BELT-FILTER PRESS DEWATERING STUDIES, IMPLEMENTATION, AND
OPERATION AT THE TENNESSEE EASTMAN COMPANY INDUSTRIAL
ACTIVATED SLUDGE WASTEWATER TREATMENT SYSTEM
Richard A. Poduska, Senior Environmental Engineer
Robert C. Stroupe, Chemist
Tennessee Eastman Company
Eastman Kodak Company
Kingsport, Tennessee 37662
INTRODUCTION
The inevitable consequence of installing and operating an activated sludge system is
the production of a waste sludge stream that must be prepared for environmentally safe
final disposal through the most economic means. Waste sludge contains both the inert
influent suspended solids and the biomass produced in the aeration basins. Several methods
of sludge handling and disposal are known, and the most suitable method can be determined
when all the various factors pertaining to a specific waste treatment situation are evaluated.
When such an evaluation was performed for the Tennessee Eastman Company Industrial
Wastewater Treatment System, it was concluded that belt-fdter press dewatering was the
most suitable method of sludge handling. The final disposal method of the dewatered cake
is incineration in one of the company's coal-fired powerhouses. This chapter describes
the results obtained with the belt-fdter press dewatering system and the improved
operational reliability obtained as a result of a research and development program.
The Industrial Wastewater Treatment System at Tennessee Eastman, a division of Eastman Kodak Company, is an activated sludge process with aerobic waste sludge digestion.
The wastewater is the industrial wastes generated from manufacturing operations in the
production of organic chemicals, plastics, and fibers. The average (BOD) load is approximately 114,000 kg/d (250,000 lb/day) at a flow of 68,130 m3/day (18 MGD). Gas chromatographic analyses have shown that approximately 80 to 85% of the total BODs is
attributed to acetic acid, methanol, ethanol, acetone and isopropanol, all of which are
readdy biodegradable. The remaining waste is composed of organic compounds such as
andine derivatives and ketones. The activated sludge system has a three-day hydraulic
and between a 15- and 20-day solids retention time. Because of the soluble nature of the
influent waste components, there is no primary clarification. The annual average waste
sludge production is 32,600 kg/day (72,000 lb/day) dry weight, an average sludge yield
of 0.29 kg sludge/kg BODs. The concentration of sludge suspended solids from the aerobic
digester feeding the dewatering system is between 1.6 and 2.6%. Further details of the
wastewater treatment have been presented separately [1,2].
BELT-FILTER PRESS SYSTEM GENERAL DESCRIPTION
The belt-filter press has a history of successful commercial applications, especially in
paper manufacture. The initial application of belt-filter press systems for sludge dewatering
was in Europe and was later extended to the United States, where it has rapidly become
one of the most frequently used means for sludge dewatering. The use of this device for
waste sludge dewatering became feasible only within the last 10-15 years as a result of
the availabdity of water-soluble, high-molecular-weight anionic and cationic synthtic
polyelectrolytes for sludge conditioning [3]. Generally, belt-filter press systems operate
on the principle of gravity drainage of filtrate followed by sequentially increased pressure
zones for compression drainage of fdtrate from the sludge. As such, it is imperative that
an influent homogeneous sludge be converted into a well-flocculated heterogeneous state
which yields the maximum free-water release during gravity drainage. Also, the floe particles
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