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Rodríguez-Gómez LE, Rodríguez-Sevilla J, Hernández A, Álvarez M. Factors affecting nitrification with nitrite accumulation in treated wastewater by oxygen injection. Environ Technol 2021; 42:813-825. [PMID: 31314696 DOI: 10.1080/09593330.2019.1645742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 07/14/2019] [Indexed: 06/10/2023]
Abstract
This work provides information on nitrification with nitrite accumulation in low strength ammonia (below 50 mg L-1 NH4-N) and low organic matter (below 150 mg L-1 COD) reclaimed wastewater. In the South Tenerife reclaimed wastewater pipeline (62 km long), injection of O2 has been applied to promote a nitrification process in order to improve water quality and to avoid anaerobic conditions. Nitrification occurs, in most cases, with nitrite accumulation. The amount of oxidized nitrogen compounds produced increases with the oxygen dose applied. The nitrification process is usually favoured instead of the organic matter transformation, due to the low organic matter/ammonia nitrogen ratio of water. The influence of organic matter content on nitrification has been analysed, and a good suitability for COD has been found as an indicator for nitrification limitation (for the range of COD and NH4-N concentrations of the system). Nitrification limitation has been observed above 85 mg L-1 COD, and nitrification inhibition above a concentration of 105 mg L-1. In addition, the limitation of nitrite oxidation bacteria activity (nitrite accumulation) by free ammonia and temperature has been assessed, finding that, for the range of free ammonia (0.6-2.1 mg L-1 NH3) and temperature (20.4-27.0°C) in the study, temperature plays a much more relevant role than free ammonia on nitrite accumulation. The lower limiting temperature for nitrite build-up in the system has been 21.0°C. Below this temperature, nitrite accumulation did not exist or was very low.
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Affiliation(s)
- Luis E Rodríguez-Gómez
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Facultad de Ciencias, Universidad de La Laguna, La Laguna, Spain
| | - Juan Rodríguez-Sevilla
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Facultad de Ciencias, Universidad de La Laguna, La Laguna, Spain
| | - Antonio Hernández
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Facultad de Ciencias, Universidad de La Laguna, La Laguna, Spain
| | - Manuel Álvarez
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Facultad de Ciencias, Universidad de La Laguna, La Laguna, Spain
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González E, Díaz O, Segredo-Morales E, Rodríguez-Gómez LE, Vera L. Enhancement of Peak Flux Capacity in Membrane Bioreactors for Wastewater Reuse by Controlling the Backwashing Strategy. Ind Eng Chem Res 2018. [DOI: 10.1021/acs.iecr.8b05650] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Enrique González
- Departamento de Ingeniería Química y T.F. Universidad de La Laguna Av. Astrof. Fco. Sánchez s/n. 38200 La Laguna, España
| | - Oliver Díaz
- Departamento de Ingeniería Química y T.F. Universidad de La Laguna Av. Astrof. Fco. Sánchez s/n. 38200 La Laguna, España
| | - Elisabet Segredo-Morales
- Departamento de Ingeniería Química y T.F. Universidad de La Laguna Av. Astrof. Fco. Sánchez s/n. 38200 La Laguna, España
| | - Luis E. Rodríguez-Gómez
- Departamento de Ingeniería Química y T.F. Universidad de La Laguna Av. Astrof. Fco. Sánchez s/n. 38200 La Laguna, España
| | - Luisa Vera
- Departamento de Ingeniería Química y T.F. Universidad de La Laguna Av. Astrof. Fco. Sánchez s/n. 38200 La Laguna, España
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González E, Díaz O, Vera L, Rodríguez-Gómez LE, Rodríguez-Sevilla J. Feedback control system for filtration optimisation based on a simple fouling model dynamically applied to membrane bioreactors. J Memb Sci 2018. [DOI: 10.1016/j.memsci.2018.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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González E, Díaz O, Ruigómez I, de Vera CR, Rodríguez-Gómez LE, Rodríguez-Sevilla J, Vera L. Photosynthetic bacteria-based membrane bioreactor as post-treatment of an anaerobic membrane bioreactor effluent. Bioresour Technol 2017; 239:528-532. [PMID: 28533063 DOI: 10.1016/j.biortech.2017.05.042] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/04/2017] [Accepted: 05/07/2017] [Indexed: 06/07/2023]
Abstract
Anaerobic membrane bioreactors have attracted increasing interest in the field of wastewater treatment. However, significant amounts of organic matter, nitrogen and sulphide in the effluent may limit its reuse. A photosynthetic bacteria-based membrane bioreactor is proposed for the further treatment of this effluent. A pilot-scale unit was run outdoor for over 900h to assess the process performance at short hydraulic retention time. After an initial biomass development, simultaneous removal of soluble organic matter and nitrogen was achieved (65% and 39%, respectively). In addition, a significant concentration of sulphate was detected in the permeate, revealing an evident sulphide oxidation. Despite the accumulation of biopolymer clusters in the biological suspension, membrane fouling was effectively mitigated by air-aided backwashing, allowing a sustainable operation. Several strains of bacteria were identified including the photoheterotrophic bacteria Rhodopseudomonas sp. and the nitrifying and denitrifying bacteria Chryseobacterium sp.
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Affiliation(s)
- E González
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Universidad de La Laguna, Astrof. Fco. Sanchez s/n, 38200 La Laguna, Spain.
| | - O Díaz
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Universidad de La Laguna, Astrof. Fco. Sanchez s/n, 38200 La Laguna, Spain
| | - I Ruigómez
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Universidad de La Laguna, Astrof. Fco. Sanchez s/n, 38200 La Laguna, Spain
| | - C R de Vera
- Instituto de Bio-orgánica "Antonio González" (IUBO-AG), Centro de Investigaciones Biomédicas de Canarias (CIBICAN), Departamento de Química Orgánica, Universidad de La Laguna, Tenerife, Spain; Departamento de Química Orgánica, Universidad de La Laguna, Tenerife, Astrof. Fco. Sanchez s/n, 38200 La Laguna, Spain
| | - L E Rodríguez-Gómez
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Universidad de La Laguna, Astrof. Fco. Sanchez s/n, 38200 La Laguna, Spain
| | - J Rodríguez-Sevilla
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Universidad de La Laguna, Astrof. Fco. Sanchez s/n, 38200 La Laguna, Spain
| | - L Vera
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Universidad de La Laguna, Astrof. Fco. Sanchez s/n, 38200 La Laguna, Spain
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Ruigómez I, González E, Guerra S, Rodríguez-Gómez LE, Vera L. Evaluation of a novel physical cleaning strategy based on HF membrane rotation during the backwashing/relaxation phases for anaerobic submerged MBR. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2016.12.042] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Rodríguez-Gómez LE, Alvarez M, Rodríguez-Sevilla J, Marrero MC, Hernández A. Reclaimed wastewater quality enhancement by oxygen injection during transportation. Water Sci Technol 2011; 63:641-648. [PMID: 21330708 DOI: 10.2166/wst.2011.220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In-sewer treatments have been studied in sewer systems, but few have been carried out on reclaimed wastewater systems. A study of oxygen injection has been performed in a completely filled gravity pipe, 0.6 m in diameter and 62 km long, in cast iron with concrete inside coating, which is part of the reclaimed wastewater reuse scheme of Tenerife (Spain). A high pressure oxygen injection system was installed at 16.0 km from pipe inlet and a constant dosage of 30 mg/L O(2) has been injected during six months, under three different operational modes (low COD, 63 mg/L; high COD, 91 mg/L; and partially nitrified water). Oxygen has been consumed in nitrification and organic matter reduction. Generally, nitrification is clearly favored instead of the organic matter oxidation. Nitrification occurs, in general, with nitrite accumulation due to the presence of free ammonia above 1 mg/L. Denitrification is in all cases incomplete due to a limitation of easily biodegradable organic matter content, inhibiting the appearance of anaerobic conditions and sulfide generation. A notable reduction of organic matter parameters is achieved (TSS below 10 mg/L), which is significantly higher than that observed under the ordinary transport conditions without oxygen. This leads to a final cost reduction, and the oxygen injection system helps water reuse managers to maintain a final good water quality in the case of a treatment plant malfunction.
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Affiliation(s)
- L E Rodríguez-Gómez
- Dpt. Chemical Engineering, University of La Laguna, Av. Astrof. Fco. Sánchez S/N. 38200 La Laguna, Spain.
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Rodríguez-Gómez LE, Alvarez M, Rodríguez-Sevilla J, Marrero MC, Hernández A. Nitrogen transformation of reclaimed wastewater in a pipeline by oxygen injection. Environ Technol 2009; 30:715-723. [PMID: 19705609 DOI: 10.1080/09593330902896187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A study of oxygen injection was performed in a completely filled gravity pipe, which is part of the South Tenerife reclaimed wastewater reuse scheme (Spain), in order to inhibit the appearance of anaerobic conditions by a nitrification-denitrification process. The pipe was 0.6 m in diameter and 62 km long and made of cast iron with a concrete inner coating, A high-pressure oxygen injection system was installed at 16 km from the pipe inlet, where severe anaerobic conditions appear. Experiments on oxygen injection were carried out with three different concentrations (7, 15 and 30 mg l(-1) O2). In all experiments, oxygen dissolved properly after injection, and no gas escapes were detected during water transportation. Most oxygen was consumed in the nitrification process, due to the low COD/NH4-N ratio, leading to a maximum production of oxidized nitrogen compounds of 7.5 mg l(-1) NO(x)-N with the 30 mg l(-1) O2 dose. Nitrification occured with nitrite accumulation, attributed to the presence of free ammonia within the range 1.2-1.4 mg l(-). Once the oxygen had been consumed, an apparent half-order denitrification took place, with limitation of biodegradable organic matter. The anoxic conditions led to a complete inhibition of sulphide generation.
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Rodríguez-Gómez LE, Delgado S, Alvarez M, Elmaleh S. Inhibition of sulfide generation in a reclaimed wastewater pipe by nitrate dosage and denitrification kinetics. Water Environ Res 2005; 77:193-198. [PMID: 15816683 DOI: 10.2175/106143005x41762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Sulfide generation should be avoided during wastewater transportation. The efficiency of nitrate dosing for the inhibition of sulfide generation was evaluated during reclaimed wastewater transport with two nitrate doses, 2.5 and 5 mg/L nitrate-nitrogen (NO3-N). A calcium nitrate [Ca(NO3)2] solution was injected at the beginning of the 61-km-long gravity pipe, which is part of the Reclaimed Wastewater Reuse System of South Tenerife (Spain). During transportation, after dissolved oxygen depletion, a denitrification process took place. With the 5 mg/L NO3-N dose, nitrate was not completely removed at the end of the pipe, whereas with 2.5 mg/L NO3-N, a complete denitrification was achieved. Sulfide generation was completely inhibited with the 5 mg/L dose. However, with 2.5 mg/L, sulfide generation was not completely inhibited but delayed and minimized to a great extent. Denitrification was stoichiometrically limited by the availability in biodegradable matter. An empirical equation enables one to predict the nitrate concentration.
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Affiliation(s)
- Luis E Rodríguez-Gómez
- Department of Chemical Engineering, Faculty of Chemistry, University of La Laguna, Tenerife, Spain.
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Delgado S, Alvarez M, Rodríguez-Gómez LE, Elmaleh S. Transportation of reclaimed wastewater through a long pipe: inhibition of sulphide production by nitrite from the secondary treatment. Environ Technol 2004; 25:365-371. [PMID: 15176751 DOI: 10.1080/09593330409355470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The agricultural reuse of reclaimed wastewater has become a necessity in places with water shortages. Frequently, this involves the operation of long transportation pipelines, like in the South Tenerife reuse system, whose main element is a completely filled 61 km long gravity pipe in cast iron. Sulphide generation, which could contribute to pipe corrosion, is a usual process taking place during transportation if anaerobic conditions prevail. In the Wastewater Treatment Plant of Santa Cruz (Tenerife, Spain) a partial nitrification process was achieved by increasing the mean residence time through the aeration step at low dissolved oxygen concentration. Such conditions, combined with the right temperature and a free ammonia concentration above 1 mg l(-1), inhibited nitratation and favoured nitritation, which led to concentrations of NO2-N above 8 mg l(-1) in the secondary effluent. During the transportation, nitrite inhibited the appearance of anaerobic conditions, and, consequently, no sulphide generation occurred. At the same time, a nitrite reduction process took place with a first order kinetics and a rate coefficient of 0.052 h(-1)' at 25 degrees C. A parallel behaviour between the nitrite depletion and the oxidation-reduction potential evolution along the pipeline was also observed.
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Affiliation(s)
- S Delgado
- Dpt. Chemical Engineering, University of La Laguna, Av. Astrof. Fco. Sánchez, S/N. 38200 La Laguna. Spain
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Delgado S, Alvarez M, Rodríguez-Gómez LE, Elmaleh S, Aguiar E. How partial nitrification could improve reclaimed wastewater transport in long pipes. Water Sci Technol 2001; 43:133-138. [PMID: 11436772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Reclaimed wastewater transport is studied in a concrete-lined cast iron pipe, where a nitrification-denitrification process occurs. The pipe is part of the Reuse System of Reclaimed Wastewater of South Tenerife (Spain), 0.6 m in diameter and 61 km long. In order to improve wastewater quality, at 10 km from the inlet there is injection of fresh water saturated in dissolved oxygen (DO), after which a fast nitrification process usually appears (less than two hours of space time). The amount of oxidized nitrogen compounds produced varies between 0.8 and 4.4 mg/l NOx(-)-N. When DO has disappeared, a denitrification process begins. The removal of nitrite is complete at the end of the pipe, whereas the nitrate does not disappear completely, leaving a concentration of about 0.4-0.5 mg/l. For a COD/NOx(-)-N ratio higher than 5, a first order nitrification rate in NOx(-)-N has resulted, with the constant k20 = 0.079 h-1, for a NOx(-)-N concentration range of 0.8-4.4 mg/l. Finally the following temperature dependency for the first order denitrification rate constant has been found: k = k20 x 1 x 15T-20. Although nitrogen could be used as nutrient in the agricultural reuse, its removal from reclaimed wastewater could be useful in order to diminish the chlorine needs for reclaimed wastewater disinfection.
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Affiliation(s)
- S Delgado
- Department Chemical Engineering, University of La Laguna, Av. Astrof. Fco. Sánchez, S/N 38200 La Laguna, Spain
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