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Promoting the culinary profile of a nation is a commonly used tool when marketing the food, drink, and culinary tourism sectors of a country. Different versions of gastronationalism (i.e., images of the culinary excellence of a nation) appear in this context. This article explores Swedish gastronationalism. The aim is to nuance and widen the discussion of gastronationalism by offering a historic contextualization and a focus on frictions in the national narrative. Based on a bricolage of ethnographic material—interviews, observations, archive material and official documents—the article takes a historical approach to explore the attempts to develop a new culinary nation. Specific focus is devoted to the absence of culinary heritage. The results show that Swedish gastronationalism consists of a specific view of nationality, where progress, innovativeness, and multiculturalism is highlighted, and heritage and tradition is downplayed. As a result, Sweden has developed a postnationalist gastronationalism. The article traces the roots of this phenomenon to a combination of structures and habits from the time of rationing (1914–1955) and the new national narrative that coincided with the gastronomic revolution starting in the mid-1980s. In conclusion, the article argues that while many versions of gastronationalism use heritagization as a strategy, Sweden attempts to deheritagize the culinary profile of the nation.

Commensality (the act of eating together) is studied in a range of disciplines and often considered important for social communion, order, health and well-being, while simultaneously being understood as in decline (especially the family meal). However, such claims are also contested in various ways. In this paper, we discuss the expanding field of commensality research and critically reflect on the debates surrounding its social functions, including its role in public health. We illuminate the deep social and cultural significance of commensality, through time and space, and conclude that whether or not commensality is the preferred social form of eating for any given individual, it is difficult to escape its sociocultural desirability and idealization. As a cross-cultural phenomenon in both past, present, and future, we suggest that commensality deserves further research. This includes commensality as a research topic in itself and as an entry point to unveil different dimensions of social relations between people, as well as interactions between humans and material objects.

Over a period of 12 months, the fate of three hormones, 12 antibiotics and 30 pharmaceutically active substances (PhACs) was investigated during open-air storage without and with composting of anaerobically digested and dewatered sewage sludge. The effect of oxidation conditions during storage on degradation of hormones and PhACs in the sludge biomass was also examined. Under summer and winter conditions in Uppsala County, Sweden. two field-scale sludge windrows were constructed: open-air storage of sewage sludge windrow without composting (NO-COM)) and open-air storage windrow with composting (COM). NO-COM achieved effective removal of Sigma Hormones (85%) and Sigma Antibiotics (95%), but lower removal of Sigma PhACs (34%), during the study year. The top layers of the sludge pile had significantly lower concentrations of Sigma PhACs (3100-5100 ng/g ash) than deeper layers (8000-11,000 ng/g ash). After one year of composting, the degradation in the COM windrow resulted in concentrations of Sigma Hormones (

A paradigm shift to waste reuse has started in the wastewater sector with many experts calling for greater resource recovery, often facilitated by alternative solutions such as source separation. Source separation has been shown to be advantageous for improving treatment capacity, food security, and efficiency; yet these systems are still immature, considered risky by professionals and scarcely implemented. This study attempts to answer the question of why source separation is still marginalized by examining the Swedish experience with source separated wastewater from the perspective of Technology Innovation Systems (TIS) in order to identify obstacles and policy recommendations. Considering that source-separation is still in a development phase, the study found that source separation works moderately well within the on-site niche and that blackwater systems in general perform better than urine diversion. Knowledge development is found to be the weakest function. A major blocking mechanism is the weakness of interchange between knowledge development and entrepreneurial activity. Policy recommendations include: increased R & D; building networks and communication platforms; and establishing guidelines for technologies, legislation interpretation and organizational models.

Sewage sludge (SS) contains beneficial plant nutrients and organic matter, and therefore application of SS on agricultural land helps close nutrient loops. However, spreading operations are restricted to certain seasons and hence the SS needs to be stored. Storage and land application of SS are both potential sources of greenhouse gases and ammonia, leading to global warming, acidification and eutrophication. Covering the stored SS, treating it with urea and choosing the correct time for land application all have the potential to reduce emissions from the system. Using life cycle assessment (LCA), this study compares storage and land application options of SS in terms of global warming potential (GWP), acidification potential, eutrophication potential and primary energy use. The system with covered storage has the lowest impact of all categories. Systems with autumn application are preferable to spring application for all impact categories but, when nitrate leaching is considered, spring application is preferable in terms of eutrophication and primary energy use and, for some SS treatments, GWP. Ammonia addition reduces nitrous oxide and ammonia emissions during storage, but increases these emissions after land application. Storage duration has a large impact on GWP, while amount of chemical nitrogen fertiliser substituted has a large impact on primary energy use.

This study investigated the effect on greenhouse gas emissions during storage of digested sewage sludge by using a cover during storage or applying sanitisation measures such as thermophilic digestion or ammonia addition. In a pilot-scale storage facility, nitrous oxide and methane emissions were measured on average twice monthly for a year, using a closed chamber technique. The thermophilically digested sewage sludge (TC) had the highest cumulative emissions of nitrous oxide (1.30% of initial total N) followed by mesophilically digested sewage sludge stored without a cover (M) (0.34%) and mesophilically digested sewage sludge stored with a cover (MC) (0.19%). The mesophilically digested sewage sludge sanitised with ammonia and stored with a cover (MAC) showed negligible cumulative emissions of nitrous oxide. Emissions of methane were much lower from TC and MAC than from M and MC. These results indicate that sanitisation by ammonia treatment eliminates the production of nitrous oxide and reduces methane emissions from stored sewage sludge, and that thermophilic digestion has the potential to reduce the production of methane during storage compared with mesophilic digestion. The results also indicate a tendency for lower emissions of nitrous oxide and higher emissions of methane from covered sewage sludge compared with non-covered.

Aim This study evaluated treatment of greywater (GW) by a biochar filter in Jordan and assessed the annual risks of infection (Pi-annual), annual risk of disease (Pd-annual) and disease burden (in disability-adjusted life years; DALYs) of gastroenteritis caused by Salmonella typhi and rotavirus due to ingestion of GW during system maintenance and consumption of green onions irrigated with treated and non-treated GW. Methods and results The biochar filter efficiently removed 93% of biochemical oxygen demand (BOD5) and 85% of solids, while removal of Escherichia coli was insignificant. Treatment of GW decreased the median Pd-annual due to ingestion of GW from 1.39×10-2 to 6.0×10-3 for Salmonella typhi, but did not affect Pd-annual of rotavirus (9.73×10-1 ‒ 1.0). Consumption of onions irrigated with treated GW had a median Pd-annual of 1.25×10-9 ‒ 1.2×10-8 for Salmonella typhi and 4.96×10-4 ‒ 4.37×10-3 for rotavirus infection, which was 99.9% and 90% lower, respectively, than the risk when consuming onions irrigated with non-treated GW. The highest risks of gastrointestinal disease were thus associated mainly with direct ingestion of GW when maintaining the system Conclusions Garden produce irrigated with GW treated in biochar filter did not display intolerable risks of rotavirus‒based gastroenteritis during summer season in the study area given that the produce is harvested 1‒2 days and washed before consumption.

This study addresses the enduring problem of the mismatch between firms’ offerings and consumers’ desires. It combines the general framework of modernity theory with the concept of regimes and uses the food area as the empirical context. Our cultural analytical study of consumers’ and firms’ articulation of values of food and meal demonstrates that firms are largely entrenched in the modern era, characterized by rationality, resource efficiency, and progress as means to improve human lives by providing more and better products. The consumers, on the other hand, have shifted to the late modern era, identified by risk aversion, local production, naturalism, hedonism, and a focus on identity and everyday life. The study concludes that the dichotomy in values and the structural constraints inherent within the contemporary food system explain much of the mismatch between firms and consumers in the Swedish food market. Another reason is that firms have difficulties to respond to new consumer demands. Our results are summarized in a conceptual model of differences in values between firms and consumers. They provide guidelines on how firms can rethink the present structure and better understand consumers.

This study investigated, for the first time, the occurrence and fate of 29 multiple-class pharmaceuticals (PhACs) in two source separated sanitation systems based on: (i) batch experiments for the anaerobic digestion (AD) of fecal sludge under mesophilic (37 °C) and thermophilic (52 °C) conditions, and (ii) a full-scale blackwater treatment plant using wet composting and sanitation with urea addition. Results revealed high concentrations of PhACs in raw fecal sludge and blackwater samples, with concentrations up to hundreds of μg L−1 and μg kg−1 dry weight (dw) in liquid and solid fractions, respectively. For mesophilic and thermophilic treatments in the batch experiments, average PhACs removal rates of 31% and 45%, respectively, were observed. The average removal efficiency was slightly better for the full-scale blackwater treatment, with 49% average removal, and few compounds, such as atenolol, valsartan and hydrochlorothiazide, showed almost complete degradation. In the AD treatments, no significant differences were observed between mesophilic and thermophilic conditions. For the full-scale blackwater treatment, the aerobic wet composting step proved to be the most efficient in PhACs reduction, while urea addition had an almost negligible effect for most PhACs, except for citalopram, venlafaxine, oxazepam, valsartan and atorvastatin, for which minor reductions (on average 25%) were observed. Even though both treatment systems reduced initial PhACs loads considerably, significant PhAC concentrations remained in the treated effluents, indicating that fecal sludge and blackwater fertilizations could be a relevant vector for dissemination of PhACs into agricultural fields and thus the environment.

By recycling sewage sludge (SS) to productive land, its plant nutrients can be utilised. However, the use of organic fertilisers carries health risks and causes emissions of nitrous oxide (N2O), methane (CH4) and ammonia (NH3). One measure to sanitise SS from human pathogens is addition of NH3. Mesophilically digested and dewatered SS treated with urea and stored, or only stored, was applied to arable land in spring and autumn, respectively, and the effects of immediate or delayed incorporation (by 4 h) on emissions of N2O, CH4 and, in spring, NH3 were investigated. N2O emissions in autumn from soil treated with SS were significantly higher than from soil without SS application (0.09, 1.31 and 0.68 kg N2O-N ha−1 for control, immediate and delayed incorporation, respectively). These emissions were significantly correlated with volumetric water content in soil. Corresponding N2O emissions in spring were 0.15, 0.57 and 0.41 kg N2O-N ha−1. Delayed incorporation (0.20 and 0.34 % of added N in spring and autumn, respectively) tended to reduce N2O emissions compared with immediate incorporation (0.32 and 0.71 % of added N in spring and autumn, respectively). Nitrous oxide emissions from SS were apparently lower after spring than after autumn application, likely because of drier soil and crop uptake of nitrogen in spring. Methane emissions were negative or negligible. Timing of incorporation had no statistically significant effect on NH3 emissions. Nitrous oxide emissions from soil treated with SS at a rate based on the maximum permissible P level were moderate and CH4 emissions negligible.

Emissions of methane (CH₄) and nitrous oxide (N₂O) from composting of source-sorted food waste were studied at set temperatures of 40, 55 and 67°C in 10 trials performed in a controlled environment 200L compost reactor. CH₄ and N₂O concentrations were generally low. In trials with 16% O₂, the mean total CH₄ emission at all temperatures was 0.007% of the mineralized carbon (C), while at 67°C this fraction was 0.001%. Total CH₄ production was higher in the 40°C trial and the limited oxygen (1% O₂) trial, with emissions of 0.029 and 0.132% of the mineralized C respectively. An early increase in N₂O production was observed in trials with higher initial nitrate contents. Increased CH₄ and N₂O production in trials at 40 and 55°C after 50% of the initial C was mineralized resulted in higher total greenhouse gas emissions. Overall, the global warming potentials in CO₂-equivalents from CH₄ emissions were higher than from N₂O, except for composts run at 67°C.

Most of the waste collected in sub-Saharan African cities is biodegradable but it is usually dumped in landfills, creating environmental and health challenges for residents. However, there are biodegradable waste treatment methods that could mitigate these challenges. This study analysed anaerobic digestion, composting, vermicomposting and fly larvae waste treatments using life cycle assessment (LCA). The impact categories assessed were energy use, global warming and eutrophication potential. The results showed that anaerobic digestion performed best in all impact categories assessed. However, management of the anaerobic digestion process is critical and methane losses must be kept very small, as otherwise they will cause global warming.

This study assessed the environmental impacts of recycling the plant nutrients in anaerobically digested food waste as fertilizer in agriculture. This was compared with the impacts of using chemical fertilizer, where the food waste was incinerated, producing heat. The study site was a biogas plant in central Sweden and life cycle assessment methodology was used. The impacts studied were primary energy use, global warming potential (GWP), potential acidification, potential eutrophication, cadmium flow to farmland and use of phosphate rock. Use of digested food waste as fertilizer proved to have larger negative results than use of chemical fertilizer in all categories assessed except use of non-renewable phosphate rock. Sensitivity analyses showed that the scenarios were comparable in terms of primary energy use and better for GWP if some improvements in the anaerobic digestion system were made. However, acidification and eutrophication caused by digestate handling and the cadmium content of digestate should still be considered.

To evaluate the treatment performance of vertical flow sand filters, the HYDRUS wetland module was used to simulate treatment in an experimental set-up. The laboratory filters were intermittently dosed with artificial greywater at a hydraulic loading rate of 0.032 m3 m−2 day−1 and an organic loading rate of 0.014 kg BOD5 m−2 day−1. The hydraulic properties of the filter were characterised, as were inflow and outflow concentrations of chemical oxygen demand (COD), biochemical oxygen demand (BOD), ammonia, nitrate and total nitrogen. The inverse simulation function of the HYDRUS software was used to calibrate the water flow model. The observed effect of water flowing faster along the column wall was included in the inverse simulations. The biokinetic model was calibrated by fitting heterotrophic biomass growth to measurements of potential respiration rate. Emphasis was put on simulating outflow concentrations of organic pollutants. The simulations were conducted using three models of varying degree of calibration effort and output accuracy. The effluent concentration was 245 mg COD L−1 for the laboratory filters, 134 mg COD mg L−1 for the model excluding wall flow effects and 338 mg COD mg L−1 for the model including wall flow effects.

This study explored the effects of greywater application on the dynamics and functions of biofilms developed in bark, activated charcoal and sand filters used for removal of organic matter and nitrogen. Duplicate columns (20 cm diameter, 60 cm deep) were packed with bark, charcoal or sand with effective size 1.4 mm and uniformity coefficient 2.2, and dosed with 32 L m−2 day−1 of an artificial greywater (14 g BOD5 m−2 day−1) for 116 days. Potential respiration rate (PRR), determined in filter samples after addition of excess glucose, and bacterial diversity and composition, analysed by 454-pyrosequencing of bacterial 16S ribosomal DNA, were measured at different times and depths in the filters. The bark and charcoal filters were more efficient in removing BOD5 than the sand (98, 97% and 75%, respectively). The highest PRR in the 0–2 cm layer of the columns on day 84 was found in the bark filters, followed by the charcoal and sand filters (632 ± 66, 222 ± 34 and 56 ± 2 mg O2 L−1, respectively; n = 2). Bacterial community in the bark filters showed the highest richness. The charcoal and sand filters both developed more diverse and dynamic (changing over time and depth) bacterial communities than the bark. In addition to the greywater, the lignocelluosic composition of the bark and its lower pH probably selected for the bacterial community structure and the organic content provided additional substrate, as shown by its higher PRR and its different nitrifying bacterial genera. In the oligotrophic charcoal and sand, the composition of the greywater itself defined the bacterial community. Thus, the initially low bacterial biomass in the latter filters was enriched over time, allowing a diversified bacterial community to develop. The top layers of the bark and charcoal filters displayed a high dominance of Rhizobium, Pseudomonas and Acinetobacter, which were less evident in the 60 cm layer, whereas in the sand filters these genera were prominent at both 0–2 cm and 60 cm. The PRR, bacterial diversity and composition profiles indicated that organic matter degradation occurred mainly in the top 20 cm of the bark and charcoal filters. This means that bark and charcoal filters could be designed to be shallower than sand filters.

Globally, waste generation is continually increasing, with landfill as the main destination for biological waste. Composting is a simple alternative for handling waste, but when poorly managed poses a risk of greenhouse gas emissions. The moisture content of substrate affects emissions of methane (CH4) and nitrous oxide (N2O) from composting, but the scale and mechanisms behind these effects are poorly understood. This study examined effects of different moisture levels (44–66%) on CH4, N2O and carbon dioxide (CO2) emissions during 20 days of composting food and garden waste under controlled conditions (55 °C, 16% oxygen) in a 200-L reactor. Total CO2 emissions were 400–500 g CO2-C kg−1 initial C. Total CH4 emissions were highest, 35 g CH4-C kg−1 initial C, for the wettest substrate (66% moisture) and decreased exponentially with declining moisture content, with the lowest total emissions, 0.04 g CH4-C kg−1 initial C, observed with the driest substrate. Total N2O emissions were negatively correlated with moisture content, decreasing from 1.2 g N2O-N kg−1 initial N at 44% moisture to 0.3 g N2O-N kg−1 initial N at 59%, but the wettest substrate (66% moisture) had the highest N2O emissions, 1.4 g N2O-N kg−1 initial N. NH4-N accumulated in the wettest material, suggesting that the increased N2O emissions were due to reduced oxygen availability. The results indicate potential to reduce greenhouse gas emissions from large-scale composting by adjusting the moisture content at different stages of composting, thus lowering its overall environmental impact. This finding can be used in guidelines for large-scale composting process to avoid moisture conditions causing large greenhouse gas emissions.

Greywater flows and concentrations vary greatly, thus evaluation and prediction of the response of on-site treatment filters to variable loading regimes is challenging. The performance of 0.6 m × 0.2 m (height × diameter) filters of bark, activated charcoal and sand in reduction of biochemical oxygen demand (BOD 5 ), chemical oxygen demand (COD), total nitrogen (Tot-N) and total phosphorus (Tot-P) under variable loading regimes was investigated and modelled. During seven runs, the filters were fed with synthetic greywater at hydraulic loading rates (HLR) of 32–128 L m −2 day −1 and organic loading rates (OLR) of 13–76 g BOD 5 m −2 day −1 . Based on the changes in HLR and OLR, the reduction in pollutants was modelled using multiple linear regression. The models showed that increasing the HLR from 32 to 128 L m −2 day −1 decreased COD reduction in the bark filters from 74 to 40%, but increased COD reduction in the charcoal and sand filters from 76 to 90% and 65 to 83%, respectively. Moreover, the models showed that increasing the OLR from 13 to 76 g BOD 5 m −2 day −1 enhanced the pollutant reduction in all filters except for Tot-P in the bark filters, which decreased slightly from 81 to 73%. Decreasing the HLR from 128 to 32 L m −2 day −1 enhanced the pollutant reduction in all filters, but decreasing the OLR from 76 to 14 g BOD 5 m −2 day −1 detached biofilm and decreased the Tot-N and Tot-P reduction in the bark and sand filters. Overall, the bark filters had the capacity to treat high OLR, while the charcoal filters had the capacity to treat high HLR and high OLR. Both bark and charcoal filters had higher capacity than sand filters in dealing with high and variable loads. Bark seems to be an attractive substitute for sand filters in settings short in water and its effluent would be valuable for irrigation, while charcoal filters should be an attractive alternative for settings both rich and short in water supply and when environmental eutrophication has to be considered.

In Sweden, 16% of all biologically treated food waste is home composted. Emissions of the greenhouse gases CH4 and N2O and emissions of NH3 from home composts were measured and factors affecting these emissions were examined. Gas and substrate in the compost bins were sampled and the composting conditions assessed 13 times during a 1-year period in 18 home composts managed by the home owners. The influence of process parameters and management factors was evaluated by regression analysis. The mean CH4 and N2O concentration was 28.1 and 5.46 ppm (v/v), respectively, above the ambient level and the CH4:CO2 and N2O:CO2 ratio was 0.38% and 0.15%, respectively (median values 0.04% and 0.07%, respectively). The home composts emitted less CH4 than large-scale composts, but similar amounts of N2O. Overall NH3 concentrations were low. Increasing the temperature, moisture content, mixing frequency and amount of added waste all increased CH4 emissions.

Faecal sludge has the potential to be used as a sustainable fertiliser in agriculture, but the sludge must be sanitised due to its content of pathogenic microorganisms. The intrinsic ammonia from the urine may be sufficient for sanitisation of the sludge if it is not too diluted by flush water or lost by ventilation. To evaluate the potential for this sanitisation method, inactivation of Enterococcus faecalis , Salmonella typhimurium and Ascaris suum eggs during treatment were assessed. The inactivation was studied at different storage temperatures (10–28 °C) and in several sludge mixes with different contents of urine, faeces and flush water, and with ammonia concentrations from 40 to 400 mM. All pathogens were inactivated by the ammonia, and ascaris eggs were the most persistent. Lower flush water volume and higher urine content favoured inactivation, mainly due to increased uncharged ammonia (NH 3 ) concentration. The lag phase in ascaris inactivation was shortened by increasing temperature and NH 3 concentration, while post-lag phase inactivation was not influenced by NH 3 concentration. Faecal sludge can be sanitised by airtight storage without the use of additives when flush water volumes are sufficiently low. For temperatures of 23–28 °C, a 3 log reduction of ascaris egg viability can be achieved within 1–6 months depending on ammonia concentration and temperature.

With a growing world population, the lack of reliable water sources is becoming an increasing problem. Reusing greywater could alleviate this problem. When reusing greywater for crop irrigation it is paramount to ensure the removal of pathogenic organisms. This study compared the pathogen removal efficiency of pine bark and activated charcoal filters with that of conventional sand filters at three organic loading rates. The removal efficiency of Escherichia coli O157:H7 decreased drastically when the organic loading rate increased fivefold in the charcoal and sand filters, but increased by 2 log10 in the bark filters. The reduction in the virus model organism coliphage phiX174 remained unchanged with increasing organic loading in the charcoal and sand filters, but increased by 2 log10 in the bark filters. Thus, bark was demonstrated to be the most promising material for greywater treatment in terms of pathogen removal.

Mussels can be used as fertiliser in organic farming, particularly on stockless farms, which need external nutrients but have limited access to fertiliser products. Mussels are filter feeders and accumulate nutrients bound in e.g. phytoplankton. When harvested and used onshore, their accumulated nutrients are removed from the water, thus decreasing eutrophication. This LCA study assessed the environmental impact of mussel farming on the Swedish coast of the Baltic Sea for subsequent use as agricultural fertiliser. The functional unit was related to the agronomic value of the mussels, including plant-available nitrogen, phosphorus and liming effect. Flow of cadmium to soil was also assessed. In one scenario the mussels were composted and in another they were inertly stored to avoid nitrogen losses and other emissions from storage. Use of mussels on agricultural land fulfils three functions: fertilisation, liming and a reduction in eutrophication. The results clearly showed the importance of integrated assessment of these three functions. Due to significant nitrogen losses from the composting process, the compost scenario resulted in a higher impact on acidification, global warming potential and energy use than the inert storage scenario. Alternative techniques to composting for handling mussels should thus be developed, for example direct use of the mussels as fertiliser without prior storage, or inert storage. Energy use was strongly related to production of materials for mussel cultivation, so choice and life length of materials is important when introducing mussel farming. The cadmium content of mussels is relatively high, but they often supply less cadmium to the field than the fertiliser and liming products they replace. Reducing eutrophication by cultivating mussels for fertiliser proved more energy-efficient than reducing eutrophication in wastewater treatment plants.

Source-separation of urine enables energy-efficient recycling of large quantities of high quality plant nutrients from the wastewater system to food production. To manage the risk of diseases transmission the urine should be sanitised, which is commonly done by storage. The sanitisation of urine at three ambient exposures, resulting in fluctuating storage temperatures, was studied in 10 L plastic jerry cans in Kampala, Uganda. Follow-up studies using similar temperature cycles were performed under laboratory conditions. Daily mean mid-point temperature in jerry cans in full sun, adjacent to a wall and indoors was 24, 24 and 22 °C (amplitude 7.5, 4.7 and 1.2 °C), respectively. In urine stored at full sun (total ammonia nitrogen 4 ± 1.5 g L −1 , pH 9) Escherichia coli , Salmonella and Enterococcus spp. (initially 10 5 –10 6 cfu mL −1 ) were not detected ( 1 cfu mL −1 ) after 11 h, 14 h and 50 d, respectively. No viable Ascaris suum eggs were found after 40 d. The t 90 for enterobacteria phage MS2, coliphage Φx 174 and Salmonella typhimurium phage 28B in sun-exposed cans was 8.2, 37 and 55 d respectively. Fluctuating temperatures in combination with ammonia gave faster inactivation of bacteria and Ascaris suum eggs than the same constant mean temperature.

Source separation of urine for recycling has been applied in small-scale and decentralized wastewater systems in Sweden for the past 25 years and for blackwater for pollution control even longer. The Swedish experience with source separating nutrient recycling systems is relatively well documented; however, few reports have specifically studied the potential for expansion of this practice. The aim of this study is to fill this knowledge gap by assessing the status of source-separating technologies in Sweden based on transition theory. This study uses a multi-level perspective to determine how ready the Swedish wastewater sector is for transitioning to alternative systems. Given the stability of the existing sewage wastewater regime, it seems unlikely that changes within the regime will lead to a quick and large-scale transition to source separation. Instead, the initiative must come from the niche itself, exploiting institutional cracks in the regime and opportunities from shifting trends in the landscape. If source separation is to be mainstreamed in Sweden, it will need to break into markets within the wastewater jurisdictions. In order to do so, further knowledge needs to be developed that will overcome glitches with immature technologies, uncertain legal conditions/status, investigate potential risks, and clearly define complementary system advantages. This may require the use of new perspectives that focus on holistic sustainable use of resources, including other nutrients than phosphorous, and taking into account global issues such as planetary boundaries and effects from climate change, such as water scarcity. This knowledge can then be used to establish guidelines, norms, and standards, as well as clarify the legislative structures that can support such a transition. There is also a strong need to improve knowledge dissemination regarding best-practices for implementing source-separation technologies and supporting organizational structures. Similarly, support for entrepreneurial activities within the niche needs to increase, not least through strengthening social networks and communication platforms.

Highlights ► High odour emission from food waste compost was correlated to low pH. ► Microbes in high-odour samples included Lactic acid bacteria and Clostridia. ► For odour prevention, try high initial aeration rate and recycled compost as additive., A major problem for composting plants is odour emission. Slow decomposition during prolonged low-pH conditions is a frequent process problem in food waste composting. The aim was to investigate correlations between low pH, odour and microbial composition during food waste composting. Samples from laboratory composting experiments and two large scale composting plants were analysed for odour by olfactometry, as well as physico-chemical and microbial composition. There was large variation in odour, and samples clustered in two groups, one with low odour and high pH (above 6.5), the other with high odour and low pH (below 6.0). The low-odour samples were significantly drier, had lower nitrate and TVOC concentrations and no detectable organic acids. Samples of both groups were dominated by Bacillales or Actinobacteria, organisms which are often indicative of well-functioning composting processes, but the high-odour group DNA sequences were similar to those of anaerobic or facultatively anaerobic species, not to typical thermophilic composting species. High-odour samples also contained Lactobacteria and Clostridia, known to produce odorous substances. A proposed odour reduction strategy is to rapidly overcome the low pH phase, through high initial aeration rates and the use of additives such as recycled compost.

Greywater is a potential resource of water that can be improved to meet the quality needed for irrigation. This study evaluated the performance of bark, activated charcoal, polyurethane foam and sand filters in removing biochemical oxygen demand (BOD5), surfactants, phosphorus, nitrogen and microbial indicators from greywater during start-up and steady state. In column experiments, 0.6 m high filters (diameter 20 cm) were fed for 113 days with artificial greywater at a hydraulic loading rate of 0.032 m3 m−2 day−1 and an organic loading rate of 0.014 kg BOD5 m−2 day−1. Bark and activated charcoal efficiently reduced the concentrations of organics (BOD5), surfactants (methylene blue active substances—MBAS), total phosphorus (Tot-P) and total thermotolerant coliform numbers, while sand and foam were less efficient. Bark, activated charcoal, foam and sand reduced influent BOD5 by 98, 97, 37 and 75 %; MBAS by >99, >99, 73 and 96 %; Tot-P by 97, 91, 36 and 78 %; and total nitrogen by 19, 98, 13 and 5 %, respectively. BOD5 and MBAS were efficiently reduced directly from start-up by bark and activated charcoal, while foam needed 30 days to achieve about 50 % reduction in BOD5. Bark was the most efficient filter in reducing thermotolerant faecal coliforms (2.4 log10), while foam achieved the lowest reduction (0.5 log10). Overall, bark and activated charcoal filters appeared to be the most suitable filters for improving greywater quality to reach irrigation quality in terms of organic matter reduction. Performance of these filters under higher and fluctuating loadings and the long-term sustainability of the filter materials need further investigation.

Composting is the most widely used biological treatment method for recovering the plant nutrients of organic waste. Composting is an aerobic process and it is well known that mismanagement, e.g. insufficient ventilation, can seriously affect the turnover and performance of the process. The turnover is also strongly inhibited if the operation temperature rises above 40°C before the pH has increased above 6. Such a combination of high temperature and low pH also seriously increases the odour emission potential of the compost operation as the initial high odorous stage is prolonged until the pH increases. When the pH increases beyond 6.5, the odour potential rapidly decreases. The pH development can be accelerated by good cooling and ventilation, and/or by addition of alkaline amendment, e.g. recycling of alkaline compost or addition of wood ash. When the compost is turned, the structure of the compost matrix, and thus the aeration, is improved which decreases odour generation and also the proportion of anaerobic processes and thus the emissions of methane.Studies of food waste home composts show that these have a much higher moisture content (70-80%) compared to what is normally recommended for composting (40-65%). The common assumption has therefore been that methane emissions from home composts are greater than from large scale municipal composts. However, recent studies in both Sweden and Denmark show that the methane emissions from home composts usually are smaller than from large municipal composts. Furthermore, both studies indicate that the emissions seem to increase if the composts are frequently turned, quite contrary to what was expected. The emissions also seem to increase if the feeding is too high. This means that the capacity of the home compost should not be exceeded and that the efforts for its operation can be kept low, as turning does not seem to be an advantage, at least from the point of view of greenhouse gas emissions.

The aim of this article is to discuss how changes in tomato food regulation, production and consumption, can be seen as part of a broader societal change from Modernity to Late Modernity. Based on evidence from the Swedish and European food systems we demonstrate how a system, which has been successfully managing development in food production for several decades by stressing rationality, homogeneity and standardization, is being challenged by a system that has adapted to, and also exploited, consumer preferences such as heterogeneity, diversity and authenticity. The article shows how tomato growers develop differentiation strategies, adapting to and cultivating this new consumer interest, and how authorities responsible for regulations of trade and quality struggle to adapt to the new situation. As the products become more diversified, taste becomes an important issue and is associated with a view that traditional and natural are superior to standardized and homogeneous products. The analytical approaches for the discussion come from two study areas: ethnological, and marketing and policy perspective, thus showing a multidimensional picture of a changing food system.

Data on greenhouse gas (GHG) emissions from full-scale composting of municipal solid waste, investigating the effects of process temperature and aeration combinations, is scarce. Oxygen availability affects the composition of gases emitted during composting. In the present study, two experiments with three covered windrows were set up, treating a mixture of source separated biodegradable municipal solid waste (MSW) fractions from Uppsala, Sweden, and structural amendment (woodchips, garden waste and re-used compost) in the volume proportion 1:2. The effects of different aeration and temperature settings on the emission of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) during windrow composting with forced aeration following three different control schemes were studied. For one windrow, the controller was set to keep the temperature below 40 °C until the pH increased, another windrow had minimal aeration at the beginning of the process and the third one had constant aeration. In the first experiment, CH4 concentrations (CH4:CO2 ratio) increased, from around 0.1% initially to between 1 and 2% in all windrows. In the second experiment, the initial concentrations of CH4 displayed similar patterns of increase between windrows until day 12, when concentration peaked at 3 and 6%, respectively, in two of the windrows. In general, the N2O fluxes remained low (0.46 ± 0.02 ppm) in the experiments and were two to three times the ambient concentrations. In conclusion, the emissions of CH4 and N2O were low regardless of the amount of ventilation. The data indicates a need to perform longer experiments in order to observe further emission dynamics.

Animal by-products (ABP) are rich in nutrients and energy. This LCA study assessed and compared the environmental impact of using meat meal as fertilizer with that of using chemical fertilizer. In one system the nutrient content of ABP Category 2 was recovered and used as a meat meal fertilizer on arable land, replacing chemical fertilizers. In the other system a chemical fertilizer was used and the energy content of the ABP material recovered. The functional unit consisted of one kg of harvested spring wheat and treatment of 0.59 kg of ABP Category 2. The system for nutrient recovery and chemical fertilizer replacement had lower emissions of greenhouse gases and acidification than the energy recovery system, but had higher total use of energy and eutrophying emissions. Overall, the results of the study greatly depended on the fuels replaced.

Most findings on the triple helix system derive from studies based on high-tech sectors, and seldom so on traditional industries. A foresight exercise aimed at renewal of the mature food industry in the Skane region in southern Sweden was conducted in 2006-2007. The findings suggest that a multilevel triple helix policy ought to be used in a systemic way from a bottom up perspective, including companies as well as other triple helix actors throughout the value chain. Further, the findings underscore the importance of the role intermediaries play enhancing the integrative abilities of actors in the regional food system. Cultural analysis is used to elicit a deeper understanding of the different regimes that influence the actors. This is consistent with the observation highlighted in this article that the actors in the food system bear values arising from a time when the Swedish food system catered for national self-sufficiency under a regime of limited market competition.

in Undetermined An analysis of the environmental effects and resource consumption by four systems for management of wastewater and organic household waste in a new city area have been performed, as follows: (1) conventional system complemented with advanced sludge treatment for phosphorus recovery, (2) blackwater system with urine diversion and food waste disposers, (3) blackwater system with food waste disposers and reverse osmosis, and (4) local wastewater treatment plant with nutrient recovery by using reverse osmosis. Substance-flow analysis and energy/exergy calculations were performed by using the software tool URWARE/ORWARE. Emissions were calculated and classified based on the impact categories global warming potential, acidification, and eutrophication, according to ISO14042 (2000). The analysis also included nutrient recovery (i.e., the potential to use nutrients as a fertilizer). Depending on which aspects are prioritized, different systems can be considered to be the most advantageous. (Less)

Composting of source separated municipal biowaste has at several plants in Scandinavia been hampered by low pH. In this study the hypothesis that increased aeration would improve the process was tested in full-scale experiments at two large composting plants. The O2 concentrations were high (>15%) even at the low aeration rates, so the prevailing low pH was not due to an anaerobic process environment. In spite of this, increased aeration rates at the start of the process resulted in higher microbial activity, increased pH and a more stable compost product. At one plant the decomposition rate varied in proportion to the aeration rate, to the extent that the temperatures and O2 concentrations were similar during the early processes even though aeration rates varied between 10 and 50 m3/(h, m3 compost). However, increased aeration caused severe drying of the compost, but at one plant the addition of water was adequate to prevent drying. In conclusion, by increasing the aeration rates and adding water to compensate for drying, it was possible to shorten the time needed to produce a stable compost product and thus to increase the efficiency of the composting plants.

This study collects experiences from existing systems with urine diversion and dry handling of faecal matter and presents design recommendations for improved function of new systems. Urine collection and piping systems were studied in four large residential areas in Scandinavia and South Africa where urine had been collected separately for 5–9 years and dry faeces collected for 4–15 years. We found that larger (>1 toilet) urine collection systems should have odour traps. Blockages in u-bend odour traps can be efficiently prevented by cleaning the u-bend 1–4 times per year with a sewage auger, caustic soda solution or strong acetic acid. A urine pipe diameter of 75 mm and a gradient of at least 1% are recommended. In small systems without a u-bend, a diameter of 25 mm can be used in combination with a gradient of at least 4%. For faecal collection, the most important factors for good function and high acceptability of the system are diversion of the urine, small collection bins (high emptying frequency) and easy access for emptying of bins.

Reducing the negative impact from on-site systems and promoting recycling are important tasks for municipal authorities, especially as regards phosphorus. The objective of this scenario study was to compare energy turnover in a life cycle perspective, recycling potential and expected reduction of nitrogen and phosphorus emissions for three upgraded small-scale wastewater systems based on local recycling of plant nutrients. The systems studied were urine separation, blackwater separation and chemical precipitation in the septic tank. The urine was sanitised through storage, the blackwater through liquid composting and the precipitated sludge through chemical treatment with urea before reuse in agriculture. The system boundaries included the operational phase as well as investment in capital goods required for upgrading the existing on-site systems. The urine separation system used least energy. The potential recycling and reduction of phosphorus was lower than for the other two systems, while that of nitrogen was higher than for the chemical precipitation system but lower than for the blackwater separation system. The blackwater separation system reduced both nitrogen and phosphorus to a high extent and also enabled a large proportion of both nitrogen and phosphorus to be recycled to arable land. However, a major drawback with this system was its significantly higher use of electricity, related to the aeration and stirring required when sanitising the blackwater by liquid composting. When urea treatment replaced liquid composting, the use of electricity decreased substantially in the blackwater separation system. The chemical precipitation system was efficient in reducing and recycling phosphorus, while inefficient for nitrogen. The use of fossil fuels was significantly higher than for the other two systems, primarily due to the production of the precipitation chemical.

Life cycle assessment methodology was used to compare conventional wheat production with a scenario where source-separated human urine replaced mineral fertilisers. A change-orientated perspective was used, including differences in capital goods between the scenarios. An optimal fertilising strategy regarding application time, technique and substitution of mineral fertiliser was demonstrated to be important for energy use, global warming and acidification. For reducing the energy use, a well designed collection system for urine also proved important, while recovery of the urine was essential for reducing eutrophication. Applying an agricultural perspective when evaluating the system highlighted potential conflicts regarding nutrient utilisation.

The present Swedish design values (DV) for urine, faeces, greywater and biodegradable solid waste were scrutinised and compared to the composition of these fractions in two blocks of flats, Gebers and Ekoporten. For evaluation of the greywater composition, two additional areas were included: the housing area Vibyasen and a calculation based upon the composition of the sewage sludge in Ryaverken sewage treatment plant in Gothenburg. The parameters scrutinised were dry mass, wet mass, BOD7, COD, N, P, K, Cu, Cr, Ni, Zn, Cd, Hg and Pb. Based on the results, new updated Swedish DV were proposed for these parameters in the fractions urine, faeces, greywater and biodegradable solid waste.

Summary Food in general has a high nutrient content, which essentially passes through the human organism and ends up in the sewage system. This high nutrient content in sewage, however, is rarely included in environmental systems analyses of food products or production systems. At the same time, several studies on sewage systems have shown the significance of plant nutrients in sewage system outlets. This means that important environmental effects may be neglected in environmental systems studies of food. We present a method for including emissions that occur after food consumption in environmental systems analyses of foods. The method uses easily accessible input data to calculate the postconsumption emissions caused by certain food products. The method was tested by completing the results for eutrophication from seven life-cycle assessments (LCAs) on food products with the corresponding emissions caused by outlets from a sewage plant. The results showed that postconsumption eutrophication was a significant part of the products' total life-cycle impact, ranging from 5.5% (beef) to 86% (apples). The conclusion is that including postconsumption emissions is important for studies aiming at mapping a product's life cycle to find the most environmentally relevant parts, as well as for eco-labeling purposes. If the purpose of the study is decision support, the postconsumption phase should be included where the decision affects this part of the system, otherwise not. When products are compared, postconsumption emissions should be included if their nutrient contents differ.