Semi-continuous treatment of recalcitrant anaerobic effluent from pulp and paper industry using hybrid pellets of Trametes versicolor

2007 ◽  
Vol 55 (6) ◽  
pp. 125-133 ◽  
Author(s):  
A. Ortega-Clemente ◽  
M.T. Ponce-Noyola ◽  
M.C. Montes-Horcasitas ◽  
M.T. Vicent ◽  
J. Barrera-Cortés ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Trametes Versicolor ◽  
Statistical Significance ◽  
Paper Industry ◽  
Black Liquor ◽  
Post Treatment ◽  
Pollutant Removal ◽  
Holm Oak ◽  
Continuous Treatment ◽  
Removal Efficiencies

The objective of this work was to evaluate the semi-continuous post-treatment of anaerobically-pre-treated weak black liquor (anaerobic effluent, AnE) by aerobic post-treatment using hybrid pellets of Trametes versicolor. The latter consisted of fungus immobilized onto holm oak sawdust (mixed or double pellets) or a mixture of holm oak sawdust and powdered activated carbon (triple pellets). First, a semi-continuous experiment was run to compare the effectiveness of triple and mixed pellets in agitated flasks for 15 cycles of 7 days each. A second extended batch test was implemented with 500 mL AnE and triple pellets to give 400 mg fungal biomass; some units were spiked with protease inhibitor. In the first experiment, triple pellets displayed consistently higher removal efficiencies of pollutant parameters than double pellets (10 to 15% higher), although overall averages were moderate and no statistical significance to the difference could be set because of the noise of fluctuations. Periodic fluctuations of removal were characterized by three periods of approximately six cycles each with maximum removals occurring at cycles 3–4, 7–9, 13, and 14. Evaluating pooled removals of the latter cycles showed that triple pellets were significantly more effective than double pellets, with removal efficiencies as high as 47% of COD, colour, and absorbance at 254 nm (A254). In general, protease activity seemed to increase in the third period (last six cycles), whereas activities of MnP, LiP and Lac significantly decreased. In the second experiment, pollutant removals and enzymatic activities of triple pellets with protease inhibitor were significantly higher than those of units without added protease inhibitor. These results indicate that protease could be the main cause of periodic falls of pollutant removal efficiencies found in the first experiment.

Development of slow sponge sand filter (SpSF) as a post-treatment of UASB-DHS reactor effluent treating municipal wastewater

2016 ◽  
Vol 74 (1) ◽  
pp. 65-72 ◽  
Author(s):  
N. Maharjan ◽  
K. Kuroda ◽  
K. Dehama ◽  
M. Hatamoto ◽  
T. Yamaguchi
Keyword(s):  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Community Analysis ◽  
Total Coliform ◽  
Post Treatment ◽  
Pollutant Removal ◽  
Microbial Community Analysis ◽  
Anaerobic Sludge ◽  
Sand Filter ◽  
Removal Efficiencies

In this study, conventional slow sand filter (SSF) and modified slow sponge sand filter (SpSF) were investigated for the post-treatment of up-flow anaerobic sludge blanket (UASB)-down-flow hanging sponge (DHS) reactor effluent. The seasonal variation did not show significant differences in removal efficiencies of both filters. However in summer, both filters were able to achieve high total suspended solids and total biochemical oxygen demand removal averaging 97% and 99%, respectively. Contrary to organic removal, total nitrogen removal efficiency was satisfactory, showing increased removal efficiencies averaging 58% and 62% for SSF and SpSF in summer. On the other hand, average total coliform removal of SSF and SpSF was 4.2 logs and 4.4 logs and corresponding Escherichia coli removal was 4.0 logs and 4.1 logs, respectively. From our observation, it could be concluded that the relative performance of SpSF for nutrients and coliforms was better than SSF due to the effectiveness of sponge media over fine sands. Moreover, microbial community analysis revealed that the members of phylum Proteobacteria were predominant in the biofilms of both filters, which could have contributed to pollutant removal. Therefore, SpSF could be concluded to be a suitable post-treatment of UASB-DHS system in warmer conditions.

Corrosion monitoring and root cause identification in high solids concentrators

TAPPI Journal ◽  
2016 ◽  
Vol 15 (7) ◽  
pp. 467-477
Author(s):  
PASI NIEMELAINEN ◽  
MARTTI PULLIAINEN ◽  
JARMO KAHALA ◽  
SAMPO LUUKKAINEN
Keyword(s):  
Paper Industry ◽  
Black Liquor ◽  
Construction Materials ◽  
Open Circuit ◽  
Process Conditions ◽  
Potential Range ◽  
Corrosion Monitoring ◽  
General Corrosion ◽  
High Solids ◽  
Passive Area

Black liquor high solids (about 80%) concentrators have often been found to suffer from aggressive corrosion. In particular, the first and second effect bodies are susceptible to corrosion attacks resulting in tube leaks and wall thinning, which limit the availability and lifetime of evaporator lines. Corrosion dynamics and construction materials have been studied extensively within the pulp and paper industry to understand the corrosion process. However, it has been challenging to identify root causes for corrosion, which has limited proactive measures to minimize corrosion damage. Corrosion of the first phase concentrator was studied by defining the potential regions for passive area, stress corrosion cracking, pitting corrosion, and general corrosion. This was achieved by using a technique called polarization scan that reveals ranges for the passive area in which the equipment is naturally protected against corrosion. The open circuit potential, also known as corrosion potential, and linear polarization resistance of the metal were monitored online, which allowed for definition of corrosion risks for stainless steel 304L and duplex stainless steels 2205 and SAF 2906. An online temperature measurement added insight to the analysis. A process diagnostics tool was used to identify root causes of the corrosion attacks. Many of the root causes were related to process conditions triggering corrosion. Once the metal surface was activated, it was difficult to repassivate the metal naturally unless a sufficient potential range was reached.

Treatment of Different Wastewaters from Pulp and Paper Industry in Methane Reactors

1985 ◽  
Vol 17 (1) ◽  
pp. 223-230 ◽  
Author(s):  
P K Latola
Keyword(s):  
Power Plant ◽  
Paper Industry ◽  
Granular Sludge ◽  
Paper Mill ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Plastic Foam ◽  
Loading Rates ◽  
Multi Stage ◽  
Removal Efficiencies

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.

433 Insomnia and Restless Legs Syndrome in Patients with Upper Airway Stimulation Therapy

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A171-A172
Author(s):  
Mohammed Jomha ◽  
Shalini Manchanda ◽  
Stephanie Stahl ◽  
Noah Parker
Keyword(s):  
Restless Legs Syndrome ◽  
Statistical Significance ◽  
Upper Airway ◽  
Post Treatment ◽  
Apnea Hypopnea Index ◽  
Upper Airway Stimulation ◽  
Therapy Adherence ◽  
Restless Legs ◽  
Obstructive Sleep ◽  
Pre Treatment

Abstract Introduction Insomnia and restless legs syndrome (RLS) are common sleep disorders that may impact obstructive sleep apnea (OSA) treatment. To our knowledge, no studies have investigated whether these comorbidities affect upper airway stimulation (UAS) therapy adherence and outcomes. This study aims to explore possible effects of insomnia and RLS in patients using UAS therapy. Methods All patients who underwent UAS system implantation for treatment of OSA at our facility were retrospectively studied. Pre- and post-implant histories and data, including diagnostic sleep testing, otolaryngology evaluation, activation results, and treatment evaluation, were analyzed. Patients with no insomnia or RLS were compared to patients with insomnia, RLS, or both. Apnea-hypopnea index (AHI), Epworth Sleepiness Scale (ESS), and adherence were compared pre- and post-treatment for each group. Results Sixty-four patients who have undergone UAS implantation at our center have completed post-treatment in-lab titration and evaluation of their UAS system. Insomnia was present in 47%, RLS in 28%, and both insomnia and RLS in 14%. In all groups, the overall AHI during in-lab titration was >50% lower than the pre-treatment AHI (16.1+/-14.3/h vs 32.5+/-13.1/h, p<0.001). While the trend in AHI reductions suggested a lower AHI in those without insomnia or RLS, the reduction did not reach statistical significance (no insomnia or RLS 15.7+/-12.9/h, insomnia 16.9+/-16.7/h, RLS 19.0+/-15.5/h, both insomnia and RLS 23.4+/-18.4/h). UAS therapy usage was reduced in patients with RLS (3.9+/-2.6 h/night, p=0.029) and in patients with both insomnia and RLS (3.9+/-1.3 h/night, p=0.046) compared to patients with neither comorbidity (5.9+/-1.9 h/night). Mean reduction in ESS was similar across groups, averaging from 11+/-5 pre-treatment to 7+/-5 post-treatment (p<0.001). Conclusion Insomnia and RLS are common in patients using UAS therapy for OSA. Pre- and post-treatment residual AHI and ESS significantly improved in all patient groups assessed. A decrease in UAS usage was present in patients with RLS and both RLS and insomnia. Our study suggests that identification and treatment of RLS and insomnia may play an important role for UAS therapy adherence and efficacy, thus, optimizing care. Support (if any):

Spray atomization simulation of bamboo kraft black liquor with high solid content at splash-plate nozzle

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 6599-6612
Author(s):  
Yongjian Xu ◽  
Shenglin Chen ◽  
Xin Du ◽  
Xiaopeng Yue
Keyword(s):  
Paper Industry ◽  
Black Liquor ◽  
Injection Pressure ◽  
Development Trend ◽  
Solid Content ◽  
Nozzle Diameter ◽  
Spray Atomization ◽  
Kraft Black Liquor ◽  
Fluent Software ◽  
Solids Content

Increasing the solids content of pulping black liquor burned in a furnace is a development trend of the alkali recovery system in the pulp and paper industry. However, the viscosity of kraft black liquor increases exponentially with an increase in solids content, especially in the case of non-wood pulping black liquor, such as bamboo. This brings great difficulties to the pulping system and atomization of black liquor at the splash-plate nozzle, which is a complete atomization unit constituted of a splash nozzle and a splash plate. To obtain instructive results for industry, a simulation of the atomization process was made using Fluent software for the bamboo kraft black liquor with solids contents of 70 wt% and 80 wt%, which flowed through splash nozzles with the diameter of 22 or 20 mm. The studies were conducted on the distribution of flow field in the nozzle and atomization region through changing the injection pressure and nozzle diameter. The variation of atomization characteristic parameters, such as liquid film thickness, and breakup length, were elucidated. The results reveal the relationship between spray atomization with injection pressure and nozzle diameter, which provides a theoretical basis for improving the concentration of black liquor entering alkali recovery in the future.

Abstract WP375: Gender Differences in Etiologies of Stroke-Related Deaths in an Era of Availability for Stroke Intervention

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Alyssa Bautista ◽  
Sai P Polineni ◽  
Seemant Chaturvedi
Keyword(s):  
Medical History ◽  
Social History ◽  
Causes Of Death ◽  
Statistical Significance ◽  
Post Treatment ◽  
Hospital Data ◽  
Systemic Complications ◽  
Treatment Complications ◽  
Index Stroke ◽  
Iv Tpa

Background: Stroke is a disease that affects women unequally more than men. With the aging of the US population, stroke prevalence is projected to increase, especially among elderly females. In an era of stroke where the availability of treatment for acute stroke and its early complications continues to rise, we sought to determine if there are identifiable differences for causes of stroke-related death among women and men. Methods: We used a registry of stroke deaths following acute ischemic stroke at a single academic center from 2009 to 2017. Past medical history, in-hospital data, and cause of death was retrospectively collected from chart review. Female baseline characteristics were compared to male. Causes of deaths among females >/=65 versus <65 were compared using student’s t- and x 2 tests. Results: Among all stroke deaths (n=162), there were 72 (44.%) females, 90 (55.6%) males, with a mean age of 73 and 69, respectively. The proportion of smokers was higher among men (60.2% v 28.6%, p<0.001). Other medical history and social history did not have baseline differences. Among causes of death, there was no difference seen between female and male groups for malignant edema (43.1 v 33.3%,p=0.20), index stroke (2.8 v 3.3%,p=1.00), systemic complication (27.8 v 35.6%, p=0.29), withdrawal of care (12.5 v 22.2%,p=0.11); however among post-treatment hemorrhage/complications, a trend was seen towards females that did not reach statistical significance (13.9 v 5.6%,p=0.07). Of these female deaths from post-treatment complications, 6 or 60% received both IV thrombolysis (IV-tPA) and endovascular treatment (EVT), while the minority received either (30% IV-tPA, 10% EVT). Comparing causes of death among elderly females >/=65 versus <65, there were no differences as well (malignant edema 43.1 v 42.9%, p=0.98; index stroke 3.9 v 0%, p=1.00; systemic complications 27.5 v 28.6%, p=0.92; post-treatment complications 17.7 v 4.8%, p=0.26; withdrawal of care 7.8 v 23.8%, p=0.11). Conclusion: The trend for higher rate of post-treatment complications in women deserves further study in larger datasets. Women could be at higher risk for hemorrhage following IV-tPA and EVT due to older age.

Impact of microaeration bioreactor on dissolved sulfide and methane removal from real UASB effluent for sewage treatment

2020 ◽  
Vol 81 (9) ◽  
pp. 1951-1960 ◽  
Author(s):  
C. S. Cabral ◽  
A. L. Sanson ◽  
R. J. C. F. Afonso ◽  
C. A. L. Chernicharo ◽  
J. C. Araújo
Keyword(s):  
Sewage Treatment ◽  
Oxygen Demand ◽  
Post Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Sulfide Removal ◽  
Dissolved Sulfide ◽  
Removal Efficiencies ◽  
Anaerobic Sludge Blanket

Abstract Two bioreactors were investigated as an alternative for the post-treatment of effluent from an upflow anaerobic sludge blanket (UASB) reactor treating domestic sewage, aiming at dissolved sulfide and methane removal. The bioreactors (R-control and R-air) were operated at different hydraulic retention times (HRT; 6 and 3 h) with or without aeration. Large sulfide and methane removal efficiencies were achieved by the microaerated reactor at HRT of 6 h. At this HRT, sulfide removal efficiencies were equal to 61% and 79%, and methane removal efficiencies were 31% and 55% for R-control and R-air, respectively. At an HRT of 3 h, sulfide removal efficiencies were 22% (R-control) and 33% (R-air) and methane removal did not occur. The complete oxidation of sulfide, with sulfate formation, prevailed in both phases and bioreactors. However, elemental sulfur formation was more predominant at an HRT of 6 h than at an HRT of 3 h. Taken together, the results show that post-treatment improved the anaerobic effluent quality in terms of chemical oxygen demand and solids removal. However, ammoniacal nitrogen was not removed due to either the low concentration of air provided or the absence of microorganisms involved in the nitrogen cycle.

scholarly journals Influence of inducers, Tween 80, and agitation on the enhancing decolorization of black liquor by Trametes versicolor F200

2020 ◽  
Vol 1442 ◽  
pp. 012044
Author(s):  
Z Zahra ◽  
U Hanifah ◽  
R I F Anggraini ◽  
A A Sari ◽  
A Saefumillah
Keyword(s):  
Trametes Versicolor ◽  
Black Liquor ◽  
Tween 80

Experimental reedbed systems for the treatment of airport runoff

1997 ◽  
Vol 36 (8-9) ◽  
pp. 385-390 ◽  
Author(s):  
D. M. Revitt ◽  
R. B. E. Shutes ◽  
N. R. Llewellyn ◽  
P. Worrall
Keyword(s):  
Pilot Scale ◽  
Surface Flow ◽  
Pollutant Removal ◽  
Biological Processes ◽  
Metal Concentrations ◽  
Physical Chemical ◽  
Flow Systems ◽  
Total Ammonia ◽  
Removal Efficiencies

The relative efficiencies of pollutant removal from airport runoff by three different designs of pilot scale reedbed treatment systems located at Heathrow airport are described. The sub-surface flow and surface flow systems generally performed more effectively than the rafted systems for reduction of BOD, COD, total ammonia, nitrate, phosphate and metal concentrations. The variable removal efficiencies are explained in terms of the physical, chemical and biological processes which are relevant to each reedbed system.

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