I takt med ökad återvinning av avfall uppstår nya utmaningar gällande vattenhantering på avfallsanläggningar. Stora variationer förekommer i material som lagras, sorteras och behandlas i återvinningsprocessen, vilket kan leda till situationer med tillfälligt höga föroreningshalter i vatten på anläggningen. Detta kan kräva snabba punktinsatser, som komplement till redan etablerade reningstekniker. Syftet med detta arbete har varit att ta fram en rekommendation gällande sådana punktinsatser vid olika situationer som kan uppstå på avfallsanläggningen Högbytorp i Upplands- Bro kommun. I den riskbedömning som genomfördes inledningsvis bedömdes löst kadmium och klorider i lakvatten, partikelbunden kadmium och löst nickel i vatten från verksamhetsytor, samt nitratkväve och löst koppar i sluttäckningsvatten vara av sådan risknivå att reningslösningar i form av punktinsatser bör sättas in. Rekommendationen som ges baseras på analys av förekomstformer av nämnda föroreningar samt en litteraturstudie kring lämpliga reningstekniker för dessa. I rekommendationen förordas att partikelbunden kadmium bör avskiljas genom sedimentering. För avskiljning av lösta metaller föreslås reaktiva filter; torvfilter för rening av kadmium och nickel, samt tallbark eller Polonite för rening av koppar. För avskiljning av nitratkväve rekommenderas en denitrifierande bioreaktor. Svårigheter i att hitta kostnadseffektiva punktinsatser för klorider gör att inget förslag till reningslösning ges för detta fall. Rekommendationen kan användas som utgångspunkt i framtagandet av hållbar vattenreningsteknik på anläggningen, men bör åtföljas av kontinuerlig uppföljning och utvärdering för att upprätthålla den kunskapsutveckling som krävs i ett aktivt riskhanteringsarbete. / The amount of waste is increasing as a consequence of population growth and increased consumption. This coupling between economic growth and waste production is a global problem, and decoupling requires a transition from linear to circular material flows. Sustainable waste management plays an important role in achieving a circular economy by treating waste so that it can be returned to the production and consumption chain. However, the handling of waste gives rise to various types of polluted waters that may harm the environment if not handled properly. Studies have shown that many of the water treatment techniques applied at waste facilities are not suitable for dealing with a complex and fluctuating water pollutant content and not sufficient in meeting stricter emission requirements. This has led to an increased need for small-scale water treatment solutions that can be used as a complement to already established large-scale solutions. One of Sweden’s leading waste management companies is Ragn-Sells. At the facility Högbytorp, polluted waste streams such as ashes and contaminated soils are handled. Högbytorp is an example of a complex waste facility where water streams with situations of fluctuating pollutant content may arise. Knowledge about these situations and what measures can be taken is an important part of the active approach that is required to achieve a circular economy and environmental goals. The aim with this study has therefore been to come up with a recommendation for how temporarily high pollution contents in waters generated at Högbytorp can be handled by selective measures. The method used for the development of the recommendation follows the approach of systematic risk management. Initially, a risk assessment was performed to identify risk scenarios related to temporarily high water pollution levels at the site. Crucial input for the choice of relevant treatment techniques is knowledge about the speciation of pollutants. The identified risk scenarios were therefore further elaborated on regarding the chemical species by analysing the company’s existing water sampling data. A literature study, guided by a set of sustainability criteria, was then conducted in order to find suitable treatment techniques for the identified risk scenarios. Six different risk scenarios, including three different water types, were identified and considered to be at such a risk level that selective measures are required. These scenarios are dissolved cadmium and chloride in landfill leachate, particulate bound cadmium and dissolved nickel in water from surfaces where waste has been handled, and nitrate nitrogen and dissolved copper in drainage water from covered landfills. The recommendation suggests that particle bound metals, namely particulate bound cadmium, could be removed from the water by means of sedimentation. Dissolved metals can be reduced using different reactive filter media. Regarding both dissolved cadmium and dissolved nickel, a peat filter is recommended whereas for dissolved copper, pine bark or Polonite is suitable as a filter media. Depending on the amount of suspended solids in the waters, the filters may be preceded by a step for particle removal. For removal of nitrate nitrogen in drainage water from covered landfills, a denitrifying bioreactor is recommended. In the case of chlorides in landfill leachate, difficulties in finding cost-effective selective measures has led to that no recommendation for that specific risk scenario is given. The recommendation given in this report can be seen as a starting point for which sustainable water treatment techniques that are suitable in reducing the pollutants in question. Due to the complexity of the waters generated at waste facilities, proposed treatment techniques must however be evaluated on the actual waters at the specific place. Knowledge from such an evaluation should integrated in the risk management process for constant progress in the active work with polluted waters at the site.
Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kth-298595 |
Date | January 2021 |
Creators | Bivall, Emma |
Publisher | KTH, Hållbar utveckling, miljövetenskap och teknik |
Source Sets | DiVA Archive at Upsalla University |
Language | Swedish |
Detected Language | English |
Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
Format | application/pdf |
Rights | info:eu-repo/semantics/openAccess |
Relation | TRITA-ABE-MBT ; 21198 |
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