Characterization and dewatering of activated sludge from the pulp and paper industry

Jaakko Pere, Raimo Alen, Liisa Viikari, Leif Eriksson

Research output: Contribution to journalArticleScientificpeer-review

58 Citations (Scopus)

Abstract

Floc properties and dewatering of activated sludge from the pulp and paper industry were studied prior to and after an oxidative conditioning using Fenton's reagent Sludge samples were taken from four treatment plants, which differed with respect to organic loadings and wastewater source. Poor dewaterability was typical of heavily loaded sludges and a positive correlation between filtrability and the concentration of exopolysaccharides was observed. Oxidative conditioning improved the dewaterability of all the sludges tested, but especially that of heavily loaded sludges. Lab-scale piston press results were also comparable with those of controls conditioned with polyelectrolytes. As a result of the conditioning, the surface charge density of the flocs decreased and the contact angles of filter cakes were increased, which enhanced flocculation and settleability. It is possible that hydroxyl groups are oxidized during the oxidative treatment to carboxyl groups, which are more hydrophobic at low pH. This hypothesis was partly supported by FTIR-analysis, but obviously other mechanisms were also involved.

Original languageEnglish
Pages (from-to)193 - 201
Number of pages9
JournalWater Science and Technology
Volume28
Issue number1
DOIs
Publication statusPublished - 1993
MoE publication typeA1 Journal article-refereed

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pulp and paper industry
Paper and pulp industry
Dewatering
Flocculation
Surface charge
Charge density
dewatering
Polyelectrolytes
Pistons
Contact angle
activated sludge
Wastewater
sludge
conditioning
flocculation
wastewater

Cite this

Pere, Jaakko ; Alen, Raimo ; Viikari, Liisa ; Eriksson, Leif. / Characterization and dewatering of activated sludge from the pulp and paper industry. In: Water Science and Technology. 1993 ; Vol. 28, No. 1. pp. 193 - 201.
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author = "Jaakko Pere and Raimo Alen and Liisa Viikari and Leif Eriksson",
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Characterization and dewatering of activated sludge from the pulp and paper industry. / Pere, Jaakko; Alen, Raimo; Viikari, Liisa; Eriksson, Leif.

In: Water Science and Technology, Vol. 28, No. 1, 1993, p. 193 - 201.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Characterization and dewatering of activated sludge from the pulp and paper industry

AU - Pere, Jaakko

AU - Alen, Raimo

AU - Viikari, Liisa

AU - Eriksson, Leif

N1 - Project code: POV9009

PY - 1993

Y1 - 1993

N2 - Floc properties and dewatering of activated sludge from the pulp and paper industry were studied prior to and after an oxidative conditioning using Fenton's reagent Sludge samples were taken from four treatment plants, which differed with respect to organic loadings and wastewater source. Poor dewaterability was typical of heavily loaded sludges and a positive correlation between filtrability and the concentration of exopolysaccharides was observed. Oxidative conditioning improved the dewaterability of all the sludges tested, but especially that of heavily loaded sludges. Lab-scale piston press results were also comparable with those of controls conditioned with polyelectrolytes. As a result of the conditioning, the surface charge density of the flocs decreased and the contact angles of filter cakes were increased, which enhanced flocculation and settleability. It is possible that hydroxyl groups are oxidized during the oxidative treatment to carboxyl groups, which are more hydrophobic at low pH. This hypothesis was partly supported by FTIR-analysis, but obviously other mechanisms were also involved.

AB - Floc properties and dewatering of activated sludge from the pulp and paper industry were studied prior to and after an oxidative conditioning using Fenton's reagent Sludge samples were taken from four treatment plants, which differed with respect to organic loadings and wastewater source. Poor dewaterability was typical of heavily loaded sludges and a positive correlation between filtrability and the concentration of exopolysaccharides was observed. Oxidative conditioning improved the dewaterability of all the sludges tested, but especially that of heavily loaded sludges. Lab-scale piston press results were also comparable with those of controls conditioned with polyelectrolytes. As a result of the conditioning, the surface charge density of the flocs decreased and the contact angles of filter cakes were increased, which enhanced flocculation and settleability. It is possible that hydroxyl groups are oxidized during the oxidative treatment to carboxyl groups, which are more hydrophobic at low pH. This hypothesis was partly supported by FTIR-analysis, but obviously other mechanisms were also involved.

U2 - 10.2166/wst.1993.0046

DO - 10.2166/wst.1993.0046

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JO - Water Science and Technology

JF - Water Science and Technology

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ER -