Category Archives: English

Can Sweden achieve a circular economy for phosphorus?

The need for a more circular use of nutrients, notably phosphorus (P), has been widely discussed in Sweden, not least in response to the release of the new enquiry on sustainable use of sewage sludge (SOU 2020:3). But what would a transition to a circular economy for phosphorus look like? How much phosphorus is needed for biomass production in Sweden? And what possibilities are there to replace the widely used virgin mineral phosphorus with phosphorus from secondary sources?

Continue reading Can Sweden achieve a circular economy for phosphorus?

New master student writing thesis about

My name is Linnéa and I am doing my master thesis at Uppsala University (UU) and the Swedish University of Agricultural Sciences (SLU). I am currently in my last semester as a civil engineer in molecular biotechnology at UU. I was born and raised in Västerås but have lived and studied in Uppsala since 2016. I had never been to SLU before my master thesis, so I think it is exiting to discover new environments and meet new people during my semester here writing my master thesis!

My thesis is a collaboration between UU, SLU and two companies called Nanoform Science and Sanitation 360. Nanoform Science is a company that has developed a technology for manufacturing very acidic metal oxide surfaces which should have antimicrobial properties. Sanitation 360 is a company that wants to turn human urine into dry fertilizer by using treatment systems in connection with urine-separating toilets. These two companies are both interested in investigating the properties of these very acidic metal oxide surfaces. Nanoform Science wants to investigate whether the surfaces have antimicrobial activity, since they thereafter could develop the surfaces into environments where biofilms thrive, e.g. hospitals, dental clinics and sewage systems. Sanitation 360 is interested in the surfaces since biofilm growth in their treatment system leads to loss of nutrition in their fertilizer product.

During my work, I will mainly focus on developing a method for growing urease-positive biofilms, then I want to test the method on the surfaces from Nanoform Science.

Emma Enström investigates food systems in Skåne

My name is Emma Enström and I am studying for a master degree in Strategic Environmental Work at Lund University. My master in science contain topics like contaminated soil, blue-green solutions, environmental impact assessments but also about circular economy, life cycle assessments, policy instruments and system assessments. I am writing my master thesis for Sweden Water Research in collaboration with Robin Harder in the Environmental Engineering Group.

The study aims to map nutrient flows in food system within the region of Skåne, which are linked to the global food system. The study includes internal and external flows of nutrients (N, P and K) within the existing food, agricultural and residual electricity system. The study will thus examine opportunities and barriers in a future with a more sustainable management of these nutrients. The study is intended to contribute to the ongoing discussion in Skåne regarding nutrient flows in the region and provide a greater understanding of nutrient flows related to food production, consumption and residual flows. The study will also explore future scenarios to contribute with knowledge of whether food consumption in Skåne can be supported by local food production. The method I will use has been designed by Robin Harder and is a system assessment that takes into account the connections between a regional food system and the global food system in which it is embedded.

Welcome to our new PhD-student, Abood!

Hi! My name is Abdulhamid Aliahmad, and since it’s hard to read and pronounce my name correctly, I go by Abood. I am an environmental engineer with multi environmental backgrounds gained through my bachelor’s degree, a 9-month internship, and two former jobs in Palestine focusing mostly on sanitation.  I have recently earned my master’s degree in energy & environmental engineering with focus on Sustainability Engineering from Linköping University and my thesis has been carried out together with Volvo Construction equipment in Carbon Neutrality domain using GHG Protocol.

Most recently, I was fortunate to become a part of the environmental engineering group in the Department of Energy and Technology at SLU as a new doctoral candidate working with Jennifer as my supervisor. My contribution to the project will be;

  • sustainability assessment for the nutrient recovery technologies from sanitation, mostly urine. The assessment will be performed using TIS (technology innovation systems), LCA (life cycle assessment) tools, and possibly QMRA (quantitative microbial risk assessment).
  • multi-criteria sustainability assessment of systems will be performed using case studies.

Prithvi Simha’s pre-dissertation PhD seminar

On 5th of March, Prithvi had his pre-dissertation seminar: Alklaine Urine Dehydration – how to dry urine and recover nutrients. David Gustavsson from VA SYD/Sweden Water Research was Prithvi’s opponent at the seminar and he quizzed Prithvi on his published papers as well as his preliminary thesis (or kappa). Overall, it was very interesting and long discussion ranging on topics like reactive nitrogen and ammonia capture, the use of different alkaline substrates, the use of IoT in sanitation and global sanitation outlook. With this successful seminar, Prithvi will now proceed further and have his PhD defence which is scheduled to be held on the 2nd of June in Uppsala and via zoom online. We thank David again for his thorough and insightful discussion on the topic!

Red containers at Campus

Two treatment modules in form of modified shipping containers (6m x 2,4m x 2,5m) have arrived at Campus Ultuna and will house the larvae production for our animal feed projects.

One module (=first container) is designed to process the feed for the BSF larvae. This module consists of an area for milling and storing the feed stuff and washing the used treatment boxes. In the same module also the harvesting, washing and drying of the larvae is taking place.

The other module (=second container) is holding the treatment units, 22 racks with 11 boxes each. Each box itself can yield up to 2kg larval biomass reared on feedgraded organic sidestreams. The containers are well insulated against the current outdoor conditions of up to -15°C and a strong ventilation keeps the indoor environment at optimal conditions.

In future, the two modules can be moved and placed to any area with high waste generation. The modules each need a connection to electricity (32 amp) but only one of the modules need a connection to water and sewage.

The aim is to produce feed for our 5FiskiDisk project, rearing the larvae on bread and vegetable waste. For the chicken project, we will continue one of our projects from summer 2020 and will provide a total of 320 kg live larvae to the hens.

The project will use larvae provided by the fly colony at the SLU campus.

Tobias Eisert – new intern in the Black Soldier Fly lab

My name is Tobias Eisert. Since August 2020 am I in Uppsala as an exchange student. At my home university in Kassel/Germany am I studying Ecological Agriculture Sciences and I am about to finish my bachelor’s degree. One of my main interests regarding my studies are sustainable agriculture practices. For me, a functioning nutrient cycle is an important part of improved sustainability in the agricultural sector. The two-month long internship in the Black Soldier Fly Larvae lab gives me the opportunity to get some insights into this specific topic of BSFL composting but also more general in data collection, planning and carrying out of experiments.

Using MgO for Alkaline Dehydration of Human Urine Collected in Source-Separated Sanitation Systems

We recently published a new paper on the use of Magnesium Oxide as an alkaline substrate for dehydrating urine in the journal Frontiers in Environmental Science.

Abstract: Fresh human urine, after it is alkalized to prevent the enzymatic hydrolysis of urea, can be dehydrated to reduce its volume and to produce a solid fertilizer. In this study, we investigated the suitability of MgO to alkalize and dehydrate urine. We selected MgO due to its low solubility (<2 gL−1) and relatively high saturation pH (9.9 ± 0.2) in urine. Using a laboratory-scale setup, we dehydrated urine added to pure MgO and MgO mixed with co-substrates (biochar, wheat bran, or calcium hydroxide) at a temperature of 50°C. We found that, dehydrating urine added to a mixture of MgO (25% w/w), biochar, and wheat bran resulted in a mass reduction of >90% and N recovery of 80%, and yielded products with high concentrations of macronutrients (7.8% N, 0.7% P and 3.9% K). By modeling the chemical speciation in urine, we also showed that ammonia stripping rather than urea hydrolysis limited the N recovery, since the urine used in our study was partially hydrolyzed. To maximize the recovery of N during alkaline urine dehydration using MgO, we recommend treating fresh/un-hydrolysed urine a temperature <40°C, tailoring the drying substrate to capture NH+4 as struvite, and using co-substrates to limit the molecular diffusion of ammonia. Treating fresh urine by alkaline dehydration requires only 3.6 kg MgO cap−1y−1 and a cost of US$ 1.1 cap−1y−1. Therefore, the use of sparingly soluble alkaline compounds like MgO in urine-diverting sanitation systems holds much promise.

Contact: Prithvi Simha