Assessment of pulp machine white water quality at market kraft pulp mills

TAPPI Journal ◽  
2012 ◽  
Vol 11 (3) ◽  
pp. 71-76
Author(s):  
LUC LAPIERRE ◽  
JEAN BOUCHARD ◽  
RICHARD BERRY
Keyword(s):  
Water Quality ◽  
Kraft Pulp ◽  
Quality Monitoring ◽  
Pulp Mills ◽  
Significant Cost ◽  
Brightness Reversion ◽  
Kraft Pulp Mills ◽  
Monitoring Procedure ◽  
White Water

The bleaching of pulp is a significant cost, yet the brightness achieved in the bleaching plant can be diminished in the pulp machine because of white water (WW) quality. Monitoring WW quality can control these losses. A method was developed to assess WW quality that allows differentiation between the effect of fibers, fines, and dissolved solids (DS) in the WW. It was found that the quality of the WW varied greatly from mill to mill. The brightness loss was mainly affected by the presence of fines, through a combination of their concentration and color. The DS were significantly less detrimental to the optical properties of the final furnish. None of the constituents present in the pulp machine WW caused significant brightness reversion (except the hardwood fine fractions). It is therefore recommended that a monitoring procedure for WW quality at the mill site be used to diagnose and prevent the occurrence of brightness problems. Such monitoring offers a way to reduce bleaching costs.

scholarly journals Optimization of Water Quality Monitoring Networks Using Metaheuristic Approaches: Moscow Region Use Case

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 888
Author(s):  
Elizaveta Yudina ◽  
Anna Petrovskaia ◽  
Dmitrii Shadrin ◽  
Polina Tregubova ◽  
Elizaveta Chernova ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Quality Monitoring ◽  
Training Sample ◽  
Quality Monitoring ◽  
Monitoring Networks ◽  
Monitoring Procedure ◽  
Dataset Size ◽  
Sample Set ◽  
Moscow Area

Currently many countries are struggling to rationalize water quality monitoring stations which is caused by economic demand. Though this process is essential indeed, the exact elements of the system to be optimized without a subsequent quality and accuracy loss still remain obscure. Therefore, accurate historical data on groundwater pollution is required to detect and monitor considerable environmental impacts. To collect such data appropriate sampling and assessment methodologies with an optimum spatial distribution augmented should be exploited. Thus, the configuration of water monitoring sampling points and the number of the points required are now considered as a fundamental optimization challenge. The paper offers and tests metaheuristic approaches for optimization of monitoring procedure and multi-factors assessment of water quality in “New Moscow” area. It is shown that the considered algorithms allow us to reduce the size of the training sample set, so that the number of points for monitoring water quality in the area can be halved. Moreover, reducing the dataset size improved the quality of prediction by 20%. The obtained results convincingly demonstrate that the proposed algorithms dramatically decrease the total cost of analysis without dampening the quality of monitoring and could be recommended for optimization purposes.

The solubility of calcium carbonate  in green liquor handling systems

TAPPI Journal ◽  
2019 ◽  
Vol 18 (10) ◽  
pp. 595-602
Author(s):  
ALISHA GIGLIO ◽  
VLADIMIROS G. PAPANGELAKIS ◽  
HONGHI TRAN
Keyword(s):  
Calcium Carbonate ◽  
Systematic Study ◽  
Kraft Pulp ◽  
Thermodynamic Simulation ◽  
Solubility Data ◽  
Pulp Mills ◽  
Persistent Problem ◽  
Green Liquor ◽  
Kraft Pulp Mills ◽  
Salt Systems

The formation of hard calcite (CaCO3) scale in green liquor handling systems is a persistent problem in many kraft pulp mills. CaCO3 precipitates when its concentration in the green liquor exceeds its solubility. While the solubility of CaCO3 in water is well known, it is not so in the highly alkaline green liquor environment. A systematic study was conducted to determine the solubility of CaCO3 in green liquor as a function of temperature, total titratable alkali (TTA), causticity, and sulfidity. The results show that the solubility increases with increased temperature, increased TTA, decreased causticity, and decreased sulfidity. The new solubility data was incorporated into OLI (a thermodynamic simulation program for aqueous salt systems) to generate a series of CaCO3 solubility curves for various green liquor conditions. The results help explain how calcite scale forms in green liquor handling systems.

Toward Production of Bioethanol Using Pulp Rejects from Kraft Pulp Mills as Raw Materials

2013 ◽  
Vol 67 (11) ◽  
pp. 1248-1251
Author(s):  
Masanori Kishino ◽  
Ken Orihashi ◽  
Akira Harada
Keyword(s):  
Kraft Pulp ◽  
Raw Materials ◽  
Pulp Mills ◽  
Kraft Pulp Mills

Activated Sludge Treatment of Kraft Mill Effluents from Conventional and Oxygen Bleaching

1991 ◽  
Vol 24 (3-4) ◽  
pp. 427-430 ◽  
Author(s):  
J. Nevalainen ◽  
P.-R. Rantala ◽  
J. Junna ◽  
R. Lammi
Keyword(s):  
Activated Sludge ◽  
Kraft Pulp ◽  
Activated Sludge Process ◽  
Chlorinated Phenols ◽  
Pulp Mills ◽  
Main Interest ◽  
Sludge Treatment ◽  
Kraft Pulp Mills ◽  
Activated Sludge Processes ◽  
Oxygen Bleaching

Conventional and oxygen bleaching effluents from hardwood kraft pulp mills were treated in laboratory-scale activated sludge processes. The main interest was the fate of organochlorine compounds in the activated sludge process. In the treatment of conventional bleaching wastewaters the BOD7-reduction was 80-91 % and in oxygen bleaching wastewaters 86-93 %. The respective CODCr removals were about 40 % and about 50 %. The AOX reductions were on average 22 % and 40 % in the treatment of conventional and oxygen bleaching effluents, respectively. The reductions of chlorinated phenols, guajacols and catecols were usually more than 50 % in both reactors. Very little accumulation of AOX into the sludge was observed. The stripping of AOX from aeration unit was insignificant.

State of the art methods for combined water and energy systems optimisation in Kraft pulp mills

2021 ◽  
Author(s):  
Elvis Ahmetović ◽  
Zdravko Kravanja ◽  
Nidret Ibrić ◽  
Ignacio E. Grossmann ◽  
Luciana E. Savulescu
Keyword(s):  
Kraft Pulp ◽  
State Of The Art ◽  
Energy Systems ◽  
Pulp Mills ◽  
Art Methods ◽  
Kraft Pulp Mills

Fate of phosphorus in the recovery cycle of the kraft pulping process

TAPPI Journal ◽  
2020 ◽  
Vol 19 (3) ◽  
pp. 139-148
Author(s):  
MARYAM SADEGH MOUSAVI ◽  
NIKOLAI DEMARTINI
Keyword(s):  
Kraft Pulp ◽  
Pulp Mill ◽  
Field Studies ◽  
Kraft Pulping ◽  
Pulp Mills ◽  
Recovery Cycle ◽  
Green Liquor ◽  
Green Liquor Dregs ◽  
Kraft Pulp Mills ◽  
Negative Effect

The accumulation of nonprocess elements in the recovery cycle is a common problem for kraft pulp mills trying to reduce their water closure or to utilize biofuels in their lime kiln. Nonprocess elements such as magne-sium (Mg), manganese (Mn), silicon (Si), aluminum (Al), and phosphorus (P) enter the recovery cycle via wood, make-up chemicals, lime rock, biofuels, and process water. The main purge point for these elements is green liquor dregs and lime mud. If not purged, these elements can cause operational problems for the mill. Phosphorus reacts with calcium oxide (CaO) in the lime during slaking; as a result, part of the lime is unavailable for slaking reactions. The first part of this project, through laboratory work, identified rhenanite (NaCa(PO4)) as the form of P in the lime cycle and showed the negative effect of P on the availability of the lime. The second part of this project involved field studies and performing a mass balance for P at a Canadian kraft pulp mill.

Statistical and Data Mining Techniques for Understanding Water Quality Profiles in a Mining-Affected River Basin

2018 ◽  
Vol 9 (2) ◽  
pp. 1-19 ◽  
Author(s):  
Jose Simmonds ◽  
Juan A. Gómez ◽  
Agapito Ledezma
Keyword(s):  
Data Mining ◽  
Water Quality ◽  
River Basin ◽  
Suspended Solids ◽  
Water Quality Monitoring ◽  
High Flow ◽  
Quality Monitoring ◽  
Low Flow ◽  
Inverse Relation

This article contains a multivariate analysis (MV), data mining (DM) techniques and water quality index (WQI) metrics which were applied to a water quality dataset from three water quality monitoring stations in the Petaquilla River Basin, Panama, to understand the environmental stress on the river and to assess the feasibility for drinking. Principal Components and Factor Analysis (PCA/FA), indicated that the factors which changed the quality of the water for the two seasons differed. During the low flow season, water quality showed to be influenced by turbidity (NTU) and total suspended solids (TSS). For the high flow season, main changes on water quality were characterized by an inverse relation of NTU and TSS with electrical conductivity (EC) and chlorides (Cl), followed by sources of agricultural pollution. To complement the MV analysis, DM techniques like cluster analysis (CA) and classification (CLA) was applied and to assess the quality of the water for drinking, a WQI.

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