Notice: Undefined index: mime in /pages/ae/e2/d0008859/home/htdocs/sites/susanaforum3x/libraries/joomla/document/feed.php on line 215
Topics in Category: Treatment processes for wastewater, sludges, organic waste, excreta - SuSanA Forum Mon, 29 May 2017 17:23:17 +0200 Joomla! - Open Source Content Management /media/kunena/images/icons/rss.png Topics in Category: Treatment processes for wastewater, sludges, organic waste, excreta - SuSanA Forum en-gb Key documents for the sub-category on DEWATS (decentralised wastewater treatment systems) - by: muench For more information about why I am creating this new thread, please see here:


This thread is a "sticky thread" which means it will always remain at the top of this sub-category. It contains a recommendation and orientation for newcomers regarding the most important five documents and website links in this thematic area.

Recommended top five documents in the thematic area of "DEWATS (decentralised wastewater treatment systems)" *, in reverse chronological order:

* Not everyone calls these system DEWATS, as this is thought to be a bit of a trademark of BORDA. E.g. GIZ in Kenya calls such systems DTF, which stands for Decentralised Treatment Facility.

WSTF (2015). Design and Technologies of Decentralised Treatment Facilities - Manuals and further documents developed in the context of GIZ’s Water Sector Reform Programme. Water Services Trust Fund (WSTF), Nairobi, Kenya

The manuals provided here are from a series of three manuals, prepared by the Water Services Trust Fund (WSTF). You will find the following documents for download here:
- DTF Design Adaption Manual
- DTF Construction Manual
- Payment Schedule Overview
- Workplan
- Bill of Quantity
- DTF 3D Simulation
- Structural Drawings of DTF Modules
- Architectural Drawings of DTF Modules

Reynaud, N. (2015). Operation of Decentralised Wastewater Treatment Systems (DEWATS) under tropical field conditions. PhD thesis, Faculty of Environmental Sciences, Technical University, Dresden

Decentralised Wastewater Treatment Systems (DEWATS) such as disseminated by the Bremen Overseas Research and Development Association (BORDA) are increasingly being recognized by decision makers across the world as an option for service delivery in densely populated low-income areas. This thesis investigates full-scale anaerobic reactors of communal DEWATS implemented in tropical regions in order to consolidate the basis of future design and support monitoring, operation and maintenance procedures. Special focus is laid on the operation of the Anaerobic Baffled Reactor (ABR) as the core technology of DEWATS.

This document was discussed here on the forum:

WRC (2014). DEWATS process for decentralised wastewater treatment - Technical lessons from eThekwini Municipality. Water Research Commision (WRC), Gezina ZA, South Africa

EThekwini Municipality, in common with other municipalities in South Africa, are faced with the increasing challenge of providing housing and infrastructure to the population of the city. The city therefore looked to the DEWATS approach as a possible sanitation solution for future housing developments. The document looks at the technical lessons learnt from the evaluation of the DEWATS process under different operating conditions.

Ross, K., Abeysuriya, K., Mikhailovich, N., and Mitchell, C. (2014). Governance for decentralised sanitation: Global Practice Scan - A working document. Prepared by the Institute for Sustainable Futures, UTS as part of the Australian Development Research Award Scheme (ADRAS)

This Global Practice Scan of relevant practices, experiences and lessons from sanitation and other decentralised sectors was conducted to inform and inspire the research team and collaborators. We used a governance framework that is new for the sanitation sector as our lens for the scan, separating day-to-day operational responsibilities from the institutional arrangements that help or hinder successful operation. Four key governance domains emerged: sustaining demand, effective management, sustainable financing, and functioning technology.

Gutterer, B., Sasse, L., Panzerbieter, T., Reckerzügel, T. (2009). Decentralised wastewater treatment systems (DEWATS) and sanitation in developing countries - A practical guide - sample version, selected pages only as this book is for sale. Water, Engineering and Development Centre (WEDC), Loughborough University, UK, in association with Bremen Overseas Research (BORDA), Germany

This guidebook is addressed to Urban Service Providers or National and local governments as well as to academic institutions, international NGOs or local community-based organizations. The guidebook not only explains technical requirements for efficient treatment of wastewater in locations with a special geographic focus in developing countries. It also includes socio-economic conditions and steps for community action planning.

Alternative option to replace number 3 or 5:
United Nations Economic and Social Commission for Asia and the Pacific (ESCAP),
United Nations Human Settlements Programme (UN-Habitat) and Asian Institute
of Technology (AIT), 2015. Policy Guidance Manual on Wastewater Management
with a Special Emphasis on Decentralized Wastewater Treatment Systems.

Bangkok. Thailand
or here:

Mughal had mentioned this document here:

You can find further important documents and website links dealing with this topic here: Please provide your feedback. What do you think of this selection?

It should be noted that these systems usually produce some biogas, but the biogas production is normally not in focus, and the biogas may not even be utilised in some/many cases. A sticky post with five key documents for processes focussing on biogas production are available here:

There is by the way another similar sub-category on the forum which deals specifically with DEWATS-type systems in Kenya (this sub-category was set up by GIZ in Kenya):

DEWATS (decentralised wastewater treatment systems) Tue, 26 Apr 2016 12:00:58 +0200
Key documents for the sub-category on composting processes - by: Wolfgang Berger
Both books focus on composting garden residues and are very good introductions for beginners to gain first experiences. Human urine and animal manure are recommended for composting, but not human feces. Beside fundamental information, both publications show innovative solutions under different conditions. I recommend to start with composting of organic kitchen and garden waste, before handling and operating with feces. So a relationship and an understanding of the process can grow without risk.

Best regards

Composting Mon, 07 Mar 2016 11:59:12 +0100
Key documents for the sub-category on biogas sanitation (systems focusing on biogas production) - by: muench For more information about why I am creating this new thread, please see here:


This thread is a "sticky thread" which means it will always remain at the top of this sub-category. It contains a recommendation and orientation for newcomers regarding the most important 5 documents and website links in this thematic area.

Recommended top five documents in the thematic area of "Biogas sanitation (systems focusing on biogas production)" , in reverse chronological order: *

EVI (2013). Waste to Energy Technical and Financial Analysis, India - Technical and financial analysis for opportunities and obstacles associated with various FS to energy processing options. Consultancy report of Emergent Ventures India commissioned by Bill & Melinda Gates Foundation, Seattle, USA

EVI has been commissioned by Bill & Melinda Gates Foundation for carrying out a technical and financial analysis for opportunities and obstacles associated with various FS to energy processing options. The project's focus is on urban India.

Ingle, R., Sundberg, C., Wendland, C., Reuter, S., Jurga, I., Olt, C. (2012). Links between sanitation, climate change and renewable energies - Factsheet of Working Group 3. Sustainable Sanitation Alliance (SuSanA)

This factsheet emphasises the need for climate change mitigation and adaptation measures in the area of sanitation. In addition, it provides an overview of the possibilities of using sanitation systems for renewable energy production, nutrient recovery and it explains the financial benefits that emission trading can bring.

Water Information Network (2011). Biogas for sanitation - Closing the nutrient loop through sanitation, hygiene, environmental protection and food security in Lesotho. WIN-SA Water Information Network, Gezine, South Africa

In 2002, a group of technicians with strong interest in the link between environmental protection and human well-being, started to implement household biogas digesters for sanitation purposes in Maseru/Lesotho. Since then, biogas systems for decentralised wastewater treatment (or Biogas DEWATS) were constructed for individual households especially in urban and peri-urban settlements and at institutions like schools, orphanages, prisons and holiday resorts countrywide. This document gives an overview on the technology as it is implemented in Lesotho.

CNSS (2011). 4-in-1 biogas systems - Sanitation aspects & acceptance issues. China Node for Sustainable Sanitation, Beijing, China

China plays a leading role in the development and dissemination of household biogas technology. One of these technologies is the 4-in-1 biogas system, which has been promoted and implemented in colder regions of China. A survey on the acceptability of 4-in-1 biogas systems in two townships in Liaoning Province was undertaken in July, 2010. The purpose of the survey was to clarify the status of 4-in-1 biogas systems and to learn more about people’s attitude and behavior towards them.

Mang, H.-P., Li, Z. (2010). Technology review of biogas sanitation (draft) - Biogas sanitation for blackwater, brown water or for excreta and organic household waste treatment and reuse in developing countries. Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, Eschborn, Germany

Anaerobic treatment units as part of an on-site decentralised or semi-decentralised wastewater treatment system are an alternative to centralised wastewater treatment systems due to their energy and soil conditioner production capacity, low-tech components and adaptability. It is also an excellent technology for organic sludge treatment, collected from septic tanks, holding tanks, dry toilets, settlers or from aerobic wastewater treatment systems.

You can find further important documents and website links dealing with this topic here: Please provide your feedback. What do you think of this selection?


* In the documents and links provided here, you will find some overlap with DEWATS systems, but those will have their own sticky post with key documents. DEWATS systems also produce biogas but they are usually not designed to maximise biogas production. In contrast, the key documents and links listed here deal with technologies that aim to achieve the maximum possible amount of biogas from human excreta, wastewater, animal excreta, organic waste.]]>
Biogas sanitation (systems focusing on biogas production) Thu, 25 Feb 2016 12:39:57 +0100
Key documents for the sub-category on constructed wetlands - by: muench For more information about why I am creating this new thread, please see here:


This thread is a "sticky thread" which means it will always remain at the top of this sub-category.
It contains a recommendation for new people regarding the most important 3-5 documents in the thematic area of "constructed wetlands".

The initial selection was done by me, but this is open for discussion and can be adjusted regularly.

Recommended top 3 documents in the thematic area of "constructed wetlands" in reverse chronological order:

Langergraber, G. (2013). Are constructed treatment wetlands sustainable sanitation solutions? Water Science and Technology 67(10), 2133-2140, doi: 10.2166/wst.2013.122

The paper discusses the features that make constructed treatment wetlands a suitable solution in sustainable resources-oriented sanitation systems, the importance of system thinking for sustainability as well as key factors for sustainable implementation of constructed wetland systems. Constructed treatment wetlands meet the basic criteria of sustainable sanitation systems by preventing diseases, protecting the environment, being an affordable, acceptable, and simple technology.

Hoffmann, H., Platzer, C., von Münch, E., Winker, M. (2011). Technology review of constructed wetlands - Subsurface flow constructed wetlands for greywater and domestic wastewater treatment. Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, Eschborn, Germany
A Spanish version is also available: .

This booklet focuses on treating domestic/municipal wastewater or greywater with subsurface flow constructed wetlands with coarse sand as a filter medium. The emphasis is on the application in developing countries and countries in transition. In the publication, an overview and basic guidance is provided on the design and maintenance of horizontal flow beds (HFBs), vertical flow beds (VFBs) and the “French System”. A description of the most common pre-treatment systems is also included due to their vital importance for the proper functioning of CWs.

Morel, A. and Diener, S. (2006). Greywater management in low and middle-income countries, review of different treatment systems for households or neighbourhoods - Sandec Report No. 14/06. Sandec (Water and Sanitation in Developing Countries) at Eawag (Swiss Federal Institute of Aquatic Science and Technology), Dübendorf, Switzerland

This report compiles international experience in greywater management on household and neighbourhood level in low and middle-income countries. In urban areas of LMIC, greywater is commonly discharged untreated into drainage channels, use untreated greywater for agricultural purposes, thereby leading to environmental degradation and exposing the population to health risks. Though greywater is generally less polluted than domestic or industrial wastewater, it may still contain high levels of pathogenic microorganisms, suspended solids and substances such as oil, fat, soaps, detergents, and other household chemicals.

You can find further important documents and website links dealing with this topic here: Please provide your feedback. What do you think of this selection? We can update it from time to time.

Constructed wetlands, soil filters and infiltration beds Wed, 10 Dec 2014 10:38:05 +0100
What can we reliably say about pathogen removal with vermifilters? - by: muench

Hi Elisabeth,

I think the first thing to make clear is that we do not see the main purpose of the Tiger Toilet to be the production of compost for use on soil. In fact we have deliberately tried to minimise production of vermicompost so as to reduce the amount of maintenance for the user. Our current estimates are that it will be 8-10 years before any removal of vermicompost is necessary and the amounts involved will be quite small and not very useful to a farmer. Our oldest systems are over three years old and have not yet been emptied. The whole purpose of the Tiger Toilet is to provide safe, effective and low maintenance treatment of faecal waste for low income households ….we are not promoting re-use with this system.

We agree that there could be helminths present in the vermicompost and therefore would not advise using it as a soil conditioner without some kind of further treatment.

Kind regards,

Vermifilters (or vermi-digesters) Fri, 26 May 2017 23:42:32 +0200
Call for specific small-scale / decentralised sewage treatment plant case studies and contacts in India - by: ulrichl
As part of the 4S project (factsheet attached), we aim to visit and investigate up to 400 small-scale sewage treatment plants in South Asia (Nepal, Pakistan, Bangladesh and with a particular focus on India). We are now at a point where we have a good number of some of the most common treatment technologies assessed (activated sludge, SBR, MBBR, DEWATS), and we are trying to find and get access to units of more specific and innovative technologies on the Indian territory.

We are currently looking for more case studies and contacts for the following technologies:
  • Constructed wetlands and soil filtration systems (Horizontal Flow and Vertical Flow CW, Hybrid HFCW + VFCW, SIBF, SBT, Phytorid, etc.…)
  • Anaerobic digestion systems (DRDO Biodigester, UASB, Biogas or other systems)
  • Membrane bioreactors (MBR)
  • Attached growth processes, other than MBBR (Trickling filter, Rotating Biological Contractor RBC, Submerged Aerated Fixed Film Reactor SAFF)
  • Chemoautotrophic Activated Carbon Oxidation (CAACO)
  • Electrocoagulation systems (EADOx, EC, …)
  • Advanced oxidation processes (Fenton method, etc.…)
  • Other interesting, innovative or lesser-known small-scale sanitation systems, case studies and design alternatives (e.g. prefabricated package plants etc.)

To fit in our study, the system must answer two selection criteria:
  1. It should serve 10-1000 households, i.e. its capacity should be in the range from 5 to 700 KLD (m3/day)
  2. It must be at least 2 years old (current functionality and operational status doesn’t matter)

We hope that the resourceful SuSanA community can help us in the last race for data collection for the 4S project. Any contacts, case studies or comments are welcome. Also, if you have a proven and promising small-scale wastewater treatment solution (ideally with 30 or more installations in place) and wish to include it in this study, this is the moment to get in touch with us.
Please rest assured that any data and information collected as part of this project will be treated confidentially and will be used only for research purposes.

We request you to share any information by emailing us at This email address is being protected from spambots. You need JavaScript enabled to view it. or This email address is being protected from spambots. You need JavaScript enabled to view it..
Thank you very much in advance!

Best wishes,
Lukas Ulrich and Marius Klinger]]>
Comparisons of various wastewater treatment technologies Thu, 18 May 2017 13:47:40 +0200
Vermi-Trickling Filters (or vermifilters) for Sewage Treatment (looking for help to design) - by: BPopov
Look what I have done with the crates!

Vermifilters (or vermi-digesters) Sat, 13 May 2017 09:03:26 +0200
Launching of Fortifer in Ghana: Innovating Sanitation to feed the nation - by: Funke A new compost plant has opened in the greater Accra Region in Ghana which recycles human and food waste and turns it into Fortifer, a safe, nutrient rich fertilizer. Established in partnership with the Tema Metropolitan Assembly and Jekora Ventures Ltd, JVL Fortifer Compost Plant builds on years of research done by the International Water Management Institute (IWMI) to simultaneously improve sanitation services and food security through private-public partnerships. The plant will treat 12,500 cubic meters of fecal sludge and 700 tonnes of organic food waste in order to produce 500 tons of Fortifer in the next year. ]]>
Treatment processes for wastewater, sludges, organic waste, excreta Fri, 12 May 2017 10:53:14 +0200
Anaerobic digestion reactor for bio gas production from distillery wastewater - by: JKMakowka For a industrial setup like you are suggesting, it might be interesting to utilize process waste heat to build a termophilic biogas reactor, which usually show several beneficial characteristics and significantly faster gas production.]]> Biogas sanitation (systems focusing on biogas production) Thu, 04 May 2017 17:32:55 +0200 Regular septic tanks vs Biodigester septic tanks - by: Marijn Zandee
To start, "biodigester" is somewhat loose term. Some seem to equate it to a biogas plant, others seem to use it for any anaerobic treatment system. I would go with the latter. In that sense a septic tank is a type of biodigester by definition. For me, it would only be a biogas plant if purposely build to capture the biogas. In that case, it would probably also be at least institutional size if used for digesting human waste only. Otherwise the gas production would not be sufficient to justify a biogas plant.

It seems from your post that some of the people advertising are trying to benefit somewhat from the biogas plant vs biodigester confusion.

I would not belief the claim that one never has to desludge the product they advertise. That would only work if there is no settling of solids on the bottom of the tank (no separation of water and solids in the tank). Considering the water-solids ratio in the sewage going into a septic tank this is not feasible. In fact, a septic tank requires liquid solid separation for it to function.


Septic tanks (conventional and upgraded versions) Fri, 28 Apr 2017 14:11:16 +0200
Inspiring "simple" Nano-bubbles (Ultra fine bubbles) technology for "simple" wwtp's !? - by: AquaVerde - ~1.000 x higher surface area and
- by keeping air-bubble with ~20% O2 on a longer term (weeks-months) within the water body, by nano size bubbles compared to micro- and millimetre bubbles with max. seconds to minutes.

I regret, important neutral information by technology providers still missing in order to compare this generators to "normal" aeration technology:
- basic information about condition of test-water used,
- Oxygen introduction in [gO2/h] and
- Oxygen yield in [kgO2/kWh].

Marketing bla-bla just like "...with minimal energy and maximum gas utilization." could not help.

Up to now, we "believe" (just wishfully thinking;-) because of its different charging, these buoyancy bubbles will stick together with sessile bacteria and on biofilm around roods too and may enhance treatment performance in a longer term, than our ordinary mm-aeration. We just guess that the bacteria of biofilm may "suck" O2 out of these bubbles over time and new buoyancy bubbles will be delivered by slow and smooth -circulation to biofilm.

We doubt that the existing nano-bubble-generators on the market, which mixes air and water within the generator will make it in the industrial application under rather "rustic" sewage condition and blockages will occur very fast.]]>
Decentralised treatment plants Thu, 27 Apr 2017 06:28:09 +0200
design and technology option to be used for a decentralised unit in a location having less space - by: goeco wikipedia article for reference.

Vision Earthcare's product offering also uses vermifiltration, combined with plants. Rather than addressing the question (how to use less space), features are presented to promote the product.

What jincysan wants is a technology option that uses less space than conventional DEWATS. I'm suprised that Kevin would say that:

To save space, you should probably look at a system that incorporates anaerobic treatment.

I'm pretty sure that aerobic treatment technology uses less space for the same treatment level. Anaerobic DEWATS seem to me to be a technology of last century, one to be phased out... not much better than a septic tank... unless methane is to be harvested and utilised, which is probably not what jincysan is asking for.

Assuming that jincysan wishes for onsite treatment of both blackwater and greywater, before anybody can make suggestions or recommendations, we'd need to know:
  1. what scale (number of users) she is envisioning, and;
  2. whether land is available for effluent disposal.
  3. what quality of treatment is required (surface or subsurface disposal)?
My interest is in technologies for onsite wastewater treatment to a level suitable for surface irrigation of crops, again probably not what jincyan is asking for.

Comparisons of various wastewater treatment technologies Tue, 25 Apr 2017 04:38:31 +0200
HDPE septic tank apply to the Rural sewage treatment in China and South east Asia - by: nityajacob
Thank you for the information, very useful given India's sanitation priorities. How does this company ( ) compare in terms of performance and price. They have been in the business for sometime but I have not seen any of their installations so cannot comment on efficacy.

Septic tanks (conventional and upgraded versions) Thu, 13 Apr 2017 02:01:46 +0200
in-vessel composting for faecal waste (or any other organic wastes) ? - by: jmr
Composting Wed, 12 Apr 2017 14:49:11 +0200
Any successful experience with siphon system? - by: AquaVerde siphon-update:
on "flexible self-acting siphon`s for raw sewage", based on idea of fixed self-acting siphon by Dr. Werner HEYN from Hamburg, Germany


~1929: now open Patent US1727828 - Self-acting siphon by Dr.-Ing. Werner HEYN from Hamburg, Germany,

4 French suppliers for self-acting siphon`s for raw sewage by now:

Any other "inventors" for "flexible self-acting siphon`s for raw sewage" around the globe?

Detlef SCHWAGER]]>
Decentralised treatment plants Thu, 06 Apr 2017 16:22:33 +0200