Large-scale nitrogen removal demonstration at the blue plains wastewater treatment plant using post-denitrification with methanol

1998 ◽  
Vol 38 (1) ◽  
pp. 79-86 ◽  
Author(s):  
Walter Bailey ◽  
Akile Tesfaye ◽  
Jerry Dakita ◽  
Michael McGrath ◽  
Glenn Daigger ◽  
...  

The Chesapeake Bay Agreement of 1987 calls for an overall reduction in nutrient loading of forty percent of 1985 levels by the year 2000. Signatories to the agreement include the states located in the Bay's watershed and the District of Columbia. The District's 16.2 m3/sec (370 mgd) Blue Plains Regional Wastewater Treatment Plant is the single, largest point source of nitrogen load to the Bay, discharging approximately 18 metric tons per day. In an effort toward meeting the nitrogen reduction goal, a post-denitrification demonstration study was recently begun to access its potential for long-term implementation. The denitrification demonstration project involves operating half of the nitrification facilities in a nitrification-denitrification mode using methanol as a carbon source for post-denitrification. The other half continues operation in a nitrification-only mode as a control. The post-denitrification process was selected for demonstration because it utilizes existing facilities and may offer substantial long-term cost savings. Objectives of the study are to demonstrate the process without a negative impact on effluent quality, to verify performance and capacity, to determine the stability and limitations of the project, and to compare the process to other nitrogen-removal technologies. Thus far, the process has been successful in removing nitrogen despite problems with phosphorus limitation and with the settling characteristics of the denitrification sludge. It is believed that insufficient phosphorus availability has been responsible for problems associated with settling, sludge yield, methanol use, and denitrification rates. Recently, phosphorus input to the denitrification process has been increased by reducing metal salt addition in upstream processes and preliminary results have been promising. If performance criteria are achieved without sacrificing plant capacity, the process will be continued at full scale.

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1315-1323 ◽  
Author(s):  
H. Aspegren ◽  
B. Andersson ◽  
U. Nyberg ◽  
J. la C. Jansen

Optimization of wastewater treatment plants with extensive phosphorus and nitrogen removal is complicated. The Klagshamn wastewater treatment plant in Sweden is operated with pre-precipitation of phosphorus with ferric chloride and denitrification with methanol as carbon source. An activated sludge process, operated with pre-precipitation and denitrification with external carbon source in a compartmentalized plant, requires only small tank volumes but increases the need for proper operation and optimization. On-line nitrogen, ammonia, and TOC sensors are used for a day-to-day control and optimization while mathematical modelling is used for long term strategic planning. The on-line measurements are further used as the basis for the modelling. TOC and ammonia sensors at the influent clearly identify typical and extreme loading variations and nitrate measurements in the activated sludge tanks and the effluent shows the dynamics of the processes. These measurements provide a basis for model calibration. In combination low residuals of nitrogen, phosphorus and organic matter can be achieved.


1990 ◽  
Vol 22 (1-2) ◽  
pp. 101-111 ◽  
Author(s):  
J. Wanner ◽  
M. Sýkora ◽  
M. Kos ◽  
J. Miklenda ◽  
P. Grau

The situation in the treatment of wastewaters from small sources in Czechoslovakia has been discussed and two types of manufactured rotating biological contactors have been described. The evaluation of RBCs' operation showed the main disadvantages of the contactors with conventional discs, viz. the low 0C and low mixing effect. In a newly designed RBC, the discs or packets of discs were replaced by a cage packed with a random medium. The cage was equipped with tubular aeration and mixing elements. The long-term tests with a pilot-plant and a full-scale unit using synthetic as well as municipal wastewaters proved the ability of the packed-cage RBC to achieve a low effluent BOD with such organic loadings when the effluent from the conventional RBCs already deteriorated. Besides the BOD removal the 0C of the packed-cage RBCs was tested to verify the possibility of the combined cultivation of suspended and fixed-film biomass. On the basis of results presented here, a new package wastewater treatment plant for about 500 PE will be designed.


1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.


2010 ◽  
Vol 62 (8) ◽  
pp. 1965-1965
Author(s):  
S. Park ◽  
J. Lee ◽  
J. Park ◽  
I. Byun ◽  
T. Park ◽  
...  

Publisher‘s note. We regret that the published version of this article erroneously denoted the first author as corresponding author; in fact the formal corresponding author of this paper is Professor Taeho Lee, whose address is repeated below.


2010 ◽  
Vol 61 (9) ◽  
pp. 2259-2266 ◽  
Author(s):  
Styliani Kantartzi ◽  
Paraschos Melidis ◽  
Alexander Aivasidis

In the present study, a laboratory scale system, consisting of a primary settling tank, a continuous stirred tank reactor and a clarifier were constructed and operated, using wastewater from the municipal wastewater treatment plant in Xanthi, Greece. The system operated under intermittent aeration in aerobic/anoxic conditions and feeding of the wastewater once in every cycle. The unit was inoculated with sludge, which originated from the recirculation stream of the local wastewater treatment plant. The wastewater was processed with hydraulic retention time (HRT) of 12 h, in which various experimental states were studied regarding the combination of aerobic and anoxic intervals. The wastewater was fed in limited time once in every cycle of aerobic/anoxic conditions at the beginning of the anoxic period. The two states that exhibited highest performance in nitrification and total nitrogen removal were, then, repeated with HRT of 10 h. The results show that, regarding the nitrification stage and the organic load removal, the intermittent system achieved optimum efficiency, with an overall removal of biological oxygen demand (BOD5) and ammonium nitrogen in the range of 93–96% and 91–95% respectively. As far as the total nitrogen removal is concerned, and if the stage of the denitrification is taken into account, the performance of the intermittent system surpassed other methods, as it is shown by the total Kjeldahl nitrogen (TKN) removal efficiency of 85–87%. These operating conditions suppressed the growth of filamentous organisms, a fact reflected at the SVI values, which were lower than 150 ml/g.


2000 ◽  
Vol 41 (4-5) ◽  
pp. 5-12 ◽  
Author(s):  
E.v. Münch ◽  
K. Barr ◽  
S. Watts ◽  
J. Keller

The Oxley Creek wastewater treatment plant is a conventional 185,000 EP BOD removal activated sludge plant that is to be upgraded for nitrogen removal to protect its receiving water bodies, the Brisbane River and Moreton Bay. Suspended carrier technology is one possible way of upgrading this activated sludge wastewater treatment plant for nitrogen removal. Freely moving plastic media is added to the aeration zone, providing a growth platform for nitrifying bacteria and increasing the effective solids residence time (SRT). This paper presents the results from operating a pilot plant for 7 months at the Oxley Creek WWTP in Brisbane, Australia. Natrix Major 12/12 plastic media, developed by ANOX (Lund, Sweden), was trialed in the pilot plant. The pilot plant was operated with a mixed liquor suspended solids concentration of 1220 mg/L and a total hydraulic residence time of 5.4 hours, similar to the operating conditions in the full-scale Stage 1&2 works at the Oxley Creek WWTP. The plastic carriers were suspended in the last third of the bioreactor volume, which was aerated to a DO setpoint of 4.0 mg/L. The first third of the bioreactor volume was made anoxic and the second third served for carbon removal, being aerated to a DO setpoint of 0.5 mg/L. The results from the pilot plant indicate that an average effluent total inorganic nitrogen concentration (ammonia-N plus NOx−N) of less than 12 mg/L is possible. However, the effluent ammonia concentrations from the pilot plant showed large weekly fluctuations due to the intermittent operation of the sludge dewatering centrifuge returning significant ammonia loads to the plant on three days of the week. Optimising denitrification was carried out by lowering the DO concentration in the influent and in the carbon removal reactor. The results from the pilot plant study show that the Oxley Creek WWTP could be upgraded for nitrogen removal without additional tankage, using suspended carrier technology.


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