TEXTILE WASTE TREATMENT AT A MUNICIPAL PACT® FACILITY
C. A. Pitkat, Superintendent
Water Pollution Control Facility
Vernon, Connecticut 06066
C. L. Berndt, Senior Systems Engineer
Zimpro Inc.
Rothschild, Wisconsin 54474
INTRODUCTION
This chapter describes the initial operation and performance of the 24,5000-m3/day (6.5-
mgd) powdered activated carbon treatment (PACT) process located in the Town of Vernon,
Connecticut. The municipal treatment facility at Vernon serves a residential population of
approximately 30,000 people, and an industrial fraction that consists of textile dyehouse
operations, metal plating and manufacturing industries.
Prior to 1978 wastewater treatment at Vernon consisted of primary settling, trickling
filters, clarification and chlorination prior to discharge to the Hockanum River. Primary
sludge solids and trickling filter humus were anaerobically digested, chemically conditioned
and landfilled. Performance of the trickling filter plant was less than adequate due, in part,
to the dyehouse wastes. BOD5 and suspended solids removals averaged approximately 60 to
70%. Color removal was nonexistent.
In addition to its poor performance, the trickling filter was operating near its design flow
capacity.
Since the receiving stream, the Hockanum River, experiences extremely low flow periods
during the summer, and the desired stream quality dictated that plant effluent BOD5 levels
be less than 20 mg/1 with color discharges controlled, it became necessary to upgrade treatment at Vernon. Though numerous treatment systems were considered for application, the
process selected and implemented was the PACT process-the use of powdered activated carbon in the aerator of the activated sludge process.
DESCRIPTION OF TREATMENT SYSTEM
The treatment facility flow scheme is shown in Figure 1. Raw wastewater enters the treatment facility at the preliminary treatment area receiving coarse screening and comminution.
Grit is removed from the waste by two parallel aerated grit chambers and transported to
landfill. The raw wastewater is subsequently pumped to two 24.4-x 24.4-m (80- x 80-ft)
primary clariflocculators. Primary solids are pumped to two gravity thickeners. Thickened
primary sludge at 6 to 8% solids is chemically conditioned with ferric chloride and lime
and dewatered to 25% solids on two rotary vacuum filters. The dewatered sludge, presently transported  to landfill, is to be incinerated in a seven-hearth multiple-heart furnace.
Figure 1. Flow diagram of the wastewater treatment
facility at Vernon, CT.
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