Publications – Page 3 – Kretsloppsteknik

New Publication on drying human urine using different alkaline media & temperatures

Published 13 May, 2020
By Prithvi Simha

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.

Using Hermetia illucens larvae to process biowaste from aquaculture production

Published 30 January, 2020
By Evgheni Ermolaev

Journal of Cleaner Production 251 – 119753 (2020)

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).

Pharmaceutical pollution of water resources in Nakivubo wetlands & Lake Victoria, Uganda

Published 7 January, 2020
By Prithvi Simha

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.

Pharmaceuticals in source separated sanitation systems: Fecal sludge and blackwater treatment

Published 25 November, 2019
By Prithvi Simha

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 .

New publication in the Global Water Pathogen Project about Salmonella

Published 5 November, 2019
By Prithvi Simha

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. 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 treatment.

New publication on pre-treatment of banana peels for BSFL composting

Published 25 October, 2019
By Prithvi Simha

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.

Moisture content affects greenhouse gas emissions from thermophilic food waste composting

Published 18 September, 2019
By Evgheni Ermolaev

The effects of moisture on thermophilic composting process are investigated in the latest paper published in the Journal of Cleaner Production: https://doi.org/10.1016/j.jclepro.2019.118165

It is known that too wet active composts can cause excessive methane (CH₄) emissions, but there is no consensus on how much and what exactly the rate of this change is with changing moisture.

Greenhouse gas emissions from small-scale fly larvae composting

Published 18 September, 2019
By Evgheni Ermolaev

Frida Erlöv taking a gas sample. Photo: Evgheni Ermolaev

A new paper evaluating the greenhouse gas (GHG) emissions from small-scale fly larvae composting is published. The full paper is available here: https://doi.org/10.1016/j.wasman.2019.07.011

The aim of the study was to evaluate GHG and ammonia (NH₃) emissions from fly larvae composting treatment of food waste and the effects of pre-treatment and seeding of the food waste substrate with BSF larvae-associated bacteria on the efficiency and rate of the fly larvae composting process.

Book chapter within the framework of the Global Water Pathogen Project about Salmonella in relation to wastewater

Published 16 September, 2019
By Prithvi Simha

The chapter brings up, occurrence, epidemiology, analysing techniques and treatment technology. The chapter is available at the link below

Hasan, R., Nordin, A.C., Shakoor, S., Keenum, I. and Vinneras, B. 2019. Salmonella, Enteric Fevers, and Salmonellosis. In: J.B. Rose and B. Jiménez-Cisneros, (eds) Global Water Pathogen Project. http://www.waterpathogens.org ( A. Pruden, N. Ashbolt and J. Miller (eds) Part 3 Baceteria) http://www.waterpathogens.org/book/salmonella-enteric-fevers-salmonellosis. Michigan State University, E. Lansing, MI, UNESCO.
https://doi.org/10.14321/waterpathogens.2 7

New Publication Polymers 2019, 11, 287; doi:10.3390/polym11020287

Published 11 February, 2019
By Prithvi Simha

The material that was produced by the defatted larvae.

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.