Chemical characterization and biotreatability of effluents from an integrated alkaline-peroxide mechanical pulping/machine finish coated (APMP/MFC) paper mill

1997 ◽  
Vol 35 (2-3) ◽  
pp. 7-14 ◽  
Author(s):  
A. Schnell ◽  
M. J. Sabourin ◽  
S. Skog ◽  
M. Garvie

As part of an extensive audit of the Alkaline-Peroxide Mechanical Pulping (APMPTM) plant at the Malette Quebec Inc. mill in St. Raymond, Que., effluents were sampled from various stages of the process for comprehensive chemical characterizations, aquatic toxicity testing and anaerobic biotreatability assessments. In addition, untreated and secondary treated combined effluent from the integrated paper mill were sampled to determine the effectiveness of a conventional activated sludge process at the mill site. During the one-day sampling period, the APMP plant processed a mixed wood furnish consisting of 50% spruce/balsam fir and 50% aspen, with a chemical charge of 3.5% sodium hydroxide and 3.8% hydrogen peroxide on oven-dry fibre, while the Machine Finish Coated (MFC) paper production rate was 100 odt/d (oven dry metric tonnes per day). Measured production-specific contaminant discharge loadings from the novel APMP process were 56 kg BOD5/odt and 155 kg COD/odt in a combined effluent flow of 28 m3/odt. Sources of process effluent were chip washing, three stages of wood chip pretreatment and chemical impregnation (i.e., Impressafiner stages), interstate washing and pulp cleaning. The three Impressafiner pressates were found to be the most concentrated (i.e., 12-26 g COD/L) and toxic streams. Microtox testing of the pressates revealed EC50 concentrations of 0.07-0.34% v/v. The warm and concentrated effluents generated by the non-sulphur APMP process were found to be highly amenable to anaerobic degradation as determined by batch bioassay testing. Filterable BOD5 and COD(f) of the process effluents were reduced by 87-95% and 70-77%, respectively, with corresponding theoretical methane yields being attained. Acid-soluble dissolved lignin compounds exhibited biorecalcitrance, as revealed by limited removals of 34-55%, and were the main constituents contributing to residual COD(f), while resin and fatty acids (RFA) were reduced by 80-94%. The conservatively operated full scale activated sludge treatment process achieved a similar high 74% COD(f) removal from the whole mill effluent, while BOD5 and RFA reductions were virtually complete and the treated effluent was non-toxic, as measured by Microtox.

2003 ◽  
Vol 48 (8) ◽  
pp. 103-110 ◽  
Author(s):  
N.I. Galil ◽  
Ch. Sheindorf ◽  
N. Stahl ◽  
A. Tenenbaum ◽  
Y. Levinsky

The full-scale existing treatment plant in a paper mill in Hedera, Israel, includes equalization, solids separation by either straining or by dissolved air flotation and biological treatment by activated sludge. The operation of the existing biological process is often characterized by disturbances, mainly bad settling, voluminous bioflocs, followed by wash-out of the biosolids. This paper summarizes the results obtained in a study based on a pilot plant including a membrane biological reactor (MBR) compared to the “conventional” activated sludge process in the aerobic treatment of the effluent obtained from an anaerobic reactor. During the pilot operation period (about 90 days after achieving steady state) the MBR system provided steady operation performance, while the activated sludge produced effluent characterized by oscillatory values. The results are based on average values and indicate much lower levels of suspended solids in the MBR effluent, 2.5 mg/L, as compared to 37 mg/L in the activated sludge. As a result, the total organic mater content was also substantially lower in the MBR effluent, 129 vs 204 mg/L as COD, and 7.1 vs 83 mg/L as BOD. The MBR enabled better nitrification. The ability to develop and maintain a concentration of over 11,000 mg/L of mixed liquor volatile suspended solids in the MBR bioreactor enabled an intensive bioprocess at relatively high cell residence time. As a result the biosolids which had to be removed as excess sludge were characterized by relatively low volatile/total suspended solids ratio, around 0.78. This could facilitate and lower the cost of biosolids treatment and handling. The results of this comparative study indicate that in the case of MBR there will be no need for further treatment, while after activated sludge additional filtration will be required. The study leads to the conclusion that MBR will be the best technology for aerobic treatment of the anaerobic effluent of the paper mill.


1993 ◽  
Vol 28 (3) ◽  
pp. 571-596 ◽  
Author(s):  
Susan F. Liver ◽  
Henry K. Miyamoto ◽  
Steve A. Black

Abstract A continuous bench-scale treatability study determined the most desirable design and operating parameters for waste treament of effluent from an integrated Canadian TMP newsprint operation. An initial batch study indicated that the effluent was biologically treatable and provided initial biological kinetic (biokinetic) parameters for this wastewater. This information was used to design the continuous study. Conventional activated sludge treatment of the mill wastewater can produce an effluent which meets the federal regulations for BOD5, suspended solids, and toxicity to D. magna. Predictions using cumulative toxicity units (CTU) indicate that the treated effluent would also be non-toxic to O. mykiss as well. Analyses of ammonia in the treated effluent indicated that un-ionized ammonia concentrations would be non-toxic to rainbow trout. Mass balances incorporating the results of the bench-scale studies and the effect of fibre carry-over from the primary clarifier, defined the full-scale operating conditions selected as: an F/M of 0.35 d−1, HRT of 0.5 days, SRT of 6 days and an MLSS of 4400 mg/L (when no polymer is used at the primary clarifier). These conditions were arrived at by selecting the smallest HRT which still corresponded to an MLSS < 5000 mg/L, an F/M < 0.4 d−1 and an SRT > 5 days. Based on the kinetics for biological treatment of mill effluent, at the maximum mill production, adequate BOD5 removal will still easily be obtained under the above operating conditions, even during cold weather periods. Operational concerns identified by bench-scale testing indicated that a full-scale facility should incorporate an anoxic selector (although the anoxic selector did not show measurable improvement in the bench-scale tests) and micronutrient addition for filamentous bulking control.


TAPPI Journal ◽  
2016 ◽  
Vol 15 (2) ◽  
pp. 127-137
Author(s):  
ALEKSANDRA RACˇ ICˇ KOZMUS ◽  
ANDREJA ŽGAJNAR GOTVAJN ◽  
ALEKSANDRA LOBNIK ◽  
NINA NOVAK ◽  
ALJAZ KLASINC ◽  
...  

Investigations were conducted to explore the use of anaerobic treatment options that may allow complete recovery of primary and waste activated sludge streams for incineration from a graphic paper mill with an integrated deinked pulp plant. The effective reduction of waste activated sludge quantity (55%–65%) was obtained by the anaerobic treatment of wastewater from the deinked pulp plant or by the anaerobic stabilization of the mill effluent from primary treatment, where chemical oxygen demand (COD) removal efficiency of 67.6% and 64.8%, and biogas potential of 440 and 496 m3/t CODremoved were achieved, respectively. The anaerobic treatment of wastewater and alkali hydrolysis of waste activated sludge decreased the dewatering properties of solids residue in treated effluent resulting in a negative impact on the sludge recovery energy balance. The addition of municipal wastewater to anaerobic treatment in the amount of 18 vol%, representing 10% of the total COD, increased the reduction of waste activated sludge to 78%, with a positive impact on the treatment costs and efficiency. Anaerobic treatment of the studied effluents may enable incineration of all mill sludge with a positive energy balance, a reduction of biological wastewater treatment operational cost by up to 83%, and mill conventional energy demands by up to 2.7%, resulting in total cost savings of up to EUR 5.2 (USD 5.60) per ton of paper.


1997 ◽  
Vol 35 (2-3) ◽  
pp. 235-243 ◽  
Author(s):  
R. Saunamäki

The performance of Finnish activated sludge plants (primary clarifier, equalization basin, buffer basin, aeration basin, secondary clarifier and sludge handling) was surveyed. Performance was generally found to be excellent. BOD7 removal averaged 94% at paper mills (21mg/l effluent concentration, 0.43 kg/t discharge) and 95% at chemical pulp mills (18 mg/l, 0.83 kg/t). CODCr removal averaged 82% at paper mills (158 mg/l effluent concentration, 3.52 kg/t discharge) and 60% at pulp mills (531 mg/l, 20.7 kg/t). Treated effluent from paper mills contained 0.57 mg/l (13.3 g/t) of total phosphorus and from pulp mills 1.31 mg/l (47.3 g/t). AOX removal was 45-65% and discharge 0.15-0.90 kg/t. Suspended solids removal averaged 91% at paper mills and 76% at pulp mills, the average overflow concentration in primary clarifier being about 150 mg/l at both types of mill. All activated sludge plants are designed according to either the low load or extended aeration principle; high load plants are no longer in use. The average sludge load was 0.15 kg BOD/(kg MLSS d), the sludge age at the extended aeration plants ranging from 20 to 50 d. Low load appearance to be the main reason for the good performance of the plants. Other factors included the introduction of equalization and buffer basins at many plants, and particularly the fact that aeration factors and nutrients were under control. All paper mill activated sludge plants use nitrogen and phosphorus additions, whereas pulp mill plants manage without phosphorus. Optimization of nutrient addition is vital because almost every mill in Finland has a limit for its phosphorus discharge. Total sludge production at the paper mill plants averaged 40.9 t/d, 15% of which (5.9 t/d, 6.0 kg/t) was biosludge. At the pulp mills the figures were 27.2 t/d (11.5 t/d biosludge, 9.5 kg/tp). Belt filter presses are used for dewatering at most plants and dry solids contents are usually 25-35%. New-generation screw presses have been introduced, mainly at new pulp mill activated sludge plants, yielding dry solids contents of 40%. Combined and dewatered sludge is normally burned in bark-fired boilers, although some mills still landfill their sludge.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (3) ◽  
pp. 14-20 ◽  
Author(s):  
YUAN-SHING PERNG ◽  
EUGENE I-CHEN WANG ◽  
SHIH-TSUNG YU ◽  
AN-YI CHANG

Trends toward closure of white water recirculation loops in papermaking often lead to a need for system modifications. We conducted a pilot-scale study using pulsed electrocoagulation technology to treat the effluent of an old corrugated containerboard (OCC)-based paper mill in order to evaluate its treatment performance. The operating variables were a current density of 0–240 A/m2, a hydraulic retention time (HRT) of 8–16 min, and a coagulant (anionic polyacrylamide) dosage of 0–22 mg/L. Water quality indicators investigated were electrical con-ductivity, suspended solids (SS), chemical oxygen demand (COD), and true color. The results were encouraging. Under the operating conditions without coagulant addition, the highest removals for conductivity, SS, COD, and true color were 39.8%, 85.7%, 70.5%, and 97.1%, respectively (with an HRT of 16 min). The use of a coagulant enhanced the removal of both conductivity and COD. With an optimal dosage of 20 mg/L and a shortened HRT of 10 min, the highest removal achieved for the four water quality indicators were 37.7%, 88.7%, 74.2%, and 91.7%, respectively. The water qualities thus attained should be adequate to allow reuse of a substantial portion of the treated effluent as process water makeup in papermaking.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (5) ◽  
pp. 19-25 ◽  
Author(s):  
PETER W. HART ◽  
DARRELL M. WAITE ◽  
LUC THIBAULT, ◽  
JOHN TOMASHEK ◽  
MARIE-EVE ROUSSEAU ◽  
...  

Eucalyptus wood chips were subjected to impregnation with various blends of novel fiber modify-ing enzymes before chemical pretreatment and two stages of refining using the preconditioning refiner chemical–alkaline peroxide mechanical pulping (PRC-APMP) process. Wood chip impregnation and pulp processing was con-ducted at a pilot plant in the United States. When compared under constant chemical application and at a constant 350 mL CSF, enzyme treatment reduced specific refining energy by at least 24%. The effect of one versus two stages of impregnation and of enzyme action upon several physical pulp properties was determined.


1988 ◽  
Vol 20 (2) ◽  
pp. 143-152 ◽  
Author(s):  
A. Langi ◽  
M. Priha

The mutagenic properties of pulp and paper mill effluents were studied in three mills: bleached kraft mill with aerated lagoon treatment (Mill 1), bleached kraft mill with activated sludge treatment (Mill 2) and mechanical pulp/paper mill (Mill 3). Both treated and untreated effluents, process streams and molecular fractions were tested for mutagenicity (Ames test. Salmonella typhimurium TA100 and SCE sister chromatid exchange test, Chinese hamster ovary cells). To verify the potential environmental effects the mutagenic activity of concentrated recipient lake water (Mill 2) was also studied. The Ames mutagenicity of the bleached kraft mill effluent (BKME) originated from the first chlorination filtrate, SCE mutagenicity also occurred in the alkali extraction stage filtrate (Mill 1). No Ames mutagenicity was detected in the paper mill effluent, but it was SCE mutagenic. Activated sludge treatment of BKME removed both Ames and SCE mutagenicity, but the aerated lagoon treated BKME was still SCE mutagenic. No mutagenic activity was detected in the recipient water concentrates.


1994 ◽  
Vol 30 (6) ◽  
pp. 31-40 ◽  
Author(s):  
Hiroyshi Emori ◽  
Hiroki Nakamura ◽  
Tatsuo Sumino ◽  
Tadashi Takeshima ◽  
Katsuzo Motegi ◽  
...  

For the sewage treatment plants near rivers and closed water bodies in urbanized areas in Japan and European countries, there is a growing demand for introduction of advanced treatment processes for nitrogen and phosphorus from the viewpoints of water quality conservation and environmental protection. In order to remove nitrogen by the conventional biological treatment techniques, it is necessary to make a substantial expansion of the facility as compared with the conventional activated sludge process. In such urbanized districts, it is difficult to secure a site and much capital is required to expand the existing treatment plant. To solve these problems, a compact single sludge pre-denitrification process using immobilized nitrifiers was developed. Dosing the pellets, which are suitable for nitrifiers growth and physically durable, into the nitrification tank of single sludge pre-denitrification process made it possible to perform simultaneous removal of BOD and nitrogen in a retention time equal to that in the conventional activated sludge process even at the low water temperature of about 10 °C. The 3,000 m3/d full-scale conventional activated sludge plant was retrofitted and has been successfully operated.


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