1
|
Nadeem K, Alliet M, Plana Q, Bernier J, Azimi S, Rocher V, Albasi C. Modeling, simulation and control of biological and chemical P-removal processes for membrane bioreactors (MBRs) from lab to full-scale applications: State of the art. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 809:151109. [PMID: 34688739 DOI: 10.1016/j.scitotenv.2021.151109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/16/2021] [Accepted: 10/16/2021] [Indexed: 06/13/2023]
Abstract
Phosphorus (P) removal from the domestic wastewater is required to counter the eutrophication in receiving water bodies and is mandated by the regulatory frameworks in several countries with discharge limits within 1-2mgPL-1. Operating at higher sludge retention time (SRT) and higher biomass concentration than the conventional activated sludge process (CASP), membrane bioreactors (MBRs) are able to remove 70-98% phosphorus without addition of coagulant. In full-scale facilities, enhanced biological phosphorus removal (EBPR) is assisted by the addition of metal coagulant to ensure >95% P-removal. MBRs are successfully used for super-large-scale wastewater treatment facilities (capacity >100,000 m3d-1). This paper documents the knowledge of P-removal modeling from lab to full-scale submerged MBRs and assesses the existing mathematical models for P-removal from domestic wastewater. There are still limited studies involving integrated modeling of the MBRs (full/super large-scale), considering the complex interactions among biology, chemical addition, filtration, and fouling. This paper analyses the design configurations and the parameters affecting the biological and chemical P-removal in MBRs to understand the P-removal process sensitivity and their implications for the modeling studies. Furthermore, it thoroughly reviews the applications of bio-kinetic and chemical precipitation models to MBRs for assessing their effectiveness with default stoichiometric and kinetic parameters and the extent to which these parameters have been calibrated/adjusted to simulate the P-removal successfully. It also presents a brief overview and comparison of seven (7) chemical precipitation models, along with a quick comparison of commercially available simulators. In addition to advantages associated with chemical precipitation for P-removal, its role in changing the relative abundance of the microbial community responsible for P-removal and denitrification and the controversial role in fouling mitigation/increase are discussed. Lastly, it encompasses several coagulant dosing control systems and their applications in the pilot to full-scale facilities to save coagulants and optimize the P-removal performance.
Collapse
Affiliation(s)
- Kashif Nadeem
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France.
| | - Marion Alliet
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France.
| | - Queralt Plana
- Parisian Sanitation Public Service (SIAAP), Direction Innovation, 92700 Colombes, France
| | - Jean Bernier
- Parisian Sanitation Public Service (SIAAP), Direction Innovation, 92700 Colombes, France
| | - Sam Azimi
- Parisian Sanitation Public Service (SIAAP), Direction Innovation, 92700 Colombes, France.
| | - Vincent Rocher
- Parisian Sanitation Public Service (SIAAP), Direction Innovation, 92700 Colombes, France.
| | - Claire Albasi
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France.
| |
Collapse
|
2
|
Bora RR, Richardson RE, You F. Resource recovery and waste-to-energy from wastewater sludge via thermochemical conversion technologies in support of circular economy: a comprehensive review. ACTA ACUST UNITED AC 2020. [DOI: 10.1186/s42480-020-00031-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
AbstractWith the rapid rise in global population over the past decades, there has been a corresponding surge in demand for resources such as food and energy. As a consequence, the rate of waste generation and resultant pollution levels have risen drastically. Currently, most organic solid wastes are either land applied or sent to landfills, with the remaining fraction incinerated or anaerobically digested. However, with the current emphasis on the reduction of emissions, nutrient recovery, clean energy production and circular economy, it is important to revisit some of the conventional methods of treating these wastes and tap into their largely unrealized potential in terms of environmental and economic benefits. Wastewater sludge, with its high organic content and fairly constant supply, provides a great opportunity to implement some of these strategies using thermochemical conversion technologies, which are considered as one of the alternatives for upcycling such waste streams. This paper summarizes the results of prominent studies for valorizing wastewater sludge through thermochemical conversion technologies while drawing inferences and identifying relationships between different technical and operating parameters involved. This is followed by sections emphasizing the environmental and economic implications of these technologies, and their corresponding products in context of the broader fields of waste-to-energy, nutrient recycling and the progress towards a circular economy.
Collapse
|
3
|
Rashid SS, Liu YQ. Assessing environmental impacts of large centralized wastewater treatment plants with combined or separate sewer systems in dry/wet seasons by using LCA. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:15674-15690. [PMID: 32080814 PMCID: PMC7190677 DOI: 10.1007/s11356-020-08038-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 02/10/2020] [Indexed: 05/15/2023]
Abstract
Rainfall can affect influent flow rate and compositions of wastewater, and thus further affect wastewater treatment performance and the effluent quality. This study aims to study the influence of rainfall on the environmental impacts of centralized wastewater treatment plants. The correlations between rainfall, and influent flow rate and compositions of wastewater in wet and dry seasons with two sewer systems, i.e. combined and separate sewer systems, were primarily established. Environmental impacts were assessed with life cycle assessment (LCA) to understand the temporal environmental burdens in wet and dry seasons. Functional units as per m3 treated wastewater (FU1) and as per kg PO43-eq. removed (FU2), respectively, were used to evaluate impacts of wastewater treatment to the environment. Strong correlation between rainfall and the influent flow rate was found in the wastewater treatment plants with either a combined sewer system (with Pearson correlation coefficient r at 0.66) or a separate sewer system (with r at 0.84), where r represents the strength of the association between two variables. The rainfall effect is more obvious on the eutrophication potential and global warming potential than on other environmental indicators while sewer system, i.e. combined or separate, seems not important in the two cases studied. Both wastewater treatment plants (WWTPs) show a lower environmental burden in the wet season than in the dry season partially due to the dilution of wastewater by using FU1. The WWTP receiving high strength wastewater, however, demonstrates higher environmental impacts in the wet season by using FU2 than FU1, due to the less efficient treatment caused by heavy rainfall. Meanwhile, it is found that environmental impacts from the WWTP receiving low strength wastewater have no difference when using either FU1 or FU2. The results indicate that the environmental burdens particularly eutrophication and global warming caused by WWTPs are dependent on the correlations of rainfall intensity with wastewater quantity and quality instead of combined or separate sewer system. This could be used to guide a stricter control of eutrophication in a more sensitive season in more vulnerable receiving waters.
Collapse
Affiliation(s)
- Siti Safirah Rashid
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, SO17 1BJ, UK
| | - Yong-Qiang Liu
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, SO17 1BJ, UK.
| |
Collapse
|
4
|
Bai F, Tian H, Ma J. Advanced treatment of sewage by membrane bioreactor associate with genetically engineered autotrophic nitrifying bacteria. BIORESOURCE TECHNOLOGY 2019; 288:121341. [PMID: 31129517 DOI: 10.1016/j.biortech.2019.121341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/06/2019] [Accepted: 04/10/2019] [Indexed: 06/09/2023]
Abstract
This study introduced a process of MBR combing with genetically engineered bacteria of expressing nirs and ppk genes (GEB-Nirs/PPK) for advanced treatment of sewage in scenic area. An industrial scale application was staged anaerobic digestion, aerobic digestion. Over more than 150 days of continuous operation, TMP in this system was less than 0.18 bar. With a membrane flux of 6.48 m3/h, TMP remained below 0.2 bar and effluent remained above 70 m3 during continuous operation. Average COD and BOD removals averaged 94.2% and 93.6%, and were obtained with average effluent COD and BOD below 10.4 mg/L and 4.2 mg/L, respectively. The TN and TP removals averaged 98.8% and 94.3%, and never higher than 3.2 mg/L and 0.2 mg/L, respectively, in the processing system. In conclusion, these results indicate that the process of MBR associate with genetically engineered autotrophic nitrifying bacteria is of high-efficiency for advanced treatment of sewage.
Collapse
Affiliation(s)
- Fuliang Bai
- State Key Laboratory of Urban Water and Environment, Harbin Institute of Technology, Harbin, Heilongjiang, People's Republic of China; Lubin Environmental Protection Equipment (Shanghai) Co., Ltd, Shanghai, People's Republic of China
| | - Hui Tian
- School of Life Science, Harbin University of Commerce, Harbin 150090, People's Republic of China
| | - Jun Ma
- State Key Laboratory of Urban Water and Environment, Harbin Institute of Technology, Harbin, Heilongjiang, People's Republic of China.
| |
Collapse
|
5
|
Belli TJ, Bernardelli JKB, da Costa RE, Bassin JP, Amaral MCS, Lapolli FR. Effect of solids retention time on nitrogen and phosphorus removal from municipal wastewater in a sequencing batch membrane bioreactor. ENVIRONMENTAL TECHNOLOGY 2017; 38:806-815. [PMID: 27408986 DOI: 10.1080/09593330.2016.1212934] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 07/08/2016] [Indexed: 06/06/2023]
Abstract
This study evaluated the removal of organic matter, nitrogen and phosphate from a municipal wastewater in a sequencing batch membrane bioreactor (SBMBR) operated at different solids retention times (SRTs) and subjected to different aeration profiles. The results demonstrated that SRT reduction from 80 to 20 d had a negligible effect on chemical oxygen demand (COD) removal and only a slight negative effect on nitrification. COD removal efficiency remained stable at 97%, whereas ammonium removal decreased from 99% to 97%. The total nitrogen removal efficiency was improved by SRT reduction, increasing from 80% to 86%. Although the total phosphorus (TP) removal was not significantly affected by the SRT reduction, ranging from 40-49%, the P-release and P-uptake processes were observed to increase as the SRT was reduced. The implementation of a pre-aeration phase in the SBMBR operating cycle allowed a higher TP removal performance, which reached up to 76%. Batch tests suggested that the fraction of phosphate removed anoxically from the total (anoxic + aerobic) phosphate removal decreased with the SRT reduction.
Collapse
Affiliation(s)
- Tiago José Belli
- a Department of Sanitary and Environmental Engineering , Federal University of Santa Catarina , Florianópolis , SC , Brazil
| | | | - Rayra Emanuelly da Costa
- a Department of Sanitary and Environmental Engineering , Federal University of Santa Catarina , Florianópolis , SC , Brazil
| | - João Paulo Bassin
- c Chemical Engineering Program - COPPE, Federal University of Rio de Janeiro , Rio de Janeiro , RJ , Brazil
| | - Miriam Cristina Santos Amaral
- d Department of Sanitary and Environmental Engineering , Federal University of Minas Gerais , Belo Horizonte , MG , Brazil
| | - Flávio Rubens Lapolli
- a Department of Sanitary and Environmental Engineering , Federal University of Santa Catarina , Florianópolis , SC , Brazil
| |
Collapse
|
6
|
Kim M, Park K, Kim JM. Phosphate recovery from livestock wastewater using iron oxide nanotubes. Chem Eng Res Des 2016. [DOI: 10.1016/j.cherd.2016.06.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
7
|
Zuthi MFR, Guo WS, Ngo HH, Nghiem LD, Hai FI. Enhanced biological phosphorus removal and its modeling for the activated sludge and membrane bioreactor processes. BIORESOURCE TECHNOLOGY 2013; 139:363-374. [PMID: 23659759 DOI: 10.1016/j.biortech.2013.04.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Revised: 04/08/2013] [Accepted: 04/10/2013] [Indexed: 06/02/2023]
Abstract
A modified activated sludge process (ASP) for enhanced biological phosphorus removal (EBPR) needs to sustain stable performance for wastewater treatment to avoid eutrophication in the aquatic environment. Unfortunately, the overall efficiency of the EBPR in ASPs and membrane bioreactors (MBRs) is frequently hindered by different operational/system constraints. Moreover, although phosphorus removal data from several wastewater treatment systems are available, a comprehensive mathematical model of the process is still lacking. This paper presents a critical review that highlights the core issues of the biological phosphorus removal in ASPs and MBRs while discussing the inhibitory process requirements for other nutrients' removal. This mini review also successfully provided an assessment of the available models for predicting phosphorus removal in both ASP and MBR systems. The advantages and limitations of the existing models were discussed together with the inclusion of few guidelines for their improvement.
Collapse
Affiliation(s)
- M F R Zuthi
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | | | | | | | | |
Collapse
|
8
|
Sabelfeld M, Geißen SU. Verfahren zur Eliminierung und Rückgewinnung von Phosphor aus Abwasser. CHEM-ING-TECH 2011. [DOI: 10.1002/cite.201000187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
9
|
Ong Y, Chua A, Ngoh G. Establishment of Enhanced Biological Phosphorus Removal in a Sequencing Batch Reactor by using Seed Sludge from a Conventional Activated Sludge Wastewater Treatment Process. ACTA ACUST UNITED AC 2010. [DOI: 10.3923/jas.2010.2643.2647] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
10
|
Monclús H, Sipma J, Ferrero G, Rodriguez-Roda I, Comas J. Biological nutrient removal in an MBR treating municipal wastewater with special focus on biological phosphorus removal. BIORESOURCE TECHNOLOGY 2010; 101:3984-3991. [PMID: 20137918 DOI: 10.1016/j.biortech.2010.01.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 12/29/2009] [Accepted: 01/10/2010] [Indexed: 05/28/2023]
Abstract
The performance of an MBR pilot plant for biological nutrient removal was evaluated during 210days 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 150days of operation amounted to 13.6mgPg(-1)VSSh(-1) and 5.6mgPg(-1)VSSh(-1), for PAOs and DPAOs, respectively.
Collapse
Affiliation(s)
- Hector Monclús
- Laboratory of Chemical and Environmental Engineering (LEQUiA), Institute of the Environment, University of Girona, E17071 Girona, Spain
| | | | | | | | | |
Collapse
|
11
|
Horgan CJ, Coats ER, Loge FJ. Assessing the effects of solids residence time and volatile fatty acid augmentation on biological phosphorus removal using real wastewater. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2010; 82:216-226. [PMID: 20369565 DOI: 10.2175/106143009x12487095236559] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The purpose of the research presented herein was to evaluate the effects of solids residence time (SRT) and organic acid augmentation on biological phosphorus removal (BPR), with a focus on how these operational variables affect key metabolisms and the distribution of the microbial population. Using laboratory-scale sequencing batch reactors seeded with a mixed microbial consortium and fed real wastewater, we observed that longer SRTs can improve BPR performance; organic acid augmentation can stabilize BPR, but it is not necessary for process success; and higher volatile suspended solids concentrations correlate with improved phosphorus removal. The results also suggest that organic acids may not be critical in driving anaerobic phosphorus release, but in driving aerobic growth. Finally, given an observed population similarity across all tested bioreactors, BPR variability appears to be less influenced by the presence of specific microbes and more affected by the induction of critical metabolisms.
Collapse
Affiliation(s)
- Christopher J Horgan
- Department of Civil Engineering, University of Idaho, Moscow, Idaho 83844-1022, USA
| | | | | |
Collapse
|
12
|
Radjenović J, Matošić M, Mijatović I, Petrović M, Barceló D. Membrane Bioreactor (MBR) as an Advanced Wastewater Treatment Technology. THE HANDBOOK OF ENVIRONMENTAL CHEMISTRY 2008. [DOI: 10.1007/978-3-540-79210-9_2] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
13
|
Monti A, Hall ER, Koch FA, Dawson RN, Husain H, Kelly HG. Toward a high-rate enhanced biological phosphorus removal process in a membrane-assisted bioreactor. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2007; 79:675-86. [PMID: 17605336 DOI: 10.2175/106143007x156790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A membrane enhanced biological phosphorus removal (MEBPR) process was studied to determine the impact of hydraulic retention time (HRT) and solids retention time (SRT) on the removal of chemical oxygen demand (COD), nitrogen, and phosphorus from municipal wastewater. The MEBPR process was capable of delivering complete nitrification independent of the prevailing operating conditions, whereas a significant improvement in COD removal efficiency was observed at longer SRTs. In the absence of carbon-limiting conditions, the MEBPR process was able to achieve low phosphorus concentrations in the effluent at increasingly higher hydraulic loads, with the lowest HRT being 5 hours. The MEBPR process was also able to maintain optimal phosphorus removal when the SRT was increased from 12 to 20 days. However, at higher suspended solids concentrations, a substantial increase was observed in carbon utilization per unit mass of phosphorus removed from the influent. These results offer critical insights to the application of membrane technology for biological nutrient removal systems.
Collapse
Affiliation(s)
- Alessandro Monti
- Department of Civil Engineering, University of British Columbia, Vancouver, Canada
| | | | | | | | | | | |
Collapse
|
14
|
Shu L, Schneider P, Jegatheesan V, Johnson J. An economic evaluation of phosphorus recovery as struvite from digester supernatant. BIORESOURCE TECHNOLOGY 2006; 97:2211-6. [PMID: 16364632 DOI: 10.1016/j.biortech.2005.11.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2005] [Revised: 11/02/2005] [Accepted: 11/05/2005] [Indexed: 05/05/2023]
Abstract
Phosphorus can be recovered from wastewater through crystallisation of struvite, MgNH(4)PO(4).6H(2)O. Approximately 1 kg of struvite can be crystallised from 100 m(3) of wastewater. Crystallisation is profitable compared to chemical and biological removal of phosphorus due to savings from the reduction in (i) chemicals used for precipitation and sludge disposal; and (ii) downtime for cleaning unwanted struvite formed during chemical and biological removal. The struvite produced annually from a wastewater treatment plant that processed 100 m3/d, would be sufficient to apply on 2.6 ha of arable land, as fertilizer. If struvite were to be recovered from wastewater treatment plants worldwide, 0.63 million tons of phosphorus (as P(2)O(5)) could be harvested annually, reducing phosphate rock mining by 1.6%. Therefore, this technology could provide opportunities to recover phosphorus sustainably from waste streams and preserve phosphorus reserves.
Collapse
Affiliation(s)
- L Shu
- School of Engineering, James Cook University, Townsville, QLD, Australia
| | | | | | | |
Collapse
|
15
|
Monti A, Hall ER, Dawson RN, Husain H, Kelly HG. Comparative study of biological nutrient removal (BNR) processes with sedimentation and membrane-based separation. Biotechnol Bioeng 2006; 94:740-52. [PMID: 16477659 DOI: 10.1002/bit.20896] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A membrane-enhanced biological phosphorus removal (MEBPR) process was operated in parallel with a conventional EBPR (CEBPR) process under challenging operating conditions to uncover fundamental differences in their ability to remove chemical oxygen demand (COD), nitrogen (N), and phosphorus (P) from municipal wastewater. Both systems exhibited the same potential to achieve excellent soluble-P removal when a favorable COD to P ratio was maintained in the influent. The MEBPR train generated a superior effluent quality when measured as total P. The CEBPR effluent contained significantly lower levels of nitrates due to the extra denitrification occurring in the sludge blanket of the secondary clarifier. The observed sludge yield in the MEBPR system was estimated to be between 0.23 and 0.28 g VSS/g COD, and this was 15% lower than the CEBPR sludge yield. When the influent volatile fatty acids (VFAs) became limiting, the CEBPR train exhibited better performance in the removal of soluble-P, due to the higher observed sludge yield and an overall greater denitrification activity that led to a more efficient use of VFAs in the anaerobic zone. After experiencing a severe deterioration of the biological P activity in both processes, the MEBPR train exhibited faster recovery than the CEBPR side. In this experimental work, it was demonstrated that an MEBPR process can sustain long-term satisfactory bio-P performance at HRTs as low as 7 h. However, the lower sludge yield and the reduced denitrification capacity are two important factors that impact the design of high rate membrane-assisted biological nutrient removal (BNR) processes.
Collapse
Affiliation(s)
- Alessandro Monti
- Environmental Engineering Group, Department of Civil Engineering, The University of British Columbia, 6250 Applied Science Lane, Vancouver, British Columbia, Canada
| | | | | | | | | |
Collapse
|
16
|
Vocks M, Adam C, Lesjean B, Gnirss R, Kraume M. Enhanced post-denitrification without addition of an external carbon source in membrane bioreactors. WATER RESEARCH 2005; 39:3360-8. [PMID: 16045965 DOI: 10.1016/j.watres.2005.05.049] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Revised: 04/29/2005] [Accepted: 05/30/2005] [Indexed: 05/03/2023]
Abstract
This study investigates a post-denitrification process without the addition of an external carbon source combined with an enhanced biological phosphorus removal (EBPR) in a membrane bioreactor (MBR). Three trial plants, with two different process configurations, were operated on two different sites, and a variety of accompanying batch tests were conducted. It was shown that even without dosing of an external carbon source, denitrification rates (DNR) much above endogenous rates could be obtained in post-denitrification systems. Furthermore, the anaerobic reactor located ahead of the process had a positive impact on the DNR. Given these surprising results, the project team decided to identify the carbon source used by the microorganisms in the post-denitrification process. Batch tests could demonstrate that lysis products do not play a major role as a C-source for post-denitrification. The following hypothesis was proposed to explain the observations: the glycogen, internally stored by the substrate accumulating bacteria, if anaerobic conditions are followed by aerobic conditions could act as carbon source for denitrification in post-denitrification system. First exploratory batch tests, where the glycogen evolution was monitored, corroborate this assumption.
Collapse
Affiliation(s)
- M Vocks
- Technische Universität Berlin, Institut für Verfahrenstechnik, Ackerstr. 71-76, ACK 7, D-13355 Berlin, Germany.
| | | | | | | | | |
Collapse
|