Research

RedMic aims at identifying critical organic micropollutants pollutants (MPs) emitted from on-site sewage treatment facilities (OSSFs) and provide new science based reduction tools and reduction strategies. Nearly 700 000 private households in Sweden are not connected to any central wastewater treatment plants and emissions of organic MPs from OSSFs are in large unknown. RedMic hypothesize that OSSFs provide a large share of overall diffuse emissions of MPs to surface and ground waters. The main objectives of the RedMic project are thus to;

  • I. Identify and quantify emissions of MPs from OSSFs
  • II. Develop and evaluate novel innovative small scale sewage treatment techniques
  • III. Identify sources of relevant MPs emitted from private households
  • IV. Suggest an efficient strategy for reduction of diffuse emissions from private households

RedMic is designed to study diffuse emissions from OSSFs applying a strategy with five major research oriented WPs. Data and new knowledge generated from these WPs will be synthesized in work package (WP) 6, which applies system and multi-criteria analysis aiming at developing a new decision strategy as a tool to reduce emissions from OSSFs. Below is a brief description of each WP; for more details see "Research".
WP1 aims at identifying potential MPs released from OSSFs applying a non-target screening methodology combined with a multi-residue target analysis. The target analysis will be focused on major sewage effluent MPs, incl. pharmaceuticals, flame-retardants, fluorinated chemicals, and pesticides. The analyses will be performed using state of the art GC- and LC- time-of-flight mass spectrometry (ToF-MS) and LC/GC-MS-MS.
The fate of identified potential MPs will be further studied in WP2 applying batteries of in silico tools combined with chemical analysis to assess if these MPs are persistent and pose a threat to recipient ecosystems. Sampling downstream selected OSSFs and target chemical analysis will be performed to validate the in silico models. WP2 aims at answering the questions; how large is the problem with MPs emitting from OSSFs?
Novel innovative small-scale sewage facilities will be developed and studied in WP3 with focus on reduction of MPs. These studies will be performed in the laboratory and in situ in an OSSF research facility using e.g. sewage spiked with selected MPs and simulating typical OSSFs operational settings. WP3 aims at answering what is the reduction capacity of today's technique and how could these be improved by adding new treatment steps?
Unravelling emission sources in private households of MPs of concern is the major aim of WP4. A recently developed in silico based emission model will be combined with studies in an emission chamber on selected goods and materials and usage information on household chemicals, pharmaceuticals and personal care products (PPCPs), etc. Major flows of chemicals and specific emission factors of most critical MPs will be determined.
In WP5 causes are searched that underlie human behaviour and risk perception in different settings, such as consumption preferences, attitude towards recycling and perception of responsibility for emissions using interviews and survey studies as major tools. In addition, analysis of relevant legislation and the potential for regulatory steering will be conducted in order to better address these issues in future reduction strategies.

The projects has six parts, "Workpackages":


WP1

WP1 Effluent characterization: Non-target and target chemical analysis
It will be essential to study the emissions from different type of households and the removal efficiency of different OSSFs, initially using multi-residue and non-target analysis, later using high-throughput techniques.
Sampling will be performed in OSSFs (WP3) and downstream OSSFs (WP2) using time-integrating sampling techniques, followed by a minimum cleanup, e.g. macromolecule removal and analysis with powerful complementary techniques (see below). These provide full-scan data on all (ionized) pollutants, which results in a huge amount of data, and an intelligent evaluation scheme is needed. We start with target screening using multi-residue methods for common sewage pollutants, pharmaceuticals, and pesticides followed by post-target screening using MS libraries for other man-made chemicals, with focus on persistent, bio-accumulative and toxic compounds (EDC and CMRs). The largest peaks of the remaining compounds will be characterized using their retention times, mass spectrum, and chemical formulas. GC×GC retention times may also provide information on their volatility and polarity, and automatic classification of EI mass spectrum provides information on functional groups. Through interaction with public databases (e.g. ChemSpider, KemI product register) a tentative identity may be assigned – to be validated using reference materials.
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WP2

WP2 Fate analysis for reduction prioritization
Once organic pollutants have been released from OSSFs into the environment, they are subjected to various transformation processes. Hence, along a water path, the concentrations of pollutants and transformation products may change and so would the associated effects.
Chemicals identified in WP1 will be compared to regulatory limits such as the EU environmental quality standard and subjected to fate and effect evaluation using in silico models targeting persistence, bioaccumulation, and ecotoxicological effects. Batteries of available models including the OECD QSAR toolbox and EPISUITE will be run. Selected chemicals will be further studied along an environmental transect from the primary recipient and downstream to a larger water body (e.g. lake or estuary) on a seasonal basis. Through the combined use of measurement and modelling, it will be possible to make a short-list of 10-20 high priority pollutants. We will also use state of the art mass spectrometry to search for stable transformation products of the target chemicals.
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WP3

WP3 Existing and novel small-scale sewage treatment techniques
In order to take actions against on-going discharges, new treatment techniques should be developed that can improve their treatment efficiency.
A literature review will form the basis for a state of the art report on the ability of current OSSF techniques to remove MPs and also to find optional additional treatment steps. The performance of OSSFs in operation will be studied by chemical analysis of selected target chemicals from phase I. Studies on novel techniques will cover e.g. activated carbon and reactive filters, and hydrogen peroxide, ozone and UV-light treatment. Studies will include lab-scale and full-scale tests where spiked sewage will be used and modulation of operational parameters tested to simulate various residence times. In addition, correlations will be searched between molecular structural information of studied organics and their removal efficiency aimed at increasing our understanding of removal processes.
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WP4

WP4 Source tracing – measurement and modelling of emissions
Chemicals originating from products that are intentionally used in such a way that emissions are inevitable, e.g. PPCPs, detergents, and food, are relatively easy to track; while slowly emitting chemicals in consumer goods and building materials are difficult to track.
Major sources of the 10-20 MPs selected in WP2 will be searched for in private households by an initial literature and data base survey and using a combination of in silico based estimations and experimental measurements of emission factors (in field or laboratory). We also aim to screen chemicals in silico with identical functionality in products as the case chemicals to reach a better understanding of future emission scenarios.
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WP5


WP5 Risk perception and regulatory strategies
Issues of risk perception, responsibility and the perceived effectiveness of reduction strategies are of vital importance to investigate from the perspective of individuals.
A study on the relevant actors' perceptions of risk and incentives will be carried out in relation to diffuse emissions from private households and OSSFs. The specific areas under study will include a number of different households, e.g. summerhouse areas, ecovillages, and permanent residents in rural settings. A critical study of the existing regulatory order will also be carried out, in order to assess the potential for regulatory steering of developing OSSFs as proposed in the study. Especially the limits of reasonableness and proportionality in the regulatory steering of private persons will be discussed and reflected on in context of steering through economic incentives and information. The potential for such regulatory steering, and the appropriate coordination with other measures, will be discussed in comparison to alternatives regulatory strategies, including especially upstream regulatory control of chemicals including the REACH legislation.
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WP6

WP6 Synthesis and dissemination of results
A huge amount of data will be compiled in WPs 1-5 covering a large range of aspects on emissions from OSSFs. These will be synthesized in WP6 and dissemination will be coordinated.
Data integration and synthesis of the interdisciplinary knowledge generated in RedMic will form the corner stone for suggesting decision support strategies for management of diffuse emissions from OSSFs. This will be done with a step-wise systems analysis approach starting with 1) definition of system boundaries 2) selection of criteria covering ecological, economical and social dimensions 3) selection and formulation of different possible options for reducing MPs including source control, changes in human behavior and technical improvements, 4) comparison of the different options using the criteria from step 1. The comparison will be done using substance flow-, cost- and energy analysis and also qualitative assessment. Finally, in step 4, a multi-criteria analysis will be used for an integrated assessment of all dimensions to reach a decision support system.
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