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| 2. |
- Dalahmeh, Sahar, et al.
(författare)
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Quality of greywater treated in biochar filter and risk assessment of gastroenteritis due to household exposure during maintenance and irrigation
- 2016
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Ingår i: Journal of Applied Microbiology. - : Oxford University Press (OUP). - 1364-5072 .- 1365-2672. ; 121, s. 1427-1443
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Tidskriftsartikel (refereegranskat)abstract
- AimThis 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 spp. and rotavirus due to ingestion of GW during system maintenance and consumption of green onions irrigated with treated and nontreated GW.Methods and resultsThe 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 139x10(-2) to 60x10(-3) for Salmonella spp. but did not affect Pd-annual caused by rotavirus (973x10(-1) to 10). Consumption of onions irrigated with treated GW had a median Pd-annual of 125x10(-9) to 12x10(-8) for Salmonella spp. and 496x10(-4) to 437x10(-3) for rotavirus infection, which was 999 and 90% lower, respectively, than the risk when consuming onions irrigated with nontreated GW. The highest risks of gastrointestinal disease were thus associated mainly with direct ingestion of GW when maintaining the system.ConclusionsGarden produce irrigated with GW treated in biochar filter did not display intolerable risks of rotavirusbased gastroenteritis during summer season in the study area given that the produce is harvested 1 to 2days, and washed, before consumption.Significance and Impact of the StudyThis study contributes to scientific-based knowledge on the suitability of biochar filters for onsite greywater treatment and confirms the microbial safety of recycling treated greywater for garden irrigation.
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| 4. |
- Ermolaev, Evgheni, et al.
(författare)
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Greenhouse gas emissions from small-scale fly larvae composting with Hermetia illucens
- 2019
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Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 96, s. 65-74
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Tidskriftsartikel (refereegranskat)abstract
- Fly larvae composting is an emerging waste treatment alternative with great potential to increase revenue from food waste management. For wider implementation, fly larvae composting has to be evaluated in comparison with conventional systems, based on direct greenhouse gas (GHG) emission data for the treatment process, which are currently limited. This study evaluated direct emissions of CO2, CH4, N2O and NH3 from composting of food waste using black soldier fly (BSF) larvae (Hermetia illucens). Use of BSF larvae-associated bacteria in 7-day pre-treatment and seeding at larvae treatment start were evaluated and compared to larvae treatment without bacteria addition. The treatments were performed in a set of 14-day laboratory-scale experiments. Mean substrate reduction was 49 +/- 8% and bioconversion ratio was 24 +/- 8% (both dry matter basis). Direct GHG emissions from the fly larvae treatment process were generally very small, with emissions of CH4 and N2O equivalent to 0.38 kg CO2-equivalents per ton food waste treated assuming global warming potential over 100 years, while mean total CO2 emissions were 96 g CO2 per kg food waste treated. Additional emissions could be expected to occur in the pre-treatment process, which did not provide any significant improvement in bioconversion ratio or reduction in total GHG emissions during treatment. Similarly, use of BSF larvae-associated bacteria did not significantly improve process efficiency. No NH3 emissions were detected, as reflected in total N mass balance over the treatment cycle. The results show that total direct GHG emissions from food waste treatment by fly larvae composting are lower than those from conventional food waste treatment, and that pre-treatment and seeding of food waste with BSF larvae-associated bacteria do not further reduce total GHG emissions. (C) 2019 Elsevier Ltd. All rights reserved.
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| 5. |
- Ermolaev, Evgheni, et al.
(författare)
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Model selection for waste conversion efficiency and energy demands in a pilot for large-scale larvae treatment
- 2019
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Ingår i: Linköping electronic conference proceedings. - : Linköping University Electronic Press. - 1650-3686 .- 1650-3740. ; , s. 118-124
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Konferensbidrag (refereegranskat)abstract
- Implementations of conversion systems for segregated food waste into larval biomass are reliant on stability of production environment and predictable outcomes. However, the knowledge is currently lacking for large scale implementation modelling allowing to adjust the process for reaching a stable production quality and predicting the treatment capacity and output product quantity. This study contributed to the development of such knowledge and investigated models for prediction of larvae mass gain in the conversion process, food waste degradation due to larval and microbial activity, heat production based on metabolic activity in the conversion process. These models were used to evaluate the amount of heat produced and compared to the demand for water removal for achieving a minimal total solids content (50%) in the treatment residue for easy larvae separation by sieving. Based on these models’ predictions and measurements of the conversion efficiency it was established that, assuming no heat loss from the system, the heat generated by the process was sufficient to achieve a desirable total solids content in the residue after 14 days of treatment. An exponential heat production from waste degradation can be expected, and thus, for wetter food waste, the treatment period can be expanded to achieve the desired residue total solids content.
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| 6. |
- Isibika, Alice, et al.
(författare)
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Pre-treatment of banana peel to improve composting by black soldier fly (Hermetia illucens (L.), Diptera: Stratiomyidae) larvae
- 2019
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Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 100, s. 151-160
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Tidskriftsartikel (refereegranskat)abstract
- Use of black soldier fly (Hermetia illucens (L), Diptera: Stratiomyidae) larvae (BSFL) is among the solutions being explored to shift the value chain in organic waste management by producing valuable products. Although BSFL consume a range of substrates, nutrient-imbalanced materials with high hemicellulose and lignin content, e.g. manure and banana peel, yield low conversion into larval biomass. This study explored pre-treatment methods to improve the nutrient composition and digestibility of banana peel to achieve higher substrate conversion into BSFL biomass. The pre-treatment methods evaluated were microbial, chemical (non-protein nitrogen), heat-based, and combinations of these. All pre-treatments tested except heating resulted in more efficient BSFL conversion in terms of final larvae weight. The low BSFL responses in pre-treatments were caused by the observed high amounts of tannins and phenolic compounds mainly from the heating pre-treatment. Waste to biomass conversion ratio correlated negatively with substrate volatile solids (VS) and positively with the decrease in VS in pre-treatment. Microbial - 14 days pre-treatments provided the optimum pre-treatment time for the microorganisms to achieve maximum degradation of the substrates, facilitating larval assimilation of the released nutrients. Rhizopus oligosporus-14 days and ammonia + Rhizopus resulted in the most efficient BSFL treatment, measured as protein produced per kg incoming material. (C) 2019 The Author(s). Published by Elsevier Ltd.
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| 7. |
- Lalander, Cecilia, et al.
(författare)
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A comparison in product-value potential in four treatment strategies for food waste and faeces – assessing composting, fly larvae composting and anaerobic digestion
- 2018
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Ingår i: GCB Bioenergy. - : Wiley. - 1757-1693 .- 1757-1707. ; 10, s. 84-91
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Tidskriftsartikel (refereegranskat)abstract
- Municipalities are expected to provide solid waste management, which is funded by tax revenue or/and waste treatment fees. In many low- and middle-income countries, municipalities struggle to provide an adequate level of service, and in these places, the informal sector plays a major role in the collection and treatment of solid waste. In contrast to the plastic and metal fraction, the organic fraction is not managed by the informal sector, primarily because it has low or no financial value and treatment would cost more than the possible revenue. If the organic fraction could be converted to valuable products, the treatment could bear its own cost and this could act as an incentive to collect and treat this fraction. In this study, the potential product value generated through four treatment strategies treating food waste and faeces was compared in a Swedish context: (i) thermophilic composting; (ii) black soldier fly treatment (BSF treatment); (iii) anaerobic digestion (AD); and (iv) BSF treatment followed by AD (BSF + AD). In order to assess the AD strategies, the biomethane potentials of the substrates were assessed. Food waste had the highest biomethane potential, while BSF-treated faeces had the lowest (417 and 188 NmL g VS-1, respectively). Thermophilic composting yielded the lowest value product (organic fertilizer; 26 (sic) t(-1) treated food waste) and BSF treatment + AD the highest total value of products (animal feed, vehicle gas and organic fertilizer; 215 (sic) t(-1) treated food waste). The treatment costs were not taken into account here; the total value gives an indication of the cost margin for the different strategies studied. In places with an existing AD plant, BSF treatment + AD strategy is the most economically viable. In places where no such plant exists, BSF treatment is likely to be the most economically favourable treatment.
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| 8. |
- Lalander, Cecilia, et al.
(författare)
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Effects of feedstock on larval development and process efficiency in waste treatment with black soldier fly (Hermetia illucens)
- 2019
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 208, s. 211-219
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Tidskriftsartikel (refereegranskat)abstract
- Global population growth has led to an urgent need for more efficient food production systems. Moreover, as income levels increase, dietary preferences are shifting to more animal-based products. However, current feed protein sources deplete wild fish populations and contribute to rainforest deforestation. Capturing the resources in organic waste could help alleviate environmental impacts of food production. The larvae of the black soldier fly (Hermetia illucens) are ferocious feeders on decomposing organic material and could be used as protein source in animal feed. This study evaluated development of black soldier fly larvae on eight urban organic waste fractions and two control substrates. Principal component analysis was conducted to identify substrate properties that contributed to treatment efficiency and larval development. The main treatment factors found to be affected by substrate were waste-to-biomass conversion ratio, larval development time and final prepupal weight. The substrate properties with the greatest impact on biomass conversion ratio and larval development time were content of total volatile solids and protein content, while only total volatile solids content affected final prepupal weight. It was concluded that black soldier fly larvae are versatile in their feedstock preferences and can be used to treat a variety of organic waste streams, provided that the total volatile solids and nitrogen content are sufficiently high to support larval development. Abattoir waste, food waste, human faeces and a mixture of abattoir waste - fruits & vegetables are waste streams that are highly suitable for fly larvae treatment. (C) 2018 The Authors. Published by Elsevier Ltd.
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| 9. |
- Lalander, Cecilia, et al.
(författare)
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Fate of pharmaceuticals and pesticides in fly larvae composting
- 2016
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 565, s. 279-286
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Tidskriftsartikel (refereegranskat)abstract
- A novel and efficient organic waste management strategy currently gaining great attention is fly larvae composting. High resource recovery efficiency can be achieved in this closed-looped system, but pharmaceuticals and pesticides in waste could potentially accumulate in every loop of the treatment system and spread to the environment. This study evaluated the fate of three pharmaceuticals (carbamazepine, roxithromycin, trimethoprim) and two pesticides (azoxystrobin, propiconazole) in a fly larvae composting system and in a control treatment with no larvae. It was found that the half-life of all five substances was shorter in the fly larvae compost (<10% of control) and no bioaccumulation was detected in the larvae. Fly larvae composting could thus impede the spread of pharmaceuticals and pesticides into the environment. (C) 2016 The Authors. Published by Elsevier B.V.
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| 10. |
- Lalander, Cecilia, et al.
(författare)
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High waste-to-biomass conversion and efficient Salmonella spp. reduction using black soldier fly for waste recycling
- 2015
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Ingår i: Agronomy for Sustainable Development. - : Springer Science and Business Media LLC. - 1774-0746 .- 1773-0155. ; 35, s. 261-271
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Tidskriftsartikel (refereegranskat)abstract
- The recycling of organic waste worldwide is not effective, which leads to water pollution and loss of potential crop fertilizers. Available resources have to be used more efficiently as the world population increases. An innovative solution is to use insects for the management of organic waste. Here, we used black soldier fly to convert organic waste into animal feed protein, as fly larvae, and plant fertilizer, as compost residue. A continuous fly reactor was monitored for 9 weeks. We analyzed physicochemical and microbial parameters, and we evaluated the sanitary risk. Results show 55.1 % of material degradation and 11.8 % of biomass conversion based upon total solids. We observed higher levels of N and P in the treatment residue than in the inflow material. Results also show a lower concentration of Salmonella spp. and viruses. Compost treatment with black soldier fly is therefore an efficient system for nutrient recycling.
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