Controlling filamentous sludge bulking by regulating oxygen supply in the start of BISURE system

2021 ◽  
pp. 130487
Author(s):  
Wenji Li ◽  
Ping Zheng ◽  
Dongdong Xu ◽  
Wenda Chen ◽  
Chao Pan ◽  
...  
Keyword(s):  
Oxygen Supply ◽  
Sludge Bulking

Progress on FISH Probes of Sludge Bulking Caused by Filamentous Bacteria

2012 ◽  
Vol 18 (4) ◽  
pp. 705
Author(s):  
Ping WANG ◽  
Zhisheng YU ◽  
Rong QI ◽  
Hongxun ZHANG
Keyword(s):  
Filamentous Bacteria ◽  
Sludge Bulking

The Use of Anoxic Selectors for the Control of Low F/M Activated Sludge Bulking

1989 ◽  
Vol 21 (6-7) ◽  
pp. 609-619 ◽  
Author(s):  
Y.-J. Shao ◽  
David Jenkins
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Pilot Plant ◽  
Detention Time ◽  
Substrate Removal ◽  
Batch System ◽  
Sludge Bulking ◽  
N Removal ◽  
Soluble Substrate ◽  
Activated Sludge Systems

Laboratory and pilot plant experiments on anoxic selector activated sludge systems were conducted on two wastewaters in some cases supplemented with nitrate, acetate or glucose. To prevent bulking sufficient anoxic selector detention time and nitrate levels must be available to reduce selector effluent soluble COD to below 100 mg/l and to reduce readily metabolizable organic matter to virtually zero (< 1 mg/l). Soluble COD/NO3-N removal stoichiometry is in the range 6.0-6.7. Selector systems have elevated soluble substrate removal and denitrification rates compared to CSTR systems. These rates are not affected greatly by temperature (20-25°C) for CSTR sludges but are for selector sludges. Upon exhaustion of nitrate in a selector soluble COD leaks out of the activated sludge in significant amounts. Thiothrix sp. and type 021N denitrify only to NO2 and at much slower rates than Zoogloearamigera does to N2. A sequencing batch system provides an optimistic estimate of the SVI that can be obtained by an anoxic selector system.

scholarly journals Effect of magnetic field on biomass properties and their role in biodegradation under condition of low dissolved oxygen

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Nur Syamimi Zaidi ◽  
Johan Sohaili ◽  
Khalida Muda ◽  
Mika Sillanpää ◽  
Norelyza Hussein
Keyword(s):  
Magnetic Field ◽  
Dissolved Oxygen ◽  
Biomass Concentration ◽  
Aerobic Bacteria ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Great Chance ◽  
Sludge Bulking ◽  
The Magnetic Field ◽  
High Biomass Concentration

AbstractLow condition of dissolved oxygen (DO) is commonly associated with sludge bulking problem that was able to disrupt the efficiency of wastewater treatment performances. Relatively, very little attention was paid to the possibility of applying magnetic field in controlling the bulking problem. Hence, this study aims to investigate the performance of magnetic field on biomass properties and its effect on biodegradation under low condition of DO. Two continuous laboratory-scale sequencing batch reactors—Reactor A (SBRA) and Reactor B (SBRB)—were setup. SBRA was equipped with the magnetic device to exhibit magnetic field of 88 mT, while SBRB acted as a control system. The results showed that the biomass concentration in SBRA was higher compared to SBRB. High biomass concentration in SBRA resulted to better settleability with mean SVI of less than 30 mL/g. SBRA also showed consistently high removal performances of organic and inorganic contents compared to SBRB. These observations confirmed that the magnetic field was able to enhance the biomass properties, which further enhance the biodegradation ability of the aerobic bacteria under low DO condition. This also indicates that under the sludge bulking circumstances, the use of magnetic field stands a great chance in maintaining high biodegradation of the treatment system.

scholarly journals Lymphopenia as a Biological Predictor of Outcomes in COVID-19 Patients: A Nationwide Cohort Study

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 471
Author(s):  
Jongmin Lee ◽  
Sung-Soo Park ◽  
Tong Yoon Kim ◽  
Dong-Gun Lee ◽  
Dong-Wook Kim
Keyword(s):  
Oxygen Supply ◽  
Multivariable Analysis ◽  
Clinical Use ◽  
Invasive Ventilation ◽  
Group Iii ◽  
Group I ◽  
Severity Levels ◽  
Group Ii ◽  
Absolute Lymphocyte Counts ◽  
Using Data

We aimed to identify whether lymphopenia is a reliable prognostic marker for COVID-19. Using data derived from a Korean nationwide longitudinal cohort of 5628 COVID-19 patients, we identified propensity-matched cohorts (n = 770) with group I of severe lymphopenia (absolute lymphocyte counts [ALC]: <500/mm3, n = 110), group II of mild-to-moderate lymphopenia (ALC: ≥500–<1000/mm3, n = 330), and group III, no lymphopenia (ALC: ≥1000/mm3, n = 330). A significantly higher mortality rate was associated with lymphopenia severity: 40% in group I, 22.7% in group II, and 13.0% in group III (p < 0.001). At 28 days, the estimated inferior overall survival associated with intensified lymphopenia: 62.7% in group I, 79.9% in group II, and 89.0% in group III (p < 0.001). Lymphopenia contributed significantly toward a greater need for interventions in all groups but at varying degrees: requirements of invasive ventilation, intensive oxygen supply, or adequate oxygen supply, respectively (p < 0.001). The lymphopenia intensity was independently associated with higher COVID-19 mortality in multivariable analysis; adjusted odds ratios of 5.63 (95% CI, 3.0–10.72), and 2.47 (95% CI, 1.5–4.13) for group I and group II, respectively. Lymphopenia and its severity levels may serve as reliable predictive factors for COVID-19 clinical outcomes; thus, lymphopenia may provide the prognostic granularity required for clinical use in the management of patients with COVID-19.

scholarly journals Role of myoglobin in the oxygen supply to red skeletal muscle

1975 ◽  
Vol 250 (23) ◽  
pp. 9038-9043
Author(s):  
BA Wittenberg ◽  
JB Wittenberg ◽  
PR Caldwell
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Supply

Oxygen Supply Method Using Gas-Permeable Film for Wastewater Treatment

1993 ◽  
Vol 28 (7) ◽  
pp. 243-250 ◽  
Author(s):  
Y. Suzuki ◽  
S. Miyahara ◽  
K. Takeishi
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Oxygen Supply ◽  
Oxygen Transfer Rate ◽  
High Energy ◽  
High Rate ◽  
N Removal ◽  
High Energy Consumption

Gas-permeable film can separate air and water, and at the same time, let oxygen diffuse from the air to the water through the film. An oxygen supply method using this film was investigated for the purpose of reducing energy consumption for wastewater treatment. The oxygen transfer rate was measured for the cases with or without biofilm, which proved the high rate of oxygen transfer in the case with nitrifying biofilm which performed nitrification. When the Gas-permeable film with nitrifying biofilm was applied to the treatment of wastewater, denitrifying biofilm formed on the nitrifying biofilm, and simultaneous nitrification and denitrification occurred, resulting in the high rate of organic matter and T-N removal (7 gTOC/m2/d and 4 gT-N/m2/d, respectively). However, periodic sloughing of the denitrifying biofilm was needed to keep the oxygen transfer rate high. Energy consumption of the process using the film in the form of tubes was estimated to be less than 40% of that of the activated sludge process.

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