Grey water

[Michaelangelica]

This Guy is not getting the info he needs.

Any good chemists out there that can give him the good gen??

http://forums.permaculture.org.au/viewtopic.php?t=3123

PostPosted: Wed Aug 30, 2006 5:17 am Post subject: Using

laundry greywater

We are using laundry greywater for veggies and trees.
We should perhaps build a filter like mentioned in another thread, but first we should avoid the false laundry powders.
I read that sodium an phosphate are the ingredients which are bad for the soil. With phosphate it is simple because it is marked on the box, but how do I find out the sodium level?Are there sheets with brands and ingredients?
Is sodium (cooking salt?) necessary for laundry and are there powders without sodium? Or should we all write to our supermarkets demanding what is in the laundry powder?

[matrixscarface]

what....is..... he... talking about?!?!?

[Qfwfq]

Well, I'm not a great chemist but AFAIK the trouble with the phosphates in detergent is that they fertilize, which is an eco-problem in rivers because it causes excessive vegetation. It shouldn't be a problem for the trees and veggies that you want to grow as much as possible...

As for the sodium, there may be a reasonable way to precipitate at least some of it out.

[Igby]

All sodium salts are soluble in water, so you wouldn't be able to precipitate it out. Adding a lot of sodium to the soil would, of course, make it saline, and fertilisers and other chemical agents have no effect. You have to leach the salts out of the soil. I'm pretty sure all detergents are sodium salts, so that would be one of the big problems with using grey water.

The nitrates and phosphates need to be largely removed. Using too much of any fertiliser will have a negative effect on your garden. Phosphates don't have much of an effect on the pH of the soil, but nitrates will lower the pH and burn your plants. Q is right about the phosphates and nitrates contributing to cultural eutrophication in water sources, too. If the vegetable patch is near a fishpond or something like that, you'd run the risk of killing your fishies off with an algae plague.

That guy really should get a filter and something to treat the water, especially if he's eating the vegetables raw. I assume he's just watering his garden with the grey water, as opposed to having a submerged irrigation system. The water should really be treated with chlorine to kill bacteria, and the phosphates can be precipitated with calcium compounds, I'm sure.

[Michaelangelica]

I am going to have to start to use greywater myself soon.
Local dams are down to 14% and 97% of the State (NSW) is drought declared.
I have discovered there are some eco-friendly washing machine detergents. I assume they are low in phosphates and nitrogen. Australian natives hate phosphates as a rule.
I can't see that there will be much of a problem with my bathwater because there is so little soap in it. In fact it might act as a wetting agent (?) but the washing machine might cause problems but it will be going on to lawn and a few camellias.
Many Local Council regulations proscribe the uses of grey water. I am not sure why, but it does scare people off using it.(Especially in the veggie garden??)

[Turtle]

Originally Posted by Michaelangelica

I am going to have to start to use greywater myself soon.
Many Local Council regulations proscribe the uses of grey water. I am not sure why, but it does scare people off using it.(Especially in the veggie garden??)

I propose a simple solution is to build a small greenhouse distiller. With the floor a water-tight tray, the gray water is poured in. Clear plastic walls and roof set on angles collect the condensed water & direct it to gutters which direct the now fresh water to a collection vessel. As salts etc. collect in the tray it is periodically collected & disposed of in the regulatory fashion.

[Michaelangelica]

Originally Posted by Turtle

I propose a simple solution is to build a small greenhouse distiller. With the floor a water-tight tray, the gray water is poured in. Clear plastic walls and roof set on angles collect the condensed water & direct it to gutters which direct the now fresh water to a collection vessel. As salts etc. collect in the tray it is periodically collected & disposed of in the regulatory fashion.

Good suggestion-a simple solar still. That would get rid of the salt.
Would it also get rid of detergent/soap do you think?

[Igby]

Yep; it's just evaporating the water out and condensing it elsewhere, leaving the solutes in the tray. Natural soaps are just sodium or potassium salts of fatty acids, and laundry detergents, dishwashing liquids and powders are sodium salts of a long chain alkylbenzene sulfonate. Hair conditioners are just quaternary ammonium salts- a nitrogen atom bonded to four carbon chains, and positively charged. Remove the water and you're left with the solid salts.

[Michaelangelica]

Thanks igby
There is alot of chemistry in soap!
I found this site
http://www.harvestingrainwater.com/g...nd-detergents/

Choosing greywater-compatible soaps and detergents

Cleaning products labeled “biodegradable” or “natural” or even “eco-friendly” may not be garden-friendly or “biocompatible” — suitable for the plants and soils of your greywater-irrigated landscape.

According to State of California Department of Water Resource’s Graywater Guide: Using Graywater in Your Landscape [2], specific ingredients to avoid include:

-chlorine or bleach
-peroxygen
-sodium perborate
-sodium trypochlorite
-boron
-borax
-petroleum distillate
-alkylbenzene
-”whiteners”
-”softeners”
-”enzymatic” components

Two common ingredients in synthetic detergents and soaps (including homemade kinds) are sodium and boron. High levels of sodium and other salts in soil are a special concern in arid areas where soils tend to be high in salts already. Salts can raise the alkalinity of soil, degrade the structure of soil, and harm plants.
To prevent a buildup of salts in garden soil, minimize your use of soaps and detergents that are made with sodium compounds.
Avoid powdered soaps and detergents especially, because in addition to normal amounts of sodium used, they include “filler” ingredients that usually are high in sodium.

[Michaelangelica]

A Grey water link:-
http://forums.permaculture.org.au/viewtopic.php?t=3123