29 results on '"UF"'
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2. Enhancing performance of ultrafiltration with inline dosing of coagulant and powdered activated carbon: Effect on fouling and removal of organic micropollutants including poly- and perfluoroalkyl substances
- Author
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Vis, Anna (author) and Vis, Anna (author)
- Abstract
In this study simultaneous and continuous inline dosing of PAC and coagulant in UF was investigated. Surface water was directly treated with PAC-UF and performance of the system was assessed by looking at membrane fouling and organic micropollutants removal. Combining adsorption and membrane processes in one technique, hybrid membrane processes, enhances performance of OMP removal by membrane processes. Powdered activated carbon (PAC) combined with coagulation and ultrafiltration (UF) is a possible treatment technique for surface water. Permeability in UF-membranes remains steady, when dosing coagulant. Only a small increase in irreversible fouling of 0.2-0.7*109 m-1h-1 is visible. However, absence of coagulant dosing causes irreversible fouling to increase to 8.7*1010 m-1h-1 and can not be easily reversed with a chemically enhanced backwash (CEB). Inline dosing of PAC alone causes an irreversible fouling of 11.4*1010 m-1h-1 and highest increase in reversible fouling of 11.7*1010 m-1h-1. Addition of coagulant (1.2 mg/l) lowers reversible fouling compared to no dosing, on the other hand addition of PAC to coagulant shows no clear increase or decrease in reversible fouling. Coagulation has a negative effect on capillary blocking, an increase of 4-8% compared to no coagulant or adsorbent. PAC and no dosing did not influence pore blocking. Highest removal of low to good adsorbable OMP was 10-63% for continuous and simultaneous dosing of 12 mg PAC/l and 1.2 mg FeCl3/l. Increasing filtration time (30 to 60 min) showed highest removal efficiency of 75% of Sotalol and 5-Methyl-1H-Benzotriazole, both good adsorbable OMP. Removal of PFAS varies between a few percent and 37%. Continuous dosing of coagulant (1.2 mg/l) with PAC (10 mg/l) has a negative impact on OMP adsorption including PFAS. With a higher PAC dose (15 mg/l) removal efficiency was not affected. Addition of coagulant with PAC-UF showed to be effective to prevent irreversible fouling, with direct su, Civil Engineering
- Published
- 2022
3. SOLAR POWER OPERATED WATER PURIFIER PLANT
- Author
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MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, MR. ZAGADE NITIN VISHNU, MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, and MR. ZAGADE NITIN VISHNU
- Abstract
The first domestic filter to be made was by Greek scientist Hippocrates called theHippocratic sleeve. The lack of clean water is amajorproblem of plagues many area of theworld in today. There are various technology available in the market such as RO membrane, UV radiation UF filtration. But these technologiesare very expensive and consume too much power to be effective in rural area. Most of the rural area there is no availability of electricity. So we decide to use the solar power. Water purification is the process to remove the contaminated water from the surface water. Due tocontaminated water can cause the various diseases like as Kidney Stone, Malaria, Stomach Pain, untold misery and brain damage. Hence we can use the RO membrane technology to purify the water using solar power.
- Published
- 2021
4. SOLAR POWER OPERATED WATER PURIFIER PLANT
- Author
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MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, MR. ZAGADE NITIN VISHNU, MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, and MR. ZAGADE NITIN VISHNU
- Abstract
The first domestic filter to be made was by Greek scientist Hippocrates called theHippocratic sleeve. The lack of clean water is amajorproblem of plagues many area of theworld in today. There are various technology available in the market such as RO membrane, UV radiation UF filtration. But these technologiesare very expensive and consume too much power to be effective in rural area. Most of the rural area there is no availability of electricity. So we decide to use the solar power. Water purification is the process to remove the contaminated water from the surface water. Due tocontaminated water can cause the various diseases like as Kidney Stone, Malaria, Stomach Pain, untold misery and brain damage. Hence we can use the RO membrane technology to purify the water using solar power.
- Published
- 2021
5. SOLAR POWER OPERATED WATER PURIFIER PLANT
- Author
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MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, MR. ZAGADE NITIN VISHNU, MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, and MR. ZAGADE NITIN VISHNU
- Abstract
The first domestic filter to be made was by Greek scientist Hippocrates called theHippocratic sleeve. The lack of clean water is amajorproblem of plagues many area of theworld in today. There are various technology available in the market such as RO membrane, UV radiation UF filtration. But these technologiesare very expensive and consume too much power to be effective in rural area. Most of the rural area there is no availability of electricity. So we decide to use the solar power. Water purification is the process to remove the contaminated water from the surface water. Due tocontaminated water can cause the various diseases like as Kidney Stone, Malaria, Stomach Pain, untold misery and brain damage. Hence we can use the RO membrane technology to purify the water using solar power.
- Published
- 2021
6. SOLAR POWER OPERATED WATER PURIFIER PLANT
- Author
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MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, MR. ZAGADE NITIN VISHNU, MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, and MR. ZAGADE NITIN VISHNU
- Abstract
The first domestic filter to be made was by Greek scientist Hippocrates called theHippocratic sleeve. The lack of clean water is amajorproblem of plagues many area of theworld in today. There are various technology available in the market such as RO membrane, UV radiation UF filtration. But these technologiesare very expensive and consume too much power to be effective in rural area. Most of the rural area there is no availability of electricity. So we decide to use the solar power. Water purification is the process to remove the contaminated water from the surface water. Due tocontaminated water can cause the various diseases like as Kidney Stone, Malaria, Stomach Pain, untold misery and brain damage. Hence we can use the RO membrane technology to purify the water using solar power.
- Published
- 2021
7. SOLAR POWER OPERATED WATER PURIFIER PLANT
- Author
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MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, MR. ZAGADE NITIN VISHNU, MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, and MR. ZAGADE NITIN VISHNU
- Abstract
The first domestic filter to be made was by Greek scientist Hippocrates called theHippocratic sleeve. The lack of clean water is amajorproblem of plagues many area of theworld in today. There are various technology available in the market such as RO membrane, UV radiation UF filtration. But these technologiesare very expensive and consume too much power to be effective in rural area. Most of the rural area there is no availability of electricity. So we decide to use the solar power. Water purification is the process to remove the contaminated water from the surface water. Due tocontaminated water can cause the various diseases like as Kidney Stone, Malaria, Stomach Pain, untold misery and brain damage. Hence we can use the RO membrane technology to purify the water using solar power.
- Published
- 2021
8. SOLAR POWER OPERATED WATER PURIFIER PLANT
- Author
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MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, MR. ZAGADE NITIN VISHNU, MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, and MR. ZAGADE NITIN VISHNU
- Abstract
The first domestic filter to be made was by Greek scientist Hippocrates called theHippocratic sleeve. The lack of clean water is amajorproblem of plagues many area of theworld in today. There are various technology available in the market such as RO membrane, UV radiation UF filtration. But these technologiesare very expensive and consume too much power to be effective in rural area. Most of the rural area there is no availability of electricity. So we decide to use the solar power. Water purification is the process to remove the contaminated water from the surface water. Due tocontaminated water can cause the various diseases like as Kidney Stone, Malaria, Stomach Pain, untold misery and brain damage. Hence we can use the RO membrane technology to purify the water using solar power.
- Published
- 2021
9. SOLAR POWER OPERATED WATER PURIFIER PLANT
- Author
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MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, MR. ZAGADE NITIN VISHNU, MR. WADEKAR ABHIJIT NARAYAN, MR. JADHAVDNYAESHWAR VITTHAL, and MR. ZAGADE NITIN VISHNU
- Abstract
The first domestic filter to be made was by Greek scientist Hippocrates called theHippocratic sleeve. The lack of clean water is amajorproblem of plagues many area of theworld in today. There are various technology available in the market such as RO membrane, UV radiation UF filtration. But these technologiesare very expensive and consume too much power to be effective in rural area. Most of the rural area there is no availability of electricity. So we decide to use the solar power. Water purification is the process to remove the contaminated water from the surface water. Due tocontaminated water can cause the various diseases like as Kidney Stone, Malaria, Stomach Pain, untold misery and brain damage. Hence we can use the RO membrane technology to purify the water using solar power.
- Published
- 2021
10. The effect of veneer-modifcation on the bond-strength in laminated veneer products
- Author
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Blomqvist, Lars, Sterley, Magdalena, Sandberg, Dick, Johansson, Jimmy, Blomqvist, Lars, Sterley, Magdalena, Sandberg, Dick, and Johansson, Jimmy
- Abstract
A major problem in the manufacture of three-dimensional laminated veneer products (LVP) is damage due to stretching and/or buckling of the veneer. To reduce or eliminate this problem, veneer densification or adding a strengthening layer to the veneer can be an alternative. To study how veneer modification influences the veneer-to-adhesive bond strength, three methods of modification were studied in relation to an unmodified reference veneer: (1) densified veneer, (2) veneer pre-bonded with paper and hot melt adhesive (HMA), (3) veneer pre-bonded with non-woven polypropylene (NW) fabric glued to the veneer (a) with a urea formaldehyde (UF) adhesive, (b) with a mixture of UF and polyvinyl acetate (PVAc) adhesive, and (c) with a PVAc adhesive. Densification, pre-bonding with paper, and NW with UF/PVAc adhesive mixture resulted in no or only a slight decrease in strength of the bond-line compared to the reference. NW glued with UF or PVAc adhesive showed a considerable reduction in the strength of the bond-line. The climatic cycling had no significant influence on the bond strength., Validerad; 2016; Nivå 1; 20151223 (dicsan)
- Published
- 2015
11. The effect of veneer-modifcation on the bond-strength in laminated veneer products
- Author
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Blomqvist, Lars, Sterley, Magdalena, Sandberg, Dick, Johansson, Jimmy, Blomqvist, Lars, Sterley, Magdalena, Sandberg, Dick, and Johansson, Jimmy
- Abstract
A major problem in the manufacture of three-dimensional laminated veneer products (LVP) is damage due to stretching and/or buckling of the veneer. To reduce or eliminate this problem, veneer densification or adding a strengthening layer to the veneer can be an alternative. To study how veneer modification influences the veneer-to-adhesive bond strength, three methods of modification were studied in relation to an unmodified reference veneer: (1) densified veneer, (2) veneer pre-bonded with paper and hot melt adhesive (HMA), (3) veneer pre-bonded with non-woven polypropylene (NW) fabric glued to the veneer (a) with a urea formaldehyde (UF) adhesive, (b) with a mixture of UF and polyvinyl acetate (PVAc) adhesive, and (c) with a PVAc adhesive. Densification, pre-bonding with paper, and NW with UF/PVAc adhesive mixture resulted in no or only a slight decrease in strength of the bond-line compared to the reference. NW glued with UF or PVAc adhesive showed a considerable reduction in the strength of the bond-line. The climatic cycling had no significant influence on the bond strength., Validerad; 2016; Nivå 1; 20151223 (dicsan)
- Published
- 2015
12. Treatment and characterisation of oily wastewaters
- Author
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Tanskanen, J. (Juha), Kuokkanen, T. (Toivo), Rämö, J. (Jaakko), Leiviskä, T. (Tiina), Karhu, M. (Mirjam), Tanskanen, J. (Juha), Kuokkanen, T. (Toivo), Rämö, J. (Jaakko), Leiviskä, T. (Tiina), and Karhu, M. (Mirjam)
- Abstract
Oily wastewaters are heterogeneous, containing various types of oils, surfactants from detergents, metals etc. Oily wastewaters are produced from a wide range of industries such as metalworking, petroleum refineries, the petrochemical industry, transportation as well as the textile and food industries. Oily wastewaters, especially those containing stable oil-in-water emulsions, require advanced treatment as conventional treatment methods have their limitations to meet ever-stricter environmental regulations. Ultrafiltration is a widely accepted and commonly used treatment method for oily wastewaters. The first aim of this thesis was to increase knowledge concerning the performance of an industrial-scaled ultrafiltration-based process treating concentrated real oily wastewaters. The demand for a more effective pre-treatment method for ultrafiltration to enhance performance and decrease fouling of membrane was observed. The second aim of the thesis was to investigate the suitability and efficiency of different methods for treating concentrated model oil-in-water emulsions and real oily wastewaters. The treatment methods studied were electrocoagulation (electrolytic dissolution of anodic metal), conventional coagulation-flocculation followed by either sedimentation or dissolved air flotation, and dissolved air flotation utilising cationic air bubbles. Electrocoagulation was discovered to be a promising treatment method for various types of oil-in-water emulsions. Dissolved air flotation with cationic modified air bubbles was proven to be an efficient method with even higher treatment results with smaller chemical doses when compared to conventional coagulation-flocculation followed by dissolved air flotation. The biodegradation of various components is an important measure of their impact on the environment in case of spillage. The third aim of the thesis was to explore the biodegradability of different types of oils and surfactants in solution conditions and, Tiivistelmä Öljyiset jätevedet ovat heterogeenisiä, sisältäen mm. erityyppisiä öljyjä, metalleja ja pesuaineiden pinta-aktiivisia aineita. Öljyisiä jätevesiä muodostuu laajalti eri teollisuuksista, kuten metallintyöstöstä, öljyn jalostuksesta, petrokemian teollisuudesta, ruoka- ja tekstiiliteollisuudesta sekä liikenteestä. Öljyiset jätevedet, varsinkin stabiileja öljyemulsioita sisältävät, vaativat tehokkaan käsittelymenetelmän, jotta ympäristölainsäädännön ja luvituksen ehdot täyttyvät. Ultrasuodatus on yleisesti käytössä oleva öljyisten jätevesien käsittelymenetelmä. Tämän väitöstyön ensimmäinen tavoite oli lisätä tietoutta teollisen mittakaavan konsentroituneiden öljyisten jätevesien ultrasuodatusprosessien tehokkuudesta. Prosessien strategisista kohdista kerättyjen öljyisten jätevesien karakterisointitulosten perusteella havaittiin, että ennen ultrasuodatusta tarvitaan tehokas esikäsittelyvaihe prosessin tehostamiseksi ja ultrasuodattimen tukkeutumisen vähentämiseksi. Täten toinen väitöstyön tavoite oli selvittää eri menetelmien soveltuvuutta ja tehokkuutta konsentroituneiden malliaineina käytettyjen öljyemulsioiden ja öljyisten jätevesien käsittelyssä. Tutkitut käsittelymenetelmät olivat elektrokoagulaatio (sähkökemiallinen flokkaavien metalli-ionien liuottaminen anodilta), koagulaatio-flokkulaatio ja laskeutus/korkeapaineflotaatio sekä korkeapaineflotaatiomenetelmä, joka hyödyntää kationisia ilmakuplia. Elektrokoagulaation todettiin olevan erittäin tehokas käsittelymenetelmä, jolla saavutettiin korkeat puhdistustulokset erityyppisille öljyemulsioille. Korkeapaineflotaatiolla, joka hyödyntää kationisia ilmakuplia, saavutettiin hyvät puhdistustulokset jopa pienemmillä kemikaalimäärillä verrattuna perinteiseen koagulaatio-flokkulaatioon ja korkepaineflotaation. Erilaisten komponenttien biohajoavuus on tärkeä suure arvioitaessa niiden ympäristövaikutuksia. Väitöstyön kolmas tavoite oli selvittää erilaisten öljyjen ja pinta-aktiivisten aineiden biohajoavuutta erila
- Published
- 2015
13. Cleaning of ultrafiltration membranes after the treatment of surface water: static–dynamic test
- Author
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Universitat Politècnica de València. Departamento de Ingeniería Química y Nuclear - Departament d'Enginyeria Química i Nuclear, García Fayos, Beatriz, Arnal Arnal, José Miguel, Sancho Fernández, María Pino, Universitat Politècnica de València. Departamento de Ingeniería Química y Nuclear - Departament d'Enginyeria Química i Nuclear, García Fayos, Beatriz, Arnal Arnal, José Miguel, and Sancho Fernández, María Pino
- Abstract
Access to safe drinkable water is a basic human right and an international development goal. AQUAPOT international project, created by Chemical and Nuclear Engineering Department of the Polytechnic University of Valencia, has been focused on research and development of low-cost and effective water treatment technologies based on membrane technology able to be used in developing countries. After several years of intensive laboratory and field research, Aquapot's ultrafiltration (UF) plants have been settled in different locations of Ecuador (province of Azuay) and Mozambique (province of Maputo). At present, most of the installed plants work successfully, producing drinking water suitable for human consumption and even for industrial use. However, installation of the designed UF-drinking water treatment facilities has shown that cleaning standard protocol of ultrafiltration membranes is not effective. This fact could affect microbiological quality and volume of the pure water produced and also life of the membrane and the UF-plant. In order to develop optimized cleaning protocols based on the use of common and accessible chemicals, Aquapot started an applied research studying several cleaning methods. Previous studies have been focused in applying different types of cleaning: chemical cleaning (by means of static tests and dynamic tests) and physico-chemical cleaning (combining chemical reagents with the hydrodynamic action of air bubbles). This work describes the experimental procedure performed in static-dynamic cleaning test, which combines soaking with dynamic circulation of cleaning solutions. Sodium hypochlorite and hydrogen peroxide at 25 degrees C performed the best results, recovering permeate flux from 10 to 12 times, respectively, compared with fouled membranes. Main results obtained for the different chemical solutions tested at 25 and 40 degrees C were also compared with previous chemical (static and dynamic test) and physicochemical cleaning. Results sh
- Published
- 2013
14. Cleaning of ultrafiltration membranes after the treatment of surface water: static–dynamic test
- Author
-
Universitat Politècnica de València. Departamento de Ingeniería Química y Nuclear - Departament d'Enginyeria Química i Nuclear, García Fayos, Beatriz, Arnal Arnal, José Miguel, Sancho Fernández, María Pino, Universitat Politècnica de València. Departamento de Ingeniería Química y Nuclear - Departament d'Enginyeria Química i Nuclear, García Fayos, Beatriz, Arnal Arnal, José Miguel, and Sancho Fernández, María Pino
- Abstract
Access to safe drinkable water is a basic human right and an international development goal. AQUAPOT international project, created by Chemical and Nuclear Engineering Department of the Polytechnic University of Valencia, has been focused on research and development of low-cost and effective water treatment technologies based on membrane technology able to be used in developing countries. After several years of intensive laboratory and field research, Aquapot's ultrafiltration (UF) plants have been settled in different locations of Ecuador (province of Azuay) and Mozambique (province of Maputo). At present, most of the installed plants work successfully, producing drinking water suitable for human consumption and even for industrial use. However, installation of the designed UF-drinking water treatment facilities has shown that cleaning standard protocol of ultrafiltration membranes is not effective. This fact could affect microbiological quality and volume of the pure water produced and also life of the membrane and the UF-plant. In order to develop optimized cleaning protocols based on the use of common and accessible chemicals, Aquapot started an applied research studying several cleaning methods. Previous studies have been focused in applying different types of cleaning: chemical cleaning (by means of static tests and dynamic tests) and physico-chemical cleaning (combining chemical reagents with the hydrodynamic action of air bubbles). This work describes the experimental procedure performed in static-dynamic cleaning test, which combines soaking with dynamic circulation of cleaning solutions. Sodium hypochlorite and hydrogen peroxide at 25 degrees C performed the best results, recovering permeate flux from 10 to 12 times, respectively, compared with fouled membranes. Main results obtained for the different chemical solutions tested at 25 and 40 degrees C were also compared with previous chemical (static and dynamic test) and physicochemical cleaning. Results sh
- Published
- 2013
15. Zuiveringsefficientie van de altrafiltratie-installatie te Glanerbrug : Gezondheidseffecten van hergebruik UF-permeaat
- Author
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LZO, cib, Rutjes SA, van den Berg HHJL, Schijven JF, de Roda Husman AM, LZO, cib, Rutjes SA, van den Berg HHJL, Schijven JF, and de Roda Husman AM
- Abstract
RIVM rapport:Ultrafiltratie (UF) is een techniek waarmee micro-organismen met behulp van zeer fijnmazige filters uit water kunnen worden verwijderd. Door ultrafiltratie op te nemen als onderdeel van een afvalwaterzuivering worden de aantallen virussen en bacteriën in afvalwater tenminste een miljoen keer verlaagd. Dit blijkt uit onderzoek van het RIVM dat in opdracht van het waterschap Regge en Dinkel en producent Pentair X-flow is uitgevoerd. Schoner afvalwater na ultrafiltratie: In dit onderzoek zijn de aantallen virussen en bacteriën in ongezuiverd afvalwater vergeleken met het afvalwater van de rioolwaterzuiveringsinstallaties te Glanerbrug en Hengelo dat met een UF-filter is behandeld. In het behandelde afvalwater (UF-permeaat) zijn lage aantallen bacterien aangetroffen en konden ziekteverwekkende virussen niet meer worden aangetoond. Lozing UF-permeaat geen nadelige gezondheidseffecten: Vervolgens is onderzocht of een eventuele lozing van het UF-permeaat op het water van de nabijgelegen Voskampvijver (Enschede) gezondheidseffecten veroorzaakt voor kinderen die daarin zwemmen. Deze effecten zijn geschat op basis van de concentraties virussen en bacteriën in het UF-permeaat en in de Voskampvijver. De risico's blijken afhankelijk te zijn van het type microorganisme. Het risico op een infectie door een blootstelling aan entero- en rotavirussen in de vijver, al dan niet aangevuld met UF-permeaat, is zeer klein. Het risico op een infectie door de Campylobacter-bacterie is echter hoog vanwege de hoge aantallen Campylobacter in de Voskampvijver. Deze bacteriën zijn waarschijnlijk afkomstig van uitwerpselen van vogels en staan dus los van de kwaliteit van het UF-permeaat. Op basis van het risico op infectie met Campylobacter wordt zwemmen afgeraden., Ultrafiltration (UF) is a filtration technique in which a liquid is forced through a semipermeable membrane with a very small pore size in order to remove suspended particles, including micro-organisms. When used as part of a wastewater treatment system, UF reduces the concentrations of viruses and bacteria in wastewater by at least one million-fold. This is the conclusion of a study commissioned by the Regge en Dinkel Water Board and conducted by the RIVM. Cleaner wastewater by UF: In this study, the concentrations of viruses and bacteria in untreated and UFtreated wastewater of the wastewater treatment plants at Glanerbrug and Hengelo were compared. In the UF-treated wastewater (permeate), only low concentrations of bacteria were detected, and pathogenic viruses were not be detected at all. Discharge of UF-treated wastewater has no adverse effects on human health: The health effects of an eventual discharge of UF-treated wastewater from the treatment plants into a nearby pond (Voskampvijver; Enschede) were estimated by determining the concentrations of viruses and bacteria in both the UF-treated wastewater and the pond water. Depending on the type of micro-organism, the potential health risks to a child swimming in the pond, recharged or not with UFtreated wastewater, varied from very low to high. The risk of infection due to exposure to enteroviruses or rotaviruses is estimated to be very low. However, due to the presence of high numbers of Campylobacter bacteria in the Voskampvijver, probably originating from bird droppings, the infection risk from exposure to Campylobacter is high. Therefore, swimming in the pond should be discouraged because of the risk of infection due to Campylobacter.
- Published
- 2012
16. Zuiveringsefficientie van de altrafiltratie-installatie te Glanerbrug : Gezondheidseffecten van hergebruik UF-permeaat
- Author
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LZO, cib, Rutjes SA, van den Berg HHJL, Schijven JF, de Roda Husman AM, LZO, cib, Rutjes SA, van den Berg HHJL, Schijven JF, and de Roda Husman AM
- Abstract
RIVM rapport:Ultrafiltratie (UF) is een techniek waarmee micro-organismen met behulp van zeer fijnmazige filters uit water kunnen worden verwijderd. Door ultrafiltratie op te nemen als onderdeel van een afvalwaterzuivering worden de aantallen virussen en bacteriën in afvalwater tenminste een miljoen keer verlaagd. Dit blijkt uit onderzoek van het RIVM dat in opdracht van het waterschap Regge en Dinkel en producent Pentair X-flow is uitgevoerd. Schoner afvalwater na ultrafiltratie: In dit onderzoek zijn de aantallen virussen en bacteriën in ongezuiverd afvalwater vergeleken met het afvalwater van de rioolwaterzuiveringsinstallaties te Glanerbrug en Hengelo dat met een UF-filter is behandeld. In het behandelde afvalwater (UF-permeaat) zijn lage aantallen bacterien aangetroffen en konden ziekteverwekkende virussen niet meer worden aangetoond. Lozing UF-permeaat geen nadelige gezondheidseffecten: Vervolgens is onderzocht of een eventuele lozing van het UF-permeaat op het water van de nabijgelegen Voskampvijver (Enschede) gezondheidseffecten veroorzaakt voor kinderen die daarin zwemmen. Deze effecten zijn geschat op basis van de concentraties virussen en bacteriën in het UF-permeaat en in de Voskampvijver. De risico's blijken afhankelijk te zijn van het type microorganisme. Het risico op een infectie door een blootstelling aan entero- en rotavirussen in de vijver, al dan niet aangevuld met UF-permeaat, is zeer klein. Het risico op een infectie door de Campylobacter-bacterie is echter hoog vanwege de hoge aantallen Campylobacter in de Voskampvijver. Deze bacteriën zijn waarschijnlijk afkomstig van uitwerpselen van vogels en staan dus los van de kwaliteit van het UF-permeaat. Op basis van het risico op infectie met Campylobacter wordt zwemmen afgeraden., Ultrafiltration (UF) is a filtration technique in which a liquid is forced through a semipermeable membrane with a very small pore size in order to remove suspended particles, including micro-organisms. When used as part of a wastewater treatment system, UF reduces the concentrations of viruses and bacteria in wastewater by at least one million-fold. This is the conclusion of a study commissioned by the Regge en Dinkel Water Board and conducted by the RIVM. Cleaner wastewater by UF: In this study, the concentrations of viruses and bacteria in untreated and UFtreated wastewater of the wastewater treatment plants at Glanerbrug and Hengelo were compared. In the UF-treated wastewater (permeate), only low concentrations of bacteria were detected, and pathogenic viruses were not be detected at all. Discharge of UF-treated wastewater has no adverse effects on human health: The health effects of an eventual discharge of UF-treated wastewater from the treatment plants into a nearby pond (Voskampvijver; Enschede) were estimated by determining the concentrations of viruses and bacteria in both the UF-treated wastewater and the pond water. Depending on the type of micro-organism, the potential health risks to a child swimming in the pond, recharged or not with UFtreated wastewater, varied from very low to high. The risk of infection due to exposure to enteroviruses or rotaviruses is estimated to be very low. However, due to the presence of high numbers of Campylobacter bacteria in the Voskampvijver, probably originating from bird droppings, the infection risk from exposure to Campylobacter is high. Therefore, swimming in the pond should be discouraged because of the risk of infection due to Campylobacter.
- Published
- 2012
17. Entreprenörskap i skolan : en studie av lärarroll och entreprenöriella förmågor på gymnasiekurser med konceptet Ung Företagsamhet
- Author
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Larsson, Sandra and Larsson, Sandra
- Abstract
During the recent years the interest in entrepreneurial education has increased both in terms of research being made in the subject, but also in the extent of entrepreneurial courses in Swedish secondary schools, where as the concept Junior Achievement (JA) is particularly being used. A common goal of the entrepreneurial education is apart from teaching the students how to start and run a business, to develop the students’ entrepreneurial skills and competences. The main purpose of the essay is to describe and illustrate the role of the teacher in the entrepreneurial pedagogy being used in courses with the JA concept and to investigate which entrepreneurial skills are being developed by the students participating in these courses. There is also the purpose of investigate what the characteristics are of this entrepreneurial pedagogy being used in the courses using the JA concept. The main theoretical foundation underpinning this study is the pedagogical philosophy formulated by John Dewey and the theory of situational leadership. My study took place in a secondary school in the area ofStockholm, where the JA concept was used in economical and project work courses. Two teachers teaching on these courses were interviewed and a questionnaire survey was conducted to obtain data from the teachers’ students. The main findings from this study are that the entrepreneurial pedagogy being used in the courses with the JA concept show high similarities with the philosophy of John Dewey. The role of the teacher is to be a tutor, guiding the students through the work process, by being more directional and instructive at start, and more supportive and encouraging in the end. However, the results show that it‘s unclear if the amount of help and support the students receive from the teacher is sufficient. The entrepreneurial skills, for example communication ability and creativity are being developed the most when they are connected to economical work assignments. Regarding the coope
- Published
- 2012
18. Zuiveringsefficientie van de altrafiltratie-installatie te Glanerbrug : Gezondheidseffecten van hergebruik UF-permeaat
- Author
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LZO, cib, Rutjes SA, van den Berg HHJL, Schijven JF, de Roda Husman AM, LZO, cib, Rutjes SA, van den Berg HHJL, Schijven JF, and de Roda Husman AM
- Abstract
RIVM rapport:Ultrafiltratie (UF) is een techniek waarmee micro-organismen met behulp van zeer fijnmazige filters uit water kunnen worden verwijderd. Door ultrafiltratie op te nemen als onderdeel van een afvalwaterzuivering worden de aantallen virussen en bacteriën in afvalwater tenminste een miljoen keer verlaagd. Dit blijkt uit onderzoek van het RIVM dat in opdracht van het waterschap Regge en Dinkel en producent Pentair X-flow is uitgevoerd. Schoner afvalwater na ultrafiltratie: In dit onderzoek zijn de aantallen virussen en bacteriën in ongezuiverd afvalwater vergeleken met het afvalwater van de rioolwaterzuiveringsinstallaties te Glanerbrug en Hengelo dat met een UF-filter is behandeld. In het behandelde afvalwater (UF-permeaat) zijn lage aantallen bacterien aangetroffen en konden ziekteverwekkende virussen niet meer worden aangetoond. Lozing UF-permeaat geen nadelige gezondheidseffecten: Vervolgens is onderzocht of een eventuele lozing van het UF-permeaat op het water van de nabijgelegen Voskampvijver (Enschede) gezondheidseffecten veroorzaakt voor kinderen die daarin zwemmen. Deze effecten zijn geschat op basis van de concentraties virussen en bacteriën in het UF-permeaat en in de Voskampvijver. De risico's blijken afhankelijk te zijn van het type microorganisme. Het risico op een infectie door een blootstelling aan entero- en rotavirussen in de vijver, al dan niet aangevuld met UF-permeaat, is zeer klein. Het risico op een infectie door de Campylobacter-bacterie is echter hoog vanwege de hoge aantallen Campylobacter in de Voskampvijver. Deze bacteriën zijn waarschijnlijk afkomstig van uitwerpselen van vogels en staan dus los van de kwaliteit van het UF-permeaat. Op basis van het risico op infectie met Campylobacter wordt zwemmen afgeraden., Ultrafiltration (UF) is a filtration technique in which a liquid is forced through a semipermeable membrane with a very small pore size in order to remove suspended particles, including micro-organisms. When used as part of a wastewater treatment system, UF reduces the concentrations of viruses and bacteria in wastewater by at least one million-fold. This is the conclusion of a study commissioned by the Regge en Dinkel Water Board and conducted by the RIVM. Cleaner wastewater by UF: In this study, the concentrations of viruses and bacteria in untreated and UFtreated wastewater of the wastewater treatment plants at Glanerbrug and Hengelo were compared. In the UF-treated wastewater (permeate), only low concentrations of bacteria were detected, and pathogenic viruses were not be detected at all. Discharge of UF-treated wastewater has no adverse effects on human health: The health effects of an eventual discharge of UF-treated wastewater from the treatment plants into a nearby pond (Voskampvijver; Enschede) were estimated by determining the concentrations of viruses and bacteria in both the UF-treated wastewater and the pond water. Depending on the type of micro-organism, the potential health risks to a child swimming in the pond, recharged or not with UFtreated wastewater, varied from very low to high. The risk of infection due to exposure to enteroviruses or rotaviruses is estimated to be very low. However, due to the presence of high numbers of Campylobacter bacteria in the Voskampvijver, probably originating from bird droppings, the infection risk from exposure to Campylobacter is high. Therefore, swimming in the pond should be discouraged because of the risk of infection due to Campylobacter.
- Published
- 2012
19. Entreprenörskap i skolan : en studie av lärarroll och entreprenöriella förmågor på gymnasiekurser med konceptet Ung Företagsamhet
- Author
-
Larsson, Sandra and Larsson, Sandra
- Abstract
During the recent years the interest in entrepreneurial education has increased both in terms of research being made in the subject, but also in the extent of entrepreneurial courses in Swedish secondary schools, where as the concept Junior Achievement (JA) is particularly being used. A common goal of the entrepreneurial education is apart from teaching the students how to start and run a business, to develop the students’ entrepreneurial skills and competences. The main purpose of the essay is to describe and illustrate the role of the teacher in the entrepreneurial pedagogy being used in courses with the JA concept and to investigate which entrepreneurial skills are being developed by the students participating in these courses. There is also the purpose of investigate what the characteristics are of this entrepreneurial pedagogy being used in the courses using the JA concept. The main theoretical foundation underpinning this study is the pedagogical philosophy formulated by John Dewey and the theory of situational leadership. My study took place in a secondary school in the area ofStockholm, where the JA concept was used in economical and project work courses. Two teachers teaching on these courses were interviewed and a questionnaire survey was conducted to obtain data from the teachers’ students. The main findings from this study are that the entrepreneurial pedagogy being used in the courses with the JA concept show high similarities with the philosophy of John Dewey. The role of the teacher is to be a tutor, guiding the students through the work process, by being more directional and instructive at start, and more supportive and encouraging in the end. However, the results show that it‘s unclear if the amount of help and support the students receive from the teacher is sufficient. The entrepreneurial skills, for example communication ability and creativity are being developed the most when they are connected to economical work assignments. Regarding the coope
- Published
- 2012
20. Effect of wastewater colloids on membrane removal of microconstituent antibiotic resistance genes
- Author
-
Riquelme Breazeal, Maria Virginia and Riquelme Breazeal, Maria Virginia
- Abstract
Anthropogenically generated antibiotic resistance genes (ARGs) are considered emerging contaminants, as they are associated with a critical human health challenge, are persist independent of a bacterial host, are subject to transfer between bacteria, and are present at amplified levels in human-impacted environments. Given the gravity of the problem, there is growing interest in advancing water treatment processes capable of limiting ARG dissemination. This study examined the potential for membrane treatment of microconstituent ARGs, and the effect of wastewater colloids on their removal. Native and spiked extracellular vanA (vancomycin resistance) and blaTEM (β-lactam resistance) ARGs were tracked by quantitative polymerase chain reaction through a cascade of membrane filtration steps. To gain insight into potential associations occurring between ARGs and colloidal material, the wastewater colloids were characterized by scanning electron microscopy, as well as in their protein, polysaccharide, and total organic carbon content. The results suggest that extracellular DNA (eDNA) containing ARGs interacts with wastewater colloids, and can both be protected against degradation and be removed more efficiently in the presence of wastewater colloidal material. Thus, ARG removal may be achievable in sustainable water reuse scenarios using lower cost membranes than would have been selected based on molecular size alone. As membranes are likely to play a vital role in water sustainability, the results of this study enable consideration of ARG removal as part of a comprehensive strategy to manage emerging contaminants and to minimize overall public health risks.
- Published
- 2011
21. Effect of wastewater colloids on membrane removal of microconstituent antibiotic resistance genes
- Author
-
Riquelme Breazeal, Maria Virginia and Riquelme Breazeal, Maria Virginia
- Abstract
Anthropogenically generated antibiotic resistance genes (ARGs) are considered emerging contaminants, as they are associated with a critical human health challenge, are persist independent of a bacterial host, are subject to transfer between bacteria, and are present at amplified levels in human-impacted environments. Given the gravity of the problem, there is growing interest in advancing water treatment processes capable of limiting ARG dissemination. This study examined the potential for membrane treatment of microconstituent ARGs, and the effect of wastewater colloids on their removal. Native and spiked extracellular vanA (vancomycin resistance) and blaTEM (β-lactam resistance) ARGs were tracked by quantitative polymerase chain reaction through a cascade of membrane filtration steps. To gain insight into potential associations occurring between ARGs and colloidal material, the wastewater colloids were characterized by scanning electron microscopy, as well as in their protein, polysaccharide, and total organic carbon content. The results suggest that extracellular DNA (eDNA) containing ARGs interacts with wastewater colloids, and can both be protected against degradation and be removed more efficiently in the presence of wastewater colloidal material. Thus, ARG removal may be achievable in sustainable water reuse scenarios using lower cost membranes than would have been selected based on molecular size alone. As membranes are likely to play a vital role in water sustainability, the results of this study enable consideration of ARG removal as part of a comprehensive strategy to manage emerging contaminants and to minimize overall public health risks.
- Published
- 2011
22. Manufacture of straw MDF and fibreboards
- Author
-
Halvarsson, Sören and Halvarsson, Sören
- Abstract
The purpose of this thesis was to develop an economical, sustainable, and environmentally friendly straw Medium Density Fibreboard (MDF) process, capable of full-scale manufacturing and to produce MDF of requested quality. The investigated straw was based on wheat (Triticum aestivum L.) and rice (Oryzae sativa L.). In this thesis three different methods were taken for manufacture of straw MDF; (A) wheat-straw fibre was blowline blended with melamine-modified urea-formaldehyde (MUF), (B) rice-straw fibre was mixed with methylene diphenyl diisocyanate (MDI) in a resin drum-blender, and (C) wheat-straw fibre was activated in the blowline by the addition of Fenton’s reagent (H2O2/Fe2+) for production of non-resin MDF panels. The MUF/wheat straw MDF panels were approved according to the requirements of the EN standard for MDF (EN 622-5, 2006). The MDI/rice-straw MDF panels were approved according to requirements of the standard for MDF of the American National Standard Institute (ANSI A208.2-2002). The non-resin wheat-straw panels showed mediocre MDF panel properties and were not approved according to the requirements in the MDF standard. The dry process for wood-based MDF was modified for production of straw MDF. The straw MDF process was divided into seven main process steps. 1. Size-reduction (hammer-milling) and screening of straw 2. Wetting and heating of straw 3. Defibration 4. Resination of straw fibre 5. Mat forming 6. Pre-pressing 7. Hot-pressing The primary results were that the straw MDF process was capable of providing satisfactory straw MDF panels based on different types of straw species and adhesives. Moreover, the straw MDF process was performed in pilot-plant scale and demonstrated as a suitable method for producing straw MDF from straw bales to finished straw MDF panels. In the environmental perspective the agricultural straw-waste is a suitable source for producing MDF to avoid open field burning and to, Syftet med denna avhandling var att lägga grunden för en ekonomisk, hållbar och miljövänlig MDF process för halmråvara, kapabel för fullskalig produktion av MDF och goda skivegenskaper. Framställningen av MDF skivor utgick från halm av vete (Triticum aestivum L.) och ris (Oryzae sativa L.). Tre olika metoder användes för att producera MDF av halm; (A) fibrer av vetehalm belimmades i blåsledning med ett melaminmodifierat urea-formaldehydlim (MUF), (B) fibrer av rishalm belimmades i en limblandare med metylen difenyl diisocyanate (MDI), (C) Limfria MDF skivor av vetehalm framställdes med aktivering av fibrer genom tillsats av Fenton´s reagens (H2O2/Fe2+) i blåsledning utan någon tillsats av syntetiskt lim. Sammanfattningsvis kan det understrykas att framställda MDF-skivor av MUF/vetehalm var godkända enligt standard för MDF (EN 622-5, 2006). Dessutom var framställda MDF skivor av MDI/rishalm också godkända enligt krav i standard för MDF ”American National Standard Institute” (ANSI A2008.2-2002). Limfria vetehalmskivor visade på måttliga skivegenskaper och klarade inte kraven i MDF standard. Fiberframställningsprocessen för MDF modifierades till en produktion utgående från halm. MDF processen för halm delades upp i sju primära processoperationer. (1) Storleksreducering och sållning av halm (2) Vätning och uppvärmning av halm (3) Defibrering (4) Belimning av halmfiber (5) Mattformning (6) Förpressning (7) Pressning De viktigaste resultaten från denna studie är att MDF av halm kunde produceras utgående från olika typer av halmsorter och lim. Dessutom utfördes MDF-processen i pilotskala och visade på en lämplig metod för framställning av MDF-skivor från halmbalar till färdiga halmfiberskivor. Det miljömässiga perspektivet på att använda jordbruksavfall till framställning av halmskivor är att undvika förbränning av halm ute på fältet, men det är även möjligt att binda koldioxid (CO2) i halms
- Published
- 2010
23. Manufacture of straw MDF and fibreboards
- Author
-
Halvarsson, Sören and Halvarsson, Sören
- Abstract
The purpose of this thesis was to develop an economical, sustainable, and environmentally friendly straw Medium Density Fibreboard (MDF) process, capable of full-scale manufacturing and to produce MDF of requested quality. The investigated straw was based on wheat (Triticum aestivum L.) and rice (Oryzae sativa L.). In this thesis three different methods were taken for manufacture of straw MDF; (A) wheat-straw fibre was blowline blended with melamine-modified urea-formaldehyde (MUF), (B) rice-straw fibre was mixed with methylene diphenyl diisocyanate (MDI) in a resin drum-blender, and (C) wheat-straw fibre was activated in the blowline by the addition of Fenton’s reagent (H2O2/Fe2+) for production of non-resin MDF panels. The MUF/wheat straw MDF panels were approved according to the requirements of the EN standard for MDF (EN 622-5, 2006). The MDI/rice-straw MDF panels were approved according to requirements of the standard for MDF of the American National Standard Institute (ANSI A208.2-2002). The non-resin wheat-straw panels showed mediocre MDF panel properties and were not approved according to the requirements in the MDF standard. The dry process for wood-based MDF was modified for production of straw MDF. The straw MDF process was divided into seven main process steps. 1. Size-reduction (hammer-milling) and screening of straw 2. Wetting and heating of straw 3. Defibration 4. Resination of straw fibre 5. Mat forming 6. Pre-pressing 7. Hot-pressing The primary results were that the straw MDF process was capable of providing satisfactory straw MDF panels based on different types of straw species and adhesives. Moreover, the straw MDF process was performed in pilot-plant scale and demonstrated as a suitable method for producing straw MDF from straw bales to finished straw MDF panels. In the environmental perspective the agricultural straw-waste is a suitable source for producing MDF to avoid open field burning and to, Syftet med denna avhandling var att lägga grunden för en ekonomisk, hållbar och miljövänlig MDF process för halmråvara, kapabel för fullskalig produktion av MDF och goda skivegenskaper. Framställningen av MDF skivor utgick från halm av vete (Triticum aestivum L.) och ris (Oryzae sativa L.). Tre olika metoder användes för att producera MDF av halm; (A) fibrer av vetehalm belimmades i blåsledning med ett melaminmodifierat urea-formaldehydlim (MUF), (B) fibrer av rishalm belimmades i en limblandare med metylen difenyl diisocyanate (MDI), (C) Limfria MDF skivor av vetehalm framställdes med aktivering av fibrer genom tillsats av Fenton´s reagens (H2O2/Fe2+) i blåsledning utan någon tillsats av syntetiskt lim. Sammanfattningsvis kan det understrykas att framställda MDF-skivor av MUF/vetehalm var godkända enligt standard för MDF (EN 622-5, 2006). Dessutom var framställda MDF skivor av MDI/rishalm också godkända enligt krav i standard för MDF ”American National Standard Institute” (ANSI A2008.2-2002). Limfria vetehalmskivor visade på måttliga skivegenskaper och klarade inte kraven i MDF standard. Fiberframställningsprocessen för MDF modifierades till en produktion utgående från halm. MDF processen för halm delades upp i sju primära processoperationer. (1) Storleksreducering och sållning av halm (2) Vätning och uppvärmning av halm (3) Defibrering (4) Belimning av halmfiber (5) Mattformning (6) Förpressning (7) Pressning De viktigaste resultaten från denna studie är att MDF av halm kunde produceras utgående från olika typer av halmsorter och lim. Dessutom utfördes MDF-processen i pilotskala och visade på en lämplig metod för framställning av MDF-skivor från halmbalar till färdiga halmfiberskivor. Det miljömässiga perspektivet på att använda jordbruksavfall till framställning av halmskivor är att undvika förbränning av halm ute på fältet, men det är även möjligt att binda koldioxid (CO2) i halms
- Published
- 2010
24. Manufacture of straw MDF and fibreboards
- Author
-
Halvarsson, Sören and Halvarsson, Sören
- Abstract
The purpose of this thesis was to develop an economical, sustainable, and environmentally friendly straw Medium Density Fibreboard (MDF) process, capable of full-scale manufacturing and to produce MDF of requested quality. The investigated straw was based on wheat (Triticum aestivum L.) and rice (Oryzae sativa L.). In this thesis three different methods were taken for manufacture of straw MDF; (A) wheat-straw fibre was blowline blended with melamine-modified urea-formaldehyde (MUF), (B) rice-straw fibre was mixed with methylene diphenyl diisocyanate (MDI) in a resin drum-blender, and (C) wheat-straw fibre was activated in the blowline by the addition of Fenton’s reagent (H2O2/Fe2+) for production of non-resin MDF panels. The MUF/wheat straw MDF panels were approved according to the requirements of the EN standard for MDF (EN 622-5, 2006). The MDI/rice-straw MDF panels were approved according to requirements of the standard for MDF of the American National Standard Institute (ANSI A208.2-2002). The non-resin wheat-straw panels showed mediocre MDF panel properties and were not approved according to the requirements in the MDF standard. The dry process for wood-based MDF was modified for production of straw MDF. The straw MDF process was divided into seven main process steps. 1. Size-reduction (hammer-milling) and screening of straw 2. Wetting and heating of straw 3. Defibration 4. Resination of straw fibre 5. Mat forming 6. Pre-pressing 7. Hot-pressing The primary results were that the straw MDF process was capable of providing satisfactory straw MDF panels based on different types of straw species and adhesives. Moreover, the straw MDF process was performed in pilot-plant scale and demonstrated as a suitable method for producing straw MDF from straw bales to finished straw MDF panels. In the environmental perspective the agricultural straw-waste is a suitable source for producing MDF to avoid open field burning and to, Syftet med denna avhandling var att lägga grunden för en ekonomisk, hållbar och miljövänlig MDF process för halmråvara, kapabel för fullskalig produktion av MDF och goda skivegenskaper. Framställningen av MDF skivor utgick från halm av vete (Triticum aestivum L.) och ris (Oryzae sativa L.). Tre olika metoder användes för att producera MDF av halm; (A) fibrer av vetehalm belimmades i blåsledning med ett melaminmodifierat urea-formaldehydlim (MUF), (B) fibrer av rishalm belimmades i en limblandare med metylen difenyl diisocyanate (MDI), (C) Limfria MDF skivor av vetehalm framställdes med aktivering av fibrer genom tillsats av Fenton´s reagens (H2O2/Fe2+) i blåsledning utan någon tillsats av syntetiskt lim. Sammanfattningsvis kan det understrykas att framställda MDF-skivor av MUF/vetehalm var godkända enligt standard för MDF (EN 622-5, 2006). Dessutom var framställda MDF skivor av MDI/rishalm också godkända enligt krav i standard för MDF ”American National Standard Institute” (ANSI A2008.2-2002). Limfria vetehalmskivor visade på måttliga skivegenskaper och klarade inte kraven i MDF standard. Fiberframställningsprocessen för MDF modifierades till en produktion utgående från halm. MDF processen för halm delades upp i sju primära processoperationer. (1) Storleksreducering och sållning av halm (2) Vätning och uppvärmning av halm (3) Defibrering (4) Belimning av halmfiber (5) Mattformning (6) Förpressning (7) Pressning De viktigaste resultaten från denna studie är att MDF av halm kunde produceras utgående från olika typer av halmsorter och lim. Dessutom utfördes MDF-processen i pilotskala och visade på en lämplig metod för framställning av MDF-skivor från halmbalar till färdiga halmfiberskivor. Det miljömässiga perspektivet på att använda jordbruksavfall till framställning av halmskivor är att undvika förbränning av halm ute på fältet, men det är även möjligt att binda koldioxid (CO2) i halms
- Published
- 2010
25. Manufacture of straw MDF and fibreboards
- Author
-
Halvarsson, Sören and Halvarsson, Sören
- Abstract
The purpose of this thesis was to develop an economical, sustainable, and environmentally friendly straw Medium Density Fibreboard (MDF) process, capable of full-scale manufacturing and to produce MDF of requested quality. The investigated straw was based on wheat (Triticum aestivum L.) and rice (Oryzae sativa L.). In this thesis three different methods were taken for manufacture of straw MDF; (A) wheat-straw fibre was blowline blended with melamine-modified urea-formaldehyde (MUF), (B) rice-straw fibre was mixed with methylene diphenyl diisocyanate (MDI) in a resin drum-blender, and (C) wheat-straw fibre was activated in the blowline by the addition of Fenton’s reagent (H2O2/Fe2+) for production of non-resin MDF panels. The MUF/wheat straw MDF panels were approved according to the requirements of the EN standard for MDF (EN 622-5, 2006). The MDI/rice-straw MDF panels were approved according to requirements of the standard for MDF of the American National Standard Institute (ANSI A208.2-2002). The non-resin wheat-straw panels showed mediocre MDF panel properties and were not approved according to the requirements in the MDF standard. The dry process for wood-based MDF was modified for production of straw MDF. The straw MDF process was divided into seven main process steps. 1. Size-reduction (hammer-milling) and screening of straw 2. Wetting and heating of straw 3. Defibration 4. Resination of straw fibre 5. Mat forming 6. Pre-pressing 7. Hot-pressing The primary results were that the straw MDF process was capable of providing satisfactory straw MDF panels based on different types of straw species and adhesives. Moreover, the straw MDF process was performed in pilot-plant scale and demonstrated as a suitable method for producing straw MDF from straw bales to finished straw MDF panels. In the environmental perspective the agricultural straw-waste is a suitable source for producing MDF to avoid open field burning and to, Syftet med denna avhandling var att lägga grunden för en ekonomisk, hållbar och miljövänlig MDF process för halmråvara, kapabel för fullskalig produktion av MDF och goda skivegenskaper. Framställningen av MDF skivor utgick från halm av vete (Triticum aestivum L.) och ris (Oryzae sativa L.). Tre olika metoder användes för att producera MDF av halm; (A) fibrer av vetehalm belimmades i blåsledning med ett melaminmodifierat urea-formaldehydlim (MUF), (B) fibrer av rishalm belimmades i en limblandare med metylen difenyl diisocyanate (MDI), (C) Limfria MDF skivor av vetehalm framställdes med aktivering av fibrer genom tillsats av Fenton´s reagens (H2O2/Fe2+) i blåsledning utan någon tillsats av syntetiskt lim. Sammanfattningsvis kan det understrykas att framställda MDF-skivor av MUF/vetehalm var godkända enligt standard för MDF (EN 622-5, 2006). Dessutom var framställda MDF skivor av MDI/rishalm också godkända enligt krav i standard för MDF ”American National Standard Institute” (ANSI A2008.2-2002). Limfria vetehalmskivor visade på måttliga skivegenskaper och klarade inte kraven i MDF standard. Fiberframställningsprocessen för MDF modifierades till en produktion utgående från halm. MDF processen för halm delades upp i sju primära processoperationer. (1) Storleksreducering och sållning av halm (2) Vätning och uppvärmning av halm (3) Defibrering (4) Belimning av halmfiber (5) Mattformning (6) Förpressning (7) Pressning De viktigaste resultaten från denna studie är att MDF av halm kunde produceras utgående från olika typer av halmsorter och lim. Dessutom utfördes MDF-processen i pilotskala och visade på en lämplig metod för framställning av MDF-skivor från halmbalar till färdiga halmfiberskivor. Det miljömässiga perspektivet på att använda jordbruksavfall till framställning av halmskivor är att undvika förbränning av halm ute på fältet, men det är även möjligt att binda koldioxid (CO2) i halms
- Published
- 2010
26. Manufacture of straw MDF and fibreboards
- Author
-
Halvarsson, Sören and Halvarsson, Sören
- Abstract
The purpose of this thesis was to develop an economical, sustainable, and environmentally friendly straw Medium Density Fibreboard (MDF) process, capable of full-scale manufacturing and to produce MDF of requested quality. The investigated straw was based on wheat (Triticum aestivum L.) and rice (Oryzae sativa L.). In this thesis three different methods were taken for manufacture of straw MDF; (A) wheat-straw fibre was blowline blended with melamine-modified urea-formaldehyde (MUF), (B) rice-straw fibre was mixed with methylene diphenyl diisocyanate (MDI) in a resin drum-blender, and (C) wheat-straw fibre was activated in the blowline by the addition of Fenton’s reagent (H2O2/Fe2+) for production of non-resin MDF panels. The MUF/wheat straw MDF panels were approved according to the requirements of the EN standard for MDF (EN 622-5, 2006). The MDI/rice-straw MDF panels were approved according to requirements of the standard for MDF of the American National Standard Institute (ANSI A208.2-2002). The non-resin wheat-straw panels showed mediocre MDF panel properties and were not approved according to the requirements in the MDF standard. The dry process for wood-based MDF was modified for production of straw MDF. The straw MDF process was divided into seven main process steps. 1. Size-reduction (hammer-milling) and screening of straw 2. Wetting and heating of straw 3. Defibration 4. Resination of straw fibre 5. Mat forming 6. Pre-pressing 7. Hot-pressing The primary results were that the straw MDF process was capable of providing satisfactory straw MDF panels based on different types of straw species and adhesives. Moreover, the straw MDF process was performed in pilot-plant scale and demonstrated as a suitable method for producing straw MDF from straw bales to finished straw MDF panels. In the environmental perspective the agricultural straw-waste is a suitable source for producing MDF to avoid open field burning and to, Syftet med denna avhandling var att lägga grunden för en ekonomisk, hållbar och miljövänlig MDF process för halmråvara, kapabel för fullskalig produktion av MDF och goda skivegenskaper. Framställningen av MDF skivor utgick från halm av vete (Triticum aestivum L.) och ris (Oryzae sativa L.). Tre olika metoder användes för att producera MDF av halm; (A) fibrer av vetehalm belimmades i blåsledning med ett melaminmodifierat urea-formaldehydlim (MUF), (B) fibrer av rishalm belimmades i en limblandare med metylen difenyl diisocyanate (MDI), (C) Limfria MDF skivor av vetehalm framställdes med aktivering av fibrer genom tillsats av Fenton´s reagens (H2O2/Fe2+) i blåsledning utan någon tillsats av syntetiskt lim. Sammanfattningsvis kan det understrykas att framställda MDF-skivor av MUF/vetehalm var godkända enligt standard för MDF (EN 622-5, 2006). Dessutom var framställda MDF skivor av MDI/rishalm också godkända enligt krav i standard för MDF ”American National Standard Institute” (ANSI A2008.2-2002). Limfria vetehalmskivor visade på måttliga skivegenskaper och klarade inte kraven i MDF standard. Fiberframställningsprocessen för MDF modifierades till en produktion utgående från halm. MDF processen för halm delades upp i sju primära processoperationer. (1) Storleksreducering och sållning av halm (2) Vätning och uppvärmning av halm (3) Defibrering (4) Belimning av halmfiber (5) Mattformning (6) Förpressning (7) Pressning De viktigaste resultaten från denna studie är att MDF av halm kunde produceras utgående från olika typer av halmsorter och lim. Dessutom utfördes MDF-processen i pilotskala och visade på en lämplig metod för framställning av MDF-skivor från halmbalar till färdiga halmfiberskivor. Det miljömässiga perspektivet på att använda jordbruksavfall till framställning av halmskivor är att undvika förbränning av halm ute på fältet, men det är även möjligt att binda koldioxid (CO2) i halms
- Published
- 2010
27. Benetzbarkeit von Recyclingspänen und ,,frischen“ Holzspänen mit verschiedenen Bindemitteln : [Wettability of fresh chips (chips obtained directly from wood) and chips obtained by mechanical disintegration (M-chips) and thermohydrolytical degredation (T-chips) of particleboards with UF-, PF-resins and binders based on PMDI (polymers of diphenylmethan diisocyanates)]
- Author
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Hameed, Mahmood, Behn, Claus, Roffael, Edmone, Dix, Brigitta, Hameed, Mahmood, Behn, Claus, Roffael, Edmone, and Dix, Brigitta
- Abstract
Nach allen Messzeiten zeigten die „frischen“ Holzspäne eine bessere Benetzung mit UF-Harz, PF-Harz und PMDI-Klebstoff als die Recyclingspäne. Besonders durch mechanische Zerklei- nerung gewonnene Recyclingspäne weisen eine geringere Benet- zung auf als die „frischen“ Holzspäne. Dies ist womöglich auf das den Recyclingspänen anhaftende Binde- und Hydrophopie- rungsmittel zurückzuführen. Die bessere Benetzung der durch thermohydrolytischen Aufschluss gewonnenen Späne ist möglicherweise darauf zurückzuführen, dass während des Aufschlus- ses Teile des Bindemittels chemisch abgebaut und wasserlöslich werden. Die Benetzung der Recyclingspäne mit PMDI ist auffallend besser als mit UF- und PF-Harz. Dies ist unabhängig davon, ob die zu benetzenden Späne durch mechanische Zerkleinerung oder durch thermohydrolytischen Aufschluss gewonnen wurden.
- Published
- 2005
- Full Text
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28. Évaluation de l’éfficacité microbiologique de purificateurs d’eau et de leur application aux puits domestiques.
- Author
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Verrier, Louise-Michelle and Verrier, Louise-Michelle
- Abstract
La transcription des symboles et des caractères spéciaux utilisés dans la version originale de ce résumé n’a pas été possible en raison de limitations techniques. La version correcte de ce résumé peut être lue en PDF.Dans le but d'évaluer 1 'efficacité micro biologique de purificateurs d'eau, deux bancs d'essais ont été élaborés. Le premier banc d'essai permet des bioessais microbiens à petite échelle (lt1 L/min). Il a servi à tester quatre paires de prototypes de membranes d'ultrafiltration (UF) en PVDF ainsi qu'un purificateur d'eau s'employant au point d'utilisation (POU : «point of use») qui combine les technologies de l'irradiation UV, de 1 'ozonation et de la filtration au charbon activé. Ce banc d'essai reposait sur le passage dans les purificateurs d'un cocktail de micro organismes à base de tampon phosphate 0,1 mM pH 7 et pouvant contenir, ensemble ou séparément, des coli phages MS2, des coliphages T7 et/ou des spores de B. subtilis. Le deuxième banc d'essai consistait en de l'eau municipale déchlorée par l'ajout de thiosulfate de sodium (10 mg/L) dans laquelle sont injectés des coliphages MS2 seuls ou en suspension avec des spores de B. subtilis. Il a permis d'évaluer l'efficacité microbiologique d'une unité d'UF HomeSpring™ de Zenon Environmental Inc. et un réacteur UV SPV6 de R-Can. Ces deux appareils sont vendus au Canada pour être utilisés au point d'entrée (POE : « point of entry») mais seul le réacteur UV est présentement certifié par la NSF. Les prototypes de membranes d'UF ayant une grosseur de pores de 50nm ou moins ont permis l'enlèvement d'au moins 2 log de MS2, gt6 log de T7 et gt5 log de spores de B. subtilis. L'unité d'UF HomeSpring™ enlève au moins 3 log de MS2 au cours d'un épisode de contamination de 12 minutes. Malgré les bons résultats obtenus avec les membranes d'UF, une libération continue de particules biologiques dans le filtrat a été observée après un épisode de contamination mais, il est impossible de dire s'il s'agit d'une défect
- Published
- 2004
29. Manufacturing of fiber composite Medium Density Fiberboard (MDF) based on annual plant fiber and Urea Formaldehyde Resin
- Author
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Halvarsson, Sören, Norgren, Magnus, Edlund, Håkan, Halvarsson, Sören, Norgren, Magnus, and Edlund, Håkan
- Abstract
Production of fiber composite materials such as Medium Density Fiberboard (MDF) and particleboard (PB) is in general based on wood as a raw material. However, cereal straws and other annual agriculture waste materials have regained an interest as a potential raw material for production of MDF. The cereal straws are among the most common lignocellulosic materials that are easily accessible, non-expensive and renewable. The aim of this investigation was to produce high performance MDF based on wheat straw and urea formaldehyde (UF) resin. The usage of UF-resin for wheat straw MDF-panels has so far resulted in acceptable strength properties but poor moisture resistance and thickness swelling (TS). Application of melamine modified UF-resin for wood based MDF has improved the moisture resistance of produced MDF panels. In this investigation two commercial melamine modified UF-resins were used as binders (adhesives) in the production of wheat straw MDF. Hammer milled wheat straw was treated with water and sulfuric acid (0.6 %) before refining. The reason was to improve the curing, conditions of the UF-resins by a reduction of the pH and the pH-buffering capacity of refined wheat straw fiber. Refining of wheat straw was performed at slightly lower pressure and retention time compared with refining of wood material. However, a lot of fines and dust (wheat straw fibers < 0.5 mm) were generated during refining. A hi-h resin content of the melamine modified UF-resin was necessary (15 %) to compensate for the high ratio of wheat straw fines and dust. Final panel properties of wheat straw MDF could meet the requirements of the MDF standard (EN 622-5:1997), including the TS. Strength properties as internal bond (IB) and modulus of rupture (MOR) were increased as a function of density. Thickness swelling was reduced as a function of density. The usage of wheat straw as a raw material in combination with a melamine modified UF-resin, as an adhesive, is a possible route for manuf
- Published
- 2004
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