What is a good method of removing petroleum (for screenprinting) out of water before it drains into septic?

Question

Yes, I am doing this at home. And concern for my environment is precisely why I'm asking the question. As for the alternative water-based inks, I have explored them. While in liquid form, they are still considered hazardous materials, as are the chemicals used to clean them for the purposes of expulsing them into the septic system, or the drainfield.

Can anyone recommend a good filtration system that comes in under $500 or, better yet, one that can be built, relatively easy?

I found plans for a filter using a five gallon bucket, several layers of sand, fine nilon mesh, charcoal, more sand, more nylon, for about ten layers, with the topmost layer being a thick layer of cotton. The layers of sand slow flow of water, the thick, top layer of cotton is then able to trap the heaviest oil, and the charcoal laters, absorb the lightest patrolium. The water then flows upward, through a trap, and then into the drain.

Any ideas on if this would work? Or suggestions to make it work? :)

Answer 1

I worked in the graphic arts trade. including screen printing for many years and cannot imagine that you wouldn't have separate plumbing/disposal methods/ etc. for anything toxic.

I'm also wondering WHY anyone still uses any form of toxic INKS at all? Much of the screen print industry involves clothing?

One answer asked if this was a commercial or home based kind of business; which it seems to be; given that you mention SEPTIC.

With all due respect; I detest the expulsion of toxins into the only planet we have to live on; though I'm not a Judge or Jury. Why not explore other INKS of bases that aren't Tylol/ Methyl Ethyl Keytone; etc. based?

I guess my final note might be WHY have any residue from screen printing DRAIN anywhere but specific waste/residue tanks; as opposed to injecting them into Plumbing?

Answer 2

Are you doing this out of your house or a commercial establishment? There are filtering systems available (everything from simple in-line filters which attach to your drain line to industrial oil/water separator systems with a holding tank) which will do the job...yes they can be pricey, but's it's a lot better than being hit with fines for environmental damage/groundwater pollution.

Answer 3

Petroleum will float to the top unless its water soluble oil like used in machining. In the oil field oil and water are seperated by placing them in a large tank where the oil goes out a pipe in the top of the "gun barrel" and water is released from the bottom. The pipe in the bottom opens there but rises up to a hieght on the tank of fluid that causues fluid to remain in the tank at all times. For rapid seperation of oil and water the fluid is heated when large amounts of water and oil are passing through at all times. The placement of the oil and water release pipes is crucial to proper function.

Oil and water are seperated in much the same way in a machine shop for polution control and coolant integrity. Oil thats rises to the top of coolant vats is simply skimmed from the top much like you would seperate milk and cream.

Pouring petroleum into the septic in US is a violation of eviromental laws. It would be better to send water and oil to a disposal facility. In US where oil is produced it could be a simple matter of taking it to an oil well site and pouring into a salt water tank where is would eventually be pumped deep into the earth.

If we are talking small amounts the water and oil could be taken and placed in an oil recycling tank at a petro station perhaps.