1211ETRIWC1975_page1202 |
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Nitrate Removal from Wastewater Using Fluid Bed Technology ROBERT F. GASSER, Vice President ROGER W. OWENS, Project Engineer JOHN S. JERIS, Vice President Ecolotrol, Inc. Bethpage, New York 11714 INTRODUCTION With the aid and cooperation of Nassau County, a nominal 36,000 gallon per day pilot plant for denitrification was placed into operation in May of 1973 at the County's Bay Park Water Renovation Plant. The pilot facility consists of a column of sand through which nitrified effluent is passed upwardly at velocities sufficient to fluidize the sand. Nitrate and nitrite are removed biologically by a large population of denitrifying bacteria which completely cover each sand particle. Methanol was used as the carbon source for these bacteria. Under normal operation, the flow to the reactor was 25 gallons per minute or 15 gallons per minute per square foot of surface area. The empty bed detention time in the column at this flow rate was 6.5 minutes, not including freeboard. Under these conditions the effluent concentration was consistently less than 0.5 mg/1 nitrate plus nitrite nitrogen which was equivalent to a daily removal of 99% or higher of the influent oxidized nitrogen. For a period of one week, flow was increased to 40 gpm or 24 gpm/ sf, giving an empty bed detention time of approximately 4 minutes with no detrimental effect on the effluent quality. To determine the effect of power failure on the system, the reactor was shut down for a period of. 17 hours and repeated at a later date for a period of 25 hours. Within 45 minutes and 15 minutes respectively, after start-up, the system was again achieving 99% removal. During a high nitrogen concentration study, the influent oxidized nitrogen averaged 55 mg/1 and the effluent 2.5 mg/1 for an overall removal of 95%. On two days of this study, however, insufficient methanol was fed to the reactor. If these two days are excluded from the average, the removal of nitrogen was 99%. A run was also performed on a simulated industrial waste with NO,-N concentrations of up to 130 mg/1, and excellent removals were obtained. Operation during the winter months with temperatures as low as 8 to 12 C did not significantly affect the performance of the unit. During the latter portion of the study, a 13,600 gpd sf sand separation tank and a 4,600 gpd/sf settling tank were added to the pilot facility. The sand separation tank was used successfully to return back to the denitrification reactor any sand which might escape in the effluent. The settling tank, at this high loading rate, was able to remove all the suspended solids, which averaged about 10 mg/1, produced by the denitrification unit. 1202
Object Description
Purdue Identification Number | ETRIWC1975103 |
Title | Nitrate removal from wastewater using fluid bed technology |
Author |
Gasser, Robert F. Owens, Roger W. Jeris, John S. |
Date of Original | 1975 |
Conference Title | Proceedings of the 30th Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/u?/engext,25691 |
Extent of Original | p. 1202-1207 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Date Digitized | 2009-06-30 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | 1211ETRIWC1975_page1202 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | Nitrate Removal from Wastewater Using Fluid Bed Technology ROBERT F. GASSER, Vice President ROGER W. OWENS, Project Engineer JOHN S. JERIS, Vice President Ecolotrol, Inc. Bethpage, New York 11714 INTRODUCTION With the aid and cooperation of Nassau County, a nominal 36,000 gallon per day pilot plant for denitrification was placed into operation in May of 1973 at the County's Bay Park Water Renovation Plant. The pilot facility consists of a column of sand through which nitrified effluent is passed upwardly at velocities sufficient to fluidize the sand. Nitrate and nitrite are removed biologically by a large population of denitrifying bacteria which completely cover each sand particle. Methanol was used as the carbon source for these bacteria. Under normal operation, the flow to the reactor was 25 gallons per minute or 15 gallons per minute per square foot of surface area. The empty bed detention time in the column at this flow rate was 6.5 minutes, not including freeboard. Under these conditions the effluent concentration was consistently less than 0.5 mg/1 nitrate plus nitrite nitrogen which was equivalent to a daily removal of 99% or higher of the influent oxidized nitrogen. For a period of one week, flow was increased to 40 gpm or 24 gpm/ sf, giving an empty bed detention time of approximately 4 minutes with no detrimental effect on the effluent quality. To determine the effect of power failure on the system, the reactor was shut down for a period of. 17 hours and repeated at a later date for a period of 25 hours. Within 45 minutes and 15 minutes respectively, after start-up, the system was again achieving 99% removal. During a high nitrogen concentration study, the influent oxidized nitrogen averaged 55 mg/1 and the effluent 2.5 mg/1 for an overall removal of 95%. On two days of this study, however, insufficient methanol was fed to the reactor. If these two days are excluded from the average, the removal of nitrogen was 99%. A run was also performed on a simulated industrial waste with NO,-N concentrations of up to 130 mg/1, and excellent removals were obtained. Operation during the winter months with temperatures as low as 8 to 12 C did not significantly affect the performance of the unit. During the latter portion of the study, a 13,600 gpd sf sand separation tank and a 4,600 gpd/sf settling tank were added to the pilot facility. The sand separation tank was used successfully to return back to the denitrification reactor any sand which might escape in the effluent. The settling tank, at this high loading rate, was able to remove all the suspended solids, which averaged about 10 mg/1, produced by the denitrification unit. 1202 |
Resolution | 300 ppi |
Color Depth | 8 bit |
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