Preliminary Investigation of an Installed Pilot-Scale Biological Nutrient Removal Technology (BNRT) for Sewage Treatment (original) (raw)
Related papers
Bioresource Technology, 2009
The performance of a pilot-scale biological nutrient removal process has been evaluated for 336 days, receiving the real municipal wastewater with a flowrate of 6.8 m 3 /d. The process incorporated an intermittent aeration reactor for enhancing the effluent quality, and a nitrification reactor packed with the porous polyurethane foam media for supporting the attached-growth of microorganism responsible for nitrification. The observation shows that the process enabled a relatively stable and high performance in both organics and nutrient removals. When the SRT was maintained at 12 days, COD, nitrogen, and phosphorus removals averaged as high as 89% at a loading rate of 0.42-3.95 kg COD/m 3 d (corresponding to average influent concentration of 304 mg COD/L), 76% at the loading rate of 0.03-0.27 kg N/m 3 d (with 37.1 mg TN/L on average), and 95% at the loading rate of 0.01-0.07 kg TP/m 3 d (with 5.4 mg TP/L on average), respectively.
Biological Nutrient Removal in Municipal Wastewater Treatment: New Directions in Sustainability
Journal of Environmental Engineering, 2012
To control eutrophication in receiving water bodies, biological nutrient removal (BNR) of nitrogen and phosphorus has been widely used in wastewater treatment practice, both for the upgrade of existing wastewater treatment facilities and the design of new facilities. However, implementation of BNR activated sludge AS systems presents challenges attributable to the technical complexity of balancing influent chemical oxygen demand (COD) for both biological phosphorus (P) and nitrogen (N) removal. Sludge age and aerated/unaerated mass fractions are identified as key parameters for process optimization. Other key features of selected BNR process configurations are discussed. Emerging concerns about process sustainability and the reduction of carbon footprint are introducing additional challenges in that influent COD, N, and P are increasingly being seen as resources that should be recovered, not simply removed. Energy recovery through sludge digestion is one way of recovering energy from influent wastewater but which presents a specific challenge for BNR: generation of sidestreams with high nutrient and low COD loads. Technologies designed specifically to treat these side-stream loads are overviewed in this paper. Finally, relatively high levels of nitrous oxide emissions, a powerful greenhouse gas, have been shown to occur in the BNR process under certain conditions, particularly in the presence of high nitrite concentrations. The advantages of using process modeling tools is discussed in view of optimizing BNR processes to meet effluent requirements and to meet goals of sustainability and reducing carbon footprints.
Biological Nutrient Removal: Design Snags, Operational Problems and Costs
Water and Environment Journal, 1995
The EC urban waste water treatment Directive will lead to some sewage-treatment works in the UK having to remove nitrogen and phosphorus. The paper reviews the basic biological processes which are available for retrofitting existing activated-sludge plants to achieve this removal, and then points to some of the problems which are encountered with these processes in other countries. The authors make suggestions as to how these problems can be overcome in design and operation. The paper also provides a cost comparison of different ways of uprating an existing nitrifying activated-sludge plant to achieve nitrification/ denitrification and phosphorus removal.
On-site nutrient removal using a 5-stage biological reactor
2005
Attempts to remove nutrients from municipal wastew ater have traditionally been undertaken through physical, chemical and biological methods. However, not many efforts have been made to remove nutrients in on-site w astew ater treatment systems. This paper represents the experimental results o f an on-site biological nutrient removal process with the potential o f wastewater reuse. The performance o f this pilot-scale on-site biological reactor was evaluated according to Biochemical oxygen demand (BOD5) Total suspended solid (TSS), Total nitrogen (TN) and Total phosphorus (TP) removal efficiencies. The data revealed that this form o f on site wastewater treatment system is capable o f rem oving up to 94% o f BOD5, 97% o f TSS, 8 6 % o f TN and 81% o f TP. During the experimental period o f one year the system was quite stable, requiring the minimum amount o f m aintenance and relatively low operational cost compared to other aerated wastewater treatment systems (AWTS). Based on the experimental data this on-site system can easily provide high quality reusable wastew ater and can be used as a new alternative technology for the promotion o f water conservation strategies.
International Journal of Science and Research , 2021
Two full-scale pre-anoxic selector-equipped SBR based wastewater treatment systems were analyzed in this study to determine the role of storage products in simultaneous nutrient removal (TN and TP) via simultaneous nitrification and denitrification (SND) and enhanced biological phosphorus removal (EBPR) mechanisms, respectively. For nutrient removal, it was observed that there are specific wastewater parameters that influence the plant's performance considerably, i.e., the concentration of readily biodegradable COD fraction, soluble BOD 5 , which can be quickly taken up by the denitrifiers and polyphosphate accumulating organisms (PAOs) for their metabolism and stored in the form of Poly-β-hydroxybutyrates (PHB) in anaerobic phase and subsequent storage of polyphosphates (poly-P) in the aeration phase. The TN removal was ~71% (SND ~78%) and ~85% (SND ~94%), and TP removal was ~41% (EBPR ~18%) and ~68% (EBPR ~51%) in Roorkee, Uttarakhand (India) and Varanasi, Uttar Pradesh (India) SBR plants respectively. Both of them are working well in performing high SND, which requires optimized management of dissolved oxygen (DO) levels and C/N ratios. The Varanasi SBR plant is working more efficiently for the EBPR process because of the several conditions prevailing in the plant. It comprises of anaerobic/ anoxic selector compartments (nine selector compartments per basin, which diminishes the effects of RAS falling in the anoxic zones and maintains ORP <-200 mV to ferment the rbCOD into acetates) along with six aeration basins (ORP > +150 mV and DO ranges from 0-2.4 mg/L for effective SND). It has optimized rbCOD/ TP ratios (10-20) in the raw sewage and good TP storage (as poly-P) in the biological sludge (>3%), leading to effective Bio-P removal.
Comparative Assessment of a Novel MBR and A2O for Biological Nutrient Removal
Proceedings of the Water Environment Federation, 2008
A comparative study between two biological nutrient removal (BNR) systems i.e. one employing membranes and the other conventional A2O system was conducted at the hydraulic retention time (HRT) and solids retention time (SRT) of 8 h and 10 d respectively using synthetic wastewater (SWW) and municipal wastewater (MWW) which contains 30% of the volatile fatty acid (VFA) of the SWW. Achieved COD, N and P removal efficiencies for the MBR were 95-98, 72-75 and 70-91%, respectively, compared to 95-98, 70-76 and 70-77% for the A2O. It was confirmed that the primary factor governing P removal is VFA concentration. Accordingly, the contribution of denitrifying phosphorus accumulating organisms (DPAOs) to P removal was greatly hampered. However, the impact of an intermediate clarifier P removal in the MBR was significant for both SWW and MWW runs.
Biological nutrient removal model no. 2 (BNRM2): A general model for wastewater treatment plants
Water Science and Technology, 2013
This paper presents the plant-wide model Biological Nutrient Removal Model Nº 2 (BNRM2). Since nitrite was not considered in the BNRM1, and this previous model also failed to accurately simulate the anaerobic digestion because precipitation processes were not considered, an extension of BNRM1 has been developed. This extension comprises all the components and processes required to simulate nitrogen removal via nitrite and the formation of the solids most likely to precipitate in anaerobic digesters. The solids considered in BNRM2 are: struvite, amorphous calcium phosphate, hidroxiapatite, newberite, vivianite, strengite, variscite, and calcium carbonate. With regard to nitrogen removal via nitrite, appart from nitrite oxidising bacteria two groups of ammonium oxidising organisms (AOO) have been considered since different sets of kinetic parameters have been reported for the AOO present in activated sludge systems and SHARON reactors. Due to the new processes considered, BNRM2 allows an accurate prediction of WWTPs performance in wider environmental and operating conditions.
Bioresource Technology, 2010
The performance of an MBR pilot plant for biological nutrient removal was evaluated during 210 days of operation. The set point values for the internal recycles were determined in advance with the use of an optimisation spreadsheet based on the ASM2d model to optimise the simultaneous removal of C, N and P. The biological nutrient removal (BNR) efficiencies were high from the start of operation with COD and N removal efficiencies of 92 ± 6% and 89 ± 7, respectively. During the course of the experiment P removal efficiencies increased and finally a P-removal efficiency of 92% was achieved. The activity of poly-phosphate accumulating organisms (PAOs) and denitrifying poly-phosphate accumulating organisms (DPAOs) increased and the specific phosphate accumulation rates after 150 days of operation amounted to 13.6 mg P g À1 VSS h À1 and 5.6 mg P g À1 VSS h À1 , for PAOs and DPAOs, respectively.
2021
In addition to many other well-documented factors, local conditions are rudimentary conditions of sharp change observed in wastewater characteristics from place to place. An optimized and flexible treatment strategy is required to handle these fluctuations and variations in quality. Pre-anoxic selector-equipped sequencing batch reactors (SBR) perform efficiently in removing COD, BOD5, TSS, NH4+-N, TN, and Fecal Coliforms. The monitoring of 3-MLD Full-scale SBR installed at IIT, Roorkee, drew attention to the processes involving simultaneous nitrification and denitrification (SND) and biological phosphorous removal (BPR) undergoing with the variations in influent wastewater, particularly the readily biodegradable COD (rbCOD), and their effects on micro-biota. Regular monitoring of all the units for a period of six months revealed that the overall average treatment/ removal efficiencies were >94% COD (17.9±7.7 mg/L in effluent), >95% BOD5 (5.9±2.2 mg/L in effluent), >95% TSS ...