In early 2019, we designed and installed a pilot shell system to dry fresh urine collected from about 100 toilet users each day (or a maximum of 30 liters of urine day-1). The system was implemented at a Finnish army training ground (Camp Mauri) belonging to Pori Brigade, which is a garrison in Säkylä, Finland and was used for a period of three months between March and May 2019. In a new publication in the journal Frontiers in Environmental Science, we describe results of the evaluation of the technology. The publication can be openly accessed here:
I början av 2019 designade och installerade vi ett pilotskalssystem för att torka färsk urin som samlats in från cirka 100 toalettanvändare varje dag (eller högst 30 liter urin dag-1). Systemet implementerades på en finsk arméutbildningsplats (Camp Mauri) som tillhör Pori Brigade, som är garnison i Säkylä, Finland och användes under en period av tre månader mellan mars och maj 2019. I en ny publikation i tidskriften Frontiers in Environmental Science, vi beskriver resultaten av utvärderingen av tekniken. Publikationen kan öppnas här:
In a bio-based circular economy, domestic wastewater has a significant role to play. By separating wastewater into different fractions at the source, it is possible to create new pathways for recycling resources. In a book chapter published in Current Developments in Biotechnology and Bioengineering, Simha et al. discuss about the most nutrient-rich wastewater fraction, human urine. We present a new, simple, yet potentially revolutionary nutrient recycling technology — alkaline urine dehydration. We then describe how this technology can be combined with urine-diverting toilets and integrated with existing sanitation infrastructure to create a service chain that safely collects, contains, transports, and applies urine as fertilizer. The potential benefits, risks, knowledge gaps, and challenges surrounding the implementation of a urine-diverting and dehydrating sanitation system are discussed. Finally, the prospect of creating smart toilets and digitizing the proposed sanitation system are explored. To read the full chapter, follow the link below:
A new study assessed the inactivation of Ascaris eggs under various conditions and observed that the exposure of Ascaris eggs to elevated pH (10.5–12.5) at temperatures <27.5 °C for >70 days had no effect on egg viability. To accelerate the inactivation of STH, an increase in the treatment temperature is more effective than pH increase. Alkaline pH alone did not inactivate the eggs but can enhance the effect of ammonia, which is likely to be present in organic wastes.
In a study recently published in Science of the Total Environment, we present results from a study that investigated drying of fresh source-separated human urine in five different alkaline media (pH > 11) at elevated temperatures (50 and 60 °C) with minimal loss of urea, urine’s principal nitrogen compound. We found that it was possible to concentrate urine 48 times, yielding dry end-products with high fertiliser value: approximately, 10% N, 1% P, and 4% K. We monitored the physicochemical properties and the composition of various dehydration media to provide useful insights into their suitability for dehydrating urine. We demonstrated that it is possible to recover >90% nitrogen when treating fresh urine by alkaline dehydration by inhibiting the enzymatic hydrolysis of urea at elevated pH and minimising the chemical hydrolysis of urea with high urine dehydration rates.
A paper was published in the Journal of Cleaner Production as a result of the partnership established between the Environmental Engineering Research Group at SLU and the PhD candidate Ivã Guidini Lopes, a researcher from São Paulo, Brazil. This paper addresses the management of waste generated in aquaculture enterprises (fish carcasses) by larvae of the black soldier fly (BSF, Hermetia illucens).
This study investigated the occurrence and removal in wastewater and water bodies in Nakivubo wetland area and Inner Murchison Bay, Lake Victoria, of common prescription and non-prescription pharmaceutically-active substances (PhACs) sold in Kampala city, Uganda. A questionnaire was sent to 20 pharmacies in Kampala, to identify the most commonly sold PhACs in the city. During two sampling campaigns, samples were collected from Bugolobi wastewater treatment plant (WWTP) influent and effluent and surface water samples from Nakivubo channel, Nakivubo wetland and Inner Murchison Bay. The concentrations of 28 PhACs, organic matter, solids and nutrients in water samples were analysed. Ciprofloxacin (antibiotic), cetirizine (anti-allergy), metformin (anti-diabetes), metronidazole (antibiotic) and omeprazole (gastric therapy) were reported by pharmacies to be the PhACs most commonly sold in the study area. Chemical analysis of water samples revealed that trimethoprim (antibiotic) and sulfamethoxazole (antibiotic) were the dominant PhACs in water from all sites except Lake Victoria.
In this article, 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. For more information, please read: https://www.sciencedirect.com/science/article/pii/S004896971935524X .
Björn Vinnerås and
Annika Nordin have together with R Hasan, S Shakoor and I Keenum compiled
current knowledge regarding Salmonella. Our focus in the chapter has been the
effect upon salmonella in relation to current practices and available treatment
technologies for reduction of Salmonella in
wastewater fractions can be divided into three main types: chemical, biological
and thermal. When comparing the inactivation of Salmonella spp.
with Escherichia coli,
the latter is somewhat more resistant to most treatments and can therefore be
used as a proper indicator for salmonella during treatments. Salmonella has several
genetically-driven responses to stress related to the inactivation treatments,
which increase survival during extreme conditions. In this chapter the
inactivation time for salmonella in relation to pH, ammonia concentration and
temperature is presented. For pH, generated inactivation chemical substances
aid in the inactivation: at higher pH uncharged ammonia is the most active
molecule enhancing inactivation while at low pH carbonate and organic acids
both increase the efficiency of inactivation. For heat inactivation, increased
dry matter content increases the time of survival. Biological treatments affect
the survival, while also decreasing the number of viable Salmonella over time.
However, the effect of the biological treatment is difficult to monitor and
quantify and therefore extended treatment durations are recommended for
biological treatment if the treatment is not combined with chemical or thermal
Alice Isibika and co-authors have published a new study in the journal Waste Management, on the application of pre-treatments prior BSFL treatment of banana peels as a fibrous and nutrient imbalanced substrate to enhance bioconversion ratio. The applied pre-treatments were non-protein nitrogen for balancing the carbon/nitrogen , heat and microbes(fungi and bacteria) pre-treatments for breaking down complex compounds into more readily available forms in the banana peels to be consumed by the BSFL. They found that direct addition of ammonia solution in the banana peel and addition of both fungi (Trichoderma, Rhizopus) and bacteria (BSFL gut bacteria) improved the BSFL response efficiencies while heat treatment did not improve. For microbial pre-treatment 14 days was found to be the total time to achieve sufficient degradation of the banana peels for BSFL consumption.