Water circuit closure with membrane technology in the pulp and paper industry

2004 ◽  
Vol 50 (3) ◽  
pp. 217-227 ◽  
Author(s):  
J. Nuortila-Jokinen ◽  
M. Mänttäri ◽  
T. Huuhilo ◽  
M. Kallioinen ◽  
M. Nyström
Keyword(s):  
Membrane Fouling ◽  
Biological Treatment ◽  
Membrane Filtration ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Paper Machine ◽  
Purification Method ◽  
High Molar Mass ◽  
Pre Treatment

In this study, membrane filtration as an internal purification method, “the kidney7rdquo;, in the pulp and paper industry is discussed. Membrane filtration is economically competitive and a very versatile process. It can be used to remove the enriched organic and/or inorganic loads either partially or totally from, for example, the mechanical pulping and paper making water circuits and it can be applied to various points within the process. With the so-called shear enhanced membrane modules very high fluxes, in ultrafiltration about 400 L/(m2h) and in nanofiltration fluxes almost 200 L/(m2h), have been obtained. Depending on the membrane, suspended solids (microfiltration), polysaccharides, extractives and high molar mass lignous substances (ultrafiltration) and multivalent salts (nanofiltration) can be removed. Ultrafiltration permeate can well be used in paper machine showers to replace fresh water. The quality of the nanofiltration permeate is significantly higher than that of ultrafiltration. The membrane processes can be enhanced by various pre-treatment techniques to produce higher permeate fluxes and to eliminate membrane fouling. Such pre-treatment methods are, e.g., chemical treatment, ozonation and biological treatment. The most cost-effective processes were chemical flocculation, pH adjustment and thermophilic aerobic biological treatment.

Ultrafiltration and nanofiltration in the pulp and paper industry using cross-rotational (CR) filters

2004 ◽  
Vol 50 (3) ◽  
pp. 229-238 ◽  
Author(s):  
M. Mänttäri ◽  
M. Nyström
Keyword(s):  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Paper Machine ◽  
High Shear ◽  
Nanofiltration Membranes ◽  
Ph Conditions ◽  
Acidic Waters ◽  
Pre Treatment ◽  
Neutral Conditions

Ultra- and nanofiltration with high shear CR-filters have been utilized for cleaning of clear filtrates and effluents from the pulp and paper industry. The aim was to find out how different nanofiltration membranes operate at high shear conditions. The filtration efficiency of the membranes was evaluated by measuring flux, retention and fouling at various recovery and pH conditions. High fluxes (∼100 L/(m2h)) for nanofiltration membranes were measured when circulation waters from the paper machine were filtered at neutral conditions. In the filtration of discharge of external activated sludge treatment plants we measured fluxes around 150 L/(m2h) even at a concentration factor of 12. The best NF membranes removed over 80% of the organic carbon and of the conductivity and almost completely eliminated the color. With acidic waters fluxes and retentions were significantly lower. The NF270 membrane from Dow and the Desal-5 membranes from Osmonics had the highest flux and retention properties. However, the Desal-5 membrane lost its retention properties slowly, which restricts its use in the high shear CR-filter. CR-nanofiltration can be used in the pulp and paper industry without feed pre-treatment by ultrafiltration. This increases the attractiveness of high shear CR-nanofiltration.

The Development of Waste Water Treatment in the Finnish Pulp and Paper Industry

1988 ◽  
Vol 20 (1) ◽  
pp. 25-36 ◽  
Author(s):  
A. Luonsi ◽  
J. Junna ◽  
I. Nevalainen
Keyword(s):  
Activated Sludge ◽  
Pollution Control ◽  
Biological Treatment ◽  
Paper Industry ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Quality Criteria ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Target Values

The recent development of Finnish pulp and paper industry external wastewater treatment has created positive results by reducing the oxygen consuming load (BOD7) of the recipients. This is due to the thirteen activated sludge plants and one anaerobic reactor which have been constructed during the last four years. The target values set in the form of suspended solids (SS) and BOD7 for 1985 (400 t BOD7/d) are expected to be achieved during 1987. Activated sludge plants have also created negative effects in the form of large amounts of surplus biological sludge and increased nutrient discharges, especially phosphorus which with reduced acute toxicity will increase the eutrophication of discharge areas. The share of activated sludge plants for the increased phosphorus discharges remains to be studied. The rapid increase started before the activated sludge plants started operation. In well operated activated sludge plant nutrient discharge is not increased. Although the specific water consumption and specific organic loads continuously decrease in pulp and paper production the increased production and more stringent requirements for pollution control prerequisite investments for external treatment. Therefore it is the time for efficient biological treatment plant construction and before 1995 a good number of mainly activated sludge plants will be constructed, for which time target values and some alternative guidelines to pollution control have been planned but not yet officially issued. Also requirements for CODCr, and total organic chlorine (TOCl) will be among the effluent quality criteria in the near future. When further requirements are issued the basis must be in the requirements of the biota which it is desired to live in the discharge areas. Much research is needed to find out how many of these requirements can be satisfied by modifications of present treatment processes. Thereafter the possibility of removing specific pollutants from the low volume fractions must be identified. The results of these studies must then be compared with the tertiary processes which can be added after the biological treatment plants which process the combined mill effluent. The problem must be regarded as a complex one because any substance removed from the wastewater will be found either in the sludge or in the air. The harmful compounds should be returned to normal ecological circulation or to the least harmful form and location in the most suitable waste stream.

Burned wood in the pulp and paper industry: A literature review

2004 ◽  
Vol 80 (4) ◽  
pp. 473-477 ◽  
Author(s):  
Paul Watson ◽  
Simon Potter
Keyword(s):  
Moisture Content ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Wood Chemistry ◽  
Mechanical Pulp ◽  
Kraft Cooking ◽  
Pre Treatment ◽  
One Year ◽  
Forest Architecture

Fires play an integral part in Canadian forest architecture. Low-value wood, from burned stems, is an important source of fibre for the pulp and paper industry. Although wood chemistry changes induced by fire are substantial, burned stems exhibit a demarcation layer between the char and undamaged wood which is only a few cells thick. The loss of stem moisture content requires that burned wood is processed within one year. Aggressive debarking will minimize charcoal contamination and careful metering of chips from burned wood into any pulping process is essential. Chips with low moisture content must be pre-steamed prior to kraft cooking, and chemical pre-treatment may improve mechanical pulp quality. Key words: burn intensity, wood chemistry, charring, stem moisture content, charcoal contamination, chip metering

Energy efficient aeration of wastewaters from the pulp and paper industry

2010 ◽  
Vol 62 (10) ◽  
pp. 2364-2371 ◽  
Author(s):  
M. Sandberg
Keyword(s):  
Oxygen Transfer ◽  
Biological Treatment ◽  
Bubble Column ◽  
Paper Industry ◽  
Electrical Power ◽  
Treatment Plant ◽  
Pulp Mill ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Paper Mills

More than 50% of the electrical power needed to treat pulp and paper industry effluents is used for aeration in biological treatment stages. A large share of the oxygen that passes through the wastewater is not consumed and will be found in the off-gas. Energy can be saved by aerating under conditions where the oxygen transfer is most efficient, for example at low concentrations of dissolved oxygen Consider the sludge as an energy source; electricity can be saved by avoiding sludge reduction through prolonged aeration. High oxygen transfer efficiency can be retained by using the oxygen consumption of biosolids. Quantified savings in the form of needed volumes of air while still achieving sufficient COD reduction are presented. The tests have been made in a bubble column with pulp mill process water and sludge from a biological treatment plant. These were supplemented with case studies at three pulp and paper mills.

Techniques for Closing the Water Circuits in the Pulp and Paper Industry

1994 ◽  
Vol 29 (5-6) ◽  
pp. 11-18 ◽  
Author(s):  
Howard Edde
Keyword(s):  
Biological Treatment ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Environmental Legislation ◽  
Assimilative Capacity ◽  
Knowledge Requirements ◽  
Technological Developments ◽  
The 1960S ◽  
Organic Halogens

The focus of this paper is on the earlier, recent and future developments in closing the water circuits in pulp and paper production. During the 1960s the U.S. pulp and paper industry was in its environmental infancy concentrating mainly on removal of settleable solids and initiating river assimilative capacity studies. The 1970s began with environmental legislation having enforceable powers to achieve primary and secondary (biological) treatment which was fundamentally fulfilled during the 1980s. The late 1980s and early 1990s opened with toxicity becoming the major environmental issue as measured mainly by absorbable organic halogens (AOX) and dioxins. This paper identifies progress and key technological developments towards furthering stringent environmental enhancement and provides additional knowledge requirements leading into the next century.

scholarly journals Influence of storage time of pulp and paper industry wastewaters in AOX determination

2019 ◽  
Author(s):  
Micaela A. R. Soares ◽  
Manuela Marques ◽  
Maria Teresa Rodrigues
Keyword(s):  
Biological Treatment ◽  
Storage Time ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Experimental Protocol ◽  
Laboratory Activities ◽  
Before And After ◽  
Wastewater Samples

The feasibility of storing wastewater samples from pulp and paper industry during more than 5 days (time recommend by ISO 5667-3:2018) for AOX determination was addresses in this study. Samples were collected before and after the aerobic biological treatment of a Portuguese industry. Experimental protocol included AOX measurements at days 4, 5, 6, 8, 11, 13, 15, 18 and 20 after sampling. Results obtained indicate that storage time is not matrix-dependent and it can be extended up to 20 days, which clearly improves management of laboratory activities concerning AOX determination.

Application of ultrafiltration in the pulp and paper industry: metals removal and whitewater reuse

2007 ◽  
Vol 55 (6) ◽  
pp. 117-123 ◽  
Author(s):  
C.R. Oliveira ◽  
C.M. Silva ◽  
A.F. Milanez
Keyword(s):  
Water Use ◽  
Paper Industry ◽  
Combined Treatment ◽  
Paper Mill ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Paper Machine ◽  
Paper Mills ◽  
Metals Removal ◽  
High Level

In the pulp and paper industry, the water use minimization is a constant target. One way to reduce water use is to recycle the effluent in a closed-cycle concept. In paper mills, the main source of liquid effluent is the so-called whitewater, which is the excess water, originated from pulp stock dewatering and other fibre contaminated water. This research studied the reuse of paper mill whitewater after membrane ultrafiltration (UF) in the paper machine and in the pulp bleach plant of an integrated mill. Contaminant removal and flux behaviour of the UF system were evaluated. The treatment by ultrafiltration was technically feasible and the treated whitewater had good potential to be reused in some processes in the paper machine. The reuse of ultrafiltered whitewater in the bleaching plant was not recommended because of the high level of soluble calcium present in this stream. Therefore, a combined treatment of the whitewater using the principle of precipitation and ultrafiltration was proposed showing good results and enabling the use of the treated whitewater in the bleach plant.

The Eutrophication of Pulp and Paper Wastewater Recipients

1991 ◽  
Vol 24 (3-4) ◽  
pp. 411-415 ◽  
Author(s):  
J. Wartiovaara ◽  
P. Heinonen
Keyword(s):  
Biological Treatment ◽  
Nutrient Loading ◽  
Paper Industry ◽  
Paper Mill ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Pulp And Paper Mill ◽  
Paper Wastewater ◽  
The Cost

During recent years the BOD-loading of pulp and paper mill wastewaters has decreased dramatically, due to more effective circulation of water in the processes, and the new activated sludge biological treatment plants. This traditional threat to the environment has been forgotten by the scientists who nowadays are more interested in the role of chlorine compounds discharged from bleaching processes. However, eutrophication due to nutrient loading is still present in many recipients of pulp and paper industry. The BOD-reduction has often been carried out on the cost of adding nutrients, pnosphorus and nitrogen to the purification processes. The biological treatment has also decreased the inhibitive effect of wastewater on the biological production of the recipient water body. Therefore, the eutrophication arises immediatly. The authors worry about the research of nutrients; loadings, development trends and eutrophication effects.

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