| 1. |
|
|
| 2. |
- Andreas, Lale, et al.
(författare)
-
Chemical and hydraulic conditions in a landfill/deposit for wood-based ash
- 2004
-
Ingår i: The 3rd Intercontinental Landfill Research Symposium November 29th - December 2nd, 2004 in Toya, Hokkaido Japan. - Hokkaido : Center for Applied Ethics and Philosophy, Hokkaido University. ; , s. 121-129
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
|
|
| 3. |
- Andreas, Lale, et al.
(författare)
-
Effects of waste quality and landfill technology on the long-term behaviour of municipal landfills
- 1999
-
Ingår i: Waste Management & Research. - 0734-242X .- 1096-3669. ; 17:6, s. 413-423
-
Tidskriftsartikel (refereegranskat)abstract
- The pollution potential of old municipal landfills of the former German Democratic Republic (GDR) is not as bad as expected, even taking into consideration that most lack environmental protection systems. Compared with specific conditions in the former GDR (such as production and consumption), the disposal of waste and the long-term behaviour of landfills clearly differs from that in the old German federal states. Low quantities of deposited waste created slowly growing landfills, and therefore led to rapid degradation processes still in the aerobic milieu. As a result of the increasing similarity of waste quantities and composition in the new and old federal states after 1990, waste deposited today can be expected to have similar long- term behaviour and emissions as existing old Federal Republic of Germany (FRG) landfills which were operating during the 1970s and 1980s.
|
|
| 4. |
- Andreas, Lale, et al.
(författare)
-
Hydraulic performance of a land-fill top cover based on steel slag
- 2014
-
Ingår i: Sardinia 2013. - Cagliari : CISA, Environmental Sanitary Engineering Centre.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The steel industry is expanding and following the amount of produced steel, more and more by-products and residuals are generated. About 17.6 million tonnes of steel slags arise in Europe every year. In Sweden about 18 % of the iron- and steelmaking slags are landfilled (Jernkontoret, 2012). One application for steel slags are landfill covers where large amounts of virgin materials are needed. The legal requirement in Sweden is directed towards the maxi¬mum amount of lea¬chate generated at the bottom of the landfill: < 5 and < 50 l (m2*a)-1 for landfill class 1 and 2, respec¬ti¬vely. To secure these demands, a layer of low permeability is needed to reduce water infiltration. The hydraulic load of this layer ought to be controlled by a protective water balance layer and an effective drainage layer.Previous investigations indicate that steel slags can be used as construction material for both liner and drainage layer (Herrmann et al., 2010). In order to verify this in full scale, five tests areas (A1-5) were constructed at a municipal landfill in Sweden between 2005 and 2011. The areas were designed using different mixtures of steel slags from the local steel company in the liner. The purpose of this study was to evaluate the hydraulic performance of the cover during the first years after installation.The design of the cover construction was varied like this: a mixture of 50 % electric arc furnace slag (EAFS) and 50 % ladle slag (LS) was tested as liner material in the first test area (A1). A2 and A3 were built using less LS and coarser fractions of EAFS since laboratory tests had given satisfactory results also for these recipes. High infiltration rates in A2 and 3 led to a return to the original weight proportions in A4 and 5, yet another EAF slag was introduced in these areas. The mixing and construction techniques were refined during the first years of the project time: while A1 was built with rather poorly conceived technique, as of A3 the method can be considered as technically mature and approved.The liner performance was evaluated by lysimetry: 10 lysimeters were installed below each test area. The infiltration below the liner corresponded to 44, 74, 71, 19 and 0.4 l/m2*year for A1 to A5. Compared to the legal limit of 50 l/m2*year, the covers of A2 and A3 allowed about 50 % more water to enter the landfill than stipulated.An initial increase of the infiltration was observed, which most likely is related to increasing water saturation of the liner material in the first period after construction. The saturation occurred fastest in A2, where basically no initial increase was observed, probably due to the long time that elapsed between construction and the first sampling event (260 days). In contrast, the saturation in A1 and A4 was quite slow which can be related to the smaller particle size of the slags in these areas and, hence, a less porous liner material. The decrease in A2 and A3 might be explained by mineral transformations within the slag matrix such as carbonation of calcium and magnesium leading to the precipitation of carbonates in the pores of the liner material. Future observations will show if the decreasing trend in A2 and A3 remains such that the infiltration eventually reaches a level falling below the legal limit.The results show that the infiltration criteria can be fulfilled under the condition that at least 50 % of the liner mix consists of ladle slag, a fine-grained slag with cementitious properties. With few adaptations the steel slag can be used with standard construction processes.
|
|
| 5. |
- Andreas, Lale, et al.
(författare)
-
Hydrotermisk karbonisering : en praktisk avfallsbehandlingsmöjlighet?
- 2017
-
Rapport (populärvet., debatt m.m.)abstract
- Hydrotermisk karbonisering (HTC) är en behandling där ett fuktigt organiskt materialutsätts för en kombination av värme och tryck, t ex 200°C och 20 bar. Då löses näringsämnenupp, och strukturen hos det organiska materialet förändras, vilket leder tillatt det stabiliseras, finfördelas, och enklare kan separeras från oorganiska delar.HTC har tidigare mest används vid bränsleproduktion, men i den här studien stod metodenspotential för avgiftning och separation av avfall i fokus, och vilken roll HTCkan ha som avfallsbehandlingsmetod. Syftet med projektet var att bedöma potentialenav HTC som metod för att öka återvinningen av näringsämnen i en cirkulär ekonomimed samtidigt förbättrad avgiftning av avfall jämfört med biologisk behandling, ochminskade utsläpp av koldioxid genom annan användning av organiska avfall än sombränsle.För att uppnå målen genomfördes labbförsök med efterföljande kemiska analyser, ochresultaten låg till grund för en multivariat dataanalys och en livscykelanalys.Resultaten visar på en avgiftning genom en separation av halten av skadliga tungmetaller,och att värmevärdet ökar. Dock så bedöms det analyserade materialet inte kunnaanvändas till jordförbättringsmedel eller som anläggningsmaterial, vilket dock främstberor på att materialet redan var förorenat.HTC lämpar sig bäst för blöta avfall med en blandning av organiska och oorganiskadelar. En marknadsanalys visar på att 100 000-tals ton av dessa typer av avfall fallervarje år.Sammanfattningsvis så kan processen vara intressant som avfallshanteringsmetod,men mer forskning behövs gällande mekaniska egenskaper och mekanisk separation.
|
|
| 6. |
|
|
| 7. |
- Andreas, Lale
(författare)
-
Langzeitemissionsverhalten von Deponien für Siedlungsabfälle in den neuen Bundesländern
- 2000
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Langzeitemissionsverhalten von Deponien für Siedlungsabfälle in den neuen BundesländernZusammenfassungZiel der vorliegenden Arbeit war die Beschreibung des Langzeitverhaltens von DDR-Deponien unter besonderer Berücksichtigung der Emissionen auf dem Sickerwasserpfad.Die Beschreibung umfaßte die untersuchten Deponiestandorte, die Deponierungspraxis in der DDR, charakteristische Eigenschaften der abgelagerten Abfälle sowie der nach mehrjähriger Lagerungszeit ausgekofferten Altabfallproben, die Sickerwasseremissionen der Deponie Döbeln-Hohenlauft, das Auslaugverhalten der Altabfälle in Mehrfachelutionsversuchen und die Sickerwasser- und Gasemissionen der Deponiesimulationsversuche.Als charakteristische Eigenschaften der DDR-Deponien, die für das Emissionsverhalten von Bedeutung sind, wurden folgende Punkte herausgearbeitet:langsames Deponiewachstum,fehlende oder sehr geringe Verdichtung,vergleichsweise intensive aerobe Prozesse zu Beginn der Ablagerung.Bedingt dadurch wurde ein Großteil der biologisch abbaubaren Bestandteile des Abfalls sehr schnell umgesetzt und trägt nicht zum langfristigen Emissionsverhalten bei.Die Abfallzusammensetzung von DDR-Altabfällen ist gekennzeichnet durch:hohe Anteile von Feinmaterial (bis zu 70 Masse% sind < 8mm),hohe Anteile mineralischer Stoffe, wie Aschen und Bauschutt,hohe Salzgehalte (Sulfat, Alkalien, Erdalkalien),eine hohe Säurepufferkapazität undgeringe Anteile organischer Abfälle.Dies führt zu einem wenig reaktiven Deponiekörper und den bei den meisten alten DDR-Deponien zu beobachtenden geringen Emissionen. Die wesentlichen Emissionen erfolgen auf dem Sickerwasserpfad, die Hauptkomponente dabei sind anorganische Salze. Hinsichtlich der Zusammensetzung können die DDR-Deponien am ehesten mit Asche-/Schlackedeponien verglichen werden, die in Zukunft den wohl wichtigsten Deponietyp in Deutschland darstellen werden.Auf der Basis der Untersuchungen zur Feststoffzusammensetzung der Abfälle und ihres Auslaug- und Emissionsverhaltens wurden desweiteren Prozesse diskutiert, die in DDR-Deponien in der Vergangenheit stattgefunden haben können bzw. die zukünftig möglich sind. Hierbei sind zu nennen:die Auslaugung von Salzen,Sulfatreduktion,Karbonatanreicherung im Feststoff.Mittels multivariater Datenanalyse konnte eine Einordnung der Deponieprozesse in eine späte anaerobe Phase mit Tendenz zu semi-aeroben Prozessen hin vorgenommen werden. Die methodischen Unterschiede zwischen Mehrfachelutions- und DSR-Versuchen wurden genutzt, um biologische Prozesse in den DSR zu identifizieren und bewerten. Im Ergebnis der Untersuchungen in Deponiesimulationsreaktoren wurden langfristige Emissionspotentiale EP und notwendige Nachsorgezeiträume bis zum Erreichen von Grenzkonzentrationen im Sickerwasser abgeschätzt. Sie sind in Tabelle 1 als Medianwerte zusammengefaßt dargestellt. Die Auswertung langjähriger Sickerwassermeßreihen der Deponie Döbeln-Hohenlauft bestätigte die Repräsentativität der DSR-Versuche und unterstützt die getroffenen Prognosen.Tabelle 1 Notwendige Zeiträume TE bis zum Erreichen von umweltverträglichen Konzentrationen cE im Sickerwasser von DDR-Altdeponien [a] Grenzkonzentration cEDSR-EP(W-F ® ∞) Stoffaustrag FE bis cE [g/kg] W-FE bis cE [l/kg TS] Zeitraum TE bis cE [a]CSB200 mg/l0,60,20,557TOC 100 mg/l0,150,040,334NKj 70 mg/l0,250,091,2144Cl‾100 mg/l0,70,61,4167SO42‾250 mg/l2,72,61,5180 Die längsten Zeiträume sind für den Austrag von Stickstoff und Salzen, insbesondere des Sulfats, notwendig. Die Dauer wird im wesentlichen durch folgende Faktoren beeinflußt:Abfallzusammensetzung (Anteil neuer Abfälle auf den alten DDR-Deponien)WasserhaushaltLuftzutritt, Oxidation.Ein Ausblick auf das veränderte Emissionsgeschehen der nach 1990 weiter betriebenen DDR-Deponien zeigt, daß sich durch die Veränderungen in Abfallzusammensetzung und Ablagerungspraxis das Deponieverhalten deutlich verschlechtert hat, und eine Annäherung des Emissionsniveaus an die Verhältnisse von Siedlungsabfalldeponien der 70er/80er Jahre in den alten Bundesländern zu verzeichnen ist.Die erwarteten Nachsorgezeiträume gehen z. T. deutlich über heute in der Praxis diskutierte Werte hinaus. Um den Zeitrahmen bis zum Erreichen umweltverträglicher Sickerwasserkonzentrationen so zu verkürzen, daß die bei der Deponierung anfallenden Probleme von der gleichen Generation gelöst werden, die sie verursacht hat, sind aktive Maßnahmen zur Emissionsminimierung unbedingt notwendig.
|
|
| 8. |
|
|
| 9. |
- Andreas, Lale, et al.
(författare)
-
Steel slags in a landfill top cover : Experiences from a full-scale experiment
- 2014
-
Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 34:3, s. 692-701
-
Tidskriftsartikel (refereegranskat)abstract
- A full scale field study has been carried out in order to test and evaluate the use of slags from high-alloy steel production as the construction materials for a final cover of an old municipal landfill. Five test areas were built using different slag mixtures within the barrier layer (liner). The cover consisted of a foundation layer, a liner with a thickness of 0.7 m, a drainage layer of 0.3 m, a protection layer of 1.5 m and a vegetation layer of 0.25 m. The infiltration varied depending on the cover design used, mainly the liner recipe but also over time and was related to seasons and precipitation intensity. The test areas with liners composed of 50% electric arc furnace (EAF) slag and 50% cementitious ladle slag (LS) on a weight basis and with a proper consistence of the protection layer were found to meet the Swedish infiltration criteria of ⩽50 l (m2 a)−1 for final covers for landfills for non-hazardous waste: the cumulative infiltration rates to date were 44, 19 and 0.4 l (m2 a)−1 for A1, A4 and A5, respectively. Compared to the precipitation, the portion of leachate was always lower after the summer despite high precipitation from June to August. The main reason for this is evapotranspiration but also the fact that the time delay in the leachate formation following a precipitation event has a stronger effect during the shorter summer sampling periods than the long winter periods. Conventional techniques and equipment can be used but close cooperation between all involved partners is crucial in order to achieve the required performance of the cover. This includes planning, method and equipment testing and quality assurance.
|
|
| 10. |
- Andreas, Lale, et al.
(författare)
-
Use of secondary materials in landfill constructions
- 2007
-
Ingår i: SARDINIA 2007. - Cagliari : CISA, Environmental Sanitary Engineering Centre. - 9788862650038
-
Konferensbidrag (refereegranskat)abstract
- Many landfills are subject to closure in the near future. Roughly 2,000 hectares of landfill area have to be covered only in Sweden, equivalent to about 100 million tonnes of construction material. In addition to material costs in the order of tens of billions Euro, this also puts a strain on the environment through the exploitation of non-renewable virgin construction materials. Many landfill operators are considering alternative cover designs and materials in order to reduce resource spending. However, there is a fair amount of uncertainty with regard to functional and environmental consequences of using alternative (secondary) materials, both from the side of the companies and the authorities. This paper gives an overview over potential waste based construction materials and the use of some of them in projects presently ongoing in Sweden.Research on the use of secondary materials in landfill covers is quite recent. Substitutes for natural or synthetic materials in a landfill cover can be various types of waste from process industry, construction and demolition, or comparable activities. Alternative materials that have been investigated are ashes, slags, sewage and fibre sludges, treated soils and compost. Table 1 gives an overview over potential waste based construction materials. The total of potential materials is well in excess of the material needs for landfill construction, but they may not be available at the right time, place or quality.Besides being economically viable, the substitute materials should have suitable technical and environmental properties in order to secure a proper function of the construction. Experiences from three field studies (landfills at Tveta/Södertälje, Hagfors and Alvkarleby) are discussed looking at relevant issues during 1) construction, 2) active after care phase, and 3) long term processes.Using SCM poses additional problems compared to using conventional materials. Often, the supply of material has to be planned in advance and the materials may have to be stored on site. Storing, however, can cause problems if the materials have properties that change over time e.g. due to climate. For other materials storing may be necessary in order to achieve desired properties. One example is the ageing of strongly alkaline materials that react with atmospheric carbon dioxide and thus obtain better leaching properties. Table 1 Overview over potential waste based construction materials and examplesSourceExamplesMining and mineral industryWaste rock, flotation sand, etc...Construction and demolition (C&D)Crushed concrete, gypsum, asphalt, reinforced polymers, woodProcess industryDifferent types of slag from steel making, green liquor and fibre sludge from paper production, ashes and foundry wastesWastewater treatmentDigested sewage sludge, sandIncinerationBottom ash, fly ashThe evidence is mounting that the desired technical function of a landfill cover can be attained using suitable combinations of secondary construction materials. So far, all three field tests indicate leachate amounts between less then one and 30 l (m2 yr)-1 below the liner. In comparison with the average annual precipitation of about 600 mm yr-1 at the Swedish East coast, only 0.2-5 % of the precipitation seeped through the liner so far; i.e. the leachate generation is reduced with about 90 % or more.The issue is more if the materials may cause adverse impacts of the landfill and its recipients. A low water infiltration through the liner means that the most of infiltrating water is removed as drainage water and thus the leaching of the layers above the liner are of the greatest concern.Infiltrating water will yield a liquid to solid ratio of about 1-2 l kg-1 in the layers above the liner after about 10 years. The most mobile elements, such as nitrogen, will be leached to a great extent already at such low L/S ratios, so a forecast with regard to the need of treatment of drainage water points at about two to three decades.In the long term perspective the mineral changes of the construction materials become important. E.g. one of the incentives for using fly ash in liners is their capacity for chemical-mineralogical changes leading to the formation of clay-like structures. This could mean that a liner built of ashes will attain a lower permeability over time. Other mineral changes that can occur in ashes include the trapping of metals in the structure, e g in clay and carbonate phases.Much is still to be learned about the long term processes and the factors that control them. Ongoing studies include the assessment of climatic variables, different material combinations as well as the impact of landfill gases.The following conclusions can be drawn:The use of secondary materials in construction is important due to substantial resource and environmental impacts. An increased use should be beneficial, provided that the problems of using such materials can be managed.In addition to legislative and bureaucratic barriers, there are also practical issues which need to be dealt with in order to pave the way for a wider use of alternative construction materials. In the construction phase more planning is needed due to temporal and geographical limitation of the material availability. Some materials are not ready for immediate use but need to be pre-treated. All of these factors may cause a need for more space and time. A system for quality assurance comparable to that of traditional construction materials is another issue that needs to be resolved. Most likely some kind of legislative pressure is needed for this.In the medium term leaching of pollutants from the construction materials may be the most important issue when using secondary construction materials, which underlines the double standards applied, since traditional construction materials will not be scrutinized in the same manner. Anyhow, the long term interactions between materials and their environment need to be considered and further studies are necessary for secondary construction materials as well as for conventional materials. Existing data indicate both possibilities and problems.In the long term issues of material interactions will remain and the mechanical impact of mineral changes in the secondary construction materials may be added to the list of issues to clarify. Some of the material changes may be beneficial for the function of the construction, e.g. clay formation in liner materials may make them more impervious, but there may also be negative changes caused by deteriorated material properties. The rate and extent of such processes and the factors that enhance or retard them need to be understood better.Secondary construction materials have always been used and some of the "traditional" materials used today were wastes before. There is no reason to believe that this development should not continue.
|
|
