Nitrogen in the effluent of the pulp and paper industry

1997 ◽  
Vol 35 (2-3) ◽  
pp. 139-145 ◽  
Author(s):  
Risto Järvinen
Keyword(s):  
Inorganic Nitrogen ◽  
Paper Industry ◽  
Treatment Plant ◽  
Pulp Mill ◽  
Kraft Pulping ◽  
Bleached Kraft Pulp ◽  
Treated Effluent ◽  
Before And After ◽  
Nitrogen Concentrations ◽  
Biological Nitrogen

Nitrogen concentrations of effluent before and after treatment plant in two mills have been measured during five days time in a bleached kraft pulp mill and in a newsprint mill. In effluents before treatment the concentration of inorganic nitrogen was low but in the effluent of kraft pulping process, the main part is inorganic nitrogen. In effluent after treatment the concentration of inorganic nitrogen is low. After activated sludge treatment plant the concentration of dissolved organic nitrogen is about 0.6 mg/l and nitrogen in suspended solids determines fluctuation of nitrogen content in treated effluent. There is no need for biological nitrogen removal processes if the addition of nitrogen in the treatment is correct.

Nitrogen and Phosphorus Limits for Nutrient Deficient Industrial Wastewaters

1991 ◽  
Vol 24 (3-4) ◽  
pp. 259-267 ◽  
Author(s):  
Christian H. Möbius
Keyword(s):  
Paper Industry ◽  
Treatment Plant ◽  
Pulp Mill ◽  
Operating Conditions ◽  
Inorganic N ◽  
Nitrogen And Phosphorus ◽  
Total N ◽  
Industrial Wastewaters ◽  
Treated Effluent ◽  
Plant Optimization

For biological treatment of nutrient deficient industrial wastewaters, such as those of the pulp and paper industry, the addition of nitrogen and phosphorus is essential. As a certain surplus is necessary, both elements will be found in the effluent in varying concentrations. For the often used activated sludge treatment 5 parts of N and 1 part of P are said to be required for elimination of 100 parts of BOD. In-plant optimization generally leads to about 3.5 parts of N and 0.6 parts of P for 100 parts of BOD. In most plants N is added as urea and P as phosphoric acid. Optimized nutrient dosage aimed at stable operating conditions in the treatment plant generally gives average concentrations of 1 mg/l of both ammonia N and phosphate P in the treated effluent. However, due to fluctuations in loading and efficiency, variation coefficients of more than 100 % result in maximum concentrations in 24 hours mixed samples of more than 10 mg/l for N and P. Three examples of operational results are evaluated and discussed in detail. Water quality requirements will impose general limitations on N and P concentrations in treated effluents. Depending on the concentration limits and on the type of limited substance - i.e. ammonia N, total inorganic N or total N, phosphate P or total P - different strategies have to be developed. Nutrient dosage depending on the wastewater amount will become state of the art in the near future. The next step would be a loading dependent dosage. No results of technical operation are known which show the effluent concentrations obtainable with this technique. For cases in which limits cannot be met with this strategy the possibilities of nitrification, denitrification and biological P removal are discussed for nutrient deficient wastewaters. Results show that nitrification will work at low ammonia concentrations, however no steady nitrification will be obtained. Denitrification, on the other hand, seems to be difficult with low nitrate concentrations. At the present stage, no technical process meeting stringent total N or total inorganic N limits is known to exist for this type of effluent. Low P concentrations in the effluent can only be achieved by tertiary treatment, preferably final flocculation filtration processes. However, these will give rise to special problems in the treatment of pulp mill wastewaters, which are discussed in the paper.

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.

Desilication of bamboo for pulp production

TAPPI Journal ◽  
2015 ◽  
Vol 14 (11) ◽  
pp. 743-749 ◽  
Author(s):  
TROY M. RUNGE ◽  
SCOTT PAUL
Keyword(s):  
Mechanical Treatment ◽  
Paper Industry ◽  
Black Liquor ◽  
Pulp Mill ◽  
Common Species ◽  
Silica Content ◽  
Kraft Pulping ◽  
High Silica ◽  
Pulp Properties ◽  
Dermis Layer

Bamboo is one of the world’s fastest growing feedstocks. It is a promising nonwood resource that can be used in the pulp and paper industry. Among more than 1200 species of bamboo, the timber varieties can be processed much like trees, allowing current pulp mill logistical systems to be used. Bamboo can be difficult to pulp because of its high silica content, which creates issues for black liquor recovery. This study compares two methods of reducing the silica content of a common species of timber bamboo. Specifically, the dermis layer of Moso bamboo (Phyllostachys edulis) was removed through mechanical treatment and then chipped. The same species was also chipped without treatment. The two chipped materials were then alkali extracted and subjected to kraft pulping experiments. The pulps were bleached with an OD0(EP)D1 sequence. The material was then refined and formed into handsheets. The results indicate that 80% of the silica could be removed from the bamboo material through a combination of dermal mechanical treatment and caustic chip extraction. Caustic chip extraction removed a significant portion of hemicellulose materials, which in turn lowered cooking yields but had minimal effect on pulp properties.

Recirculation of treated effluent in the bleaching of kraft pulp

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8944-8964
Author(s):  
Erika Nascimben Santos ◽  
Claudia Mudadu Silva ◽  
Jorge Luiz Colodette ◽  
Samilly B. Zanith de Almeida ◽  
Antonio José Vinha Zanuncio ◽  
...  
Keyword(s):  
Kraft Pulp ◽  
Treatment Plant ◽  
Pulp Mill ◽  
Effluent Treatment ◽  
Organic Load ◽  
Kraft Pulp Mill ◽  
Treated Effluent ◽  
Effluent Treatment Plant ◽  
Attractive Option ◽  
Washing Water

The bleaching plant of a kraft pulp mill is the sector that consumes water and generates effluent with the highest volume. Water recycling is an attractive option to reduce water consumption and effluent generation. This study evaluated the technical feasibility of using treated effluent as washing water in the bleaching stages. The bleaching sequence was simulated in the laboratory using four types of washing water: deionized water, whitewater, low organic load effluent, and high organic load effluent. To achieve 90% ISO pulp brightness, the ClO2 consumption increased from 8.1 kg ClO2 odt-1 when using water to 13.8 and 16.3 kgClO2 odt-1 for the low and high organic effluents. Physical and optical tests of the hand-sheet papers did not show any statistical difference between various washing waters. The filtrates showed values that did not burden the efficiency of the effluent treatment plant. It was possible to use effluent in the bleaching stages, considering that the filtrates and the produced paper complied with the quality standards.

Irrigation of eucalyptus plantation using treated bleached kraft pulp mill effluent

2010 ◽  
Vol 62 (9) ◽  
pp. 2150-2156 ◽  
Author(s):  
A. A. P. Rezende ◽  
A. T. de Matos ◽  
C. M. Silva ◽  
J. C. L. Neves
Keyword(s):  
Kraft Pulp ◽  
Management Practices ◽  
Pulp Mill ◽  
Biomass Productivity ◽  
Pulp Mill Effluent ◽  
Eucalyptus Plantation ◽  
Kraft Pulp Mill ◽  
Bleached Kraft Pulp ◽  
Application Rates ◽  
Treated Effluent

The use of treated pulp mill effluent on eucalyptus plantation appears to be an attractive option for plant nutrition and water supply. It also constitutes a supplementary treatment process and a final disposal option for the mill effluent. This study aimed at the investigation and evaluation of the effects of bleached kraft pulp mill treated effluent on three typical Brazilian soils used for eucalyptus plantation. The effluent was characterized and five different application rates, defined according to the load of sodium, were tested in controlled environment experiments (greenhouse). After effluent application over a six month period an increase in the salinity of the studied soils was observed, although no soil dispersion was detected. The low content of some nutrients in the treated effluent indicated the need for fertilizer complementation. In general, the best biomass productivity and plant growth results were obtained in fine textured soil at a loading rate of 6.49 t Na ha−1. The good response of the soil-plant system under different effluent application rates showed the feasibility for the eucalyptus irrigation if adequate management practices and monitoring are carried out.

Anaerobic-Aerobic Treatment of Potato-Starch Wastewater

1993 ◽  
Vol 28 (2) ◽  
pp. 165-176 ◽  
Author(s):  
U. Abeling ◽  
C. F. Seyfried
Keyword(s):  
Potato Starch ◽  
Treatment Plant ◽  
Aerobic Treatment ◽  
Nitrogen And Phosphorus ◽  
Essential Parameter ◽  
Nitrogen Concentrations ◽  
High Concentrations ◽  
Biological Nitrogen ◽  
Nitrogen Elimination ◽  
Anaerobic Pretreatment

Production of potato starch produces wastewaters with high concentrations of COD, nitrogen and phosphorus. The best known and most economical solution for the nearly full elimination of these substances is the two-stage anaerobic-aerobic treatment. The anaerobic pretreatment must only go so far as to maintain enough COD for biological nitrogen and phosphorus elimination in the aerobic stage. To optimize this process, several tests have been carried out on nitrification/denitrification by means of the intermediate product nitrite. The carbon consumption amounts to only 60% in comparison with denitrification via nitrate. The essential parameter for regulating the process is the concentration of free ammonia in the reactor. Concentrations of 1 to 5mg NH3/l inhibit the nitratation but not the nitritation. A separation of both partial steps is possible. The content of ammonia was controlled by means of continuous NH4 and pH measuring. The process is suitable for many wastewaters with low COD/TKN ratios and high nitrogen concentrations. If there are undesired nitrite peaks in an aerobic treatment plant caused by high pH values and temperatures, specific nitrogen elimination by means of nitrite is a reliable treatment system.

Role of Wood Extractives in Black Liquor Corrosiveness

CORROSION ◽  
2006 ◽  
Vol 62 (10) ◽  
pp. 911-917 ◽  
Author(s):  
P. E. Hazlewood ◽  
P. M. Singh ◽  
J. S. Hsieh
Keyword(s):  
Carbon Steel ◽  
Wood Species ◽  
Paper Industry ◽  
Black Liquor ◽  
Wood Chip ◽  
Pulp Mill ◽  
Kraft Pulping ◽  
Extractive Content ◽  
Operational Parameters ◽  
Black Liquors

Abstract In the pulp and paper industry, variability in the process and wood source may result in highly corrosive waste liquors, called black liquors, from the Kraft pulping process. Prior research has demonstrated corrosion rates of carbon steel in pulp mill equipment ranging from <0.03 mm/y to >2.54 mm/y, depending on the wood species pulped. In this study wood species-dependent corrosion is confirmed and age-dependent corrosion is investigated as a function of organic extractive content. The composition of the organic portion of black liquor depends largely on the wood species used. Organic components come from extractives in the wood chips or are generated from the degradation of lignin and other wood constituents during the pulping process. Depending upon the wood species used, some black liquor constituents have been identified to increase the corrosiveness of black liquors whereas others may act as corrosion inhibitors. Our research demonstrates the importance of operational parameters for wood species and wood chip usage and delivery to downstream process corrosion. Further, results show the importance of water-extracted organics in wood, such as long chain fatty acids, using a novel methodology for the separation of extractives and lignin breakdown products in the testing of black liquor corrosiveness with carbon steel A516-Grade 70 (UNS K02700).

Biological treatment and ultrafiltration of woodchip pre-hydrolysis liquor from dissolving pulp mills

2018 ◽  
Vol 33 (2) ◽  
pp. 358-364
Author(s):  
Tatiana Aurora Condezo Castro ◽  
Claudio Mudadu Silva ◽  
Jorge Luiz Colodette ◽  
Ann H. Mounteer
Keyword(s):  
Energy Demand ◽  
Biological Treatment ◽  
Black Liquor ◽  
Hydrothermal Process ◽  
Treatment Plant ◽  
Wood Chip ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Pulp Mills ◽  
Treated Effluent

Abstract Dissolving pulps could be considered as the future biorefineries, which normally generate liquor during the wood chip pre-hydrolysis (PHL). PHL has high chemical oxygen demand (COD) and biochemical oxygen demand (BOD). Mills do not have efficient means for disposal of PHL, being in general burned in the recovery boiler with a high cost due to its low consistency. The objectives of this work were to evaluate i) the biotreatability of PHL and the effects it would have on a kraft mill effluent biological treatment plant and ii) the use of ultrafiltration (UF) membrane to treat the PHL prior to biological treatment. PHL was generated into lab with a hydrothermal process and was mixed with kraft pulp mill effluent in different proportions and added to sequencing batch reactors (SBRs). The SBRs achieved high rates of COD removal (>75 %). However, treated effluent COD increased with the increase in PHL dose. This treatment using UF membranes reduced the COD load. Biotreatability of the UF permeate was higher than that of PHL. UF retentate, with 28 % of the volume and a much higher solids content than the initial PHL, would have a significantly lower evaporation energy demand if sent to the black liquor evaporators.

Combined chemical biological treatment of bleached eucalypt kraft pulp mill effluent

2007 ◽  
Vol 55 (6) ◽  
pp. 143-150 ◽  
Author(s):  
D.B. Ruas ◽  
A.H. Mounteer ◽  
A.C. Lopes ◽  
B.L. Gomes ◽  
F.D. Brandão ◽  
...  
Keyword(s):  
Biological Treatment ◽  
Kraft Pulp ◽  
Pulp Mill ◽  
Equivalent Dose ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Bleached Kraft Pulp ◽  
Before And After ◽  
Ozone Pretreatment ◽  
Recalcitrant Organic Matter

Effectiveness of ozonation before and after biological treatment for removal of recalcitrant organic matter in bleached kraft pulp effluents was compared. Two industrial ECF bleached eucalypt kraft pulp effluents (E1 and E2) were pretreated with 100 mg O3/L. Raw and pretreated effluents were treated biologically in bench-scale sequencing batch reactors, under constant conditions. Following biological treatment, effluents were post-treated with 100 and 200 mg O3/L. Effluent pretreatment increased effluent biodegradability by 10% in E1 and 24% in E2. Combined O3-biological treated led to small but significant increases in COD, BOD and lignin removal over biological treatment alone, but pretreatment had no significant effect on effluent colour and carbohydrate removal. Ozone pretreatment did not affect biological activity during treatment of effluent E1 but resulted in a 38% lower specific oxygen uptake rate in effluent E2. At an equivalent dose of 100 mg/L, pre-ozonation produced better quality effluent than post-ozonation, especially with regard to COD and colour. Likewise, when an equivalent dose of 200 mg/L was applied, splitting the dose equally between pre- and post-treatments was more efficient than applying the entire dose in the post-treatment. The potential for combined chemical–biological treatment to improve effluent quality has been confirmed in this study.

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