Replacing petroleum-based with bio-based ingredients in articles and chemical products is one important step towards reducing the environmental impact, and promoting circular economy practices, aligning with the goal “Responsible Consumption and Production” within United Nations’ Agenda 2030. The aim of the project was to develop bio-based prototype ski waxes and to evaluate and benchmark them with commercial petroleum-based PFAS-free ski waxes, in terms of hydrophobicity, glide performance and biodegradation.

Bio-based ski wax prototypes were blended using a mixture of ingredients approved for either topical application or ingestion by humans. Which ingredients and relative ratios to mix were based on melting points, general hydrophobic properties and generated knowledge from testing of earlier prototypes. It should be noted that only Vallakokerskan has the information about the exact content in the ski wax prototypes.

The hypothesis is that more hydrophobic, i.e. more water repellent, ski wax allows better transportation of the water film away from the ski/snow interface, providing lower friction and better glide. The hydrophobicity of ski waxes and ingredients was quantified from contact angle measurements using water and ethylene glycol as the liquid in a climate-controlled room (23°C and 50% relative humidity). To measure contact angles at sub-zero degrees, a less sensitive but portable device was put in a freezer room at -5°C where contact angles were measured using ethylene glycol.

The ski waxes showed similar hydrophobicity, in the measured static, advancing and receding contact angles, both in room temperature and at -5°C. However, the roll-off angle when the water droplet started to roll, was slightly lower for the commercial ski waxes than the bio-based prototypes. Greater differences in hydrophobicity and roll-off angles were observed for the ingredients compared to the ski wax.

In the glide tests on snow, it was difficult to separate the bio-based and commercial ski wax. This was both when considering the total glide time from four skiers testing each ski wax (ski pair) twice, and in the pairwise comparisons as is normally done when selecting skis before competition. These results show that the bio-based prototypes are comparable to commercial ski wax that is used both for competition and recreational skiing. While having similar glide function, the advantage of the bio-based ski wax is that it contains only naturally derived ingredients and that it seems to degrade slightly more rapidly in the environment. The biodegradation was compared between one bio-based and one petroleum-based ski wax using a respiration test where formed CO₂ was quantified over time. The estimated number of days required for complete degradation of the bio-based ski wax and commercial ski wax would be 223 days and 335 days, respectively, if the degradation continues at the same rate and if all carbon is converted to CO₂. In comparison to cellulose, both ski waxes degrade relatively slowly, most likely due to their hydrophobic properties.

During the project it was decided to also quantify and compare the hardness of the waxes since that is being discussed more and more as one additional characterisation technique in the project. The hardness measurements were done at -5°C. The maximum force encountered (firmness) when a probe was lowered into the sample during the compression test was taken as the hardness. Differences were obtained between the samples where the average firmness (hardness) was higher for the commercial green, blue and purple commercial ski waxes compared to the corresponding bio-based wax. However, the bio-based yellow was harder than the corresponding yellow commercial ski wax. Large differences in hardness at -5°C for the ingredients were noted.

The prototypes have been made with a mixture of different ingredients. The results from the hydrophobicity and hardness measurements of ingredients, can be used to select and modify the relative amount of each ingredient in the ski wax. If the hypothesis is that more hydrophobic and harder ingredients are better for the glide, it could be interesting to see if a wax containing a higher amount of those harder and more hydrophobic ingredients could increase the performance.

The focus in this project has been to develop a bio-based ski wax matrix. As a next step it would be interesting to develop and incorporate bio-based additives to try to increase the performance further. Another future outlook is to make the bio-based wax as a liquid product that are becoming more popular due the ease of application and less waste during the waxing procedure.

Biological methanation of syngas from pyrolysis and gasification – promising concepts for implementation The need for increased biogas production is significant, and in the EU, there are plans for a substantial expansion in the coming years through the RePowerEU initiative. Part of the increase will come from the expansion of conventional digestion technology, where organic materials such as food waste, manure, and crop residues are used for biogas production. However, to meet the future increased demand, it is also necessary to utilize more difficult-to-digest substrates, such as biomass rich in lignocellulose, for biogas production. This could be forest residues such as branches and tops, sawdust, or bark. This type of substrates cannot be used in a conventional digestion process, and other technology chains are therefore required to convert such biomass into biomethane. This can be done by first converting the biomass into syngas through a thermochemical process such as gasification or pyrolysis. This is followed by a methanation process where the syngas is converted into biogas, and finally, the gas is upgraded to reach biomethane quality. These types of technology chains are not currently available on a commercial scale, but they have been demonstrated, for example, through the Gobigas project, where gasification was followed by catalytic methanation for biomethane production. As full-scale implementation of catalytic methanation of bio-syngas has not yet been achieved, thereis a need to develop alternative conversion technologies that can more cost-effectively achieve the methanation of woody biomass. One possible opportunity for to this is to apply biological methanation instead of a catalytic process. A biological process comes with several advantages, including a greater ability to handle contaminants, higher selectivity in the conversion of syngas, and operation at relatively low temperature and pressure, which simplifies material selection and reactor design. RISE, together with its partners, are developing a concept based on biological methanation of syngas. This project has examined the biological process's ability to handle contaminants in syngas through continuous experiments in carrier-filled trickle bed reactors with an active volume of 5 liters. The process's ability to handle and break down contaminants is an important parameter that can affect and simplify the design of the gas cleaning that occurs after gasification or pyrolysis. Another aspect of the project has been to put the experimental results into context at the concept and system level. Different production techniques for syngas have been mapped out, which could be combined with biological methanation. Based on the mapping, three types of plants have been selected for more detailed analyses of techno-economics, carbon footprint, and opportunities for increased carbon efficiency. The methanation experiments lasted for 552 days, and overall, it was a stable process with high turnover of syngas and high methane production over a long time. There have been some operational disturbances, mainly related to the supply of gas to the process (i.e. delivery of gas cylinders). However, biochemical inhibition or disturbances have been rare, demonstrating a high robustness for biological methanation of syngas. The breakdown of contaminants has been excellent in the process, with levels decreasing below the detection limit. At the same time, as contaminants have been continuously added to the process, microbiology has been able to maintain high turnover of hydrogen and carbon monoxide to methane. The specific methane production was high both during the reference period without contaminants and during the experimental periods with added contaminants. During long periods, the specific methane production has been around 4 L CH4/Lbed volume /day, which is about 4 times higher than our previously achieved results. The transition to thermophilic temperature and using carriers with higher effective surface area has contributed to this increase. During the project, three types of plants have been selected for more detailed analysis: 1) Gasification with Cortus process, which generates a relatively clean syngas with minimal purification needs before biological methanation. There is no need for co-location with a heating plant, but it is an advantage if there is access to the district heating network to sell waste heat. 2) Gasification with Bioshares' concept, where the gasifier is integrated into a larger cogeneration plant and where the produced syngas is purified with an RME-scrubber before biological methanation. Co-location with a larger cogeneration plant provides interesting synergies and integration opportunities, but also sets the boundaries for where the plants can be located. 3) Slow pyrolysis according to Envigas' concept, where the primary product is biochar and where the produced syngas is seen as a by-product. The syngas contains some impurities but generally requires no other purification than cooling to the right temperature (condensing out tars) before being added to biological methanation. This type of plant differs from plant types 1-2 in that the syngas formed is not the primary product, and the syngas has a relatively low energy value compared to the others. Syngas from plant types 2 and 3 contains some hydrocarbons (C1-C3) that are considered inert over the methanation step and therefore do not negatively affect the process. This means that heavier hydrocarbons do not need to be removed upstream, which would likely have been required with catalytic methanation. This leads to a higher system efficiency, and the need for reactor capacity for biological methanation decreases since there is less gas to be processed (more of the end-product consists of hydrocarbons already formed during the thermochemical conversion upstream). For all plant types, downstream of the methanation step, there is a need for further gas purification and upgrading. During the upgrading step carbon dioxide is separated to reach the product specification required by the end user. If long distance distribution is required a final process step consisting of a liquefaction plant for the production of liquid biogas (LBG) can be added to the concept. As another option, the systems can be supplemented with treatment of the carbon dioxide flow out of the upgrading plant, where the flow is processed by drying, compression, and cooling to produce liquid carbon dioxide. For plant type 2, where benzene is present in the syngas, this gas is expected to be separated with relatively high precision in the system and thereby generate a small flow of liquid benzene as a side product. The carbon dioxide emissions for the final product LBG are in the range of 1.6 to 2.6 gCO2-eq/MJLBG, which compares favorably to other types of second-generation biofuels. Compared to fossil gas, the reduction in greenhouse gas emissions is 96-97%. The carbon efficiency of the systems can be significantly increased if excess carbon dioxide is utilized either through BECCS or BECCU. If the carbon dioxide stream from the upgrading plant is processed into liquid carbon dioxide, the production cost is estimated to be 187-204 SEK/ton. If the product is to be sent to permanent storage the cost for transportation and storage would need to be added to estimate total cost of BECCS, but this is out of scope for the current project.. Assuming that BECCS is applied and that the entire carbon sink is allocated to the final product LBG, this will result in negative emissions in the range of -35 to -104 gCO2-eq/MJLBG. An alternative is to utilize excess carbon dioxide directly in the methanation process by boosting incoming gas with extra hydrogen. Hydrogen and carbon dioxide are then converted by methanogens, which generates extra methane. Since the addition of extra hydrogen is assumed to come from electrolysis, the additional methane production can likely be classified as electrofuel, so-called e-methane. The techno-economic evaluation results in a production cost ranging from 740 to 1300 SEK/MWhLBG, including all sensitivity scenarios. The lower price scenarios include a lower investment cost, which can be assumed to represent cases with public investment support. Overall, a large part of the scenarios are considered to be within the range of what can be considered market relevant production costs. This leads to the conclusion that there is techno-economic potential at this stage to justify continued development of concepts based on biological methanation of syngas. With scaling up and continued development in the right direction, the concepts may eventually lead to cost-effective utilization of forest residues for the production of biomethane at a commercially relevant scale. The next step in the development is scaling up to pilot scale, which will take place during 2023-2025 through an EU-funded project and will be carried out by RISE, Wärtsilä, Cortus and Swedish Gas Association. A pilot plant for biological methanation will then be operated with syngas from Cortus' gasifier in Höganäs.

The pulp and paper (P&P) industry holds significant global importance. However, the industry’s processes substantially demand water and energy resources. Consequently, there is a pressing need for the industry to adopt more sustainable production practices, aiming to trim environmental impact and strengthen resilience against climate change. Recent research has highlighted the potential for substantial increases in Swedish biogas production using anaerobic wastewater (WW) treatment methods within P&P mills. The P&P sector traditionally relies on aerobic biological WW treatment, overlooking the valuable opportunity for WW resource recovery. This study aims to evaluate anaerobic moving bed biofilm reactors (AnMBBR) to enhance energy recovery while enabling treatment capacity for the P&P industry’s anaerobic WW treatment. The results of this study showed the resilience of the AnMBBR system. It proved capable of recovering from overload conditions and operating even during prolonged periods at low pH levels. However, the system removes mainly soluble COD, suggesting higher capabilities on P&P WW with a high fraction of soluble COD. Its ability to produce methane-rich biogas demonstrates efficient gas production while maintaining simple operational procedures. 

Agricultural Biorefinery - combining local and regional scale In order to achieve Sweden's sustainability goals and an increased degree of self-sufficiency, our resources need to be used in an innovative way. Resources that today are classified as residual streams can be used in a smarter way to produce the future's food, feed, fuel and energy. There is a great potential in utilizing agricultural biomasses. In the project, the potential of agriculture to supply ILUC-free feedstock to a local and regional biorefinery concept was calculated and the system was evaluated through mass and energy flow calculations, cost calculations and case descriptions on Vårgårda Herrljunga Biogas Plant (VH Biogas). In addition, practical tests were carried out on bio-oil production from dewatered digestate from participating biogas plants. Quantifications were also carried out of how the concept contributes to more resource-efficient crop cultivation with maintained humus content in soil despite increased removal of biomass from the farm. ...

Microbial community development within an anaerobic trickle bed reactor (TBR) during methanation of syngas (56% H2, 30% CO, 14% CO2) was investigated using three different nutrient media: defined nutrient medium (241 days), diluted digestate from a thermophilic co-digestion plant operating with food waste (200 days) and reject water from dewatered digested sewage sludge at a wastewater treatment plant (220 days). Different TBR operating periods showed slightly different performance that was not clearly linked to the nutrient medium, as all proved suitable for the methanation process. During operation, maximum syngas load was 5.33 L per L packed bed volume (pbv) & day and methane (CH4) production was 1.26 L CH4/Lpbv/d. Microbial community analysis with Illumina Miseq targeting 16S rDNA revealed high relative abundance (20–40%) of several potential syngas and acetate consumers within the genera Sporomusa, Spirochaetaceae, Rikenellaceae and Acetobacterium during the process. These were the dominant taxa except in a period with high flow rate of digestate from the food waste plant. The dominant methanogen in all periods was a member of the genus Methanobacterium, while Methanosarcina was also observed in the carrier community. As in reactor effluent, the dominant bacterial genus in the carrier was Sporomusa. These results show that syngas methanation in TBR can proceed well with different nutrient sources, including undefined medium of different origins. Moreover, the dominant syngas community remained the same over time even when non-sterilised digestates were used as nutrient medium. Key points: •Independent of nutrient source, syngas methanation above 1 L/Lpbv/D was achieved. •Methanobacterium and Sporomusa were dominant genera throughout the process. •Acetate conversion proceeded via both methanogenesis and syntrophic acetate oxidation. Graphical abstract: [Figure not available: see fulltext.] © 2022, The Author(s).

Use of biofilter for the treatment of pesticide contaminated water Despite many measures to reduce the risk of pesticides spreading to sensitive environments, their residues are still often found in surface and groundwater. Point sources are a significant cause of such contamination, mainly associated with localized situations, e.g., filling of the tank and washing of the sprayer. According to Sweden's official statistics, 54% of farmers choose some form of concrete surface connected to a collecting tank as a safe pesticide handling place. The collected liquid is later spread on biologically active soil, such as fallow or on stump. However, farmers’ experience indicates that there can be large amounts of water to handle annually, and chemical residues in the spread liquid can have a negative effect on crops. There is a need to improve the existing and future pesticide handling sites to manage large volumes of water safely, easily, and economically. An appropriate and simple solution is the use of a biofilter to treat the collected liquid. The biofilter has been developed based on the Swedish biobed and is used in several countries. It consists of several 1 m3 – plastic containers filled with biomix, and the different units are stacked in a vertical pile and connected with plastic valves and pipes. Contaminated water is collected and circulated through the biofilter and pesticide residues are retained in the biomix where they are degraded by microbial activity. The aim of the project was to adapt the use of the biofilter to Swedish conditions and gain knowledge about how it should be operated. Since water dynamics are an important factor in the biofilter function, the specific goals of the project were to study the effect of the inflow rate on water balance, microbial activity, and pesticide retention in a typical Swedish biomix. For the project a pilot biofilter was built at RISE workshop in Uppsala. A list of the materials needed, the approximate cost of building a biofilter and a preliminary instruction manual for the construction were produced within the frame of the project. The cost of building a 3-unit biofilter was estimated to be approx. 15,000 Swedish crowns. The study was divided into two trials under controlled conditions. First, the effect of inflows on water content and microbial activity in the biomix was investigated. A constant flow rate of 25 L/d was tested in one of the units and an increasing flow of 7, 22 and 40 L/d in another unit. The results showed that the outflow increased with flow rate and was between 50 and 96% of the inflow. Water content in the biomix was lower and fluctuated more on the surface compared to the bottom of the biomix and water retention capacity decreased over time. A tendency to reduced carbon content and microbial activity (measured as respiration rate) over time was observed with the flows > 20 L/d. The levels of glyphosate and diflufenican in the effluent were very low, 0,1 % of the levels in incoming water, regardless the flow. The higher flow reduced the retention capacity of bentazone, i.e., a higher inflow led to higher levels of bentazone in the effluent. According to our results, a typical Swedish biomix, under the conditions tested in this study, can treat a flow lower than 20 L/d without having a major impact on microbial activity and on the pesticide retention capacity. Assuming that the biofilter can be used for 210 days/year (not in winter), approximately 4000 L can be treated in one year with a flow of 20 L/d. Biofilters are a good option for farms with indoor or outdoor pesticide handling areas under roof. For farms with an outdoor concrete area without a roof, where precipitation also ends up in the collection tank, the volumes to treat become too high for a biofilter.

The study concerns acidification at the beginning of storage to reduce ammonia emissions during storage. The aim of the study was to evaluate the reduction of ammonia emissions by the acidification of cattle slurry, digested and non-digested, in storage under summer conditions.

Cattle slurry (CS) and digested cattle slurry (DCS) were taken from a dairy farm with a digester plant. The sulphuric acid required for acidification to pH 5.5 was determined by titration before the pilot-scale experiment began. In the pilot-scale experiment, each slurry type was divided into two containers. One batch was acidified to pH<5.5 by adding sulphuric acid (96%) slowly with gentle mixing. The other batch was not acidified. During acidification, the pH was measured frequently and the total amounts of acid added were noted. Temperatures were measured during the four-month storage period with loggers at 0.1 m from the bottom and 0.1 m from the surface of each container. Data were continuously recorded hourly.

Ammonia emissions were measured using a micrometeorological mass balance method with passive flux samplers. There were five measuring periods during the warm storage period from May to August. The length of the measuring periods ranged from 3 to 14 days, with the shortest period at the start of storage.

On a pilot scale, the acid consumption for reaching pH< 5.5 was 1.1 L/m³ for CS and 6.2 L/m³ for DCS. The change in pH after acidification was rather limited and the pH stayed <6 throughout the four-month storage period for both CS and DCS.

On a laboratory scale, more acid was needed to reach pH 5.5, and the pH increased more, with less buffering, than on a pilot scale. The reasons for this could be higher temperatures, frequent mixing, small volumes, and the use of diluted acid on a laboratory scale compared with on a pilot scale. On a laboratory scale, it was possible to show differences in acid demand between slurry types, but the amounts of acid needed seem to be different (higher) compared with pilot scale.

The estimated cumulative NH₃-N emissions corresponded to about 19% of total-N for CS and about 26% of total-N for DCS. The estimated cumulative NH₃-N emissions were about the same as a percentage of TAN for CS and for DCS (57.8 and 53.9% respectively).

Emissions from the acidified batches of slurry were overall negligibly low. The addition of acid decreased ammonia emissions very effectively, for both CS and DCS.

Denna studie handlar om hur surgörning av flytgödsel vid start av lagringen kan minska ammoniakavgången under lagringsperioden maj till augusti. Målet var att bestämma minskningen av ammoniakavgången genom att surgöra nötflytgödsel, både orötad och rötad och se effekten jämfört med gödsel utan syratillsats.

Flytgödsel (CS) och rötad nötflytgödsel (DCS) hämtades från en mjölkkogård med en biogasanläggning. För att få ett riktvärde för den syramängd som skulle åtgå för att sänka pH hos respektive gödseltyp till 5,5, utfördes titreringar i laboratorium innan uppstart av lagringsförsöket i pilotskala. Lagrings­anläggningen bestod av fyra behållare á 3 m³. Vid fyllningen av lagren, delades varje gödselslag upp mellan två behållare, varav det i en av behållarna tillsattes svavelsyra (96 %-ig) samtidigt som gödseln rördes om försiktigt med en eldriven propeller. Den andra behållaren rördes om också men utan tillsats av syra. Under syratillsättningen mättes pH vid upprepade tillfällen och totala mängden syra noterades. Gödseln lagrades under fyra månader från maj till augusti samtidigt som gödseltemperaturen registerades på två nivåer i varje behållare, vid gödsel­ytan och nära botten, och temperaturvärdena registrerades varje timme.

Under lagringen mättes ammoniakavgången med en mikrometeorologisk massbalansmetod med passiva fluxprovtagare. Fluxprovtagarna var monterade på master runt varje behållare under exponeringen. Totalt var det fem mät­perioder, som varade 3 till 14 dagar, med den kortaste perioden direkt efter fyllningen i maj.

För att sänka pH till 5,5 åtgick 1,1 liter per m³ för CS och 6,2 liter  per m³ för DCS. Under lagringen steg pH hos de surgjorda gödselslagen obetydligt och låg i slutet av lagringen på pH mindre än 6 hos båda gödselslagen. Vid titreringen i laboratorium före start av lagringsförsöket behövdes det betydligt mer syra för att nå pH 5,5 än i pilotskalan. Orsaker till det kan vara att i laboratoriet var temperaturen högre, gödselvolymerna små, gödseln blandades om ofta, samt att vid titreringen användes utspädd syra. Men även i laboratorieskalan var det stora skillnader mellan CS och DCS i syraförbrukning, så titrering kan användas som en grov uppskattning och för att se skillnader mellan olika gödselslags syrabehov. Däremot kan det vara svårt att förutse behovet av mer exakta syramängder i större skala.

Totalt uppskattades den kumulativa ammoniakavgången i kvävemängd uppgå till ca 19 % av totala kväveinnehållet hos nötflytgödsel (CS) och 26 % av kväve­innehållet i den rötade gödseln (DCS) när ingen syra hade tillsatts.  Motsvarande siffror i procent av innehållet av det lättlösliga ammoniumkvävet var 57,8 % för CS och 53,9 % för DCS.

Ammoniakavgången från den surgjorda CS och DCS gödseln var mycket liten och i stort negligerbar. Det betyder att tillsats av syra minskade ammonia-kavgången mycket effektivt, både för CS och DCS.

Källsorterande avloppssystem kan minska utsläpp av läkemedelsrester till akvatiska miljöer och möjliggör samtidigt kretslopp av näringsämnen. Kunskapen om läkemedels-förekomst i källsorterade avloppsfraktioner är dock delvis bristfällig, liksom kunskapen om vilken reducerande effekt som erhålls i de behandlings- och hanteringsprocesser som används för dessa fraktioner idag. Även kunskapen om vad som händer i miljön är begränsad vad gäller upptag i växter, nedbrytning, transport och spridning.

Syftet med projektet var att samla den kunskap som finns och den forskning som pågår relaterad till läkemedel i källsorterade avloppsfraktioner i Sverige och internationellt, för att identifiera prioriterade frågeställningar framåt. Projektet syftade även till att beskriva hur behandling av avloppsfraktioner från källsorterande avloppssystem påverkar halterna av läkemedelsrester i slutprodukten.

Projektet genomfördes utifrån en litteraturstudie med fokus på genomförda och pågående studier/forskning relaterad till läkemedel i källsorterade avloppsfraktioner globalt. Inga analyser har genomförts inom projektet. De data över innehåll av läkemedelssubstanser i obehandlade och behandlade fraktioner som redovisas är hämtade från tidigare genomförda studier. Förutsättningarna för studier kring läkemedel i källsorterade avloppsfraktioner varierar, vilket försvårar möjligheten att jämföra resultat och dra slutsatser kring innehåll och reduktion av läkemedel i källsorterade avloppsfraktioner.

De flesta studier behandlar urin. Merparten av behandlingsmetoderna för urin är utförda i labbskala medan studier på klosettavloppsvatten är gjorda på anläggningar som är i drift idag. För latrin har endast en studie som behandlar läkemedel hittats.

Olika behandlingsmetoder fungerar olika bra på olika typer av läkemedelssubstanser. För urin har tester utförts med många olika behandlingstekniker. Av de som beaktats i denna studie är det endast ozon och UV-ljus som har en bred effekt och som till störst del reducerar de flesta läkemedelssubstanser som har analyserats i urin. För klosettavloppsvatten har tre behandlingsmetoder studerats. Ingen av metoderna reducerade alla läkemedel, men behandling med UASB-reaktor gav en god reduktion då de flesta läkemedel som analyserats reducerades till ca 60 %. För latrin påverkades de flesta läkemedel varken av mesofil eller termofil rötning.

De flesta studierna kring läkemedelssubstanser i miljön har fokus på akvatiska system och informationen om hur substanserna beter sig i marken är begränsade – både vad gäller nedbrytning samt läkemedelsinnehåll i växande gröda. Inom dessa områden behövs mer forskning.

Läkemedel i källsorterade avloppsfraktioner är ett komplext område där flera kunskapsluckor finns och där mer forskning behövs. Förhoppningsvis bidrar denna sammanställning till en översiktlig bild av hur det kan se ut, vilken kunskap som finns inom området samt förenklar beslut och prioritering av framtida forskning.

Systems with different source-separated toilet fractions (blackwater, fecal sludge and urine) can reduce the number of pharmaceuticals to the aquatic environment and at the same time allow circulation of nutrients. However, knowledge of the occurrence of pharmaceutical residues in source-separated toilet fractions is partly insufficient. There is also a lack of knowledge of how the different treatment processes effect the occurrence of pharmaceutical residues and if they are reduced or maintained thru different treatments. Knowledge of their faith in the environment is also limited, in terms of uptake in plants, degradation, transport and spreading.

The purpose of this project was to gather current knowledge related to pharmaceutical residues in source-separated toilet fractions from both Sweden and internationally, to be able to identify prioritized research areas for the future. The project also aimed to describe how treatment of source-separated toilet fractions affects the levels of pharmaceutical residues in the final product.

A review of literature was made, focusing on studies and research related to pharmaceutical residues in the different fractions. No analyzes have been carried out within this project. Data on the content of pharmaceutical residues in untreated and treated source-separated toilet fractions was collected from previous studies and summarized. The basis in the different studies varies a lot, which makes it difficult to compare the results of the content and reduction of pharmaceutical residues in the different source-separated toilet fractions.

Most of the studies that was found treated pharmaceuticals residues in urine. Most of the treatment methods for urine are performed in lab scale while studies on blackwater are made on plants that are in operation today. For fecal sludge, only one study that treats pharmaceuticals residues has been found.

Different treatment methods work differently on different types of pharmaceutical residues. For urine, there are studies with many different treatment techniques. Of those considered in this study, only ozone and UV-light have a broad effect and reduces most of the pharmaceutical residues that have been analyzed. Three treatment methods have been studied for blackwater. None of the methods reduced all pharmaceutical residues, but treatment with UASB reactor provided a good reduction as most pharmaceutical residues analyzed were reduced to about 60 %. For fecal sludge, most pharmaceutical residues were not affected by either mesophilic or thermophilic digestion.

Most studies on pharmaceutical residues in the environment focus on aquatic systems and the information on how the pharmaceutical residues behave in the soil is limited - both in terms of degradation and content in growing crops. More research is needed in these areas.

Pharmaceutical residues in source-separated toilet fractions are a complex area with several gaps of knowledge and more research is needed. Hopefully, this rapport contributes to an overview of some data and treatment processes and brings more knowledge into the area that simplifies decisions and prioritization of future research.

Samples of three different concrete qualities were prepared and hardened, before exposure in cattle slurry without sulphuric acid (A) and with sulphuric acid added until pH<5.5 (B). The samples were exposed for two years in containers with about 45 L slurry. The boxes with slurry and concrete samples were placed in a ventilated room at 20 °C. The slurry and air temperatures were recorded continuously with temperature loggers, data being recorded every third hour. The slurry level in the boxes and the slurry pH were checked regularly during the experiment. Slurry or acid was added, if necessary, to maintain the level and pH<5.5. Before pH measurements, the slurry was stirred gently in both boxes. To restrict evaporation, the containers had non-airtight plastic covers between measurements.

Half-way through exposure, the old slurry was replaced with fresh slurry (acidified and non-acidified treatments) to mimic conditions in farm storage where fresh slurry is added continuously during storage. After two years’ storage, the experiment was finalised. The concrete samples were taken out of the slurry, washed gently with water and put into labelled plastic bags.

The samples were delivered to RISE CBI’s concrete laboratory, where the structural analyses were performed. These used petrographic microscopy techniques to examine the effects of exposure to two potentially aggressive environments, non-acidified and acidified cattle slurry, on concrete with three different mixes. The studied surfaces in the concrete samples were oriented vertically in the plastic containers. Polished sections were evaluated with a stereo microscope, and thin sections were evaluated using a polarising microscope and sources for visible and UV light.

The results of the study show that the acidified slurry is more chemically aggressive to the cement paste in all the concrete mixes analysed. This can be explained by the solution’s lower pH.

The extent of the chemical attack correlates with the initial quality of the concrete mix (water-powder ratio and type of binder). The deepest chemical attacks were observed in samples A1 and B1 consisting of “regular” concrete mix with w/c 0.59. The “long lasting quality” (LLC) concrete with a binder specially developed for low-pH environments shows markedly better resistance to chemical attack.

The effects of the chemical attack on concrete after two years’ exposure can be classified as weak, consisting mainly of an increase in the capillary porosity of the cement paste in the outer layer of the concrete. The increase in porosity is considered to be due to the partial leaching of calcium hydroxide.

Surgörning av flytgödsel används som en metod för att minska ammoniak­avgången från stallgödsel vid hanteringen. För att minimera emissionerna under lagringen, eftersträvas ett pH-värde av 5,5 hos gödseln. Svavelsyra är den vanligaste syran eftersom svavelsyran är stark och prisvärd. En pH-sänkning hos gödseln kan dock innebära frätskador på betongen i lager, som kan betyda kortare livslängd om inte betongkvaliteten anpassas till gödselns pH. Syftet med denna studie var att se hur surgjord gödsel (B) påverkar betongytan hos olika betongkvaliteter jämfört med icke-surgjord nötflytgödsel (A).

I studien ingick betongprover av tre olika kvaliteter, som motsvarade kvaliteten hos 1) bottenplattan hos flytgödsellager, 2) prefabricerade väggelement till flytgödsellager samt 3) en betongkvalité kallad ”Long Lasting Concrete”, som utvecklats av Abetong AB för lagring av material med lågt pH, t.ex. ensilage. Betongprover (0,1 m x 0,1 m x 0,1 m) tillverkades av Abetong AB och exponerades under två år i nötflytgödsel utan syra (A) respektive surgjord nötflytgödsel (B). Behållarna med respektive gödseltyp placerades i rum med konstant temperatur ca 20°C. Under lagringen mättes regelbundet pH och vid behov tillsattes mer gödsel samt syra för att hålla pH-värdet under 5,5. Halvvägs genom studien byttes gödseln ut mot färsk gödsel för att efterlikna verkliga lager och efter två år avslutades studien. Betongproverna togs ut ur gödselbehållarna, duschades försiktigt, paketerades och fördes till RISE CBI:s betonglaboratorium.  

I laboratoriet utfördes strukturanalyser av betongen, där den studerade ytan hos betongen hade varit vertikalt orienterad i gödselbehållaren. För att undersöka gödseltypernas effekt på de olika betongblandningarna användes betongpetrografiska analysmetoder. Polerade betongsnitt och tunnslip tillverkade av betongproverna utvärderades dels med hjälp av stereomikroskop, dels med polarisationsmikroskop och ljuskällor för synligt och ultraviolett ljus. Resultaten från studierna visade att den surgörande gödseln var mer kemiskt aggressiv mot cementen i alla tre betongblandningarna. Det förklaras med det lägre pH-värdet hos den surgjorda gödseln. Graden av kemiska påverkan hade samband med kvaliteten hos betongen, dvs. förhållandet vatten:cement och typ av bindemedel i betongen. Största kemiska påverkan uppmättes i betongkvalité 1 som består av ”ordinär” betong med vattencementtal 0,59 (prover A1 och B1), motsvarande den som används för bottenplattan i flytgödsellager. Betongkvalité 3, utvecklad för material med lågt pH (LLC), visade betydligt högre motståndskraft mot kemisk påverkan.

Den kemiska påverkan på betongen var totalt sett svag efter två års exponering och bestod främst av en ökning av den kapillära porositeten hos bindemedlet i betongens yttre skikt. Den ökade porositeten bedöms bero på att en del av cementpastans kalciumhydroxid har brutits ner och lakats ur betongen. Vanligtvis är livslängden hos ett gödsellager minst 20 år, så det finns anledning att vara observant över tid på hur betongen påverkas eller att som förebyggande åtgärd använda en betong av högre kvalitet.

The aim of the work was to evaluate novel biomixtures for their use on biopurification systems (BPS) in Argentina also called biobeds. Glyphosate and aminomethylphosphonic acid (AMPA) degradation was evaluated on biomixtures containing local materials: alfalfa straw (As), wheat stubble (Ws), river waste (Rw) and soil. Glyphosate, AMPA concentrations and biological activity were followed with time. Soil was used as control. Glyphosate initial concentration was 1000 mg kg^-1. Glyphosate disappeared almost completely after 63 days in all tested biomixtures. For Ws, WsRw and AsRw glyphosate degradation was around 99% and for As 85%. The biomixture Ws showed the highest glyphosate degradation rate. In all cases AMPA was formed and degraded to concentrations between 60 and 100 mg kg^-1. In the control with only soil, glyphosate was degraded 53% and AMPA concentration at the end of the test was 438 mg kg^-1. We conclude that alfalfa straw, wheat stubble and river waste are local materials that can be used in the preparation of biomixtures since they showed higher glyphosate degradation capacity and less AMPA accumulation compared to the soil alone. Also, the presence of river waste did enhance the water retention capacity.