Collection & Treatment
For many people, dealing with wastewater ends when they flush the toilet or remove hair from the drain. This attitude is referred to as “flush and forget.” [1] An achievement of matured industrialized nations? There is no doubt that alluvial sewers and centralized wastewater treatment have made tremendous improvements in terms of health, quality of life, and environmental protection [2] . However, there is also evidence that this type of wastewater treatment has various limitations [3]. But what actually is wastewater? What risks does it pose? To explore these questions, it helps to open our eyes a bit, to move away from understanding wastewater as waste and to focus on resources and, above all, resource efficiency. After all, what flushes down the toilet and seeps into the sink are valuable nutrients, energy and, above all, a lot of water!
Wastewater treatment options
In addition to nutrients and energy, wastewater also contains pathogens such as bacteria, viruses and parasites and an increasing concentration of micropollutants (for example, from pharmaceuticals, hormones and biocides). Wastewater treatment separates the valuable from the harmful. The former is upgraded for further use and the latter is deactivated and eliminated. In the process, as little energy as possible is used and emissions of pollutants and greenhouse gases are largely avoided. In fulfilling all these tasks, central wastewater treatment plants are increasingly reaching their limits [4] . In particular, the recovery of nutrients turns out to be costly and resource-intensive if it is approached in a centralized way and after mixing different types of wastewater in the sewage sludge . The high quantities of flushing water ( usually drinking water quality), which are a prerequisite for reliable operation of the alluvial sewer system, also become a problem as water shortages increase.
Decentralized treatment as an alternative
In combination with separation at source (link article), decentralized, i.e. near-source, treatment processes offer various advantages in this context:
- The separated streams (yellow, black, gray; link to detailed discussion of separated streams, see below) are less complex in their respective compositions, allowing specific and very efficient procedures to be applied.
- By avoiding long transport routes and storage times, biological processes can be prevented and associated emissions avoided.
- Cycles for water and nutrients can be closed on site (link to Reuse and Production).
- Based on modular subsystems, new interfaces can be used, further material flows (e.g. rainwater or biowaste) can be integrated and thus the handling of resources can be approached holistically.
Decentralized, modular (waste) water management can also be attractive from an economic point of view. This is not a matter of completely replacing an existing sewer-based wastewater treatment system. In remote locations, where settlements are growing rapidly, or where investment capital is lacking, decentralized solutions can be more cost-effective. The prerequisite for this is that the technology required for the specific treatment processes, can be standardized and is not too complex, so that they can also be regulated and tested (Ref. Advocacy Group).
Decentralized treatment processes for separate wastewater streams
Various proven processes are already available today for the decentralized treatment of yellow water, or diluted urine, [5] . As a rule, the urine is stabilized in a first step (e.g. by nitrification or a strong increase in pH) and the substrate is concentrated in a second step (distillation, evaporation). Further intermediate steps exist to filter out drug residues. Pathogens are deactivated by a specific increase in pH or by heating (during distillation). The aim of these processes is to produce a fertilizer that is permissible for agriculture and horticulture [6] .
Proven technologies also exist for the decentralized treatment of graywater, ranging from simple passive applications such as plant filters to more complex processes with ozone treatment and remineralization for the treatment of water with drinking water quality [7].
For on-site treatment of blackwater / brownwater, the most experience to date has been gained with biological processes (composting, worm composting, stabilization ponds). The decisive factor here is the amount of rinsing water used for transporting and processing the black water. An extreme case here is Dry toilets , where no additional water is used. In conventional flush toilets, on the other hand, a volume ratio of water to feces of >20 can be assumed. In this case, a solid-liquid separation process is usually used, followed by different processes for the separated streams. Due to the high concentration of organic compounds, black / brown water can also be used for energy purposes. The energy stored in the fecal matter can be used as process heat in the treatment process (e.g. sterilization) or as heat for a building [8].
Text: David Hasler
Editing: Dorothee Spuhler
References
News about Collection & Treatment
Event
21.06.2024 |
Trub
Sanitärwende zur Sonnenwende: Führung Balmeggberg
Event
14.06.2024 |
Feldbach
VaLoo Workshop at KREIS-Haus: Closing water and nutrient cycles
Event
23.06.2023 |
Feldbach
VaLoo Workshop at KREIS-Haus: Closing water and nutrient cycles
First infographic published
Member projects about Collection & Treatment
PhD on Vermifiltration
Topics:
- Collection & Treatment
I am currently doing a PhD which aims to answer the following questions:
- How does a full-scale vermifilter perform? (Case study: Soubeyran)
- How does the effluent of full-scale vermifiltration installations compare to irrigation and fertigation standards?
- What is the removal of pathogens, heavy metals, and common house-hold micropollutants?
- What are the mechanisms for nitrogen treatment and how do operational parameters affect these mechanisms (lab-scale)
- How do full-scale vermifilters compare to lab-scale vermifilters?
- in terms of treatment efficiencies, greenhouse gas emissions, nitrogen cycle
- Based on the collected knowledge, how can vermifiltration be optimized?
University of Geneva
University of Geneva, Geneva, Switzerland
kayla.coppens@unige.ch
https://ch.linkedin.com/in/kayla-coppens-921b0710a
The Ressourcer V1-2024 by EAR
Topics:
- Collection & Treatment
- Reuse & Production
The Resourcer V1 is designed to combine several circular processes:
- a grow house for seedlings and plants powered by passive and active solar power.
- Electric power will supply controlled LED, humidity and temperature adjustments to enhance and prolong the natural season in the mountain area (Emmental 700 m ü.M).
- a dry toilet, separating the (re-)source material into liquids and solids.
- a feces fermentation and/or worm compost installation with drawers or a box system.
- fermented urine with evaporation installation and treated fertilizer as outcome.
- streetnoise absorption for a better garden sound.
- rainwater collector to repurpose.
- 30cm lower planting bed to use earth’s warmth into the machinery.
- tree-grow-facility as in winter protection.
- material to construct the Resourcer V1 is re-used from another construction site
- prototype and study facility like using the irradiation of the battery to enhance the composting.
- Researching on psychology of water-flush sounds.
- Collecting data on the experience of the usage of such a system from the makers and the audience of EAR.
Purpose and goal:
The Resourcer V1 project aims to grow organic material such as seedlings, bacteria, biological material, and plants using the techniques of the Resourcer V1 system. This project presents a perfect challenge for a dedicated team and aligns with the core vision of EAR.
The Resourcer V1 is an off-grid system that consists of a greenhouse with four compartments. The first compartment contains a dry-toilet and urinoir, the second compartment controls the compost climate of feces and greens, the third compartment facilitates urine-to-fertilizer evaporation, and the fourth compartment is used for growing seedlings, plants, and conducting other experiments.
The surrounding EAR garden of approximately 100m2 can nurture the seedlings that grow into food. The kitchen and community will process these plants, keep the seeds separated for the next season, and mix coffee waste and tea leaves into the circular processes. Additionally, these processes can be used to grow mushrooms and produce vegan leather. The (wurm-)compost produced by the Resourcer can be mixed into the normal compost.
The construction will also improve the soundscape in the garden, since it is built with a sound-absorption that lowers the traffic-noise.
In summary, the Resourcer V1 project is an off-grid system that aims to grow organic material using a combination of greenhouse and circular processes, aligning with the core vision of EAR. The surrounding garden, kitchen, and community play an important role in nurturing the seedlings, processing the plants, and contributing to the circular processes that keep changing and hopefully expanding.
Dimensions
The dimensions of the project are (lxbxh) 6mx 1,5 (2m roof) x 1.9-2.2m and the construction takes place in 2024. It will replace the existing shed that needs complete renovation.
Realization / timeframe
EAR will invite volunteers who have great expertise on different aspects of the project. Together we want to make a journey into combining several processes in 1 dedicated machinery that intrinsically motivates to mix in the different circularities.
Ending up with a real yield with home-made fertilizer, understanding of great compost, a knowledge on different fermenting systems, clever evaporation, controlling low-energy computers for climate-regulation and many more interactions will be found in the realization of this project.
Pls reach out to Philipp Markus for more details on the timeframe etc…
EAR Environmental Artistic Research
Philipp Markus (Sanitation Consultant), Kaspar König (Founder EAR)
Trubschachen, Schweiz
philipp.markus@bluewin.ch
https://ear.education/
Stammhäuser
Topics:
- Collection & Treatment
- Housing & Living
- Reuse & Production
Unsere Welt ist bereits erbaut, doch wie können moderne, ökologische Themen in dieses bestehende Gefüge integriert werden? Die Stammhäuser der Wohnbaugenossenschaft Hofgarten sind herausragende Beispiele dafür..
Die geplante Instandsetzung dieser Gebäude legte besonderes Augenmerk auf die Minimierung des Ressourcenverbrauchs und die Anpassung an den Klimawandel. Durch eine sanfte Sanierung konnten bestehende Elemente erhalten und wiederverwendet werden, wie beispielsweise die Küchen. Andere Elemente wie Duschen wurden komplett neu gestaltet, jedoch auch im Kreislaufkonzept durchdacht. Die Bewohner tragen aktiv zum Klimaschutz bei, indem sie einen Teil der Wärme aus dem Abwasser während des Duschens einfangen und ins System zurückführen. Diese innovative Wärmerückgewinnung findet direkt in der Duschrinne statt und wurde in Zusammenarbeit mit unserem Industriepartner Joulia umgesetzt, die verschiedene Bauformen der WRG-Rinnen anbieten. Ziel war es, die grösstmögliche Effizienz zu erreichen, was uns gelungen ist. Die Herausforderung bestand darin, den nötigen Platzbedarf für den Wärmetauscher zu finden. Da sich dieser direkt in der Duschrinne befindet, musste die Holzbalkendecke mit Schlackefüllung als Raum herhalten. Gleichzeitig wollten wir keine Kompromisse in Bezug auf Dichtigkeit, Schallschutz und Brandschutz machen. Das Fazit lautet: Es geht, und zwar mit Erfolg.
Neben diesem aktiven Beitrag zum Klimaschutz wurde auch an die Klimaanpassung gedacht. Das Gebäude profitiert von einem begrünten Freiraum abseits der Strassen, der speziell für die Hitzeminderung optimiert wurde. Ab dem Frühling 2024 tragen offene Mulden zur Hitzeminderung bei, indem sie das Dachwasser verdunsten und versickern lassen. Vor den Mulden sind einzelne Regentonnen platziert, die eine einfache Nutzung des Regenwassers ermöglichen.
Solche Projekte erfordern eine offene Bauherrschaft und grosses Vertrauen in das Projektteam. Die Wohnbaugenossenschaft Hofgarten hat uns beides grosszügig geschenkt.
Moser's Büro GmbH
Kristijan Moser
Siewerdtstrasse 95, Zürich, Schweiz
0434562333
kmo@xn--mob-joa.ch
http://www.mobue.ch
Horizontal flow constructed wetland (HFCW) greywater treatment system
Horizontal flow constructed wetland (HFCW) greywater treatment system
Topics:
- Collection & Treatment
- Housing & Living
A Horizontal flow constructed wetland (HFCW) greywater recycling system is designed and installed by alchemia-nova GmbH at the apartment complex FELZ ZWEI, which was realized by VBAU Architecture in Zürich, Switzerland in 2021. ZHAW was evaluating the cleansing capacity and water quality; the potential water, energy and financial savings; as well as the user acceptability of reusing treated greywater for toilet flushing and garden irrigation.
KREIS-Haus
InformationsKREIS-Haus
Topics:
- Collection & Treatment
- Housing & Living
- Politics & Strategy
- Reuse & Production
What does a circular economy look like in everyday life? And most importantly, how does it feel? In the KREIS-Haus, visitors experience how a circular economy works in the context of construction and living. Additionally, they will have the opportunity to participate in a research project.
KREIS-Haus stands for Klima und Ressourcen-Effizientes Suffizienz Haus (English: climate and resource efficient sufficiency house). The project shows how a functioning circular economy can be implemented in the smallest of spaces. From the building materials to the nutrients in the wastewater – everything is in circulation.
The KREIS-Haus is a joint project of the research group Eco-technology at ZHAW and the Synergy Village association, which is the location of the KREIS-Haus. The research group leads the research and educational projects in the house. The Synergy Village association is the implementation partner and owner of the house. The association is responsible for the operation of the KREIS-Haus, supports the research work and welcomes visitors to the idyllic grounds.
ZHAW
Devi Bühler
Oberschirmensee 14, 8714 Hombrechtikon, Switzerland
bued@zhaw.ch
https://www.zhaw.ch/en/lsfm/institutes-centres/iunr/ecotechnologies-and-energy-systems/ecotechnology/wastewater/kreis-haus/
Pyrolysis plant for biochar from faeces
Pyrolysis plant for biochar from faeces
Topics:
- Collection & Treatment
- Reuse & Production
«Circular Cities» of the future are expected to reuse as many resources as possible. Today, human faeces from toilets are the most important source of nutrients in wastewater. The recovery of these nutrients is easier with dry toilets than with our current water flushing system. But how can this idea be technically implemented without impairing community sanitation?
Collected material from dry toilets can be hygienized by means of pyrolysis (a heat process of > 350 °C). Experiments and measurements have shown that most nutrients from faeces are found in biochar after the pyrolysis process. These could easily be reused in agriculture or transported, which would complete the cycle. Our current research focuses on the optimal operating concept, the availability of nutrients in pyrolysis carbons and the role a system such as this could play in the future circular economy (or in space stations).
ZHAW
Andreas Schönborn
Grüentalstrasse 14, 8820 Wädenswil, Switzerland
sand@zhaw.ch
https://www.zhaw.ch/en/lsfm/institutes-centres/iunr/ecotechnologies-and-energy-systems/ecotechnology/nutrients/
MODO – Nutrient recovery and water reuse
MODO – Nutrient recovery and water reuse
Topics:
- Collection & Treatment
- Housing & Living
MODO stands for Mobile Ecotechnology Demonstration Object. The MODO shows how we can save water and keep it in a closed cycle. Inside the trailer is a urine-diverting dry toilet and a recirculating washing machine. Our researchers are investigating how the water can be purified after washing and reused for washing. Water losses are replenished with rainwater. Thanks to a photovoltaic system on the roof of the trailer, this concept makes it possible to develop a laundromat that is completely independent of the central water and electricity supply. This innovation is currently being developed into a marketable solution in South Africa as part of the LaundReCycle project. In the scope of scientific experiments, the faeces are converted to biochar by pyrolysis and used in agriculture to improve the soil. If no experiments are running, the faeces are composted in a worm composter. In both ways, the nutrients are returned to the nutrient cycle.
ZHAW
Devi Bühler
Grüentalstrasse 14, Wädenswil, Switzerland
bued@zhaw.ch
https://www.zhaw.ch/de/lsfm/institute-zentren/iunr/oekotechnologien-energiesysteme/oekotechnologie/abwasser/modo/
Équilibre – Cressy
Topics:
- Collection & Treatment
- Housing & Living
- Reuse & Production
Construit en 2011 par la coopérative d’habitation Équilibre, le bâtiment de 2 étages accueille 13 logements et son propre système d’assainissement des eaux usées dans son jardin.
Chaque appartement est équipé de toilettes sèches à séparation d’urine. Les matières fécales sont traitées en sous-sol dans des composteurs dédiés à chaque appartement et les urines sont transformées en engrais avec le système Pitribon (nitrification dans des filtres aérés sur charbon végétal). Les eaux grises sont traitées dans un filtre planté situé dans le jardin.
Vision Futurae – 100% Wasserautarkie
Topics:
- Collection & Treatment
Erstmalige komplett Wasserautarkie für Tiny Houses: Vuna GmbH plante und baute ein Wasserrecyclingsystem für die Bewohner:innen des Tinyhouses in Sörenberg, mit Trinkwasseraufbereitung aus Regen- und Grauwasser.
EPFL-École polytechnique de Lausanne (en train)
EPFL-École polytechnique de Lausanne (en train)
Topics:
- Collection & Treatment
- Housing & Living
Im Rahmen eines Umbaus von zwei Gebäuden, plant die ETH Lausanne mit Vuna Nexus ein Trenntoilettensystem und Urinaufbereitung für Düngeproduktion.
