Nitrification of synthetic wastewater in a cross flow medium trickling filter

1998 ◽  
Vol 19 (2) ◽  
pp. 149 ◽  
Author(s):  
S. Amal Raj ◽  
D. V. S. Murthy
Keyword(s):  
Cross Flow ◽  
Synthetic Wastewater ◽  
Trickling Filter ◽  
Flow Medium

Flow-Induced Forces on a Cylinder for Different Wall Confinements at High Reynolds Numbers (3.5×105)

1975 ◽  
Vol 97 (2) ◽  
pp. 110-117
Author(s):  
P. Y. Chen ◽  
P. E. Doepker
Keyword(s):  
Flow Velocity ◽  
Cross Flow ◽  
Reynolds Numbers ◽  
Circular Cylinders ◽  
Interference Effects ◽  
High Reynolds Numbers ◽  
Gap Flow ◽  
High Reynolds ◽  
Flow Medium ◽  
Available Information

The nearness of a cylinder to a wall has an important effect on the flow-induced forces exerted on that cylinder, particularly when the cylinder is relatively large compared to the cross section of the flow channel. This paper describes an investigation of wall interference effects that occur when crossflow-induced forces are exerted on circular cylinders with moderately large blockages (d/h = 0.2 to 0.33) at high Reynolds numbers (3.5 × 105 – 1.2 × 106). The results show that, within the range studied, the gap flow velocity is the correct flow velocity to compensate for wall interference effects. The data reported here represent the first available information on experimental cross-flow-induced forces at such high Reynolds numbers using water as a flow medium.

Simultaneous removal of nitrate and phosphate using cross-flow micellar-enhanced ultrafiltration (MEUF)

2004 ◽  
Vol 50 (6) ◽  
pp. 227-234 ◽  
Author(s):  
B.-K. Kim ◽  
K. Baek ◽  
J.-W. Yang
Keyword(s):  
Cationic Surfactant ◽  
Positive Charge ◽  
Cetylpyridinium Chloride ◽  
Cross Flow ◽  
Field Application ◽  
Synthetic Wastewater ◽  
Molar Ratio ◽  
Simultaneous Removal ◽  
Distilled Water ◽  
Micellar Enhanced Ultrafiltration

The feasibility of cross-flow micellar-enhanced ultrafiltration (MEUF) was investigated to remove nitrate and phosphate simultaneously. At the above critical micelle concentration (CMC), a cationic surfactant added in wastewater forms micelles, which have positive charge on their surface. Anionic contaminants such as nitrate and phosphate can be bound on the micelles by electrostatic interaction, and the micelle-pollutants complex is removed effectively by ultrafiltration. In this study, a cross-flow MEUF system was designed and investigated the feasibility of MEUF for field application. A cationic surfactant, cetylpyridinium chloride (CPC), was used, and the synthetic wastewater was treated by the polyacrylonitrile membranes with molecular weight cut-off (MWCO) of 30,000 Da and 10,000 Da. With the molar ratio of CPC to total pollutants of > 3, > 86% of nitrate and > 91% of phosphate were removed, respectively, and > 97% of CPC was also rejected. The flux was maintained 20Ð30% of the flux of distilled water. Therefore, it is feasible to remove nitrate and phosphate simultaneously using the cross-flow MEUF system.

Application of anaerobic-uf membrane reactor for treatment of a wastewater containing high strength particulate organics

1994 ◽  
Vol 30 (12) ◽  
pp. 307-319 ◽  
Author(s):  
Hideki Harada ◽  
Kiyoshi Momonoi ◽  
Shinichi Yamazaki ◽  
Satoshi Takizawa
Keyword(s):  
Membrane Reactor ◽  
Membrane Separation ◽  
Cross Flow ◽  
Biomass Concentration ◽  
High Strength ◽  
Synthetic Wastewater ◽  
Permeate Flux ◽  
Total Strength ◽  
Methanogenic Activity ◽  
Loading Rates

A cross-flow ultrafiltration (UF) membrane separation was applied to anaerobic process for treatment of a wastewater containing high proportion of particulate COD. A synthetic wastewater with the total strength of 5000 mg COD·1−1 consisting of soluble and particulate COD (cellulose) in the ratio of 1:1 was fed to the reactor. The reactor was operated for 190 days at two loading rates, i.e. 1.5 and 2.5 kg COD·m−3·d−1. More than 98% of COD removal was consistently achieved throughout the duration, and the system was furthermore likely to accommodate much higher loading. Although the permeate COD was always kept at less than 80 mg COD·1−1, soluble COD of reactor broth accumulated up to 1200 mg COD·1−1. The biomass concentration saturated around 15 000 mg ML VSS·1−1. There was no tendency for cellulose to accumulate in the reactor over the whole period, which constituted only 1-2% of the total solids retained in the reactor. The methanogenic activity of the sludge increased 3.4 times for H2/CO2 and 10 times for acetate after 40 days operation. Afterwards, however, a further cultivation caused declines to 50% of the respective peak values for both substrates, because of a low sludge loading. The methanogenic activity using cellulose as a test substrate also exhibited a similar tendency. The membrane permeate flux deteriorated significantly with the cultivation time, owing to the change in rheological properties of the reactor mixed liquor that had been caused not only by increment of MLSS but also by accumulation of soluble high molecular organics.

Intrakranieller Cross-flow als prognostischer Faktor für einen frischen Infarkt im MRT nach Carotis-TEA

2007 ◽  
Vol 34 (S 2) ◽  
Author(s):  
H Soda ◽  
A Zormann ◽  
A Agaev ◽  
G Christopoulos ◽  
H Schweiger ◽  
...  
Keyword(s):  
Cross Flow ◽  
Prognostischer Faktor

Removal of lead by sulfate-reducing bacteria in anaerobic continuous stirred tank reactors

2016 ◽  
Vol 14 (3) ◽  
pp. 557-561
Author(s):  
Nguyễn Thị Yên ◽  
Kiều Thị Quỳnh Hoa
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Stirred Tank ◽  
Synthetic Wastewater ◽  
Terminal Electron Acceptor ◽  
Stirred Tank Reactors ◽  
Sulfate Reducing ◽  
Sulfide Production ◽  
Continuous Stirred Tank ◽  
Continuous Stirred Tank Reactors ◽  
Reducing Bacteria

Lead contaminated wastewater negatively impacts to living organisms as well as humans. In recent years, a highly promising biological process using the anaerobic production of sulfide ions by sulfate-reducing bacteria has presented itself as an alternative option for the removal of lead. This process is based on microbial utilization of electron donors, such as organic compounds (carbon sources), and sulfate as the terminal electron acceptor for sulfide production. The biogenic hydrogen sulfide reacts with dissolved heavy metals to form insoluble metal sulfide precipitates Removal of lead by an enriched consortium of sulfate-reducing bacteria (DM10) was evaluated sulfate reduction, sulfide production and lead precipitation. Four parallel anaerobic continuous stirred tank reactors (CSTR, V = 2L) (referred as R1 - R4) were fed with synthetic wastewater containing Pb2+ in the concentrations of 0, 100, 150 and 200 mg L-1 of lead and operated with a hydraulic retention time of 5 days for 40 days. The loading rates of each metal in R1- R4 were 0, 20, 30 and 40 mg L-1 d-1, respectively. The results showed that there was no inhibition of SRB growth and that lead removal efficiencies of 99-100% for Pb2+ were achieved in R2 (100 mg L-1) and R3 (150 mg L-1) throughout the experiment. For the highest lead concentration of  200 mg L-1, a decrease in efficiency of removal (from 100 to 96%) was observed at the end of the experiment. The obtained result of this study might help for a better control operation and performance improvements of reactors.

Effect of Runner Position on Performance for Open Type Cross-Flow Turbine Utilizing Waterfalls

2014 ◽  
Vol 8 (6) ◽  
pp. 1012
Author(s):  
Yusuke Katayama ◽  
Shouichiro Iio ◽  
Salisa Veerapun
Keyword(s):  
Cross Flow ◽  
Open Type
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