Title page for ETD etd-06102012-040423

Type of Document Master's Thesis
Author Zoccola, Gregg
URN etd-06102012-040423
Title Effect of conditioning on the performance of a plate and frame filter press
Degree Master of Science
Department Environmental Engineering
Advisory Committee
Advisor Name Title
Novak, John T. Committee Chair
Knocke, William R. Committee Member
Randall, Clifford W. Committee Member
  • Sewage
Date of Defense 1988-03-15
Availability restricted
Experiments were performed on samples of alum,

anaerobically digested, and aerobically digested sludges

to determine optimum polymer dosages for various mixing

intensities produced during conditioning by a high-stress

mixing unit. Mean velocity gradient (G) values were

established for each of the mixing speeds used ranging

from 250 sec -1 to 4,000 sec-1. Using the optimum

conditioning dosages determined each mixing speed,

batches of optimally, conditioned sludge were introduced

into a pilot scale plate and frame filter press. Filtrate

volume per unit time and final cake solids were used to

characterize the press performance. Results indicated

that filter press, performance can be optimized by

selecting mixing. speeds during conditioning that simulate

the shear conditions produced in the filter press during

operation. It was shown that press performance was

substantially reduced using sludge conditioned at a mixing

speed of 200 rpm, corresponding to a Gt equal to 17,000.

Tests using mixing speeds of 400 rpm and 1800 rpm

corresponding to Gt values of 32,000 and 230,000,

respectively indicated better performance and, thus, the

filter press is thought to generate Gt values within this

range. A substantial increase in polymer requirements is shown for sludge conditioned at

a mixing speed of 1800 rpm, and therefore,

it was concluded that sludge

conditioned at mixing speed of 400 rpm best

characterized the filter press producing optimum

operational conditions. It was also postulated that the

filter press may not be characterized by a single Gt

value, but, by a range of values dependent on press run time.

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