Temperature Effects on Biodegradation Kinetic Parameters and Settling Characteristics of Activated Sludge Treating Pulp and Paper Wastewater

Abstract Nine sets of batch experiments, each of ten to twelve days duration, were conducted in the laboratory on return-sludge samples collected from activated sludge treatment plant at Windsor. The thickened sludge samples were blended daily in a waring blender and were continuously aerated in twelve-litres capacity jars. Parallel runs were made on control sludge samples which were not blended. Amongst the parameters varied were the speed and frequency of blending and the aeration rate. The effects of these variables on progressive bio-degradation of volatile suspended solids and the settling characteristics of the sludge were determined. Blended sludge showed significant improvement in the rate of bio-degradation and its settling characteristics as compared to the control unblended sludge

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A Technique to Determine Unsteady-State Inhibition Kinetics in the Activated Sludge Process

Water Science & Technology ◽

10.2166/wst.1989.0261 ◽

1989 ◽

Vol 21 (6-7) ◽

pp. 593-602 ◽

Cited By ~ 3

Author(s):

Andrew T. Watkin ◽

W. Wesley Eckenfelder

Keyword(s):

Activated Sludge ◽

Kinetic Parameters ◽

Curve Fitting ◽

Glucose Utilization ◽

Batch Reactor ◽

Synthetic Data ◽

Utilization Rate ◽

Fitting Algorithm ◽

Test Reactor ◽

Two Parameter

A technique for rapidly determining Monod and inhibition kinetic parameters in activated sludge is evaluated. The method studied is known as the fed-batch reactor technique and requires approximately three hours to complete. The technique allows for a gradual build-up of substrate in the test reactor by introducing the substrate at a feed rate greater than the maximum substrate utilization rate. Both inhibitory and non-inhibitory substrate responses are modeled using a nonlinear numerical curve-fitting technique. The responses of both glucose and 2,4-dichlorophenol (DCP) are studied using activated sludges with various acclimation histories. Statistically different inhibition constants, KI, for DCP inhibition of glucose utilization were found for the various sludges studied. The curve-fitting algorithm was verified in its ability to accurately retrieve two kinetic parameters from synthetic data generated by superimposing normally distributed random error onto the two parameter numerical solution generated by the algorithm.

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Mutagenicity in Pulp and Paper Mill Effluents and in Recipient

Water Science & Technology ◽

10.2166/wst.1988.0054 ◽

1988 ◽

Vol 20 (2) ◽

pp. 143-152 ◽

Cited By ~ 4

Author(s):

A. Langi ◽

M. Priha

Keyword(s):

Activated Sludge ◽

Mutagenic Activity ◽

Chinese Hamster Ovary Cells ◽

Chinese Hamster ◽

Paper Mill ◽

Pulp And Paper ◽

Pulp And Paper Mill ◽

Sludge Treatment ◽

Paper Mill Effluents ◽

Kraft Mill

The mutagenic properties of pulp and paper mill effluents were studied in three mills: bleached kraft mill with aerated lagoon treatment (Mill 1), bleached kraft mill with activated sludge treatment (Mill 2) and mechanical pulp/paper mill (Mill 3). Both treated and untreated effluents, process streams and molecular fractions were tested for mutagenicity (Ames test. Salmonella typhimurium TA100 and SCE sister chromatid exchange test, Chinese hamster ovary cells). To verify the potential environmental effects the mutagenic activity of concentrated recipient lake water (Mill 2) was also studied. The Ames mutagenicity of the bleached kraft mill effluent (BKME) originated from the first chlorination filtrate, SCE mutagenicity also occurred in the alkali extraction stage filtrate (Mill 1). No Ames mutagenicity was detected in the paper mill effluent, but it was SCE mutagenic. Activated sludge treatment of BKME removed both Ames and SCE mutagenicity, but the aerated lagoon treated BKME was still SCE mutagenic. No mutagenic activity was detected in the recipient water concentrates.

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On-line measurements of settling characteristics in activated sludge

Water Science & Technology ◽

10.2166/wst.1997.0144 ◽

1997 ◽

Vol 36 (4) ◽

pp. 307-312

Author(s):

Michael R. Rasmussen ◽

Torben Larsen

Keyword(s):

Activated Sludge ◽

Settling Velocity ◽

Continuous Measurement ◽

Batch Reactor ◽

Volume Index ◽

Sludge Volume Index ◽

Dynamic Variations ◽

On Line ◽

Settling Column ◽

Settling Characteristics

An on-line settling column for measuring the dynamic variations of settling velocity of activated sludge has been developed. The settling column is automatic and self-cleansing insuring continuous and reliable measurements. The settling column was tested on sludge from a batch reactor where sucrose was added as an impulse to activated sludge. The continuous measurement of settling velocity revealed a highly dynamic response after the sucrose was added. The results were verified with simultaneous measurement of the initial settling rate. A 200 hour experiment showed variations in settling velocity, which was not apparent in the DSVI (Diluted Sludge Volume Index).

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