The Future of Sanitation – a return to circular systems

Is urine diversion a new concept? In his presentation at SLU, Jan-Olof Drangert, Assoc. Prof. at Linköping University traces the evolution of sanitation and nutrient recycling in Sweden over the years. He suggests that, water-based sanitation used in the 20th century may have been just a brief detour in human history as we’ve strongly relied on dry sanitation systems in the past. Will our societies return to favor circular systems? Click to see what Dr. Drangert has to say about this.Post published by Prithvi Simha

 

Urine Diversion in Durban – Has it exceeded the original vision?

The eThekwini Municipality in the greater Durban region with its 80,000 urine diverting toilets is often highlighted as a success story for dry sanitation. In a recent presentation at SLU, Professor Chris Buckley, Head of the Pollution Research Group at the University of KwaZulu-Natal, South Africa reflected on the eThekwini case study.

Curious to know whether or not Professor Buckley believes urine diversion in Durban has exceeded the original vision? Click here to access the presentationPost published by Prithvi Simha

 

Hur fås högsta värdet ur biologiskt nedbrytbart avfall?

Kommuner förväntas tillgodose sina invånare med avfallshantering, vilket finansieras med skatteintäkter och/eller avfallshanteringsavgifter. I många låg-, och medel-inkomstländer kämpar kommunerna med att tillgodose en acceptable servicenivå och på dessa ställe sköter den informella sektorn ofta stora delar av insamlingen och behandlingen av avfallet. Till skillnad från plast-, och metallfraktionerna, sköter inte den informella sektorn om det biologiska nedbrytbara fraktionen; främst för värdet är så lågt att behandlingen skulle kosta betydligt mer än de möjliga inkomsterna. Om den biologiskt nedbrytbara fraktionen kunde omvandlas till produkter av högt värde skulle behandlingen kunna bära sin egen kostnad vilket skulle kunna uppmuntra insamlingen och behandlingen av denna fraktion.
I den här studien utvärderade och jämförde vi det potentiella värdet av produkter som erhölls i fyra olika behandlingsstrategier: termofil kompostering (den vanligaste förekommande behandlingen av det biologiskt nedbrytbara fraktionen globalt), fluglarvskompostering, rötning och fluglarvskompostering följt av rötning. Om ni är intresserade av vilken strategi som producerar högst värde, läs vidare här.

Kontakt: Cecilia Lalander

Posted by Prithvi Simha

English version below.

Fortsätt läsa Hur fås högsta värdet ur biologiskt nedbrytbart avfall?

Research shows Biochar is efficient in removing pharmaceutical residues at onsite sewage facilities

In a very recent study published in Science of the Total Environment, Sahar Dalahmeh, a researcher at the Environmental Engineering Unit, and her co-workers investigated the potential of biochar filters to replace or complement sand filters for the removal of pharmaceutical residues from wastewater in onsite sewage facilities.

In particular, their study examined what effects biodegradation, adsorption and a combination of these processes have on the removal of model pharmaceutical substances from wastewater. They used biochar filters operated under hydraulic loading conditions mimicking those found in onsite sand infiltration beds. In a 22-weeks experiment, concentrations and removal carbamazepine, metoprolol, ranitidine and caffeine were investigated in four treatments: biochar with active, biochar with inactive biofilm, biochar without biofilm and sand with active biofilm. They conclude that biochar is a promising filter medium for onsite sewage facilities, especially for persistent pharmaceutical residues such as carbamazepine and metoprolol.

Interested in reading more? Follow the below link to access the full publication:

Dalahmeh, S., Ahrens, L., Gros, M., Wiberg, K., & Pell, M. (2018). Potential of biochar filters for onsite sewage treatment: Adsorption and biological degradation of pharmaceuticals in laboratory filters with active, inactive and no biofilmScience of The Total Environment612, 192-201.

You can read more of Sahar’s work on ResearchGate or get in touch with her at Sahar.Dalahmeh@slu.se

 

Potential of biochar filters for onsite sewage treatment

Posted by Prithvi Simha

Licentiate Seminar: Luis Fernando Perez Mercado

Luis Fernando Perez Mercado, Doctoral Candidate at the Environmental Engineering Unit, Department of Energy and Technology will defend his licentiate thesis entitled, On-farm filtration technology for pathogen reduction: Reuse of low hygienic quality water for vegetable irrigation.

When?: 24 October 2017 at 13:30
Where?: Lecture Room 2034, MVM house, Swedish University of Agricultural Sciences

For further information, get in touch with Luis at the Department of Energy and Technology, P.O. Box 7032, SE-750 07 Uppsala, Sweden. E-mail: fernando.perez@slu.se

Abstract:  Reusing wastewater for irrigation has been widely recognized as an effective way to recirculate plant nutrients and water, particularly in arid and semi-arid regions. However, wastewater reuse in agriculture poses several hazards for human health, because of potential introduction of pathogens into agricultural production systems and therefore increasing the disease burden. Risks are higher in developing countries, where conventional wastewater treatment plants face several challenges in adequately treating the wastewater, if at all. In order to feasibly address such risks, a new management approach has been posed in which alternative measures act as barriers along the farm-to-fork pathway. The concept is that a cumulative effect of these barriers reduces exposure to pathogens. The overall aim of this study was to evaluate the hygienic quality of produce from agricultural systems using irrigation water contaminated with wastewater and to assess suitability of an on-farm filtering in this system.

To achieve this objective, the concentration of bacteriophages, E. coli and helminth eggs was measured in lettuce, water and soil during one cropping season in an agricultural system. This agricultural system used wastewater as well as riverbank filtration for irrigation of vegetables in Cochabamba, Bolivia. Five riverbank wells and the associated river were sampled every two weeks during the monitored cropping season. Soil samples were taken from the five plots that were irrigated with the monitored wells when the lettuce was planted and again when harvested. Composite lettuce samples were taken when harvested. In the laboratory, the reduction of bacteriophages (ɸX174 and MS2), E. coli, Enterococcus spp. and Saccharomyces cerevisiae by charcoal filters was investigated in relation to three grain diameter of filtering media. The tested parameters and levels were: two hydraulic loading rates 200 and 400 L m-2 d-1, three grain diameters of the biochar (Ø = 1.4, 2.8 and 5 mm), and two inflowing levels of electric conductivities of 500 and 1000 µS cm-1.

The microbial concentrations found in soil, lettuce and water sources of agricultural system evidenced high probabilities of fecal contamination along the system. Two types of riverbank filtration wells were identified: protected and unprotected. Both types exhibited significant levels (circa 4 log10 E. coli, 2 log10 bacteriophages, 1 log10 protozoa cysts and 70 % helminth eggs) of microbial reduction. Protected wells had significantly higher reduction rates for all microorganisms except virus. Results from biochar filters showed 1 log10 unit removal of all the monitored microorganisms, however, only for the smallest grain diameter (1.4 mm). No difference was found in microbial removal with either tested hydraulic loading rates nor with the tested electric conductivities. Grain diameter and uniformity of filtering media were identified as main factors for microbial removal for the two tested filtration technologies. Full-scale implementation of both is considered extremely context-dependent due to need of specific geological characteristics for riverbank filtration and due to large area requirement for biochar filters.

Posted by Prithvi Simha

Licentiate Seminar: Jenna Senecal

Jenna Senecal, Doctoral Candidate at the Environmental Engineering Unit, Department of Energy and Technology will defend her licentiate thesis entitled, Urea stabilisation and dehydration for urine-diverting toilets: System and hygiene evaluation.

When?: 24 October 2017 at 09:00
Where?: Lecture Room S, Ulls hus, Swedish University of Agricultural Sciences, Uppsala

For further information, get in touch with Jenna Senecal at the Department of Energy and Technology, P.O. Box 7032, SE-750 07 Uppsala, Sweden. E-mail: jenna.senecal@slu.se

Abstract: Over four billion people are discharging untreated human excreta into the environment without any prior treatment, causing eutrophication and spreading disease. This eutrophication is caused by nutrients found predominantly in urine. If managed adequately, urine can be used as a fertiliser because it contains the same plant nutrients as the fertilisers used to produce the food that people eat. Currently to replace the nutrients removed from fields during harvesting, more fertilisers are being manufactured and applied and ultimately more are being leached into the environment.

The use of human urine as a fertiliser is limited by its low nutrient concentration compared with commercial fertilisers. This study sought to increase the nitrogen (N) concentration (from 0.6 % to >6 %) through dehydration to produce a dry fertiliser of monetary value and where no liquid disposal from the toilet is required. The objective of this thesis was to evaluate a treatment that could stabilise urea and concentrate the urine while retaining >80 % of the NKP. Fresh human urine was added at various intervals to wood ash or biochar to first alkalise and thus inhibit the enzyme urease which catalyses the hydrolysis of urea. The urine was then dehydrated at temperatures of between 35 and 65 °C. A hygiene assessment was undertaken to observe the inactivation of five microorganisms (three indicators: Enterococcus faecalis, MS2 bacteriophage and ΦX 174 bacteriophage; and two pathogens: Ascaris suum and Salmonella enterica sub enterica Typhimurium) at the end of the alkaline dehydration process.

Urine mass was reduced by 95 % during dehydration, while preserving up to 90 % of the N and all the P and K. Ascaris inactivation data was fitted to a non-linear regression model, which estimated that 325 days of storage would be required for a 3 log10 reduction at 20 °C and 9.2 days of storage at 42 °C. The bacteria and bacteriophages were below the detection limit within four days at 20 °C. Just collecting urine separately from faeces provides a 5.2 log10 reduction. The material is concentrated during dehydration which results in a 3.5 log10 reduction overall just from urine-diversion.

This alkaline dehydration system installed in new or already existing toilets would greatly simplify the logistics and costs of storing, transporting and applying urine as a fertiliser. The truly innovative feature is the final product, a dry powder with 7.8 % N, 2.5 % P and 10.9 % K on dry weight, i.e. equivalent to commercial fertilisers. After just four days of storage, the dehydrated medium would meet WHO and USEPA guidelines for unrestricted fertiliser use.

Posted by Prithvi Simha

Sanitation Technologies of the Future

Farewell Seminar for Håkan Jönsson!

When?: 25 October 2017 at 13:00
Where?: Room: Hörsal V, Ulls hus, Swedish University of Agricultural Sciences, Uppsala

Online Streaming?: Click here

To honor Prof. Håkan Jönsson who retires during 2017, the Kretsloppsteknik research group at the Department of Energy and Technology, Swedish University of Agricultural Sciences is organizing a Farewell symposium on the 25th of October, between 13:00 and 17:30. The Symposium, entitled “Sanitation Technologies of the Future” will host several Swedish and International experts who will present their visions about the future of the sanitation sector. A schedule of the symposium can be seen below.

The symposium will be streamed online between 13:00 and 18:00 here.

Håkan Jönsson Farewell Symposium: Schedule

Posted by Prithvi Simha

Framtidens sanitetslösningar

Avtackningsseminarium till Håkan Jönsson!
Framtidens sanitetslösningar
25 Oktober 2017 kl 1300
Lokal: Hörsal V Ulls hus SLU
Seminariet kommer även att vara möjligt att följa på webben.

För att hedra Håkan Jönsson som går i pension under 2017 kommer vi att hålla ett öppet symposium för Håkan den 25 oktober mellan kl 1300 och 1730.
Titeln för symposiet är: Framtidens sanitetslösningar.
Vi kommer att ha presentationer från både svenska och internationella experter inom området (exakt schema med presentatörer kommer inom kort).

Sprid gärna inbjudan vidare till personer ni tror vill delta (ursäkta om ni får inbjudan flera gånger).

English version below.
Fortsätt läsa Framtidens sanitetslösningar

Exjobbsförslag: Livscykelanalys av fluglarvskompostering under storkaliga svenska förhållanden

Foto: Viktoria Wiklicky

Titel: Livscykelanalys av fluglarvskompostering under storskaliga svenska förhållanden Omfattning: 30 hp
Nivå: Avancerad
Ämne: Teknologi eller miljövetenskap
Start: Augusti 2017 eller senare

Bakgrund
Fluglarvskompostering är ett relativt nytt och effektivt sätt att behandla matavfall på. Behandlingen går ut på att mata larver av den svarta vapenflugan (Hermetia Illucens) med matsvinn. Larverna omvandlar effektivt matavfall till egen biomassa vilket är ett effektivt sätt att extrahera viktiga näringsämnen från avfallet. Behandlingen pågår under två veckor vartefter larverna skördas. Den kvarvarande avföringen från larverna kan användas på samma sätt som vanlig kompost, men med fördelen att avföringen är extra rik på kväve. Själva larverna kan användas på flera olika sätt men det mest optimala är troligtvis som proteinfoder, speciellt inom fiskodling eller vid uppfödning av fjäderfä. Detta är dock förbjudet i dagsläget eftersom produktionsdjur inte får utfodras med obehandlat matavfall, men det är fullt möjligt att använda larverna i mat till sällskapsdjur där de kan utgöra en viktig källa av fett och protein. Om larverna däremot skulle utfodras med vegetabilier skulle de direkt kunna användas som foder för exempelvis odlad fisk.
Fortsätt läsa Exjobbsförslag: Livscykelanalys av fluglarvskompostering under storkaliga svenska förhållanden

Torrt gödselmedel från urin

Att säga ”vi är vad vi äter” är bara en del av sanningen. Vad vi utsöndrar vad vi äter är den andra delen av sanningen när det gäller växtnäringsämnen. Mänsklig avföring innehåller samma kväve, fosfor och kalium (N-P-K) som vi finner i gödningsmedel som används för att producera den mat som vi sedan äter (Winker et al., 2009). Mänsklig avföring ses oftast som ett oönskat avfall världen över, vilket skapar humanitära och miljömässiga problem (Baum et al., 2013). För att ersätta näringsämnena som tagits bort med skörden från fälten tillverkas gödningsmedel i industriella processer som bidrar till miljöförändringar på global nivå (Rockström et al., 2009). Återvinning av mänsklig avföring tillbaka till lantbruket skulle minska det nuvarande beroendet av gödselmedel från fossila källor (Ramírez & Worrell, 2006).

Återföringen skulle dessutom förbättra avkastningen i t.ex. Afrika söder om Sahara, där gödselanvändningen är låg (FAO, 2015) och skydda marina ekosystem i Östersjön genom att begränsa flödet av överskott av näringsämnen till ytvatten (Rockström et al., 2009).

Begränsningen av mänsklig urin som gödningsmedel är Fortsätt läsa Torrt gödselmedel från urin