Efficient Biological Nutrient Removal in a Membrane Bioreactor Using Denitrifying Phosphorus Removal and Simultaneous Nitrification and Denitrification

2014 ◽  
Vol 507 ◽  
pp. 693-701
Author(s):  
Jiu Yi Li ◽  
Nian Peng Wu ◽  
Jin Li ◽  
Ai Min Wang ◽  
Yong Chen ◽  
...  

Biological nutrient removal (BNR) is generally integrated in municipal wastewater treatment plants to alleviate the impact of treated effluent on receiving watersheds. This paper studies the performance of BNR in a membrane bioreactor system consisting of anaerobic, anoxic, micro-aerobic and aerobic compartments treating a synthetic wastewater containing low organic matters. The membrane bioreactor system designed an anti-stream, stepwise return flow scheme to produce ideal conditions for the occurrence of simultaneous nitrification and denitification and denitrifying phosphorus removal processes. The proposed membrane reactor system has established higher biomass concentrations and ideal environments for biological nutrient removal processes, which results in high nutrient removal efficiencies treating low organic wastewaters. Four compartment configurations in the reactor system minimized the impact of oxidized nitrogen species in return flow on phosphorus release in the anaerobic tank and the anti-stream, stepwise return flow scheme encouraged the utilization of nitrate as the electronic acceptor in phosphorus uptake in the micro-aerobic tank. Denitrifying phosphorus removal and simultaneous nitrification and denitrification processes are the main mechanisms responsible for efficient nutrient removal. High phosphorus release activities and high phosphate concentration in the anaerobic tank make it is potentially feasible to recover phosphorus resource from wastewater.

1997 ◽  
Vol 36 (12) ◽  
pp. 61-68 ◽  
Author(s):  
Eun Lee Sang ◽  
Soo Kim Kwang ◽  
Hwan Ahn Jae ◽  
Whoe Kim Chang

Bench scale experiments were carried out with four biological nutrient removal(BNR) units, A/O, A2/O, Phostrip and P/L units, to investigate the behavior of phosphorus in the system and to compare the characteristics of phosphorus removal in four experimental BNR units. The influent COD/T-P ratio was varied from 22 to 64 by changing COD concentration while maintaining phosphorus concentration constant. In general sidestream BNR units such as Phostrip and P/L units outperformed mainstream BNR units such as A/O and A2/O units in terms of phosphorus removal. While phosphorus release and uptake in A/O and A2/O units became less significant at low influent COD/T-P, the phosphorus release in A2/O unit was further influenced by nitrate in return sludge and thus A2/O unit required even higher influent COD/T-P ratio for luxury uptake of phosphorus. The luxury uptake of phosphorus in Phostrip and P/L units were not affected by influent COD/T-P ratio and the adverse effect of nitrate in return sludge on anaerobic phosphorus release in P/L process was not significant due to the sludge blanket in P-stripper.


2007 ◽  
Vol 56 (2) ◽  
pp. 95-102 ◽  
Author(s):  
L. Rodríguez ◽  
J. Villaseñor ◽  
I.M. Buendía ◽  
F.J. Fernández

The aim of this study was to evaluate the feasibility of the re-use of the winery wastewater to enhance the biological nutrient removal (BNR) process. In batch experiments it was observed that the addition of winery wastewater mainly enhanced the nitrogen removal process because of the high denitrification potential (DNP), of about 130 mg N/g COD, of the contained substrates. This value is very similar to that obtained by using pure organic substrates such as acetate. The addition of winery wastewater did not significantly affect either phosphorus or COD removal processes. Based on the experimental results obtained, the optimum dosage to remove each mg of N–NO3 was determined, being a value of 6.7 mg COD/mg N–NO3. Because of the good properties of the winery wastewater to enhance the nitrogen removal, the viability of its continuous addition in an activated sludge pilot-scale plant for BNR was studied. Dosing the winery wastewater to the pilot plant a significant increase in the nitrogen removal was detected, from 58 to 75%. The COD removal was slightly increased, from 89 to 95%, and the phosphorus removal remained constant.


2006 ◽  
Vol 41 (4) ◽  
pp. 449-462 ◽  
Author(s):  
Jan A. Oleszkiewicz ◽  
James L. Barnard

Abstract The European Union (EU) has implemented effluent (emission) standards since 1991, while North America practices a riskbased, imission approach. Progressing eutrophication and large fees for discharged loads push EU countries toward more stringent effluent concentrations, below total nitrogen (TN) levels of 10 mg/L and total phosphorus (TP) levels of 1 mg/L. In North America, the limit of treatment technology (LOT) concept has been defined as the lowest economically achievable effluent quality, which for TN is <1.5 to 3 mg/L and TP is <0.07 mg/L. These limits are becoming targets in fragile ecoregions in North America and drive the technology solutions towards a combination of advanced biological nutrient removal process trains, followed by chemical polishing and solids separation by granular or cloth filters or membranes. In Western Canada one-biomass biological nutrient removal processes are used, such as Westbank or Step-feed, often followed by filtration to achieve low effluent total phosphorus levels. Eastern Canada has a less stringent approach to nitrogen control and practices chemical phosphorus removal. Requirement for total nitrogen removal and rising costs of phosphorus precipitation drive designers towards advanced one-biomass processes and full utilization of carbon (for denitrification and phosphorus removal) available in raw wastewater and primary sludge. New processes are developed to take advantage of carbon available in waste activated sludge or even in the recycled activated sludge. Sludge treatment return streams have high nutrient loads and novel processes are introduced for their treatment, some utilizing generated nitrifier biomass for bio-augmentation of the main stream nitrification process. The impact of sludge processing on the liquid train and vice versa is now fully embedded in the design process.


2007 ◽  
Vol 56 (6) ◽  
pp. 125-134 ◽  
Author(s):  
V. Parco ◽  
G. du Toit ◽  
M. Wentzel ◽  
G. Ekama

The impact of including membranes for solid liquid separation on the kinetics of nitrogen and phosphorus removal was investigated. To achieve this, a membrane bioreactor (MBR) biological nutrient removal (BNR) activated sludge system was operated. From batch tests on mixed liquor drawn from the MBR BNR system, denitrification and phosphorus removal rates were delineated. Additionally the influence of the high total suspended solids concentrations present in the MBR BNR system and of the limitation of substrate concentrations on the kinetics was investigated. Moreover the ability of activated sludge in this kind of system to denitrify under anoxic conditions with simultaneous phosphate uptake was verified and quantified. The denitrification rates obtained for different mixed liquor (ML) concentrations indicate no effect of ML concentration on the specific denitrification rate. The denitrification took place at a single specific rate (K2) with respect to the ordinary heterotrophic organisms (OHOs, i.e. non-PAOs) active mass. Similarly, results have been obtained for the P removal process kinetics: no differences in specific rates were observed for different ML or substrate concentrations. From the P removal batch tests results it seems that the biological phosphorus removal population (PAO) consists of 2 different sets of organisms denitrifying PAO and aerobic PAO.


Sign in / Sign up

Export Citation Format

Share Document