Does anyone know method to recycling sewage to drinking wate

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rickeldridge
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Does anyone know method to recycling sewage to drinking wate

Post by rickeldridge » Mon Feb 05, 2007 6:18 pm

Does anyone know method to recycling sewage to drinking water qualit , using ecological engineering methods??

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Bob
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Post by Bob » Tue Feb 06, 2007 1:29 pm

{this is an edited copy of a private message sent to Rick, responding to similar questions}

Hi Rick,

I think the answers to your questions are yes and no. On the one hand, yes, there is a wealth of information available that a generally knowledgeable person could put together to design a working system. On the other hand, the field is still young, and probably more experimental than what you are used to as a designer and operator of conventional WWTP's.

Googling "Ecological Engineering" "Wastewater treatment" will return representative examples. The book Ecological Engineering for Wastewater treatment, for example, contains the proceedings of a seminal conference in 1991, which I attended (See Chapter 14). Much of the literature that has been published since then is from people who were there. The field is still young, but maturing. Even the definitions are still in flux.

I'm not sure how extensively you have wandered my website, but I may have some more detailed information than you have come across--though nothing like the "textbook" information you are looking for. I have some presentation materials, and there have also been various articles (for example) published about our experimental bioshelter that may fill in more gaps. And I am currently working on a book.

WRT rigorous testing of my system, I received a small research grant in 1994 which funded testing (pH, BOD, TSS and E. coli only) of effluent from one of the components, but other than that, only my own observations, and periodic testing with 'home test kit' technology. (BOD in that original 1994 design was reduced by>98%, TSS >96%. Since then I have simplified the design).

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Bob
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Post by Bob » Thu Feb 08, 2007 5:17 pm

Here's a drawing of a subsurface root-zone filter (from George Tchobanoglous -- but I can't find the cite right now. Will add it when I find it...) similar to mine -- but with some variations. Mine is more linear and plug-flow, different plant selection, etc. But same basic idea...

Image

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Bob
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Post by Bob » Thu Feb 08, 2007 6:03 pm

Rick, you had asked if I had a process flow diagram. I had forgotten about this -- put together for a presentation at the recent Bioneers conference...


Image
Last edited by Bob on Thu Feb 08, 2007 6:08 pm, edited 1 time in total.

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Bob
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Post by Bob » Thu Feb 08, 2007 6:07 pm

And this graphic, from the ADN article linked to above...


Image

rickeldridge
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Again thanks for the info

Post by rickeldridge » Sun Feb 11, 2007 11:44 am

Bob,

I'm having trouble understanding how your big gulp air pumps{on the prealiminary treatment system} works. They seem to be a container with a series of holes around the base{presemualy to let water into the pump}. An air supply is provied to drive the water up the discharge. It is unclear to me why the water is simply not driven back out the hole by which it entered. Is it simply a matter of flow resistances. That is when the air is singaled to turn on the fluid resitance to the discharge path is so much less than back through the hole that most of the water goes that way. I don't see any foot valve type mechanism and this is what is confusing me. Please explain.

Also how are you able to aviod solid build up in the surge tank.

Also the flow pattern through the biofilter is unclear to me. The fliter effluent collects in the drum beneath. How does the solids sloughed off get returned to tha anerobic zone.

I have a couple of questions relating to the system as a whole. Do you feed your fish?? As to the questions if any pathogneicity remain in your treated water {You and your wife{and the fish} could have become adapted to some remaining low level pathogens This {if it is in fact happening} is not a bad thing just another aspect of ecological engineering. Simialr to the fact that I get stomache flu at each new watstewater plant I work in. One observation might help to answer this question. Do your house guests drink the recycled water without ill effect?

Thinking back to when you first stared up the system. How long was it before it started producing clear water?

When you got the small research grant to have your system analyzed, did you publish the results.

I have a friend who owns an environmental lab. Would you be willing to send him some samples {no cost to you}.

Why am I asking all these questions.? Besides inherent curiosity, I need to put together enough information to convince skeptical professors that replicating your work is a wothwhile endavour.

Again thanks for you help in this matter

Rick Eldridge

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Post by Bob » Fri Feb 16, 2007 4:34 pm

It is unclear to me why the water is simply not driven back out the hole by which it entered
The holes (yes you are correct, they are for letting water into the container) are located below the invert of the elbow on the riser pipe. So as the air forces the water level in the container down, it is released to escape up the pipe before it ever gets to the level of the inlet holes. No foot valve required.
Also how are you able to aviod solid build up in the surge tank.
There is some, but most of it stays in suspension to be pumped out to the next stage. (There is some buildup of crud on the walls of the tank, and I assume there is also some on the bottom of the tank, but I can't say how much, after 5-6 month's operation. Not enough to clog the pump anyway.)
Also the flow pattern through the biofilter is unclear to me. The fliter effluent collects in the drum beneath. How does the solids sloughed off get returned to tha anerobic zone.

No, all water pumped over the trickle filter returns to the middle drum via the return pipe, rather than falling back into the drum below it.
Do you feed your fish??
Not regularly. We used to, but then got lazy -- except when the grandkids are here and want to feed them. They are herbivorous, and find enough to eat browsing the bottom or algae or the duckweed.
As to the questions if any pathogneicity remain in your treated water ... Do your house guests drink the recycled water without ill effect?
Yes. We have never heard otherwise, anyway. (Also, fwiw, I'm not sure I would describe gut bacteria as 'low level pathogens'. In most cases I'd guess the temporary upset you describe could be due to a disturbance of the gut ecosystem balance, rather than to presence of actual pathogens.)
Thinking back to when you first stared up the system. How long was it before it started producing clear water?
For the current system, I'd say it was about a week - 10 days. (They were somewhat anxious days, as I fretted about whether, or how well, it would work.) And, I also assume you are talking about the primary treatment unit, rather than the whole system, correct?
When you got the small research grant to have your system analyzed, did you publish the results.

Yes. It was through the Alaska Science & Technology Foundation. Unfortunately when I do a google search for their grant database it returns a broken page. I'll see what else I can dig up.
I have a friend who owns an environmental lab. Would you be willing to send him some samples {no cost to you}.

Sure! That would be great. Let me know what you have in mind (type of tests, frequency, sampling locations, and details on how to collect and ship them.

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Re:

Post by Ice Czar » Mon Aug 24, 2009 7:53 pm

Bob wrote:It was through the Alaska Science & Technology Foundation. Unfortunately when I do a google search for their grant database it returns a broken page.
http://web.archive.org/web/200304290853 ... r=89-3-326

;)

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