PILOT SCALE INVESTIGATIONS ON THE REMOVAL
OF VOLATILE ORGANICS AND PHTHALATES FROM
ELECTRONICS MANUFACTURING WASTEWATER
Kenneth F. Whittaker, Process Consultant
Alan T. Moore, Environmental Engineer
Camp Dresser & McKee, Inc.
Boston, Massachusetts 02108
INTRODUCTION
Electronic component manufacture, although normally regarded as a "clean" industrial process,
can generate wastewaters which when discharged can reduce the quality of surface or subsurface water
supplies. To prevent this occurrence, an electronic component manufacturer retained Camp Dresser &
McKee (CDM) to design an extensive upgrading of an existing wastewater treatment plant. The
existing plant, utilizing batch treatment with pH adjustment, powdered activated carbon (PAC) addition, and subsequent flocculation and sedimentation, was to be modified and expanded to include air-
stripping, sand filtration, and granular activated carbon contact. The purposes of the expansion were
twofold: (1) to increase the overall capacity of the treatment facility; and (2) to insure that wastewater
would be treated to a level consistent with strict state and client limitations. These limits, along with
past maximum treatment plant influent and effluent concentrations for various contaminants, are
given in Table I.
CDM carried out a pilot testing program to provide operating data for the proposed plant expansion. This report dealt with the results of the activated carbon portion of that testing. Results from air
stripping studies have been reported previously [1].
Carbon studies were carried out in two stages. Initially, isotherm tests were performed to determine expected adsorption capacities and to identify unusual wastewater conditions which could affect
adsorption. Continuous flow pilot studies followed to establish capacity and breakthrough behavior
under actual operating conditions and to confirm the validity of isotherm data as a predictor of column capacity.
METHODS AND MATERIALS
Isotherm Studies
Raw wastewater was used for all isotherm testing. This wastewater was spiked using a methanol-
based solution containing the volatile organic and phthalate compounds previously identified as being
consistently present in the wastewater. The concentration of material contributed by spiking is given
in Table II.
After adjustment of the pH to 8.5 units for metals removal, wastewater was added to 250 ml glass
bottles containing pre-weighed amounts of powdered Nuchar WV-L and Nuchar WV-G activated carbon. All bottles were capped, without the introduction of air, with Teflon septa. "Blank" bottles containing solution but no carbon were also prepared to provide a measure of compound losses due to
volatilization or non-carbon related adsorption.
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