Our recovery & treatment of petroleum contaminated water has given us very elevated BOD values (807 mg/L pre-treat and 359 mg/L post-treat) and now jeopardizes our discharge permit. NEED HELP with reduction of BOD.
We recover this petro contaminated water from groundwater recovery wells via vacuum trucks, bulk store the water in a 6,000 gallon tank and process the water thru oil/water seperator, 50 micron bag filters, 3-stages of activated carbon and 25 micron bag filters before it's discharged to batch tank for stormwater discharge.
Our success with TPH and VOC reduction has never been an issue, but now that we are entering the storm drain system, elevated BOD is killing us.  Is there a simple solution to address BOD in this case? I was thinking aeration but not sure if this is the right direction. PLEASE HELP with suggestions  

The very fact that you've identified the problem as BOD probably indicates that some sort of biological treatment is required. My suggestion (I'm not a designer) would be to Install a SBR in the system. You could model an SBR in the laboratory for scale-up data with a fill and draw operation (don't forget to waste about 3 up to 10% of the total sludge daily). You may want to incorporate sludge dewatering as well.

grrun

Electrolytic oxidation uses an electrode chamber through which the wastewater is passed through along with either air or oxygen gas. Via electroysis and the conversion of the oxygen gas/air to dissolved oxygen - free radicals are created along with oxidation of aromatic and aliphatic compounds - plus dissolved oxygen reaches supersaturation levels. the higher the dissolved oxygen - the lowr the BOD - as well as oxidation of the pollutants. Ozone is also an oxidizer and will break into O2 and a free radical as it reacts. Ozone is much more dependent on the pressure of injection an the time of contact, pH, TSS, and temperature of the water as to it's efficiency. This is not true of electrolytic oxidation - pH, temperature, TSS etc are not limiting factors as to dissoved oxygen or production of free radicals.
Where batch treatment is available - and a batch design mode can be used even where water discharge is continuous - then electrolytic oxidation normally is best - as it has fewer limitations then ozone. If you want to email me directly -you can at aquaticonsult@yahoo.com and we can discuss it more directly as concerns your current situation.

I have more questions than answers...

* Is short-circuiting a possibility?  If the filtration/separation system normally works, perhaps one or more of the layers of treatment have failed.  Testing of the pre- and post-filtered water may help identify if something is present that *should* have been removed.  Comparing results from this installation to a "working" installation at another site could help to identify what is normal and what is not.

* What exactly is causing the high BOD in the post-filtered effluent?  Testing should be done to determine constituents.  Only *after* you have more information on the BOD makeup can qualified solutions be provided.  Without additional information, solutions can be considered, but the guesswork (ie. BS) factor is pretty high.  

* Regardless of the solution, bench testing and potentially pilot testing will help to verify effectiveness and necessary scale to properly treat the water

* How does COD compare to BOD?  A high BOD does lead me to assume that the pollutant is readily degradable through biological treatment.  But if the COD is far higher than the BOD, that assumption should be revisited.  If biological treatment is possible, then a lot more work is needed to determine the appropriate method and scale.  eg: Aeration may do the trick, but what detention time is needed?

* Beyond the standard methods of digestion (aerobic or anaerobic), RO filtration may also help, but depends largely on what is causing the high BOD.

* What BOD effluent requirements must you meet?  COD?  Other?

If you need more help, let us know.  

Again, I'm falling back on the "more information is required" boilerplate response.  That's my preference as a scientist, and not a marketer of prepackaged solutions or design work.