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- Envall, Ida, et al.
(author)
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Existing evidence related to soil retention of phosphorus from on-site wastewater treatment systems in boreal and temperate climate zones : a systematic map
- 2023
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In: Environmental Evidence. - : Springer Nature. - 2047-2382. ; 12:1
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Journal article (peer-reviewed)abstract
- Background: In Sweden there are nearly one million soil-based on-site wastewater treatment systems (OWTSs). OWTSs may contribute to eutrophication of surface waters, due to the discharge of phosphorus (P). Hence, in certain cases, a high P removal rate (up to 90%) of OWTSs is required by Swedish authorities. Since these requirements may have costly consequences to property owners, it is debated whether they are too strict. In this debate, it is often claimed that the soil retention of P occurring in the natural environments may be underestimated by authorities. Soil retention is the inhibition of the transport of P through the ground, due to different chemical, physical and biological processes occurring there. These processes make the P transport slower, which may reduce the unwanted impact on receiving water bodies. However, the efficiency of soil retention of P remains unclear. The objective of this systematic map was to collect, code, organise and elucidate the relevant evidence related to the topic, to be able to guide stakeholders through the evidence base, and to support future research synthesising, commissioning, and funding. The systematic map was carried out in response to needs declared by the Swedish Agency for Marine and Water Management but the conclusions should be valid for a wider range of countries across boreo-temperate regions.Methods: Searches were made for peer-reviewed and grey literature using bibliographic databases, search engines, specialist websites, and stakeholder contacts. The references were screened for relevance according to a predefined set of eligibility criteria. A detailed database of the relevant studies was compiled. Data and metadata that enable evaluation and discussion of the character and quality of the evidence base were extracted and coded. Special focus was placed on assessing if existing evidence could contribute to policy and practice decision making. Descriptive information about the evidence base was presented in tables and figures. An interactive evidence atlas and a choropleth were created, displaying the locations of all studies.Review findings: 234 articles out of 10,797 screened records fulfilled the eligibility criteria. These articles contain 256 studies, performed in the field or in the laboratory. Six different study types were identified, based on where the measurements were conducted. Most studies, including laboratory studies, lack replicates. Most field studies are observational case studies.Conclusions: It is not possible to derive valid generic measures of the efficiency of soil retention of P occurring in the natural soil environment from available research. Neither does the evidence base allow for answering the question of the magnitude of the potential impact of OWTSs on the P concentration in recipients on a general basis, or under what conditions OWTSs generally have such an impact. A compilation of groundwater studies may provide examples of how far the P may reach in x years, but the number of groundwater studies is insufficient to draw any general conclusions, given the complexity and variability of the systems. Future research should strive for replicated study designs, more elaborate reporting, and the establishment of a reporting standard.
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| 2. |
- Envall, Ida, et al.
(author)
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What evidence exists related to soil retention of phosphorus from on-site wastewater treatment systems in boreal and temperate climate zones? : A systematic map protocol
- 2020
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In: Environmental Evidence. - : BMC. - 2047-2382. ; 9:1
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Journal article (peer-reviewed)abstract
- Background Soil-based on-site wastewater treatment systems (OWSs) are suspected to contribute to eutrophication of surface waters, due to the discharge of phosphorus (P). However, along the flow path between the facilities and surface waters, different processes contribute to delay the transport of phosphorus through the ground. This may reduce the unwanted impact on receiving water bodies. However, the strength and significance of this so-called soil retention remains unclear. In Sweden, there are nearly one million OWSs. To protect surface waters, a high P removal rate (up to 90%) is often required by the local municipalities. However, since these requirements may have costly consequences to property owners, it is debated as to whether they are too strict. In this debate, it is often claimed that the retention of P occurring in natural environments may be underestimated by authorities. Accordingly, there is a need for a scrutiny of the available evidence related to soil retention of phosphorus from OWSs. This is the objective of the planned systematic map. Focus will be on boreal and temperate climate zones. Methods Searches will be made for peer-reviewed articles and grey literature using bibliographic databases, search engines, specialist websites and stakeholder contacts. The references will be screened for relevance according to a predefined set of eligibility criteria. At stage one, after testing and clarifying the eligibility criteria, the references will be single-screened based on title and abstract. At stage two, potentially relevant references will be screened in full-text independently by two reviewers. We will compile a detailed database of the relevant studies. Moreover, a narrative report will be produced, describing the research landscape in general terms. This will be carried out with a conceptual model, describing the processes involved in P retention in natural environments, as a foundation. It will be discussed where the respective studies/study types fit into the conceptual model, and also evaluated how each study/study type can be related to the overarching question of eutrophication. Moreover, we will describe identified knowledge gaps that warrant further primary research effort, as well as identified knowledge clusters that could be suitable for systematic reviews.
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| 3. |
- Hokkanen, S., et al.
(author)
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Adsorption of Ni2+, Cd2+, PO4 3- and NO3 - from aqueous solutions by nanostructured microfibrillated cellulose modified with carbonated hydroxyapatite
- 2014
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In: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 252, s. 64-74
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Journal article (peer-reviewed)abstract
- The adsorption of Ni2+, Cd2+, PO4 3- and NO3 - by carbonated hydroxyapatite (CHA) modified microfibrillated cellulose (MFC) was studied in the aqueous solution. The modified adsorbent was characterized using elemental analysis, FTIR, SEM and EDAX analysis. The adsorption studies were conducted in batch mode. The effects of pH, contact time, the concentration of metals and the regeneration efficiency were studied. The removal of Ni2+, Cd2+, PO4 3- and NO3 - was not pH dependent. The maximum removal capacities of the CHA/MFC adsorbent for Ni2+, Cd2+, PO4 3- and NO3 - were 2.021, 1.224, 0.843 and 0.209mmol/g, respectively. The Langmuir and Sips models were representative to simulate adsorption isotherms. The results of adsorption kinetic indicate that adsorption was very fast for all studied compounds.
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| 8. |
- Johansson Westholm, Lena, et al.
(author)
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Filter materials for metal removal from mine drainage-a review
- 2014
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In: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 21:15, s. 9109-9128
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Journal article (peer-reviewed)abstract
- A large number of filter materials, organic and inorganic, for removal of heavy metals in mine drainage have been reviewed. Bark, chitin, chitosan, commercial ion exchangers, dairy manure compost, lignite, peat, rice husks, vegetal compost, and yeast are examples of organic materials, while bio-carbons, calcareous shale, dolomite, fly ash, limestone, olivine, steel slag materials and zeolites are examples of inorganic materials. The majority of these filter materials have been investigated in laboratory studies, based on various experimental set-ups (batch and/or column tests) and different conditions. A few materials, for instance steel slag materials, have also been subjects to field investigations under real-life conditions. The results from these investigations show that steel slag materials have the potential to remove heavy metals under different conditions. Ion exchange has been suggested as the major metal removal mechanisms not only for steel slag but also for lignite. Other suggested removal mechanisms have also been identified. Adsorption has been suggested important for activated carbon, precipitation for chitosan and sulphate reduction for olivine. General findings indicate that the results with regard to metal removal vary due to experimental set ups, composition of mine drainage and properties of filter materials and the discrepancies between studies renders normalisation of data difficult. However, the literature reveals that Fe, Zn, Pb, Hg and Al are removed to a large extent. Further investigations, especially under real-life conditions, are however necessary in order to find suitable filter materials for treatment of mine drainage.
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| 10. |
- Johansson Westholm, Lena, et al.
(author)
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Mineral Resources
- 2013
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In: Reference Module in Earth Systems and Environmental Sciences. - : Elsevier. - 9780124095489
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Book chapter (other academic/artistic)abstract
- Throughout the history of planet Earth, minerals have formed through diverse geologic processes and at different locations, depending on the prevailing geologic conditions. Early civilizations mined minerals and rocks for a variety of purposes, initially for use in construction if the material had strength or for personal adornment if the mineral was attractive. Subsequently, minerals have been mined for a multitude of other purposes, where their chemical and physical properties have been of importance in a wide range of industrial processes. At the present time, large volumes of a variety of minerals are needed for society, and this demand is continuously increasing.
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