Case Study
The Problem
At most ground water remediation sites and for process water applications, liquids contaminated with fuel and industrial oils are pumped from a sump trench or a recovery well to an oil water separator. The oil water separator is used for the bulk removal of free and dispersed non-emulsified oil before an air stripper, organo-clay, activated carbon or other polishing filters prior to discharge. The presence of dirt, soil particles and biological growth suspended in the waste stream allow too much oil to pass through the oil water separator reducing separation efficiency. Sludge created by the dirt and soil and biomass absorb oil droplets and carry them through the oil water separator resulting in an effluent of unacceptable quality, increased cleaning frequency and expensive change out costs.
The Solution
Hydro Quip, Inc. has incorporated a new coalescing media made from a high temperature polypropylene material with a very high surface area of 132 sq. ft. per cubic ft. This new coalescing media has a natural affinity for oil. The new media provides high surface area in the form of uniformly spaced rods with no narrow joints that can occlude and trap sludge particles. A unique, patented semi-conical "Round Rod" design pointing downward allows separated solid particles to fall (slough off) from the coalescing media, this eliminates plugging, blinding and the carryover of residual oil to other treatment units in the removal process. The high surface area of the media allows 99% of oil droplets 20 micron or greater to be removed without the use of a high maintenance polishing media in the separator.
Results
Those applications that have used Hydro Quip's innovative oil water separators have achieved far superior results never before possible with other pretreatment equipment. The clarity of the effluent water has improved so dramatically that as a result air strippers are now within NPDES permit compliance, and media-based polishing filters last longer. This reduces previously labor intensive expensive cleaning and change out costs, as well as decreased frequency for the disposal of spent media-type filters. This innovative coalescing media is now used throughout the entire line of Hydro Quip's oil water separators. It has exceeded oil removal efficiencies as evidenced by independent tests using both EPA Method 413.2 and the even stricter proposed European Union Standard CEN EN 858-1.