Prediction of thickening capacity using diluted sludge volume index

Development of settling flux curves using SVI: An addendum

“…The use of solids flux analyses for activated sludge treatment plant operation, analysis, and design continues to grow because significant work has been conducted correlating the settling parameters, Vo and K, of the Vesilind equation to the SVI and its modifications (Koopman and Cadee, 1983;Pitman, 1984;Hartley, 1985;Daigger and Roper, 1985;Wahlberg and Keinath, 1988). Because the SVI is more easily and routinely performed than the multiple batch settling tests required to develop a settling flux curve, these correlations have made settling flux analyses much more convenient.…”

“…73-m (6-ft) high, six-tube, constant-temperature settling apparatus and SVI tests performed with and without stirring in two different containers, I-L graduated cylinders and 2-L Mallory settlometers. As indicated, SVIGS, SVIGN, SVISS, and SVISN are used as designators for the SVls performed in the stirred graduated cylinder, the unstirred graduated cylinder, the stirred settlometer, and the unstirred settlometer, respectively.The Vesilind equation relates the interface, or zone, settling velocity of an activated sludge slurry, V., to the solids concentration of the slurry, X:The use of solids flux analyses for activated sludge treatment plant operation, analysis, and design continues to grow because significant work has been conducted correlating the settling parameters, Vo and K, of the Vesilind equation to the SVI and its modifications (Koopman and Cadee, 1983;Pitman, 1984;Hartley, 1985;Daigger and Roper, 1985;Wahlberg and Keinath, 1988). Because the SVI is more easily and routinely performed than the multiple batch settling tests required to develop a settling flux curve, these correlations have made settling flux analyses much more convenient.Our previous work (Wahlberg and Keinath, 1988) reported on a correlation between the Vesilind settling parameters and SVI performed in a stirred, I-L graduated cylinder (SVIGS).…”

Biological Wastewater Treatment in Warm Climate Regions Volume II

“…However, its use is often difficult due to a priori lack of knowledge of the parameters characterising the sludge settleability (v o and K), unless the design is intended for expansion of an already existing plant, with an already known sludge (Section 10.5.2 presents the concept of the coefficients v o and K, used for estimation of the settling velocity of the interface, v). Aiming at expanding the use of the limiting solids flux theory, several authors (White, 1976;Johnstone et al, 1979;Tuntoolavest and Grady, 1982;Koopman and Cadee, 1983;Pitman, 1984;Daigger and Roper, 1985;Ekama and Marais, 1986;Wahlberg andKeinath, 1988, 1995;van Haandel et al, 1988;von Sperling, 1990;Daigger, 1995) tried to express the interface settling velocity according to easily determinable or assumable variables, such as the sludge volume index (SVI and its variants). Once the sludge settling velocity is estimated, the limiting flux theory can be easily employed for design and operation.…”

Activated Sludge and Aerobic Biofilm Reactors

“…However, its use is often difficult due to a priori lack of knowledge of the parameters characterising the sludge settleability (v o and K), unless the design is intended for expansion of an already existing plant, with an already known sludge. Aiming at expanding the use of the limiting solids flux theory, several authors (White, 1976;Johnstone et al, 1979;Tuntoolavest and Grady, 1982;Koopman and Cadee, 1983;Pitman, 1984;Daigger and Roper, 1985;Ekama and Marais, 1986;Keinath, 1988, 1995;van Haandel et al, 1988;von Sperling, 1990;Daigger, 1995) tried to express the interface settling velocity according to easily determinable or assumable variables, such as the sludge volume index (SVI and its variants). Once the sludge settling velocity is estimated, the limiting flux theory can be easily employed for design and operation.…”