Dear Jan,

Thanks.
Wostman.se's WMFilter looks rather complicated, as a simple minded person I prefer just simple thinks...

Any Swedish colleague at this forum know (informal) about Swedish made SplitBox with membrane technology and IN-DRÄN with simple

nylon-textile?

Detlef

Hi Detlef

I have not seen the IN-DRÄN system before, but I remember coming across a Swedish system that looks similar a few years back:

WMFilter
Manual: www.wostman.se/uploads/1/4/6/7/14679824/...lter_manual_2014.pdf

If I remember correctly, this filter bed works by distributing the septic tank effluent over a geotextile into a system of porous tubes. They weren't really clear what those tubes are (called them "bio-blocks"; but of course they want to sell the system), but the implementation is rather DIY style with instructions given in the manual. It still needs an infiltration area afterwards.

I remember it being discussed to be used in Jan-Olof Drangert's eco-house in Bangalore (more information about that house: www.bangaloremirror.com/bangalore/others...cleshow/46972563.cms? ), but it was dropped in favor of a mix of a biogas system, dry-toilets, and coconut filters from local material (each as separate systems to showcase).

Looking at the IN-DRÄN brochure, they say that for a 5 PE house, 8 of those modules would be needed. That translates to a footprint of about 10 x 1 meter if you put them all in a single row; that would be smaller than a conventional trench system, I suppose (as they also claim). However, they claim that in trenches "if the infiltration surface is overloaded by water or pollutants, the treatment is decreased and the surface can clog completely and stop the water flow", which is in my opinion not the full truth as you would want a fully developed biomat to distribute the water in the trenches effectively.

I mean, ideally it's generally not a bad idea to increase the surface area for biomat formation, right? But I agree with with you and still don't understand how bioclogging of the IN-DRÄN textiles is prevented in the long run, and in the video they say it still relies on the formation of a "secondary biomat" at the soil interface. It might be a good option if space is limited nevertheless.

The only information on performance I could find is the CE certification (according to our beloved En12566-3 standard) from the PIA in Aachen (2012): pro.fann.se/pdf/172b08prfzeugnisenglischnges_600dpi.pdf

COD	97.8%
BOD5	98.7%
SS	99.3%
NH4-N	83.8%
N_tot	53.5%
P_tot	99.3%

Dear colleagues,

Long time no practical & simple "open source"-information from AquaVerde at this place...

I came across via " blue economy ", case 18, a simplified membrane technology for sewage at domestic level, called "SplitBox-houshold", developed by Mr Bertil Eriksson from Örnsköldsvik, Sweden. www.blueeconomy.eu/ called it an "Open Source" innovation, like the rest of 99 publicized innovations. I regret, I can not "believe" in this "Open Source" statement at all!

See zeri.org/ZERI/The_Blue_Economy_files/18%...without%20Sewers.pdf

...
"The Opportunity
Whereas the savings in infrastructural cost are balanced by the investment in the treatment box steered by valves through a simple network of sensors, the real savings are in the elimination of the septic tank, the network of sewage pipelines and the water treatment plants. This saves capital expenditures both at home and at the municipality, while it eliminates the need for continuous maintenance and excess use of chemicals. This potentially relieves municipal governments of the need to borrow, raise taxes and manage something which is the least pleasant job of all: treat other people's waste. A preliminary analysis indicated that Timphu, the Capital of Bhutan, could save as much as $140 million in investments if the homes, apartments and offices were to adopt this technology."...

I guessed, maybe it "just" boils down to using membranes:

A commercial/scientific outcome of "SplitBox" seams to me "SplitBox-Agri" by "Split Vision Development AB".

For domestic application maybe it is called: "DRÄN-IN" by fann.se. I am just guessing on it, as the source is not really "open" and DRÄN-IN is using a simple nylon-fabric not an expensive membran.

The system has been tried and proven around the world since the late 1970s and has been used in Sweden since 1990.

There are currently over 40,000 systems in operation throughout Sweden and Finland.

See pro.fann.se/pdf/fann_broschyr_english.pdf

Video:

or at: pro.fann.se/en/in-dran

I could not fond much useful "open" information about "SplitBox" at Internet or neutral information (like performance appraisal by independent organizations) on "DRÄN-IN".

Have anybody more practical information/experiments about it, about reliability of SplitBox, e.g. its "normal" membrane fouling, or about DRÄN-IN, them what can be found in internet? Is this "SplitBox" story like this "artificial leave" story too, it needs further 10-20 years of "R&D" to be of any use...?

Thanks
Detlef