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LIST
OF CONTENTS
Introduction
Process Description
Typical
Contactor
Design
Criteria
Photos, Plans & Specs
Treatment
Performance
Operational
Skills
Automation
Potential
Advantages
Limitations
& Concerns
Pilot
Plant Objectives
Costs
References
Contacts & Facilities
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INTRODUCTION - CONTINUED
In U.S., the earliest limestone contactor use was in the 1930s
in New York and Pennsylvania (Cox, 1933 and Glace, 1937). These
contactors were used to treat corrosive water at capacities from
2,000 gallons per day at the New York State Health Department
Farm to 50,000 gallons per day in Dillsburg, Pennsylvania. In
South Africa, a limited number of small contactors were installed
in 1960s and 1970s. Since then, many successful facilities have
been installed in South Africa with the largest capacity of 50
MLD. The use of limestone contactors for large public water systems
is also currently being researched and developed by the Cape Water
Programme-CSIR in South Africa which has recently developed an
innovative side stream stabilization process (De Souza, Du Plessis
and Mackintosh, 2002).
To date, limestone contactors are not limited to stabilizing
drinking water, but are also used for acid mine drainage (Cravotta
et al., 1999 and Menendez et al., 2000), wastewater (Du Plessis
et al., 1994 and Maree et al., 1992) and surface water (Pearson
and McDonnell, 1975; Vaillancourt, 1981).
In water supply, the use of limestone contactors is currently
limited to small treatment plants (less than 30 MLD) due to the
large contact tanks required in large plants. Therefore, CSIR
of South Africa developed the limestone based Sidestream Stabilization
Process (SSP) and Simplified Sidestream Stabilization Process
(Simplified SSP). The SSP proposes using limestone contactors
in a manner suitable for large water treatment works (Mackintosh
et al., 1998) (De Souza et al., 2002).
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