| 1. |
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| 2. |
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| 3. |
- Albers, Eva, 1966, et al.
(författare)
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Influence of preservation methods on biochemical composition and downstream processing of cultivated Saccharina latissima biomass
- 2021
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Ingår i: Algal Research. - : Elsevier BV. - 2211-9264. ; 55
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Tidskriftsartikel (refereegranskat)abstract
- Saccharina latissima biomass cultivated along the Swedish west coast was subjected to four different scalable preservation methods after harvest; freezing, sun-drying, oven-drying and ensiling. Freeze-drying and freezing at -80 ?C were also included to provide dry and wet references. The effects of the different preservation methods on the composition of Saccharina biomass (on dry weight, DW, basis), and the recovery as well as properties of high-quality protein, alginate and biogas were evaluated. Sun-drying significantly reduced protein, alginate and fatty acid content of the seaweeds and thereby concentrated ash in the biomass compared to the other methods. Protein/amino acids and fatty acids were significantly concentrated in ensiled biomass, while mannitol and laminarin were reduced compared to the other biomasses. Oven-drying and -20 ?C freezing affected the composition the least, with lower ash content and alterations in some specific amino and fatty acids. Sun-drying and ensiling resulted in significantly lower protein solubility at high pH compared to the other biomasses which translated into the lowest total seaweed protein recovery using the pH-shift process. Highest protein yield was obtained with the freeze-dried reference. Ensiling lead to a significant decrease in the molecular weight of alginate, while sun-drying caused a negative effect on alginate by inducing a shift in the guluronic and mannuronic acids composition of alginate. Sun-drying gave the lowest methane yield in the anaerobic digestion experiments while freezing at -80 ?C gave the highest yield, closely followed by freezing at -20 ?C and ensiling. To conclude, preservation methods must be carefully chosen to protect the valuable component in Saccharina latissima, and to achieve an efficient downstream processing ultimately yielding high quality products as part of a seaweed biorefinery.
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| 4. |
- Axelsson, J, et al.
(författare)
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Decolorization of the textile dyes Reactive Red 2 and Reactive Blue 4 using Bjerkandera sp Strain BOL 13 in a continuous rotating biological contactor reactor
- 2006
-
Ingår i: Enzyme and Microbial Technology. - : Elsevier BV. - 0141-0229. ; 39:1, s. 32-37
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Tidskriftsartikel (refereegranskat)abstract
- The decolorization of two different textile dyes, Reactive Red 2 and Reactive Blue 4, was studied in batch as well as continuous experiments using Bjerkandera sp. Strain BOL 13. The batch experiments were performed to study the decolorization of the dyes separately as well as in a mixture. The results from the experiments showed that the fungus decolorized both dyes. The absorbance was measured at 538 and 595 nm, the peak absorbance wavelengths of the red and blue dyes respectively. The absorbance decreased with 99% at both 538 and 595 nm in the experiments in which the dyes were studied separately at a concentration of 100 mg/l. The corresponding figure for the experiment in which the dyes were studied in a mixture was 98%. A continuous rotating biological contactor was then used to study the decolorization of mixtures of the two dyes at three different concentrations, e.g. 50, 100 and 200 mg/l of each of the dyestuff. The decrease in absorbance at 538 nm was 96% at the two lower dye concentrations while it was 81% at the highest concentration. The corresponding figures at 595 nm were 94 and 80%. The hydraulic retention time was 3 days. Scanning of the absorbance between 200 and 800 nm showed that three peaks disappeared in the UV range during treatment (246, 283 and 323.5 nm) and that a new plateau was formed around 270 nm. (c) 2005 Elsevier Inc. All rights reserved.
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| 5. |
- Bagherpour, Mohammad Bagher, et al.
(författare)
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Effects of irrigation and water content of packings on alpha-pinene vapours biofilteration performance
- 2005
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Ingår i: Biochemical engineering journal. - : Elsevier. - 1369-703X .- 1873-295X. ; 24:3, s. 185-193
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Tidskriftsartikel (refereegranskat)abstract
- The main objective of this investigation is to determine the effect of different physical parameters on the performance of biofilters, treating hydrophobic compounds. In this respect, the effects of irrigation and water content of packings on the removal efficiency of bed in different pollutant loading rates, and gas phase flow rates, is studied. Alpha-pinene, which is produced from variety of industrial wood products, pulp and paper industries, and fragrance production units, has been selected as a model compound. Since the effectiveness of biofiltration depends strongly upon water solubility of compounds, in the case of alpha-pinene (2.5 ppm, at 25 ◦C), the process of waste gas treatment is faced with difficulties. In this paper, it is shown that performance of biofilters, treating hydrophobic contaminants, declines due to irrigation. This reduction is detected by an increase in the outlet concentration from 11% up to 22.5%. Its magnitude depends on the gas velocity inside the biofilter and outlet concentration of the bed. The result indicated that pore blocking along the bed has less effect on the performance reduction than diffusion coefficient. Also the inhibitory effects of velocity on biodegradation are considerably higher than the effects of concentration. In addition, this compost-based biofilter shows noteworthy higher elimination capacities in comparison with previous studied biofiltration systems. In this study, a maximum elimination capacity of 227 gm−3 of packing h−1 is achieved by 95% of removal efficiency. The maximum concentration in the inlet gas was 650 mgm−3.
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| 6. |
- Edström, Mats, et al.
(författare)
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Rötning av fjäderfägödsel med gödselförädling i tillämpad skala
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Ett tjugotal lantbrukare i Mönsterås kommun planerar för att bygga en stor biogasanläggning som kommer att ha fastgödsel från höns som huvudsubstrat. Den gemensamma biogasanläggning kan bli den största i sitt slag i Sverige, med en biogasproduktion på ca 70 GWh biogas/år för produktion av drivmedel. Den genererade rötresten kan kväveförsörja ca 12 000 ha/år växtodling och fosforförsörja ca 20 000 ha/år. Den rötade gödseln bidrar i princip till all växtnäring i rötresten, där fjäderfägödseln kommer att bidra med ca 80 % av rötrestens innehåll av kväve och fosfor. Ett hinder för att realisera denna anläggning är att det idag saknas erfarenhet från praktisk drift av rötningsanläggningar med betydande inblandning av fjäderfägödsel. Fjäderfägödsel är både ett fosfor- och kväverikt substrat, och innehåller dessutom både tunga och lätta partiklar som riskerar att bilda sediment och svämtäcken i rötkammaren. Idag betraktas fjäderfägödsel framför allt som ett fosforgödselmedel eftersom huvuddelen av kvävet inte är direkt upptagbart av växter, men rötning av fjäderfägödsel ökar andelen direktverkanande kväve. För att optimera hantering, spridning och utnyttjande av kväve och fosfor i fjäderfägödsel är det önskvärt att processa denna gödsel för att generera fyra stycken gödselmedel med olika kväve- och fosforkvot. För att kunna studera dessa frågeställningar och bredda gödselbasen för rötning har Vinnova, under 2016-2018, finansierat denna tillämpade studie.Under ett tillämpat försök genomfördes rötning i pilotskala av kväverik hönsgödsel som huvudsubstrat. Rötningsprocessen gick att driva stabilt vid en ammoniumkvävehalt på närmare 6 g/l inom det mesofila temperaturområdet i en totalomblandad rötkammare med volymetrisk metanproduktion som uppgick till 1,1 m3 CH4/m3 slamvolym & dag. Järnklorid tillfördes rötkammaren för att hålla biogasens innehåll av svavelväte vid ca 100 ppm. För att hålla ammoniumhalten vid angiven nivå tillfördes vatten motsvarande halva inflödet in i rötkammaren, för att späda ner kvävet till denna nivå. Efter rötningen av substratblandningen ökade dess ammoniuminnehåll med 3,7 gånger.Under pilotförsöket producerades ca 13 m3 rötrest som sparades och lagrades 4–8 månader innan den förädlades i två steg till två olika gödselmedel. I första steget genomfördes fasseparation med en dekantercentrifug följt av indunstning av surgjord tunnfas. Baserat på dessa försök beräknas fassepareringen kunna generera ett fast gödselmedel vars vikt motsvarar 23 % av i rötningsprocessen producerad rötrest. Det fasta gödselmedlets innehåll av fosfor utgör dryga 70 % av rötrestens fosforinnehåll. Vidare beräknas indunstningen kunna generera ett uppkoncentrerat flytande gödselmedel vars vikt motsvarar 2o % av i rötningsprocessen producerad rötrest. Det flytande gödselmedlets innehåll av ammoniumkvävet utgör dryga 70 % av rötrestens ammoniuminnehåll. Det producerade koncentratgödselmedlet liksom tunnfasgödselmedlet hade en hög andel lättillgängligt kväve, vilket är en viktig delförutsättning för att uppnå höga skördar vid växtodling. Gödselmedel från Mönsterås Biogas planerade biogasanläggning kan i framtiden bidra till att jordbruket i Kalmar län med omnejd kan gå mot en hållbar intensifiering av livsmedelsproduktionen.
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| 7. |
- Forss, Jörgen, et al.
(författare)
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Biodegradation of azo and anthraquinone dyes in continuous systems
- 2011
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Ingår i: International Biodeterioration & Biodegradation. - : Elsevier. - 0964-8305 .- 1879-0208. ; 65:1, s. 227-237
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Tidskriftsartikel (refereegranskat)abstract
- The purpose is to develop a complete microbiological model system for the treatment of wastewaterfrom textile mills in developing countries. Artificial wastewater was treated by microorganisms growingon wood shavings from Norway spruce during unsterile conditions. The microorganisms were inoculatedfrom forest residues. Mixtures of the azo dyes Reactive Black 5 and Reactive Red 2 were degraded inbatch as well as continuous experiments. Reactive Red 2 mixed with the anthraquinone dye ReactiveBlue 4 was also treated in the continuous system. The system consisted of three reservoirs e the first twowith an anaerobic environment and the third with an aerobic. The dye concentrations were 200 mg l 1ofeach dye in the continuous system and the retention time was approximately 4 days and 20 h perreservoir. Samples from the process were analysed with spectrophotometer and LC/MS to monitor thedegradation process. 86-90% of the colour was removed after a treatment of 4 days and 23 h in thecontinuous process. Two metabolites were found in the outlets of reactors one and two, but they weredegraded to below the detection limit in the aerobic reactor.
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| 8. |
- Forss, Jörgen, et al.
(författare)
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Biodegradation of azo dyes by natural microflora from forest residues chips cultivated on Swedish soft wood chips
- 2008
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Ingår i: 16th European Biomass Conference& Exhibition, 2-6 June 2008, Valencia,Spain. - : ETA-Forence renewable energies.
-
Konferensbidrag (refereegranskat)abstract
- By use of wood chips as a carrier and coal donator, azo dyes are biodegraded by the native microflora inhabiting forest residues chips from the south east part of Sweden. Due to background emissions from the forest residues chips the microflora are successfully transferred to soft sood chips from Norwegian spruce (picea abis) and Scots pine (pinus sylvestris). The azo dyes used in this study are reactive red 2 and reactive black 5 in combined artifical wastewater. The dyes are at a concentration of 200 mg/l degraded within 20 days with additional yeast extract of 1 g/l and 30 days without.
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| 9. |
- Forss, Jörgen, 1973-, et al.
(författare)
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Biodegradation of Textile Dyes Based on Wood Carriers
- 2010
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Ingår i: Proceedings of Linnaeus SCO-TecH'10. - : Linnaeus University. ; , s. 267-277
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Biodegradation of textile dyes from the azo class by Bjerkandera sp.and microbial consortium from forest residues. Bjerkandera’s degradation ability was evaluated in unsterile environment and put out of competition from the microbial consortium inhabiting forest residues. Microorganisms from forest residues were evaluated and transferred to soft wood shavings with maintained biodegrade performance. A continuous system was created containing anaerobic and aerobic parts and a successful degradation was monitored by spectrophotometer and High pressure liquid chromatography (HPLC).
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| 10. |
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| 11. |
- Forss, Jörgen, 1973-, et al.
(författare)
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Microbial biotreatment of actual textile wastewater in a continuous sequential rice husk biofilter and the microbial community involved
- 2017
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Ingår i: PLOS ONE. - : PLOS. - 1932-6203. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Textile dying processes often pollute wastewater with recalcitrant azo and anthraquinone dyes. Yet, there is little development of effective and affordable degradation systems for textile wastewater applicable in countries where water technologies remain poor. We determined biodegradation of actual textile wastewater in biofilters containing rice husks by spectrophotometry and liquid chromatography mass spectrometry. The indigenous microflora from the rice husks consistently performed >90% decolorization at a hydraulic retention time of 67 h. Analysis of microbial community composition of bacterial 16S rRNA genes and fungal internal transcribed spacer (ITS) gene fragments in the biofilters revealed a bacterial consortium known to carry azoreductase genes, such as Dysgonomonas, and Pseudomonas and the presence of fungal phylotypes such as Gibberella and Fusarium. Our findings emphasize that rice husk biofilters support a microbial community of both bacteria and fungi with key features for biodegradation of actual textile wastewater. These results suggest that microbial processes can substantially contribute to efficient and reliable degradation of actual textile wastewater. Thus, development of biodegradation systems holds promise for application of affordable wastewater treatment in polluted environments.
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| 12. |
- Forss, Jörgen, et al.
(författare)
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Microbial diversity in a continuous system based on rice husks for biodegradation of the azo dyes Reactive Red 2 and Reactive Black 5
- 2013
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Ingår i: Bioresource Technology. - : Elsevier. - 0960-8524 .- 1873-2976. ; 130, s. 681-688
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Tidskriftsartikel (refereegranskat)abstract
- In the present study the degradation of two common azo dyes used in dye houses today, Reactive Black 5 and Reactive Red 2 was evaluated in biofilters. In two experiments, bioreactors performed over 80% decolorization at a hydraulic retention time of only 28.4 h with little production of metabolites. Molecular analyses showed a diverse and dynamic bacterial community composition in the bioreactors, including members of the Bacteroidetes, Acinetobacter (Gammaproteobacteria) and Clostridium (Firmicutes) that possess the capacity to reduce azo dyes. Collectively, the results indicate that the development of mixed bacterial communities from natural biomaterials contributes to an efficient and robust degradation performance in bioreactors even at high concentration of dyes.
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| 13. |
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| 14. |
- Gregeby, Erik, et al.
(författare)
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Provrötning av marina substrat i laboratorie- och pilotskala : Delstudie i projektet Biogas – Nya substrat från havet
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport omfattar delstudie 4 av projektet Biogas-Nya substrat från havet. Inom delstudien har ett antal provrötningar av substrat från havet (vass, musslor, alger och skrapsill) genomförts. Syftet med delstudien var att få fram metanpotentialen för de olika substraten och att öka kunskapen kring hur dessa substrat uppför sig i en biogasprocess. Projektet var ett samverkansprojekt delfinansierat av EU Regionala fonden för Småland och öarna. Projektledare var Regionförbundet i Kalmar län. Inledningsvis genomfördes ett antal satsvisa försök med samtliga substrat. Metanpotentialerna för vassen, musslorna, algerna respektive skarpsillen var 400, 270, ca 210 och 460 Ndm3/kg VS. Ymp hämtades från Kalmar Biogas ABs industriella rötkammare. Vassen samrötades också med industriellt avfall i ett kontinuerligt våtrötningsförsök. Försöket genomfördes i två total omrörda tankreaktorer med volymen 30 l/st. Tillsatsen av vass gav en utökad metanproduktion med 220 Ndm3/kgVS.Vassen och musslorna studerades också i torrötningsförsök. Försöken i laboratorieskala genomfördes vid Avdelningen för Bioteknik i Lund medan försöket med musslor i pilotskala genomfördes vid Avdelningen för Bioenergiteknik, Linnéuniversitet. Metanpotentialen för vassen var i torrötningsförsöket ca 220 Ndm3/kg VS vilket är lika med potentialen i våtrötningsförsöket. För musslorna erhölls en metanpotential på 330 Ndm3/kg VS i laboratorieskaleförsöket. Pilotskaleförsöket visade att hydrolysen etablerades på likartat sätt som i laboratorieskaleförsöket. Metanhalten var ca 70 %. En visuell inspektion av musslorna efter rötningen visade också att endast skalen återstod. Det är dock inte möjligt att ange en metanpotential från detta försök beroende på ett antal tekniska problem med processen. Processen byggdes inför detta försök och det fanns inte tid att testköra den samma före försökets start.Arbetet med de satsvisa försöken och det kontinuerliga våtrötningsförsöket av vass genomfördes i samarbete med Kalmar Biogas AB. Detta bland annat genom att Kalmar Biogas AB tillhandahöll sin försöksanläggning med satsvisa och kontinuerliga reaktorer till projektet.
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| 15. |
- Gregeby, Erik, et al.
(författare)
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The influence of mixing, addition of buffer, silage and chicken manure on the biogas production from cattle manure
- 2010
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Ingår i: 18th European Biomass Conference and Exhibition, 3-7 May, Lyon. - : ETA Renewable Energies and WIP Renewable Energies.
-
Konferensbidrag (refereegranskat)abstract
- A number of batch experiements were performed in order to evaluate the biogas production from cattle manure adter addition of buffer, silage or chicken manure. Some experiments were also performed to investigate the effect of mixing. All experiments were performed at 35 C. The results showed that the extent of mixing did not affect the biogas production to any larger extent. The addition of buffer speeds up the start of the process and increased the volume of biogas produced. The methane content was approximately the same independently on if a buffer was added or not. Chicken manure inhibited the process adn addition of silage gave an increase in the amount of biogas produced. No significant effect of silage addition was found on the methane content of the biogas.
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| 16. |
- Gustavsson, Lillemor, 1961-
(författare)
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Change of toxicity during secondary treatment of industrial sludge containing nitroaromatics
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Wastewater treatment plants in Sweden are facing a great challenge due to the prohibition of depositing organic waste which gained legal force in January 2005. Biological and commercial available alternatives to disposal are composting and anaerobic digestion. A promising technique for wastewater and sludge treatment is the use of constructed wetland. In this thesis we have looked at the sludge from a wastewater treatment plant receiving wastewater from industries manufacturing pharmaceutical substances, chemical intermediates and explosives. The wastewater and sludge contains high concentrations of nitro-aromatic compounds and amino-aromatic compounds, both original compounds and degradation products. The degradation of nitroaromatics under different oxygen conditions is well examined and several studies have reported the alteration of nitroaromatics to more potent cytotoxic and genotoxic compounds after degradation. The use of bioassays is a practicable approach to estimate the toxic potency of complex samples such as sludge, since it is difficult to analyse all toxic compounds in a sample by using chemical analysis. The aim of this study was to follow change in toxicity in three different sludge treatment methods; aerobic composting and anaerobic digestion and constructed wetland to follow change in general and mechanism-specific toxicity. In order to detect both lipo- and hydrophilic compounds, different extraction and bioassays are necessary. We used organic solvents and multi-layer cleaned-up samples in the DR-Calux assay to detect the persistent lipophilic compounds causing dioxin-like activity. We also used both water and acetone extracts in the umu-C assay to detect genotoxicity and in the fishegg assay to detect embryotoxicty of water and semi-water soluble compounds in low concentrations. The results showed that anaerobic treatment is less suitable for this particular sludge, since the anaerobic residues showed high induction in all toxicity tests compared to the residues of the aerobic treatment. The anaerobic treatment also transformed the toxicants in the sludge to more lipophilic and persistent forms as well as to more water soluble, genotoxic compounds. This makes the treated material difficult to handle due to the toxic potential of the material as well as of the leachate. The aerobic treated material also showed an increased toxic potential of the material but the leachate showed no toxicity. However, high concentrations of nitrite were formed during both aerobic and anaerobic treatment, which is of environmental concern. The constructed wetlands eluated a non-toxic effluent and had a bed material with lower toxicity than expected considering the sludge concentrations and loaded sludge amount. The bed material contained concentration of TEQ considered as acceptable levels for sensitive ground use such as parks, lawns and other grounds without groundwater protection. However, all three treatment methods need to be optimised and the residual needs further evaluation in order to establish a suitable biodegradation method.
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| 17. |
- Håkansson, Katarina, et al.
(författare)
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Degradation of acetonitrile through a sequence of microbial processes
- 2005
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Ingår i: Water Research. - 0043-1354 .- 1879-2448. ; , s. 648-654-
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Tidskriftsartikel (refereegranskat)abstract
- Degradation of nitrogen containing organic compounds often leads to formation of ammonium and low molecular weight organic compounds. The study is focuseed on degradtion of acetonitrile in a sequence of stirred biofilm reactors, where degradation of acetonitrile to acetic acid and ammonia takes place in the first two reactors. A large fraction of the acetic acid is also degraded in these reactors. The subsequent two reactors were introduced in order to take care of the ammonia, while a fifth reactor was a polishing step before the water was released to the recipient. From earlier studies it is known that the rate of acetonitrile degradation is approximately 80 g acetonitrile/(m3 reactor h). This means that the reactors involved in remval of the nitrogen component needs to be far larger than those dealing with degradation of the more complex molecules.
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| 18. |
- Håkansson, Kristina, et al.
(författare)
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Degradation of acetonitrile through a sequence of microbial reactors
- 2005
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Ingår i: Water Research. - : Elsevier BV. - 1879-2448 .- 0043-1354. ; 39:4, s. 648-654
-
Tidskriftsartikel (refereegranskat)abstract
- Degradation of nitrogen containing organic compounds often leads to formation of ammonium and some low molecular weight organic compounds. The study is focused on degradation of acetonitrile in a sequence of stirred biofilm reactors, where the degradation of acetonitrile into acetic acid and ammonia takes place in the first two reactors. A large fraction of the acetic acid is also degraded in these reactors. The subsequent two reactors were introduced in order to take care of the ammonia, while a fifth reactor was a polishing step before the water was released to the recipient. From earlier studies it is known that the rate of acetonitrile degradation is approximately 80 g acetonitrile/(m(3) reactor h). In the present study nitrification proceeded with 10g NH4+-N/(m(3) reactor h) and the denitrification by 35g NOx--N/ (m(3) reactor h). This means that the reactors involved in removal of the nitrogen component needs to be far larger than those dealing with degradation of the more complex molecules. (C) 2004 Elsevier Ltd. All rights reserved.
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| 19. |
- Jansson, Anette, et al.
(författare)
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Pilot-Scale Experiments Using Cultivated Macro Algae for Biogas Production, Part of a Future Seafarm Biorefinery
- 2016
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Ingår i: 24th EUBCE Online Proceedings 2016. - : ETA-Florence Renewable Energies. - 9788889407165 ; , s. 627-629
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Konferensbidrag (refereegranskat)abstract
- The research is focused on evaluation of substrates not commonly used for biogas production and the development and optimization of processes adjusted to these substrates. This study deals with evaluation of sea weeds (Saccharina Lattisima and Laminaria digitata). Biomethane potential tests (BMP) have shown the methane potential of the algae to be 180-440 l CH4/kg organic material. These potentials are in the same range as potentials found for commonly used substrates such as sewage sludge and slaughterhouse waste. Sampling of produced biogas, substrate and digest were performed by using Solid Phase Microextraction (SPME) followed by analysis by a Gas Chromatograph with a Mass Spectrometrer (GC-MS) in order to develop a method to be able to characterize, monitor and possibly control the process.
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| 20. |
- Lundstrom, Ulrika Hahn, et al.
(författare)
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Surgical versus endovascular intervention for vascular access thrombosis : a nationwide observational cohort study
- 2022
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Ingår i: Nephrology, Dialysis and Transplantation. - : Oxford University Press. - 0931-0509 .- 1460-2385. ; 37:9, s. 1742-1750
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Tidskriftsartikel (refereegranskat)abstract
- Background There is no consensus whether an arteriovenous (AV) access thrombosis is best treated by surgical or endovascular intervention. We compared the influence of surgical versus endovascular intervention for AV access thrombosis on access survival using real-life data from a national access registry. Methods We included patients from the Swedish Renal Access Registry (SRR-Access) with a working AV access undergoing surgical or endovascular intervention for their first thrombosis between 2008 and 2020. The primary outcome was the risk of access abandonment (secondary patency at 30, 60, 90 and 365 days). Secondary outcomes were time to next intervention and 30-day mortality. Access characteristics were obtained from the SRR-Access and patient characteristics were collected from the Swedish Renal Registry. Outcomes were assessed with multivariable logistic regression and Cox proportional hazards regression models adjusted for demographics, clinical and access-related variables. Results A total of 904 patients with AV access thrombosis (54% arteriovenous fistula, 35% upper arm access) were included, with a mean age of 62 years, 60% were women, 75% had hypertension and 33% had diabetes. Secondary patency was superior after endovascular intervention versus surgical (85% versus 77% at 30 days and 76% versus 69% at 90 days). The adjusted odds of access abandonment within 90 days and 1 year were higher in the surgical thrombectomy group {odds ratio (OR) 1.44 [95% confidence interval (CI) 1.05-1.97] and OR 1.25 (0.94-1.66), respectively}. Results were consistent in the long-term analysis. There was no significant difference in time to next intervention or mortality, and results were consistent within subgroups. Conclusions Endovascular intervention was associated with a small short- and long-term benefit as compared with open surgery in haemodialysis patients with AV access thrombosis.
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| 21. |
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| 22. |
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| 23. |
- Möller, Anna, et al.
(författare)
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Precipitation of heavy metals from landfill leachates by microbially-produced sulphide
- 2004
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Ingår i: Environmental Technology. - 1479-487X. ; 25:1, s. 69-77
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Tidskriftsartikel (refereegranskat)abstract
- Four leachates from two landfills in Sweden were treated for the removal of heavy metals with the aid of sulphate-reducing bacteria (SRB). Both continuous and batch experiments were performed. A packed-bed process was used for sulphide production. The metals studied were As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn. The continuous experiments showed that Cd and Cu were most efficiently removed and that Cr was the most difficult to precipitate. In a continuous experiment with one of the leachates, the removal of Cd, Cu and Zn depended upon the retention time in the system. In the batch experiments, precipitation of the metals was a relatively fast process. No significant differences in metal concentrations were found between experiments terminated after a day and those terminated after a week. In a batch experiment involving one of the leachates, the precipitation of Cd and Cu was shown to be dependent upon the metal:sulphide ratio. Removal of the metals increased with an increase in the sulphide:metal ratio up to 45:1. The process with SRB showed an interesting potential for removal of heavy metals from leachates. One of the two leachates for which the highest metal removals were obtained came from a landfill for hazardous waste.
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| 24. |
- Nordström, F, et al.
(författare)
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Decolorization of a mixture of textile dyes using Bjerkandera sp. BOL 13
- 2008
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Ingår i: Environmental technology. - : Taylor & Francis. - 0959-3330 .- 1479-487X. ; 29:8, s. 921-929
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Tidskriftsartikel (refereegranskat)abstract
- The white-rot fungus Bjerkandera sp. BOL 13 was evaluated regarding decolorization of four textile dyes Reactive blue 21, Reactive black 5, Reactive orange 13 and Reactive yellow 206. Experiments were performed in batch and continuous modes. The total dye concentration in all experimtents was 100 mg/l. The results of the batch experiments showed that the fungus decolorized all dyes but at different rates. There was, however, an increase in the ultraviolet (UV) absorbance when a medium with a low concentration of nitrogen was used. No increase in UV range was observed when the nitrogen concentration was increased. A continuous experiment was performed to study the decolorization of a mixture of three of the dyes Reactive blue 21, Reactive black 5 and Reactive orange 13. Scanning of inlet and outlet samples showed that the absorbance at the peaks in the visible range decreased by 60-66%. The UV absorbance of the outlet increased during the first days of operation after which it decreased again to reach the same level as the inlet. The hydraulic retention time in the reactor was 3 days. The medium containing the higher nitrogen concentration was used in the continuous experiment.
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| 25. |
- Nordström, F, et al.
(författare)
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Decolorization of a mixture of textile dyes using Bjerkandera sp. BOL-13.
- 2008
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Ingår i: Environmental Technology. - : Informa UK Limited. - 1479-487X .- 0959-3330. ; 29:8, s. 921-929
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Tidskriftsartikel (refereegranskat)abstract
- The white-rot fungus Bjerkandera sp. BOL-13 was evaluated regarding decolorization of four textile dyes Reactive blue 21, Reactive black 5, Reactive orange 13 and Reactive yellow 206. Experiments were performed in batch and continuous modes. The total dye concentration in all experiments was 100 mg l(-1). The results of the batch experiments showed that the fungus decolorized all dyes but at different rates. There was, however, an increase in the ultraviolet (UV) absorbance when a medium with a low concentration of nitrogen was used. No increase in UV range was observed when the nitrogen concentration was increased. A continuous experiment was performed to study the decolorization of a mixture of three of the dyes Reactive blue 21, Reactive black 5 and Reactive orange 13. Scanning of inlet and outlet samples showed that the absorbance at the peaks in the visible range decreased by 60-66%. The UV absorbance of the outlet increased during the first days of operation after which it decreased again to reach the same level as the inlet. The hydraulic retention time in the reactor was 3 days. The medium containing the higher nitrogen concentration was used in the continuous experiment.
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