Ultrafiltration and Reverse Osmosis Membrane System Treatment of A Major Copper Rod Manufacturers Emulsified Coolant Oil Contaminated Wastewater for Recycle

In the spring of 2001, a major copper rod manufacturer began experiencing pressure from the EPA and their local POTW to reduce oil concentration in their wastewater discharge. The copper rod manufacturing plant was utilizing an evaporator to reduce the coolant wastewater and discharging directly to drain the evaporated water while hauling the concentrated oil off site for disposal. Due to the nature of the coolant, significant oil carry over was occurring off of the evaporator contaminating the distillate discharge. In addition the operational expense of the evaporator as compared to UF and RO was found to be non-competitive due to the energy consumption and hauling cost.

As a result, the plant conducted an ultrafiltration pilot test to determine the emulsified oil reduction capabilities. Additional tests were conducted to evaluate further treating the UF permeate utilizing reverse osmosis membranes. The overall goal was to reduce total organic carbon (TOC) concentration in the UF permeate as pretreatment to RO and determine if water as RO permeate could be recovered and recycled back to the coolant operation.

The study showed that the UF system could consistently concentrated the oil at 2.8-3.0% feed too greater than 10X (28-30%) as UF concentrate reducing the overall plant wastewater volume by greater than 90%. The study also demonstrated the capability of the RO system to consistently produce water that met the plant's quality requirement showing that greater than 85% of the wastewater volume treated could be recovered back to the cooling operation.

As a direct result of this study the copper rod manufacturing plant purchased a UF and RO system specified to treat from 14,000 gpd of heavy to 36,000 gpd of light oil and TOC contaminated wastewater.

This wastewater treatment and recovery system has been successfully operating since February of 2002 producing filtrate that meets discharge and is suitable for recycle within the plant.

eProduct Number 440