Ammonia Removal in a Physical-Chemical
Wastewater Treatment Plant
PETER F. ATKINS, JR., Associate
DALE A. SCHERGER, Assistant Engineer
Environmental Control Technology Corporation
Ann Arbor, Michigan
ROBERT A. BARNES, Partner
Ayres, Lewis, Norris & May, Inc.
Ann Arbor, Michigan
INTRODUCTION
This report discusses in detail the operation and performance of a pilot scale
wastewater treatment facility utilizing breakpoint chlorination followed by dechlorination
with granular activated carbon for the removal of ammonia-nitrogen from a domestic
wastewater source. The study was performed at the wastewater treatment facility of the City
of Owosso, Michigan.
The chlorination-dechlorination process was operated in conjunction with a complete
physical-chemical wastewater pilot treatment facility. The total treatment scheme involved
a number of chemical and physical processes operated in a sequential manner as follows:
chemical coagulation and sedimentation, deep-bed filtration, carbon adsorption prior to
chlorination (pre-adsorption), breakpoint chlorination, carbon adsorption for
dechlorination (post-adsorption).
The main emphasis of this study was to evaluate the practical feasibility of using
breakpoint chlorination followed by dechlorination using granular activated carbon for the
removal of ammonia-nitrogen from a domestic wastewater within a standard physical-
chemical treatment scheme. A secondary benefit of the investigation was the collection of
data on the effectiveness of the overall process in removing biochemical oxygen demand
(BOD), suspended solids (SS) and phosphates (P04) from the Owosso raw wastewater.
OBJECTIVES
The main objective of this study was to determine the engineering feasibility of
incorporating an ammonia-nitrogen removal process into a conventional physical-
chemical treatment process. To accomplish this objective, consideration was given to
breakpoint chlorination followed by dechlorination using granular activated carbon and
also partial chlorination (chlorine application below that required for breakpoint) followed
by chloramine removal by activated carbon.
The ammonia-nitrogen removal system was evaluated in terms of removal efficiency,
chemical cost, process by-products and operational efficiency to evaluate the optimum
mode of operation.
METHODOLOGY
Pilot Treatment Facility
The basic pilot plant configuration is shown in Figure I. The pilot unit was a trailer
mounted facility, completely self-contained, leased from Hydromation Engineering
Company of Livonia, Michigan. The pilot unit received a raw wastewater flow varying
between 10 and 15 gallons per minute (14,400 to 21,600 gallons per day) depending upon the
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