Black and Greywater use in Aquaponics System.

[jtcitrus]

Hello all, I'm looking at one of two options and need thoughts/resources on what I need to know to make option 1 work...

1) pump septic effluent (both black and grey water) through a constructed wetland (two or three stage; plants used to supplement animal feed/vermiculture operations) into a pond where fish will be maintained. That water would then be pumped from the pond into a series of grow beds for human food crops (and possibly for general irrigation.

The design I'm considering involves:
- bell-siphon/flood-drain first stage constructed wetland (as opposed to intermittent loading, I think the key term is tidal-flow).
- The second stage could be a repeat of the first stage (with partial recirculation to first stage) or a traditional Subsurface flow wetland.
- The "third stage" would be either a shallow pool where filtered water from the vegetable growbeds would mix with the wetland water before flowing downstream to the pond OR the growbed water would empty into the second stage wetland which would then dump directly into the pond.

2) If that's completely impractical or very cost prohibitive, then forget the constructed wetland, and just use the septic tank effluent for general irrigation (primarily fruit trees), and keep the pond/growbeds on their own loop. I would then Pump well water and/or harvested rainwater to maintain pond water level. So this option would be standard aquaponics knowledge

note:
- law requires that greywater go through a septic tank, so splitting out the grey and black water is cost prohibitive, as the black water will still need to be treated.
- I'm north of Houston, Texas [USDA Zone 8b/9a] border region between great piney woods and gulf coastal prarie
- I may also incorporate quackuaponics as well ...ducks/waterfowel


my concern: what do I need to be worrying about filtering from the septic effluent from the household. We already use pretentious hippy soaps for most things, but what about the impacts of liberal use of bathroom cleaners (primarily clorox or clorox"green"), etc.

Thanks All! I look forward to your input!

[jackalope]

The Asians use human waste for raising crops - including the rice we eat - my understanding is that the reason we don't use human waste for manure here in the 'developed' countries is that all the drugs (perscription or not) that people are taking would be contaminating the fertilizer value of the manure, and many of the drugs can/will be transferred to the food raised in that fertilizer

[jtcitrus]

That's part of what I'm worried about. If we truly close the loop, what household chemicals substances might be bioaccumulating in the system? They are all small concerns, but it is a worry.

The feces, I'm sure, will filter out. However, It's not clear to me the impact of advanced design on the specs of for the system. If the wetland floods and drains (via intermittent loading, bell siphon, or flout mechanism) it increases the oxygen content/aerobic bacteria in the system. This has been demonstrated to statistically significantly improve the processing of solids and nutrients ( See the Texas Commission on Environmental Quality [TCEQ] research on constructed wetlands ). But many of you aquaponics folks already know this!

What I don't know is how that improved efficiency affects the required size of the wetland in order to meet spec. It should allow for a smaller footprint.
A properly designed/functioning recirculating constructed wetland produces effluent that meets WHO guidelines for drinking water, but what about for fish?
It process organics well, but what about other stuff that might be in my well water?

The duckweed and cattails and other aquatic filter plants will double as excellent animal feed for the fish, poultry, vermiculture.


I'm now thinking that I'll need intermittent loading of large batches of septic effluent into a more traditional constructed wetland for my second stage (the first stage is a traditional septic tank)
And a flood/drain tank for the third stage (enter the bell-siphon or Flout), with recirculation from the finishing pond.
and a finally finishing pond for a final treatment where the processed water from my aquaponics grow beds will blend with the cleaned septic water before entering a shallow spillway into the fish pond. (I'm going for aesthetics as well)

I know it will work, just some technical questions to work out before I take the idea to the county for permitting, and to make sure things aren't redundant.

The only electricity would be the pump from the septic into the second stage, the pump from the finishing pond to recirculate back to the third stage, and (the bigger one) the pump to filter the fish pond water through my grow beds). It might make sense to use PV-Solar to offset some of the power drain... haven't done that math yet (I'm doubtful)


anyway, I'll make sure and post all the research to share as I go!

[jackalope]

Yeah, keep us in the loop as you progress, I, for one would like to see how it goes. If you have no pix yet, see if you can post some drawings, etc. to give us a better idea of your intentions/inventions

[robertcoogan]

...what household chemicals substances might be bioaccumulating in the system? They are all small concerns, but it is a worry.

Make sure you thoroughly check the greywater regulations where you live. I had to jump through some serious hoops to get mine established in Joshua Tree, CA and I can only use wastewater from my clothes washer to irrigate my trees. No septic use, the cost was prohibitive. We only use homemade laundry detergent as well (you can find out how at the link below, it works very well, although we do substitute Ivory soap).

http://www.ecokaren.com/2012/02/non-tox ... detergent/

[jtcitrus]

Jackalope

Here's a picture/sketch of what I'm imagining. along with some comments.

https://picasaweb.google.com/jbthomp...eat=directlink

A couple of principles I've derived from a reading of the literature on Constructed Wetlands (CW):

1) Residence of water in treatment zone is especially important for Total Phosophorous (TP) removal
2) Oxygenation of treatment zone is especially important for Total Suspended Solids (TSS), Biological Oxygen Demand (BOD), Fecal coliforms and Total Nitrogen (TN) removal, and has been shown to reduce the area required for treatment of a given quantity and quality of wastewater.
3) The inclusion of plants has been shown to increase removal of TSS, TN and TP, particularly in aerobic conditions.
4) Inclusion of baffling in Horizontal SubSurface Flow (HSSF) -CW can improve the removal of TSS and dentrification by increasing the residence time in the treatment zone and prevents the formation of preferential water routs through the wetland.
5) Inclusion of earthworms in Vertical SubSurface Flow (VSSF) -CW’s and Sand Beds has been shown to effectively combat clogging of the system by biosolids and may increase the uptake of nutrients by plants. Effects persistent as long as worms are alive.
6) Oxygenation by Tidal Flow-CW > VSSF-CW [w/intermittent loading] > VSSF-CW [with continuous loading] > Ebb & Flow HSSF-CW > continuous HSSF-CW. [Pulse-feeding is similar to ebb and flow.]
7) Hybrid sytems of constructed wetland that combine aerobic and anaerobic conditions have been shown to have greater ability to treat wastewater through varied chemical processes in those environments.
8) Highly Porous media like expanded shale has been shown to improve the filtering properties of CW by increasing oxygenation, surface area for bacterium, and improved adsorption abilities


Now to actually talk to an engineer!

[jackalope]

THX