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We are hydro-skimming crude refinery with cracking units, from last few months we are having higher Phenolic Compounds Contents in our waste water effluents. Also we do not have any waste water treatment unit in our refinery.
Could anyone tell us main sources of Phenols in waste water of a hydro-skimming refinery? Also why higher phenols are avoided in waste water effluents?
 
Answers
02/12/2010 A: Wim Bond, Licence to consult bv, wim.bond@zeggis.com
I recently joined the EPTQ website and was scrolling through the list of Q&A when I found your waste water problem. Although I am late in answering, I would like to mention that there is a transportable biotreater system on the market that can help solve your (temporary or continuous) waste water problems. The system is now operating in a tank park in Europe. All water that separated from oil storage tanks and rain water from the tank park area is collected in a temporary tank and from there Ithe water is cleaned in a "mini" biotreater. Excellent results. Please contact me if you want more detailed information.
14/05/2010 A: Prakash Pimparkar, Environmental Consulting Services , prakash.pimparkar@yahoo.in
Source of Phenols in the wastewater is from the FCC sour water. Phenols are formed in the FCC due to complex reaction of steam with hydrocarbons.
Phenols in the wastewater are not welcomed as any shock loads ( sudden increase in concentration ) kills or deactivates the microbes used in the biological waste water treatment such as Biotower or Activated sludge treatment plant.
Since you do not have wastewater treatment unit you are not affected by this.
However throughout the world probably no refinery is supposed to work without the Effluent treatment facilities. Phenols in waste water going out of refinery should normally not be more than say 0.5 mg/l and the standards could be more stringent ( Viz 0.35 mg/l).
Standard treatment scheme in a typical refinery would comprise of an Pre De-Oiler to remove bulk of free oil an API separator to remove free oil followed by Dissolved or Induced air floatation unit to remove emulsified oil and then biological treatment unit such as bio-tower or an activated sludge unit to remove BOD/COD due to dissolved organics in the wastewater. The effluent is the filtered through Duel Mwdia Filters before disposal.This is normally enough to meeet the statutory requirements of treated wastewater quality.Actual treatement would depend on what is your effluent quality and what treated water quality you want ( you also can recycle your wastewater reducing your water requirement). Hope this clarifies you doubts.