On Wednesday (13/2-2019) the Director General of SIDA Carin Jämtin and the Vice-Chancellor of SLU Karin Holmgren honoured us with a visit to our BSF facility. Also on the visit, from SIDA, were Senior Research Advisor Eva Ohlsson and Policy Advisor Esse Nilsson, and from SLU Pro Vice-Chancellor, international relations Ylva Hillbur, Head of SLU Global Sara Gräslund and communicator Malin Planting.
During the visit we demonstrated the concept of turning waste into value by converting it into larval biomass that can be used as animal feed. We in the group were pleasantly surprised by the enthusiasm with which the visitors put their hands into the fly larvae compost in order to feel the heat being generated in the degradation process and the movement of the larvae.
Just at the end of January, Kristina Lundgren presented her master thesis at Uppsala University. The aim of the thesis was to increase the understanding of how bacteria may affect fly larvae composting with the black soldier fly. The results showed no significant impact on the survival, final biomass or reduction of substrate when bacteria isolated from BSF eggs where inoculated into the substrate (food waste). However, interestingly the variation in resulting biomass and material reduction was decreased when any bacteria or group of bacteria were added to the food waste. Hence, the system became easier to predict, which especially is desirable when scaling up the system. The audience seemed intrigued by fly larvae composting as a waste management tool and had questions both regarding large scale facilities and the possibility that inoculation bacteria might yield positive effects in other substrates.
After almost half a year of work, Nils Ewald presented his master’s thesis last week for the audience at the Department of Molecular Sciences. In the thesis he investigated the relation between the fatty acid composition of the Black soldier fly larvae, and the different waste materials that were fed to the larvae. From the work it was found that the larvae contains a high proportion of saturated fatty acids, but that the growth of the larvae, as well as the fatty acid composition of the substrate, affects the fatty acid profile of the larvae. Since Black soldier fly larvae was a new topic for many in the audience, there came a lot of curious questions such as: Are the larvae safe to use? What are the ethical aspects of producing insects? There is still a lot we don’t know about the Black solider fly, but the only way to find out more is by further investigating the creature. For the future, the hope is that it will be possible to publish the results from the study in a scientific journal.
A Protein-Based Material from a New Approach Using Whole Defatted Larvae, and Its Interaction with Moisture Nazanin Alipour, Björn Vinnerås, Fabrice Gouanvé, Eliane Espuche and Mikael S. Hedenqvist
A protein-based material created from a new approach using whole defatted larvae of the Black Soldier fly is presented. After removing the larva lipid and adding a plasticizer, the ground material was compression molded into plates/films. The lipid, rich in saturated fatty acids, can be used in applications such as lubricants. The amino acids present in the greatest amounts were the essential amino acids aspartic acid/asparagine and glutamic acid/glutamine. Infrared spectroscopy revealed that the protein material had a high amount of strongly hydrogen-bonded β-sheets, indicative of a highly aggregated protein. To assess the moisture–protein material interactions, the moisture uptake was investigated. The moisture uptake followed a BET type III moisture sorption isotherm, which could be fitted to the Guggenheim, Anderson and de Boer (GAB) equation. GAB, in combination with cluster size analysis, revealed that the water clustered in the material already at a low moisture content and the cluster increased in size with increasing relative humidity. The clustering also led to a peak in moisture diffusivity at an intermediate moisture uptake.
Sahar Dalahmeh, Researcher at Kretsloppsteknik is currently visiting the Center for Global Safe WASH at Emory to develop co-operation between SLU, Emory University, and the Royal Scientific Society of Jordan in research and education about microbiological and pharmaceutical risks associated with the use of wastewater in agriculture. As part of the CGSW Seminar Series, Sahar presented her research on the “Use of Wastewater Streams in Agriculture: Potential Benefits and Risks Based on Experiences in Sweden, Jordan and Uganda”.
In this study, published in the journal Water, we assessed how several design/operating parameters affect the efficiency of biochar filtration in removing organic matter (COD) and nutrients (Tot-N, NH4-N, Tot-P, PO4-P) from wastewater. We compared the process efficiency of different biochar parent materials, biochar diameters, hydraulic and organic loading rates (HLR and OLR) and one control filtering media (sand), and related it to filtering media properties, such as porosity and chemical composition of the media.
We found that: i) all the COD removal was high regardless of all the studied parameters, ii) Tot-P and NH4-N removal were affected by the biochar diameter, and iii) Tot-N removal was higher with pine-spruce biochar than with sand. Neither HLR nor OLR were found to significantly affect the removal of the studied parameters at the tested levels.
The group is happy to share that we have received a 4 million SEK research project grant within the area of development research from the Swedish Research Council. The project, “UDT 2.0 – Urine Dehydration Technology for Sanitation 2.0“, has the broader objective of moving sanitation research beyond the toilet (Urine-Diverting Toilet; UDT) by demonstrating a safe, productive and sustainable approach to urine recycling (Urine Dehydration Technology; UDT2.0). Our focus will be on Bolivia, specifically the city of Cochabamba where water is scare, expensive, and with very few piped water connections in peri-urban areas. The work will be conducted by researchers from our group at SLU and the University of San-Simón in Bolivia over 3.5 years between 2019 and 2022.
Following a successfull application to the SLU Climate Fund, we plan to replace a conventional toilet at SLU’s MVM building with a urine-diverting flush toilet during the spring. Urine-diverting toilets handle urine and faeces separately – the toilet leads the urine to a separate collection system while faeces are flushed with water, just like a conventional toilet. The proposed installation will highlight 20+ years of Swedish research on the topic, act as an educational/research platform, and practically support building a climate-smart SLU campus.
The toilet will be designed by EOOS GmbH and there are plans make use of the group’s dehydration technology that converts urine into a dry, hygienic, nutrient-rich powder. The project also links our ongoing urine research with SLU Holding (commercialisation), Sweden Water Research (plans to install urine-diverting toilets in Skåne), and Ultuna Täppförening (for applying dried urine-based fertiliser in community gardens in Uppsala).
Sahar Dalahmeh, Researcher at our group along with Manfred Lübken is co-editing a special issue in the journal, Applied Sciences published by MDPI. The special issue focuses on “Biochar for the Environmental Wastewater Treatment”. Paper submissions are invited along the following lines:
Filtration systems are, in general, characterized as low cost, easy to operate and they have a low space requirement. Filter material should have, e.g., a large specific surface area, low bulk densities and should be locally available where wastewater treatment is to be installed. Recently, biochar has been demonstrated to be effective in the removal of organic and inorganic constituents, heavy metals or microorganisms from contaminated water. Compared to many other filter materials, biochar has the advantage that it can be produced from locally available biomass and can be used as a soil amendment after wastewater treatment. The aim of this Special Issue is to discuss both the potential and limits of biochar as a filter material for wastewater treatment.
My name is Caroline Karlsson and I am a Masters student in Environmental and Water Engineering at Uppsala University and SLU. From now until June 2019, l will work on my Master Thesis project at the Department of Energy and Technology at SLU. The project is a technical evaluation of a pilot project concerning urine drying in Tampere, Finland. I will take part in the construction and installation of the urine drying units and while the system is running I will take samples and perform analyses, such as determining the concentrations of potassium, phosphorus and nitrogen in the dried urine. I will also evaluate how well the system is functioning on site, in terms of capacity and energy consumption.