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.
On the 17th of January, Olle Castell, Caroline Gårdestedt och Malin Denninger from the Swedish Red Cross, and Axel Wurtz and Jairo Mosquera from Stockholm Environment Institute (SEI) came to visit Cecilia Lalander and Annika Nordin from the Environmental Engineering group. Several possible treatment technologies for the treatment of faecal sludge in emergency settings were discussed. Fly larvae composting and thermophilic aerobic digestion (TAD) were discussed in detail, as these are treatments that Cecilia and Annika have expert knowledge in. There was also time for a visit to the fly facility. Olle Castell and Malin Denninger updated Cecilia on the current situation in the refugee camps in Cox’s Bazar, Bangladesh. In early 2018, Cecilia spent one month in the camps with the Swedish Red Cross with the mission to evaluated possible treatment methods for the treatment of faecal sludge in the camps. We are pleased that the collaboration between the Swedish Red Cross and the Environmental Engineering group continues.
In this study, we investigated the potential of biochar filters as a replacement or complement for sand filters for removal of per- and polyfluoroalkyl substances from wastewater in onsite sewage facilities. In a 22-weeks experiment, concentrations, removal and adsorption of nine perfluoroalkyl carboxylates (PFCAs; C3- 11) and three perfluoroalkane sulfonates (PFSAs; C4, 6, 8) and one perfluorooctanesulfonamide (FOSA; C8) were investigated in four treatments: biochar with active, biochar with inactive biofilm, biochar without biofilm and sand with active biofilm. We found that biochar with no biofilm achieved higher removal efficiency (90-99%) and the adsorption capacity (73 -168 ng g-1 ) for C7-C11 PFCAs, C6, C8 PFSAs and FOSA, than the other biochar and sand treatments. For all biochar treatments, shorter-chain PFASs were more resistant to removal than longer-chain PFASs.
We congratulate Mr Nduhiu Johnson Gitahi to the degree Doctor of Philosophy achieved for his thesis work: Isolation, serotyping & molecular characterization of enteric pathogens for validation of Peepoo sanitization along handling chain at Kibera, Nairobi Kenya.
The latest additions to Kretsloppsteknik are two interns, Chinmoy Deb and Anooj Ramanathan, coming all the way from India to work on urine drying for their bachelor’s thesis. During their bachelors program, both Chinmoy and Anooj have been doing research on sanitation, working with nutrient recovery as well as removal of pharmaceutical residues from human urine. A keen interest in sanitation and hygiene technologies brings them to our group at SLU for a 3-months long internship that began in December. Over the course of the internship, they will be involved in ongoing projects related to process modelling, intensification, and optimization.
