scholarly journals Nitrogen removal in a shallow maturation pond with sludge accumulated during 10 years of operation in Brazil

2017 ◽  
Vol 76 (2) ◽  
pp. 268-278 ◽  
Author(s):  
V. A. J. Rodrigues ◽  
E. F. A. Mac Conell ◽  
D. F. C. Dias ◽  
M. von Sperling ◽  
J. C. de Araújo ◽  
...  

Accumulated sludge in polishing (maturation) ponds reduces the hydraulic retention time (smaller useful volume), and this could potentially lead to a decrease in performance. However, settled biomass, present in the sediments, can contribute to nitrogen removal by different mechanisms such as nitrification and denitrification. This study investigated the influence of the bottom sludge present in a shallow maturation pond treating the effluent from an anaerobic reactor on the nitrification and denitrification processes. Nitrification and denitrification rates were determined in sediment cores by applying ammonia pulses. Environmental conditions in the medium were measured and bacteria detected and quantified by real-time polymerase chain reaction (real-time PCR). The pond showed daily cycles of mixing and stratification and most of the bacteria involved in nitrogen removal decreased in concentration from the upper to the lower part of the sludge layer. The results indicate that denitrifiers, nitrifiers and anammox bacteria coexisted in the sludge, and thus different metabolic pathways were involved in ammonium removal in the system. Therefore, the sediment contributed to nitrogen removal, even with a decrease in the hydraulic retention time in the pond due to the volume occupied by the sludge.

1995 ◽  
Vol 32 (7) ◽  
pp. 135-142
Author(s):  
E. Görgün ◽  
N. Artan ◽  
D. Orhon ◽  
R. Tasli

Effective nitrogen removal is now required to protect water quality in sensitive coastal areas. This involves a much more difficult treatment process than for conventional domestic sewage as wastewater quantity and quality exhibits severe fluctuations in touristic zones. Activated sludge is currently the most widely used wastewater treatment and may be upgraded as a predenitrification system for nitrogen removal. Interpretation of nitrification and denitrification kinetics reveal a number of useful correlations between significant parameters such as sludge age, C/N ratio, hydraulic retention time, total influent COD. Nitrogen removal potential of predenitrification may be optimized by careful evaluation of wastewater character and the kinetic correlations.


2001 ◽  
Vol 43 (1) ◽  
pp. 269-276 ◽  
Author(s):  
N. Puznava ◽  
M. Payraudeau ◽  
D. Thornberg

The aim of this article is to present a new biological aerated filter (BAF) for nitrogen removal based on simultaneous nitrification and denitrification. Contrary to the systems which integrate both an aerated and a non-aerated zone to allow complete nitrogen removal in one compact or two different units (pre-denitrification and nitrification), this upflow BAF system is based on the principle of simultaneous nitrification and denitrification since the filter is completely aerated. The denitrification process is possible due to the diffusion effect which dominates biofilm processes. The real time aeration control allows us to maintain a low dissolved oxygen value (0.5 to 3 mg O2/l). In this case, the biofilm will not be fully (or less) penetrated with oxygen and denitrification will be carried out in a large part of the biofilm. Therefore, nitrification and denitrification is running simultaneously in different depths of the biofilm. By using 50% less air this BAF gave the same results (less than 20mg TN/l) on pilot plant as a classical nitrification and denitrification BAF (Toettrup et al., 1994). Less recirculation was necessary to achieve the same denitrification.


2022 ◽  
Vol 303 ◽  
pp. 114162
Author(s):  
Carla Limberger Lopes ◽  
Tatiane Martins de Assis ◽  
Fernando Hermes Passig ◽  
Adriana Neres de Lima Model ◽  
Juliana Bortoli Rodrigues Mees ◽  
...  

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 650 ◽  
Author(s):  
Xiefa Song ◽  
Xiaohan Yang ◽  
Eric Hallerman ◽  
Yuli Jiang ◽  
Zhitao Huang

The effects of hydraulic retention time (HRT) and influent nitrate-N concentration on nitrogen removal and the microbial community composition of an aerobic denitrification reactor treating recirculating marine aquaculture system effluent were evaluated. Results showed that over 98% of nitrogen was removed and ammonia-N and nitrite-N levels were below 1 mg/L when influent nitrate-N was below 150 mg/L and HRT over 5 h. The maximum nitrogen removal efficiency and nitrogen removal rate were observed at HRT of 6 or 7 h when influent nitrate-N was 150 mg/L. High-throughput DNA sequencing analysis revealed that the microbial phyla Proteobacteria and Bacteroidetes were predominant in the reactor, with an average relative total abundance above 70%. The relative abundance of denitrifying bacteria of genera Halomonas and Denitratisoma within the reactor decreased with increasing influent nitrate-N concentrations. Our results show the presence of an aerobically denitrifying microbial consortium with both expected and unexpected members, many of them relatively new to science. Our findings provide insights into the biological workings and inform the design and operation of denitrifying reactors for marine aquaculture systems.


2013 ◽  
Vol 1 (4) ◽  
pp. 458
Author(s):  
Dilek ÖZGÜN ◽  
Serden BAŞAK ◽  
Kevser CIRIK ◽  
ARZU KILIÇ ◽  
Dilek Akman ◽  
...  

Anaerobik amonyum oksidasyonu (Anammox) anoksik ortamda amonyumun elektron verici nitritin elektron alıcı olarak azot gazına oksitlendiği proses olarak bilinmektedir. Konvansiyonel nitrifikasyon-denitrifikasyon prosesleriyle karşılaştırıldığında Anammox prosesinde daha az oksijen kullanılmakta ve hiçbir organik madde (metanol, glikoz) içeriğine gerek duyulmamaktadır. Ancak sayılan avantajlarının yanı sıra Anammox bakterilerinin yavaş büyüme oranı (11-30 gün) dezavantajını oluşturmaktadır. Dolayısıyla bu bakterilerin zenginleştirilme safhasında özellikle kesikli reaktörler ile çalışmalar yapılmaktadır. Bu çalışmada sürekli olarak işletilen yukarı akışlı reaktörde (UASB-Upflow anaerobic sludge blanket), farklı dolgu malzemeleri kullanılarak hassas ve yavaş büyüyen Anammox bakterilerinin sistemden dışarıya atılmasının engellenmesi amaçlanmaktadır. Sistem yukarı akışlı kolon reaktörde 2 gün hidrolik bekleme süresinde (HRT-Hydraulic retention time) işletilmiştir. Çalışmada seramik taşlar ve Linpor dolgu malzemesi kullanılmıştır. Her iki dolgu malzemesi ile 45 gün işletilen reaktörlerden seramik taşların kullanıldığı reaktörde amonyum azotunun giderimin hızlı bir şekilde %90’lara ulaştığı gözlenmiştir. Linpor dolgu maddelerinin kullanıldığı reaktörde ise amonyum azotunun giderimi daha yavaş olmuştur. Nitrit azotu ise her iki reaktörde de %90’lara varan giderime ulaşmıştır. Stokiyometrik denkleme göre kıyaslandığında Linporlarda çok fazla miktarda nitrat azotunun oluştuğu görülmüştür. 25 gün sonunda Linporlu reaktörde elde edilen sonuçlarla seramik taş dolgulu reaktördeki sonuçlarla benzerlik göstermiştir. The Effect of Different Filling Materials in Anammox Bacteria Enrichment Anaerobic ammonium oxidation (Anammox) is a process that ammonium as electron donor is oxidized to nitrogen gas using nitrite as electron acceptor. Compared to conventional nitrification-denitrification processes, this process is used less oxygen and no organic material (methanol, glucose). However, the slow growth rate of Anammox bacteria (11-30 days) is disadvantages. Therefore, batch reactors have been carried out in these bacteria enrichment. In this study continuously operated upflow anaerobic sludge reactor (UASB) using different filling materials disposing of sensitive and slow-growing Anammox bacteria out of the system is purposed. System is operated up-flow column reactor at 2 days hydraulic retention time (HRT). In this study, ceramic stones and Linpor filling material are used. Both filling material reactors are operated in 45 days. Ceramic stones filling reactor is observed quickly reaches 90% were used reactor ammonium removal. The ammonium nitrogen removal was slower in Linpor filling materials reactor. Nitrite removal is reached up to 90% in both the reactor. When compared to the stoichiometric equation in Linpor was composed of large amounts of nitrate. At the end of 25 days the results were similar to ceramic stone filling reactor with Linpor filling material reactors.


2012 ◽  
Vol 455-456 ◽  
pp. 1030-1036
Author(s):  
Hui Zhou Yuan ◽  
Jian Bang Zhao ◽  
Shui Zhou Ke

This paper studied on the treatment of urban domestic wastewater with Anaerobic MBBR in the tropical and subtropical areas in the South of China. The emphasis focused on the effects of the Hydraulic Retention Time (HRT) and pH value to the CODCrconcentration and the NH3-N concentration of the outflow of the reactor. Moreover, the mechanism of denitrification was also explored. The results showed that the mechanism of denitrification of the reactor was found. When HRT was equal to or more than 8h, NH3-N was reduced mainly in the way of short-cut nitrification and denitrification. When HRT was less than 8h, the reactions of short-cut nitrification and denitrification & anaerobic ammonia oxidation both existed in the reactor.


1994 ◽  
Vol 29 (12) ◽  
pp. 185-195 ◽  
Author(s):  
Bjørn Rusten ◽  
Jon G. Siljudalen ◽  
Bjørnar Nordeidet

A new moving bed biofilm reactor (MBBR) has been developed in Norway. The biomass is attached to carrier elements that move freely along with the water in the reactor. It has been demonstrated that existing, high loaded, activated sludge plants can easily be upgraded to nitrogen removing MBBR plants. With chemically enhanced mechanical treatment, full scale tests showed that 80-90% total nitrogen could be removed in a MBBR plant at a total empty bed hydraulic retention time (HRT) of 2.6 hours. The plant was operated in the post-denitrification mode, using methanol as an external carbon source.


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