms and sustainability
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- For many surface waters, phosphorus (P) leaching is a serious problem that should be minimized to prevent eutrophication. In Sweden there is a demand for physical and technical development of high-performance P removal techniques to reduce phosphorus leaching from on-site wastewater treatment systems to the Baltic Sea. However, although these systems are designed to reduce eutrophication there are also other environmental impacts to be considered when implementing them in on-site systems; energy use and global warming potential are two examples. This study has investigated several bed filter materials (reactive media and natural soils) for their total environmental impact (in commercial applications) as well as for the predominating chemical phosphorus removal mechanisms. The use of life cycle assessment revealed that several reactive bed filters are relatively energy-consuming due to the material manufacturing process. Characterization of phosphorus compounds in used reactive media provided evidence for calcium phosphate precipitation as the predominating P removal mechanism in alkaline filter materials. However, in soil treatment systems with noncalcareous soils, batch experiments and extractions suggested that aluminium compounds were important for P removal. According to mass balance calculations that compared accumulated P with the estimated P load in a soil treatment system, the long term P removal capacity was very low; only 6.4 % of the applied phosphorus had been removed during 16 years of operation.
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| 4. |
- Eveborn, David, 1978-, et al.
(författare)
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Environmental systems analysis on enhanced phosphorus removal in onsite wastewater treatment
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In order to minimize phosphorus (P) loads to surface waters, the regulatory pressure on onsite wastewater treatment systems has increased. However, the environmental side-effects of implementing secondary P treatment have not been seriously reviewed. In this study we hypothesized that local conditions will largely govern the overall environmental benefits and drawbacks of different options for onsite wastewater treatment from a regional perspective. To explore the validity of this hypothesis an environmental systems analysis (ESA) model was developed that could handle differences in local conditions. The model was applied for four different treatment options, two conventional and two enhanced P treatment options. In a sensitivity analysis three diverse local contexts (type cases) were configured to evaluate the overall environmental impacts from the local and the regional perspective. The evaluation indicated that the eutrophication impacts from onsite wastewater treatment systems are significant in relation to the mean per capita contributions. This statement was valid even at a regional perspective as long as the natural retention was not very strong. Thus, the environmental side effects (increased emissions of greenhouse gases (GHG) and acidifying substances) of implementation of enhanced treatment solutions might be justifiable in many situations. However, due to a low impact in most of the studied environmental aspects, groundwater discharging soil treatment systems (STS) seemed to be preferable in areas were hydrogeological conditions are satisfactory and the distance to surface water is sufficient.
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| 8. |
- Eveborn, David, et al.
(författare)
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Organiska mikroföroreningar i enskild dricksvattenförsörjning
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I denna studie har 72 fastigheter med enskild vattenförsörjning undersökts för att kartlägga förekomst av organiska mikroföroreningar i enskilt dricksvatten. Vattenprover från brunnarna analyserades för en lista med ca 130 organiska föroreningar inom undergruppernaperfluorerade alkylsyror (PFAS)läkemedelsresterhygien- och kosmetikaprodukterbekämpningsmedelstimulanterindustrikemikalier.Utöver de organiska mikroföroreningarna analyserades också en bred uppsättning standard-parametrar som bakterier, pH, nitrat, fosfat och metaller (basparametrar).Studien har fokuserat på dricksvattenbrunnar som riskerar att utsättas för påverkan från enskilda avlopp. Arbetet skedde i samarbete med tio kommuner och urvalet av fastigheter för studien gjordes i samverkan mellan SGU och de lokala kommunrepresentanterna. För de fastigheter som valdes ut bedömdes det finnas en risk för påverkan på dricksvattnet från omgivande enskilda avloppsanläggningar. Inom projektet inventerades och dokumenterades 96 omgivande avlopp i syfte att ytterligare kartlägga riskbilden för påverkan.Resultaten visar att spår av organiska mikroföroreningar är vanligt förekommande i enskilda dricksvattenbrunnar. I samtliga brunnar gjordes fynd av någon organisk mikroförorening. I den brunn som hade flest fynd påvisades 13 substanser. Bland de tio vanligast förekommande substanserna återfanns ämnen från samtliga undergrupper undantaget bekämpningsmedel. Halterna var i regel låga (i storleksordningen några ng/l) och endast för ett enstaka fall kan man med hänvisning till riktvärden säga att halten utgjorde en risk ur hälsomässigt perspektiv. I detta fall rörde det sig om förekomst av bekämpningsmedel.Det är väl känt att avlopp (även enskilda hushållsavlopp) är en viktig källa för spridning till miljön för många av de föroreningar som studien omfattar. Trots detta kan denna studie inte uppvisa några tydliga samband mellan de fynd som gjordes och den bedömda risken för påverkan från närliggande avlopp. Analysresultaten (som dock omfattar osäkerheter) indikerade snarare en komplex bild av spridning där påverkanskällor från ett större sammanhang i brunnens tillrinningsområde bidrar till diffus påverkan på dricksvattnet.En stor del av analyserna för organiska mikroföroreningar utfördes med dubbelprov (två prover uttogs vid samma tidpunkt). Resultatet från dubbelproven visade på osäkerheter i analyser och/eller provtagningsutförande. Orsaken till osäkerheterna kan vara problem med representativitet mellan prover, kontamination eller analysutförande. Huvudorsaken går inte att fastställa. En viktig slutsats är därför att kvalitetssäkringsrutiner är viktiga för den här typen av screeningprojekt. Stöd för sådana rutiner kan behöva tas fram inom screeningverksamheten i Sverige och fortsatt kartläggning av analysosäkerheter är önskvärt. Det finns också fortsatt ett behov av att undersöka och spåra hur organiska mikroföroreningar kommer ut och sprids i miljön för att så småningom kunna identifieras i grundvatten.
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| 9. |
- Eveborn, David, 1978-, et al.
(författare)
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Phosphorus in soil treatment systems : accumulation and mobility
- 2014
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Ingår i: Water Research. - : Elsevier. - 0043-1354 .- 1879-2448. ; 64, s. 42-52
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Tidskriftsartikel (refereegranskat)abstract
- In several western countries, septic tanks with subsequent soil treatment systems (STS) are a common treatment technique for domestic wastewater in rural areas. However the suitability of STS (especially relatively close to surface waters) can be questioned since the discharge of phosphorus (P) from such effluents is not well known. In this study, six STS in Sweden (11 to 28 years old) were investigated by means of batch and column experiments on samples taken from the unsaturated subsoil beneath the distribution pipes. At all sites the wastewater had clearly influenced the soil. This was observed through decreased pH, increased amounts of oxalate extractable metals and altered P sorption properties. The amount of accumulated P in the STS (defined as the amount of total P in the STS samples minus the amount of total P in unused soil samples) were found to be between 0.32 and 0.87 kg m-3, which in most cases was just a small fraction of the estimated P load (< 30%). Column studies revealed that remarkably high P concentrations (up to 6 mg L-1) were leached from the material when deionized water was applied. However, the response to deionized water varied between the sites. The affinity for P in the soils was well correlated to the amount of oxalate-extractable aluminium (as evidenced by a strong relationship between oxalate-extractable Al and oxalate-extractable P) and generally soils with high content of oxalate extractable Al was also less vulnerable to P leakage.
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| 10. |
- Eveborn, David, 1978-
(författare)
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Sustainable phosphorus removal in onsite wastewater treatment
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aquatic eutrophication is a serious environmental problem that occurs all over the world. To protect surface waters (in particular the Baltic Sea), the regulatory pressure on onsite wastewater treatment (OWT) systems have increased in Sweden. Stringent requirements have led to uncertainties regarding the capability of conventional treatment techniques (soil treatment systems (STS)) to remove phosphorus (P), but they have also stimulated the development and introduction of enhanced P treatment techniques. In this thesis the accumulation and mobility of P as well as the chemical P removal mechanisms were studied in soils and reactive filter media. This knowledge was then used in environmental systems analysis. A model based on life cycle assessment (LCA) methodology was developed to evaluate the overall environmental performance of conventional and enhanced P treatment systems under various local conditions. The P accumulation in the studied STS varied (320-870 g m-3) and the accumulated P was rather mobile in some soils. Phosphorus compounds were identified in alkaline reactive filter media (calcium phosphates predominated) by means of X-ray Absorption Near Edge Structure (XANES). In sandy soils from STS aluminium was found to be a key element for P removal, as evidenced by a strong relationship between oxalate-extractable P and Al. The LCA studies indicated that enhanced P treatment systems may be beneficial from an eutrophication and P recycling perspective but causes increased impacts in terms of global warming and acidification. Despite the drawbacks, enhanced P treatment techniques should be considered suitable substitutes to surface water discharge STS under most conditions. This is because the latter systems have such a strong eutrophication impact. On the other hand, under appropriate conditions, STS with groundwater discharge may be advantageous. These systems generally caused low environmental impacts except for the dispersion of P resources.
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