40. To Quick Start or Not to Quick Start: Does This Method Influence Etonogestrel (ENG) Implant Premature Removal Rates Among Adolescents?

2021 ◽  
Vol 68 (2) ◽  
pp. S22-S23
Author(s):  
Alexandria Holliday ◽  
Seema Menon ◽  
Michelle L. Pickett ◽  
Keisha Adams ◽  
Mary Guillot ◽  
...  
Keyword(s):  
Removal Rates ◽  
Premature Removal

scholarly journals Time Between Overhaul vs Premature Removal Rates as Turbine Design Considerations

1980 ◽  
Author(s):  
C. E. Curry ◽  
A. C. Wei
Keyword(s):  
Removal Rate ◽  
Utilization Rate ◽  
General Knowledge ◽  
Removal Rates ◽  
Aircraft Flight ◽  
Design Considerations ◽  
Turbine Design ◽  
Premature Removal ◽  
Insight Into

A general knowledge of aviation practices constituted the background for the identification of three distinct variables as the major drivers for engine removals in the operation of an aircraft. This study provides an insight into the interrelationships of the major drivers which determine engine removals for an aircraft: utilization rate (U), time between overhaul (TBO), and premature removal rate (PRR). Each of these elements is of concern to nearly every aircraft operator. For this study, it was assumed to be the same as aircraft flight hours per month.

Treatment of a Municipal Leachate Under Multi-Variable Conditions

1982 ◽  
Vol 17 (1) ◽  
pp. 135-148
Author(s):  
P.T. Wong ◽  
D.S. Mavinic
Keyword(s):  
Air Temperature ◽  
Nutrient Loading ◽  
Ambient Air ◽  
Removal Rates ◽  
Ambient Air Temperature

Abstract The treatability of a municipal leachate (BOD5 = 8090 mg/L) was investigated, by aerobic biostabilization, at a nutrient loading of BOD5:N:P of 100:3.2:1.1. The first stage effluents were subsequently polished by lime-magnesium coagulation. The ranges of ambient air temperature and sludge age studied were 5° to 25°C and 5 to 20 days, respectively. In the biostabilization phase, a BOD5:N:P loading of 100:3.2:1.1 was found to be “adequate” for treatment. Organic and metal removals in the first stage units were excellent. Under all conditions investigated, except for the two units close to washout conditions (5-day sludge age units at 5° and 10°C), BOD5 and COD removals of at least 99.4 and 96.4 percent, respectively, were achieved. Similarly, removal rates for most of the metals monitored were greater than 90 percent. In general, the removal of residual contaminants was not enhanced significantly by the addition of magnesium in the lime-magnesium polishing step.

Comparative study of domestic wastewater treatment efficiencies between facultative pond and water spinach pond

1995 ◽  
Vol 32 (3) ◽  
pp. 263-270 ◽  
Author(s):  
Seni Karnchanawong ◽  
Jaras Sanjitt
Keyword(s):  
Growth Rates ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Organic Content ◽  
Water Spinach ◽  
Removal Rates ◽  
Mass Removal ◽  
Loading Rates ◽  
Tropical Conditions ◽  
Average Water

Two pilot-scale studies were comparatively conducted under tropical conditions during December 1992 to September 1993. One study involved facultative ponds(FP) and the others water spinach ponds(SP). Four rectangular concrete ponds, 0.8 m × 2.4 m × 1.1 m (width × length × depth), were employed to treat the Chiang Mai University campus wastewater. Water spinach (Ipomoea aquatica) was planted in two of the ponds. The influent characteristics noted showed a low organic content, i.e. BOD 25.4-29.9 mg/l, with BOD:N ratio around 1:1. The investigations were conducted using the following hydraulic retention times (HRT): 1.6, 2, 2.7, 4, 8 and 16 d. The results showed that the BOD, COD and SS mass removal rates increased as the mass loading rates increased and the SP was significantly more effective in reducing the organic content than the FP. No relationship was found between TN mass removal and the loading rates. However, the TP mass removal rates in the SP and the FP were rather low and were considered to be insignificant. It was observed that SS accumulated in the water spinach root systems which tended to act as a strainer. This process led to plant growth inhibition and finally die-off. The average water spinach growth rates varied from 37 to 107 g wet wt./(m2.d) and no relationship was established between the growth rates and the HRT.

Analysis of organic removal rates in the aerated submerged fixed film process

1998 ◽  
Vol 38 (8-9) ◽  
pp. 213-221 ◽  
Author(s):  
Mohamed F. Hamoda ◽  
Ibrahim A. Al-Ghusain
Keyword(s):  
Pilot Plant ◽  
Removal Rate ◽  
Domestic Wastewater ◽  
Removal Rates ◽  
Hydraulic Loading ◽  
Organic Removal ◽  
Wide Range ◽  
Fixed Film ◽  
Cod Removal Rate ◽  
And Performance

Performance data from a pilot-plant employing the four-stage aerated submerged fixed film (ASFF) process treating domestic wastewater were analyzed to examine the organic removal rates. The process has shown high BOD removal efficiencies (> 90%) over a wide range of hydraulic loading rates (0.04 to 0.68 m3/m2·d). It could also cope with high hydraulic and organic loadings with minimal loss in efficiency due to the large amount of immobilized biomass attained. The organic (BOD and COD) removal rate was influenced by the hydraulic loadings applied, but organic removal rates of up to 104 kg BOD/ m2·d were obtained at a hydraulic loading rate of 0.68 m3/m2·d. A Semi-empirical model for the bio-oxidation of organics in the ASFF process has been formulated and rate constants were calculated based on statistical analysis of pilot-plant data. The relationships obtained are very useful for analyzing the design and performance of the ASFF process and a variety of attached growth processes.

The comparison of trichloroethylene removal rates by methane- and aromatic-utilizing microorganisms

1998 ◽  
Vol 38 (7) ◽  
pp. 19-24 ◽  
Author(s):  
C.-J. Lu ◽  
C. M. Lee ◽  
M.-S. Chung
Keyword(s):  
Cell Concentration ◽  
Removal Rate ◽  
Carbon Sources ◽  
Batch Reactors ◽  
Initial Cell Concentration ◽  
Removal Rates ◽  
Initial Cell ◽  
Toluene Concentration ◽  
Cell Source ◽  
Removal Efficiencies

The comparison of TCE cometabolic removal by methane, toluene, and phenol utilizers was conducted with a series of batch reactors. Methane, toluene, or phenol enriched microorganisms were used as cell source. The initial cell concentration was about 107 cfu/mL. Methane, toluene, and phenol could be readily biodegraded resulting in the cometabolic removal of TCE. Among the three primary carbon sources studied, the presence of phenol provided the best cometabolic removal of TCE. When the concentration of carbon source was 3 mg-C/L, the initial TCE removal rates initiated by methane, toluene, and phenol utilizers were 1.5, 30, and 100 μg/L-hr, respectively. During the incubation period of 80 hours, TCE removal efficiencies were 26% and 96% with the presence of methane and toluene, respectively. However, it was 100% within 20 hours with the presence of phenol. For phenol utilizers, the initial TCE removal rates were about the same, when the phenol concentrations were 1.35, 2.7, and 4.5 mg/L. However, TCE removal was not proportional to the concentrations of phenol. TCE removal was hindered when the phenol concentration was higher than 4.5 mg/L because of the rapid depletion of dissolved oxygen. The presence of toluene also initiated cometabolic removal of TCE. The presence of toluene at 3 and 5 mg/L resulted in similar TCE removal. The initial TCE removal rate was about 95 μg/L-hr at toluene concentrations of 3 and 5 mg/L compared to 20 μg/L-hr at toluene concentration of 1 mg/L.

Relations between carbon removal rates, biofilm size and density of a novel anaerobic reactor: the inverse turbulent bed

2000 ◽  
Vol 41 (4-5) ◽  
pp. 253-260 ◽  
Author(s):  
P. Buffière ◽  
R. Moletta
Keyword(s):  
Removal Rate ◽  
Removal Rates ◽  
Carbon Removal ◽  
Biofilm Growth ◽  
Loading Rates ◽  
Biomass Activity ◽  
High Turbulence ◽  
The One ◽  
High Level ◽  
Very High

An anaerobic inverse turbulent bed, in which the biogas only ensures fluidisation of floating carrier particles, was investigated for carbon removal kinetics and for biofilm growth and detachment. The range of operation of the reactor was kept within 5 and 30 kgCOD· m−3· d−1, with Hydraulic Retention Times between 0.28 and 1 day. The carbon removal efficiency remained between 70 and 85%. Biofilm size were rather low (between 5 and 30 μm) while biofilm density reached very high values (over 80 kgVS· m−3). The biofilm size and density varied with increasing carbon removal rates with opposite trends; as biofilm size increases, its density decreases. On the one hand, biomass activity within the reactor was kept at a high level, (between 0.23 and 0.75 kgTOC· kgVS· d−1, i.e. between 0.6 and 1.85 kgCOD·kgVS · d−1).This result indicates that high turbulence and shear may favour growth of thin, dense and active biofilms. It is thus an interesting tool for biomass control. On the other hand, volatile solid detachment increases quasi linearly with carbon removal rate and the total amount of solid in the reactor levels off at high OLR. This means that detachment could be a limit of the process at higher organic loading rates.

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