Evaluation of denitrification potential of rotating biological contactors for treatment of municipal wastewater

2005 ◽  
Vol 51 (11) ◽  
pp. 131-139 ◽  
Author(s):  
O. Hanhan ◽  
D. Orhon ◽  
Kh. Krauth ◽  
B. Günder
Keyword(s):  
Contact Time ◽  
Municipal Wastewater ◽  
Rotation Speed ◽  
Nitrate Removal ◽  
Rotating Biological Contactor ◽  
Suitable Alternative ◽  
Nutrient Limitations ◽  
Speed Range ◽  
Rotating Biological Contactors ◽  
Denitrification Process

In this study the effect of retention time and rotation speed in the denitrification process in two full-scale rotating biological contactors (RBC) which were operated parallel and fed with municipal wastewater is evaluated. Each rotating biological contactor was covered to prevent oxygen input. The discs were 40% submerged. On the axle of one of the rotating biological contactors lamellas were placed (RBC1). During the experiments the nitrate removal performance of the rotating biological contactor with lamellas was observed to be less than the other (RBC2) since the lamellas caused oxygen diffusion through their movement. The highest nitrate removal observed was 2.06 g/m2.d achieved by a contact time of 28.84 minutes and a recycle flow of 1 l/s. The rotation speed during this set had the constant value of 0.8 min−1. Nitrate removal efficiency on RBC1 was decreasing with increasing rotation speed. On the rotating biological contactor without lamellas no effect on denitrification could be determined within a speed range from 0.67 to 2.1 min−1. If operated in proper conditions denitrification on RBC is a very suitable alternative for nitrogen removal that can easily fulfil the nutrient limitations in coastal areas due to the rotating biological contactors economical benefits and uncomplicated handling.

Nitrate removal from groundwater using an anoxic-aerobic rotating biological contactor

1996 ◽  
Vol 34 (1-2) ◽  
pp. 323-330 ◽  
Author(s):  
A. Mohseni-Bandpi ◽  
D. J. Elliott
Keyword(s):  
Organic Carbon ◽  
Nitrate Nitrogen ◽  
Nitrate Removal ◽  
Carbon Sources ◽  
Optimum Conditions ◽  
Rotating Biological Contactor ◽  
Nitrite Nitrogen ◽  
In Series ◽  
Rotating Biological Contactors ◽  
Final Effluent

The removal of nitrate-nitrogen from groundwater was investigated using two rotating biological contactors (RBC) in series. The first pilot plant RBC reactor was operated under anoxic condition to remove nitrate-nitrogen. A fraction of effluent of the anoxic RBC was fed to a bench scale aerobic RBC to study the degradation of residual organic carbon and oxidation of nitrite-nitrogen. The first reactor achieved a nitrate removal efficiency of 90 percent for a loading rate of 76 mg/m2.h. The corresponding effluent nitrate, nitrite and residual carbon sources concentrations amounted to 3.3, 0.34 and 3.9 mg/l, respectively. The optimum ethanol to nitrate-nitrogen (E/N) ratio was found to be 2.35. No residual ethanol and nitrite-nitrogen were observed in the final effluent under optimum conditions. Dissolved oxygen in the final effluent was found to be greater than 7 mg/l. The results of the study suggest that using a continuous anoxic-aerobic RBC is a convenient and reliable process for removal of nitrate, residual organic carbon and nitrite.

Optimal operations for groundwater denitrification of drinking water using heterotrophic biological denitrification process

2006 ◽  
Vol 6 (2) ◽  
pp. 125-130
Author(s):  
C.-H. Hung ◽  
K.-H. Tsai ◽  
Y.-K. Su ◽  
C.-M. Liang ◽  
M.-H. Su ◽  
...  
Keyword(s):  
Drinking Water ◽  
Removal Efficiency ◽  
Nitrate Removal ◽  
Drinking Water Treatment ◽  
Nitrate Content ◽  
Source Water ◽  
Nitrogen Gas ◽  
Negative Effect ◽  
Denitrification Process ◽  
Heterotrophic Denitrification

Due to the extensive application of artificial nitrogen-based fertilizers on land, groundwater from the central part of Taiwan faces problems of increasing concentrations of nitrate, which were measured to be well above 30 mg/L all year round. For meeting the 10 mg/L nitrate standard, optimal operations for a heterotrophic denitrification pilot plant designed for drinking water treatment was investigated. Ethanol and phosphate were added for bacteria growing on anthracite to convert nitrate to nitrogen gas. Results showed that presence of high dissolved oxygen (around 4 mg/L) in the source water did not have a significantly negative effect on nitrogen removal. When operated under a C/N ratio of 1.88, which was recommended in the literature, nitrate removal efficiency was measured to be around 70%, sometimes up to 90%. However, the reactor often underwent severe clogging problems. When operated under C/N ratio of 1.0, denitrification efficiency decreased significantly to 30%. Finally, when operated under C/N ratio of 1.5, the nitrate content of the influent was almost completely reduced at the first one-third part of the bioreactor with an overall removal efficiency of 89–91%. Another advantage for operating with a C/N ratio of 1.5 is that only one-third of the biosolids was produced compared to a C/N value of 1.88.

Nitrification and denitrification using a single biofilter packed with granular sulfur

2003 ◽  
Vol 47 (11) ◽  
pp. 153-156 ◽  
Author(s):  
J.-S. Kim ◽  
Y.-W. Hwang ◽  
C.-G. Kim ◽  
J.-H. Bae
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Domestic Wastewater ◽  
Organic Load ◽  
Low Carbon ◽  
Municipal Wastewater Treatment ◽  
Treatment Facility ◽  
Experimental Conditions ◽  
Nitrification And Denitrification ◽  
Denitrification Process

This study was performed to develop a granular sulfur packed nitrification/denitrification process employing a uniquely designed single biofilter, which treated a relatively low carbon loaded domestic wastewater taken from a primary clarifier at a municipal wastewater treatment facility. The system was tested on varying experimental conditions, e.g. inflow flow, organic load and nitrogen load. Regardless of flow rate being increased, SS and COD was unvaryingly removed up to 90 and 80%, respectively. Moreover, TKN was also decomposed up to 90%. Increase in COD load gradually led to escalating level of non-biodegradable compounds observed in effluent. Nitrification was accomplished as high as 92%, whereas denitrification was achieved up to approximately 87%. For a while, nitrification and denitrification were observed at 0.65 and 0.55 kg/m3áday, respectively. Eventually, T-N was decomposed as high as 46%. It was concluded that granular sulfur can be used for not only electron donor, but also for a media to properly treat low carbon loaded wastewater and to filter SS efficiently.

scholarly journals Impact of Temperature on Biological Denitrification Process

1970 ◽  
Vol 7 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Iswar Man Amatya ◽  
Bhagwan Ratna Kansakar ◽  
Vinod Tare ◽  
Liv Fiksdal
Keyword(s):  
Filtration Rate ◽  
Nitrate Nitrogen ◽  
Nitrate Removal ◽  
Biological Method ◽  
Biological Denitrification ◽  
Nitrite Nitrogen ◽  
Nitrogen Concentrations ◽  
In Series ◽  
Nitrate And Nitrite ◽  
Denitrification Process

Nitrate removal in groundwater was carried out by biological method of denitrification process. The denitrification and without denitrification were performed in two different sets of reactors. Each reactor consists of two columns connected in series packed with over burnt bricks as media. The filtration rate varied from 5.3 to 52.6 m/day for denitrification process. The ammonia, nitrate and nitrite nitrogen concentrations were measured at inlet, intermediate ports and outlet. The temperature varied from 10 to 30°C at 2°C intervals. The results demonstrated that high amount of nitrate nitrogen removed in groundwater at denitrification process. The nitrate nitrogen removed by denitrification varied from 3.50 to 39.08 gm/m3/h at influent concentration from 6.32 to 111.04 gm/m3/h. Denitrification was found more significant above 16°C.Key words: Over burnt brick, Denitrification, Filtration rate and TemperatureJournal of the Institute of Engineering, Vol. 7, No. 1, July, 2009 pp. 121-126doi: 10.3126/jie.v7i1.2070 

THE DESIGN AND MESHING EFFICIENCY ANALYSIS OF HELICAL SPUR GEAR REDUCER WITH SINGLE GEAR PAIR FOR ELECTRIC SCOOTERS

2015 ◽  
Vol 39 (3) ◽  
pp. 455-465 ◽  
Author(s):  
Long-Chang Hsieh ◽  
Tzu-Hsia Chen ◽  
Hsiu-Chen Tang
Keyword(s):  
Energy Conservation ◽  
Rotation Speed ◽  
Spur Gear ◽  
Efficiency Analysis ◽  
Gear Pair ◽  
Electric Scooter ◽  
Speed Range ◽  
Root Strength ◽  
Reduced Costs ◽  
Better Than

To achieve reduced costs and energy conservation, this paper proposes non-standard helical spur gear reducer with one gear pair (having reduction ratio 19.25) to be the gear reducer for electric scooter. This paper also focuses on the meshing efficiency analysis of non-standard helical spur gear pair. According to Buckingham’s research, the theoretical meshing efficiency formula of non-standard helical spur gear pair is derived. Three design cases of non-standard helical spur gear pair (4, 77) are proposed as examples for analyzing their meshing efficiencies at widely rotation speed range. The theoretical meshing efficiencies for the helical spur gear pair (4, 77) are between 96.47–99.26%. Its best meshing efficiency occurs at 800–1000 rpm of pinion. The meshing efficiencies of these three design cases are almost same, and their differences are less than 0.5%. Considering the root strength of pinion, Cases II and III are better than Case I.

THM formation during chlorination of treated municipal wastewater

2002 ◽  
Vol 2 (3) ◽  
pp. 235-242 ◽  
Author(s):  
E. Koukouraki ◽  
E. Diamadopoulos
Keyword(s):  
Organic Carbon ◽  
Contact Time ◽  
Municipal Wastewater ◽  
Secondary Effluent ◽  
Batch Experiments ◽  
Limited Effect ◽  
Formation Potential ◽  
Coagulation Tests ◽  
Treated Municipal Wastewater

Chlorination batch experiments were conducted in order to estimate the concentration of THM and their formation potential in nitrified and partially nitrified secondary effluent. The role of contact time (up to 2 hours), chlorine dose (3 levels), pH and temperature on the formation of THM was evaluated. THM formation, as measured by individual concentration as well as formation potential, was high for the nitrified secondary effluent, while for the partially nitrified effluent the respective concentrations were low, due to the reaction of chlorine with ammonia to form chloramines. In general, THM concentrations progressively increased as contact time, pH and chlorine dose increased. Increase in temperature (from 15-25°C) showed a rather limited effect. In addition, coagulation tests were applied prior to chlorination of the nitrified effluent for removing organic carbon and thereby controlling the formation of THM. Alum was used as the coagulant in doses varying from 0.1 mM to 2.5 mM. As the coagulant dose increased, the removal of both DOC and absorbance at 254 nm increased, while THM formation decreased. The reduction in THM formation was more pronounced for coagulant doses higher than 1.5 mM.

Sign in / Sign up

Export Citation Format

Share Document