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

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.

Fermentation ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 4 ◽  
Author(s):  
Rita Branco ◽  
Luísa Serafim ◽  
Ana Xavier

Due to the health and environment impacts of fossil fuels utilization, biofuels have been investigated as a potential alternative renewable source of energy. Bioethanol is currently the most produced biofuel, mainly of first generation, resulting in food-fuel competition. Second generation bioethanol is produced from lignocellulosic biomass, but a costly and difficult pretreatment is required. The pulp and paper industry has the biggest income of biomass for non-food-chain production, and, simultaneously generates a high amount of residues. According to the circular economy model, these residues, rich in monosaccharides, or even in polysaccharides besides lignin, can be utilized as a proper feedstock for second generation bioethanol production. Biorefineries can be integrated in the existing pulp and paper industrial plants by exploiting the high level of technology and also the infrastructures and logistics that are required to fractionate and handle woody biomass. This would contribute to the diversification of products and the increase of profitability of pulp and paper industry with additional environmental benefits. This work reviews the literature supporting the feasibility of producing ethanol from Kraft pulp, spent sulfite liquor, and pulp and paper sludge, presenting and discussing the practical attempt of biorefineries implementation in pulp and paper mills for bioethanol production.


1985 ◽  
Vol 17 (1) ◽  
pp. 223-230 ◽  
Author(s):  
P K Latola

A wastewater from an integrated paper mill with a COD of 1200 mg/dm3 was anaerobically treated in a multi-stage reactor. The BOD7 removal efficiencies of 60-75 % were achieved at maximal loading rates of 5-6 kg COD/m3d and HRT of 4-6 hours due to the granular sludge. Industrial sulphite evaporator condensates from Ca- and Na-processes were treated in anaerobic filters containing light gravel, plastic foam and power plant slag as filter media. The BOD7 removals of 78 % on average were achieved at loading rates of 1.8-3.3 kg COD/m3d with Ca-process evaporator condensates and 80 % BOD7 removals were achieved with Na-process condensates at loading rates of 3.5-4.1 kg COD/m3d.


2019 ◽  
Vol 98 (12) ◽  
pp. 1392-1401
Author(s):  
V. V. Yurchenko ◽  
Faina I. Ingel ◽  
N. A. Urtseva ◽  
E. K. Krivtsova ◽  
L. V. Akhaltseva

Introduction. Analysis of literature has shown genotoxicants (mutagens and carcinogens) to be present in the atmospheric emissions of pulp and paper industry (PPI). Moreover, among PPI workers from different countries, there was identified an additional risk of cancer, which suggests its high probability among residents of the cities where the PPI is located. The recognized index of genotoxic effects is an increased level of genome instability, which is determined, in particular, in the micronucleus test. The scope of the study - the comparative analysis of the effects of genomic instability in the two tissues - blood lymphocytes cultured with Cytochalasin B, and buccal epithelial cells in the second grade school children (8-9 years old, boys and girls), whose schools were located at different distances from the pulp and paper mill. Material and methods. The study was carried out in the city of Koryazhma, the Arkhangelsk Region (42000 citizens), where the pulp and paper plant as the city-forming industry was located. For the analysis, we subdivided the territories on which the schools were located, into 3 groups according to their distance from the pulp and paper mill. The effects of genomic instability were determined by cytome analysis in the micronucleus test. Results. Cytome analysis of cultivated lymphocytes demonstrated that levels of genome instability indices (including cell frequencies with micronuclei and nucleoplasm bridges, apoptosis, as well as changes in the spectrum of cell populations) to decrease along with the rising the distance between the pulp and paper mill and schools where the children go. In buccal epithelial cells, the manifestations of genomic instability effects were less systematic, which did not allow making a definitive conclusion. At the same time, in both tests, gender differences in the results of cytome analysis were revealed (for example, the alteration of frequency of lymphocytes with genetic damage dependence on the distance between schools and the PPI was more pronounced among boys). Conclusion. According to the results of this study and taking into consideration the data of literature, we hypothesized that the discovering of gender dimorphism in the effects of genome instability may indicate the presence of toxic and/or genotoxic compounds in an environment.


2010 ◽  
Vol 62 (2) ◽  
pp. 387-393 ◽  
Author(s):  
H. Kyllönen ◽  
J. Lehto ◽  
P. Pirkonen ◽  
A. Grönroos ◽  
H. Pakkanen ◽  
...  

Large amounts of wet sludge are produced annually in municipal and industrial wastewater treatment. Already in pulp and paper industry, more than ten million tons of primary sludge, waste activated sludge, and de-inking sludge is generated. Waste activated sludge contains large quantities of bound water, which is difficult to dewater. Low water content would be a matter of high calorific value in incineration but it also has effects on the volume and the quality of the matter to be handled in sludge disposal. In this research waste activated sludges from different pulp and paper mills were chemically characterised and dewatered. Correlations of chemical composition and dewatering properties were determined using multivariate analysis. Chemical characterisation included basic sludge analysis, elementary analysis and analysis of wood-based components, such as hemicelluloses and lignin-derived material. Dewatering properties were determined using measurements of dry solids content, flux and flocculant dosage. The effects of different variables varied according to the response concerned. The variables which were significant regarding cake DS increase in filtration or centrifugation and flocculant dosage needed in filtration were different from those which were significant regarding flux.


2010 ◽  
Vol 62 (10) ◽  
pp. 2364-2371 ◽  
Author(s):  
M. Sandberg

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.


1999 ◽  
Vol 75 (2) ◽  
pp. 247-255 ◽  
Author(s):  
Dinesh Mohta ◽  
D. N. Roy

Forests play a vital role in the social, economic, and environmental development of any country. Paper, composed principally of wood fiber, is an essential commodity in promoting literacy, communication, documentation, and packaging. However, there is much concern about the world's forests being over-utilized. This has led to serious repercussions, not only to humanity, but also to the earth's biodiversity as a whole. It is now time that forests be used in a more responsible and ethical manner. Because of reduced forest area, increasing pulpwood costs, and an increasing demand for pulp and paper products, it might be expected that the focus would shift to high yield pulping processes or to the use of cellulosic non-wood raw materials. Non-woods are available in good supply all over the world, but are currently under-utilized. It is estimated that replacing 5–10% of wood pulp with non-wood pulp would have an important impact on the conservation of forests and the environment. This replacement of wood pulp by non-wood pulp could be environmentally and economically acceptable even in developed countries. By doing so, pulp and paper mills would have a lead role in reducing their dependency on forests for fiber. This determination and commitment would enhance the long-term sustainability of forests and the pulp and paper industry. Above all, it would be a sustainable step towards "our common future." Key words: forest, sustainable development, fiber supply, pulp and paper, non-woods


1991 ◽  
Vol 24 (3-4) ◽  
pp. 411-415 ◽  
Author(s):  
J. Wartiovaara ◽  
P. Heinonen

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.


1988 ◽  
Vol 20 (1) ◽  
pp. 251-262 ◽  
Author(s):  
R. Hakulinen

Biological systems have been employed successfully for manv years in the treatment of pulp and paper mill waste water. Previously, not very much was known about enzymes and their possibilities in pulp and paper industry wastewater treatment. There is currently a lot of research activity in the enzymology of lignin degradation. Ligninase, cellulase, peroxidase, etc. are the most important enzymes, especially peroxidase, which is used for color removal in bleaching effluents. It is also possible to mix enzymes together with special microbes, which normally do not have high enzvme activity, and remove recalcitrant and harmless compounds from wastewater. The use of novel enzymes and rDNA technology in sludge and wastewater treatment will also be discussed.


2020 ◽  
Vol 5 (10) ◽  
Author(s):  
Chhotu Ram ◽  
Pushpa Rani ◽  
Kibrom Alebel Gebru ◽  
Mebrhit G Mariam Abrha

AbstractPulp and paper industry is coming under one of the most water polluting industries, and generated wastewater is highly toxic in nature. The paper mill requires huge quantity (~50–60 m3 of water to produce one ton of paper) of water, and accordingly huge quantity of chemical contaminated wastewater is discharged. The paper mill effluents have identified 240–250 chemicals in different stages of paper making. Various chemical constituents such as high chemical oxygen demand, biochemical oxygen demand, AOX, chlorinated compounds, color, suspended materials, lignin and their derivatives are released in the wastewater. The present review study is focused on the paper mill processes, wastewater generation and its effective treatment by microorganisms. The biological treatment has been identified as cost-effective and eco-friendly methods for the degradation of xenobiotic compounds for paper mill wastewater. Various studies have been performed so far to investigate the complex nature of wastewater by the application of bacteria, fungi and their enzymes at industrial scale. Therefore, the article discussed the importance of biological method as an effective technique for the degradation of paper mill wastewater.


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