Ultra- and Nano-Filtration in Advanced Effluent Treatment Schemes for Pollution Control in the Pulp and Paper Industry

1992 ◽  
Vol 25 (10) ◽  
pp. 263-276 ◽  
Author(s):  
A. Zaidi ◽  
H. Buisson ◽  
S. Sourirajan ◽  
H. Wood
Keyword(s):  
Kraft Pulp ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Reduction Factor ◽  
Pulp And Paper ◽  
Effluent Treatment ◽  
High Shear ◽  
Permeate Flux ◽  
The Cost ◽  
Low Shear

The kraft pulp and paper industry is currently faced with the challenge of substantially reducing the discharge of conventional and toxic pollutants to the receiving environment without compromising its competitiveness. Ultrafiltration (UF) and nanofiltration (NF) are among the various unit processes that are being investigated by researchers interested in developing alternative schemes for meeting this challenge. The objectives of the work presented here were: (i) to review the potential uses for UF and NF in the kraft pulp and paper industry and (ii) to evaluate the performance of eleven UF and NF membranes using a caustic extraction stage effluent from a kraft mill pulping softwood with a O D55/C45 EO H D bleaching sequence. The experimental work was conducted with two flat-sheets bench-scale units fed in parallel: a low shear and a high shear unit. The most promising UF membrane gave an average permeate flux of 9 m3m2d for a volume reduction factor (VRF) of 30, under high-shear conditions at 0.69 MPa. The associated COD rejections ranged from 85%–90% at a VRF of 1 down to 70–75% at a VRF of 30. While the results demonstrated in this study show promise, further research is needed to demonstrate the cost effectiveness of both high-shear and low-shear equipment for this application as well as options for the reuse or treatment of the diluted and concentrated streams produced by the UF/NF systems.

scholarly journals Ring removal in rotary kilns used by the pulp and paper industry

TAPPI Journal ◽  
2016 ◽  
Vol 15 (3) ◽  
pp. 205-213 ◽  
Author(s):  
J. Peter Gorog ◽  
W. Ray Leary
Keyword(s):  
Paper Industry ◽  
Cost Effective ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Ring Formation ◽  
Worst Case ◽  
Practical Standpoint ◽  
Soda Content ◽  
Rotary Kilns ◽  
The Cost

Ring formation occurs in the rotary kilns used by the pulp and paper industry to regenerate the lime needed to produce white liquor. The main rings are: burning zone rings, mid-kiln rings, dust rings and/or mud balls, and mud rings. While the exact mechanisms of ring formation are not completely understood, frequent changes in the production rate and the mud solids, high soda content in the mud, and high levels of dust are believed to play a major role in ring formation. The presence of rings can restrict the movement of material through the kiln. If undetected, this can result in overheating of the refractory lining. In the worst case, the presence of rings can lead to unscheduled downtime to clean out the ring and replace damaged refractory bricks. Depending on the severity, the cost of repairs and lost production can be in excess of US$3 million for a single event. Even if the root cause of ring formation is known, from a practical standpoint, it can be difficult to eliminate rings. In mills where ring formation is a recurring problem, mechanical ring removal systems should be considered. This paper describes the use of ring removal systems as a cost effective way to mitigate the problems associated with ring formation.

A hundred years of corrosion in the pulp and paper industry

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 253-258
Author(s):  
Max Moskal
Keyword(s):  
Paper Industry ◽  
Production Capacity ◽  
Corrosion Damage ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Corrosion Control ◽  
Materials Engineering ◽  
The Past ◽  
The Cost ◽  
Control Management

Through the decades, the pulp and paper industry greatly expanded production capacity to meet increasing demands. Correspondingly, the cost of corrosion damage soared. The most serious corrosion control challenges were researched and met by university and governmental researchers, and by task groups within the TAPPI Engineering Division’s Corrosion and Materials Engineering Committee. Today, thanks to material and process advances, mills encounter less corrosion than in the past. This overview takes a historical look back, covering many decades, at how corrosion problems have been managed in the pulp and paper industry. Yet, corrosion keeps on going, and today mills appear less able to manage corrosion problems for which known solutions are available. This paper also addresses the significant yet underrated task of optimizing corrosion control management in the present and into the future. Discussion is provided on best practices needed to mitigate new and ongoing corrosion problems.

Proposal for water reuse in the Kraft pulp and paper industry

2013 ◽  
Vol 8 (3-4) ◽  
pp. 359-374 ◽  
Author(s):  
M. J. Kossar ◽  
K. J. Amaral ◽  
S. S. Martinelli ◽  
M. C. L. Erbe
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Water Reuse ◽  
Kraft Pulp ◽  
Paper Industry ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Paper Machines

The reuse of wastewater by the pulp and paper industry reduces environmental impacts by contributing to raw water conservation, thereby making a greater volume of fresh water available for nobler purposes, and reducing wastewater treatment. This study evaluated a proposed system of water reuse at a Kraft pulp and paper plant in Brazil, based on a survey of water quality required by its consumption points, supplied by its water treatment plant. Results after ultrafiltration included: turbidity of 0,3 NTU and pH 7,5, average values of BOD 66,4 mg/L, COD 9,6 mg/L and the colour of 280,5 ppm Pt were measured after ultrafiltration. The ultrafiltered wastewater was considered available for reuse, and its quality was compared with that of the water supplied by the water treatment plant, which provided for the classification of potential reuse points. Water colour was identified as the limiting factor for reuse; thus the reuse points were two Kraft paper machines, and the water flow to the liquid ring formations that generate the vacuums inside nineteen pumps for these two machines. The advantages of this proposal for water reuse include: ultrafiltered water quality sufficient for the vacuum pumps, the small distance between the point of reused water generation and the paper machines section, and the reused water has no contact with the final product. The calculated cost and return time for the water reuse system was US$ 607.020,00 in 15 years.

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.

Treatment Technologies for Organochlorine-Containing Sludges and Concentrates from External Treatment of Pulp and Paper Wastewaters

1991 ◽  
Vol 24 (3-4) ◽  
pp. 319-329 ◽  
Author(s):  
M. Almemark ◽  
G. Finnveden ◽  
B. Frostell
Keyword(s):  
Paper Industry ◽  
Pulp Mill ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Effluent Treatment ◽  
Organochlorine Compounds ◽  
Chlorinated Phenols ◽  
Chemical Coagulation ◽  
Solids Content ◽  
Available Information

Literature data and results from current Swedish research have been used to compile characteristics of and disposal methods for sludges and concentrates from external treatment of wastewaters from the pulp and paper industry. Very little sludge from aerobic lagoon treatment in Sweden is handled, and most of the solids are deposited in the receiving waters. In North America, Finland and Japan, where activated sludge treatment is used to a great extent, sludge handling is an important part of kraft mill effluent treatment. Typically, 5-15 kg of dry solids has to be handled per ton of pulp with a process discharge of 15-20 kg of BOD5/t90- For chemical coagulation, the amounts of sludges produced are higher, typically 40-80 kg dry solids/t90. Especially in Japan, chemical coagulation is used to a great extent. Laboratory and pilot- plant experiments with Ultrafiltration of alkaline stage and total bleach plant effluents suggest that concentrates with a total solids content of approximately 20 and 50 kg dry solids/t90 are produced. The concentrations of organochlorine compounds in sludges and concentrates have not hitherto been well documented, and nor have environmental effects of different disposal methods. Chlorinated phenols, catechols and guaiacols have been found in variable concentrations; chlorinated dibenzodioxins and furans have also been detected. Vacuum filters and especially belt filter presses have been used to dewater sludges. Typical dry solids concentrations achieved vary from 20-35 % for primary sludges to 15-20 % for secondary sludges. Anaerobic digestion may be applied before dewatering of sludges, and methane yields of 200-400 1 CH4/kg VSrem have been reported. Sludge has been disposed of in landfills or incinerated. Leachates from landfilling of pulp and paper industry sludges may contain high levels of soluble organic material, but available information suggests that organochlorine compounds do not leach to a substantial extent. Incineration of pulp mill sludges and concentrates seems to be an increasingly attractive method.

Advanced Effluent Treatment in the Pulp and Paper Industry with a Combined Process of Ozonation and Fixed Bed Biofilm Reactors

1999 ◽  
Vol 40 (11-12) ◽  
pp. 343-350 ◽  
Author(s):  
Alfred Helble ◽  
Wolfgang Schlayer ◽  
Pierre-André Liechti ◽  
Rudolf Jenny ◽  
Christian H. Möbius
Keyword(s):  
Paper Industry ◽  
Continuous Process ◽  
Fixed Bed ◽  
Economic Factor ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Effluent Treatment ◽  
Design Parameters ◽  
Biofilm Reactors ◽  
Treated Effluent

An advanced treatment process was developed during the last five years to improve the treated effluent quality in view of stronger environmental regulations and the possibility for the reuse of treated effluent in the Pulp and Paper Industry. The combination of ozone with fixed bed biofilm reactors is one of the most efficient tertiary effluent treatment processes to give maximum elimination of COD, colour and AOX with a minimum of ozone dosage. Several laboratory and pilot tests with effluent from a full biological treatment works confirmed the expected targets. Ozone diffusion parameters, i. e. bubble size, and distribution, reaction time and hydrodynamic pattern are decisive for interface/film or bulk reaction. This is the key economic factor for the elimination of certain kinds of organic matter by transferring persistent “hard” COD into biodegradable compounds (BOD). Two-stage ozonation with intermediate biodegradation proved to be a valuable tool for obtaining high COD elimination efficiencies in the tertiary treatment of effluent with high persistent COD concentrations. A fully equipped bench scale plant using the ozonation - biofiltration process is in operation since the beginning of 1998. A separate batch ozonation system allows tests for optimisations which are difficult to perform in a continuous process. Results with papermill effluent are presented. This equipment gives results sufficient for determination of design parameters for an industrial size.

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