The problem was quickly solved by placing HS-200 Condensate Remediation Paks at every compressor condensate discharge. The Paks were chosen for their ease of installation and low maintenance requirements.

The problem was traced back to their compressor condensate discharge. The company has 14 – 100 to 200 HP compressors that significantly contributed to their discharge limit violations during the high humidity summer months. The initial oil & grease test results taken directly from the compressor were 25% by volume. They were utilizing conventional oil/water separators with a small activated carbon polishing filter to phase separate the oily effluent. Upon analyzing the situation, they discovered that the oil was not phase separation because it was water soluble and mechanically emulsified. The activated carbon filter was also ineffective because of the solubility of the lubricating oil. An additional problem was also identified. The particulate filter prior to the activated carbon polishing filter was becoming fouled with bacterial and fungal growth causing the system to clog the overflow.

After inital testing and success with the HS-200 Condensate Remediation Pak, they chose to remove all the conventional oil/water separators and replace and replace them with the CCRP. The resulting oil & grease levels were consistently down to 5 PPM. They also chose to install the Paks with the additional compressors recently ordered at a savings of approximately $4500 each over the oil/water separators sold by the compressor company. The Paks had saved them approximately $500 each every quarter through labor savings, reduction in wastewater treatment costs, and elimination of discharge violations.

Oil leakage and spills when servicing compressors together with maintenance wash-down water, are being satisfactorily treated with oil removal systems. The systems usually consist of a wastewater holding tank with an oil drain off valve, a coalescing oil/water separator fitted with an oil skimming weir and a effluent holding tank, and two tertiary polishing filters.

The first filter is bedded with HS-200 media which has a very high affinity for oil and grease and other sparingly water soluble contaminants. The effluent from the first filter then flows through a granular activated carbon filter for addiction polishing.

Routine system maintenance is minimal and the filter media have provided excellent bed life, usually longer than one year. Hydrocarbon concentrations are in the low PPB to non-detect range, allowing for recirculation of the water if desired.

Due to the rapidly increasing cost of water, and the possibility of discharge permit violations, from potential failures in their present treatment system, the company installed a 25 gallon per minute (100 liters per minute) reverse osmosis system (RO).

The RO system separates dissolved salts, heavy metals and organics from water by producing two streams; one high in contaminants and dissolved solids (the concentrate) and the other containing relatively pure water (the permeate).

The concentrate is returned to the clarifier for additional treatment, and the permeate is recycled back into the manufacturing process. Most of the highly soluble salts from the clarifier, such as sodium, are removed in the liquid potion of the sludge. However, the operator is prepared to “purge” the system of high TDS (total dissolved solids) in case the concentration gets too high.

Reverse osmosis membranes are very susceptible to fouling by free and mechanically emulsified oils. The oil creates a continuous film on the surface of the membrane, which plugs the pores, rendering it inoperable. Under certain flow rates, less than 5 PPM of oil can totally blind the membranes. This means the membrane can no longer remove the salts and metals from the wastewater. If the membrane is not overly fouled, it can be cleaned and most of its performance characteristics restored. This results in costly down time and added expense for cleaners.

The company installed an adsorber vessel filled with organically modified media in front of the RO unit. The media removes the oil to the non-detect level (the vessel and quantity of media was sized that way), allowing the RO unit to function unencumbered.

The original RO system required cleaning every two days. Pre-treatment of the water with organically modified media has reduced cleaning frequency to once every 30 days.

The details: Cleaning required 4 hours of labor, cleaners and extra energy, amounting to $200 for each cleaning, or total annual cost of $36,400. Furthermore, frequent cleaning slowly degrades the elements of the membrane, reducing the membrane’s life from its usual 4 years to 2 years. Replacement cost of maintenance cost of $44,900.

Conclusion: After implementing HS-200 pre-treatment, their cleaning costs were reduced to $2,400/year. In addition, the reduced stress on the membrane elements doubled their life to 4 years, slashing replacement costs to $4,250/year. Annual cost savings by polishing with organically modified media are $38,200.