1
|
Albuquerque JN, Ratusznei SM, Rodrigues JAD. Biomethane production by thermophilic co-digestion of sugarcane vinasse and whey in an AnSBBR: Effects of composition, organic load, feed strategy and temperature. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 251:109606. [PMID: 31563047 DOI: 10.1016/j.jenvman.2019.109606] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 09/10/2019] [Accepted: 09/16/2019] [Indexed: 05/25/2023]
Abstract
This work investigated the application of a thermophilic (55 °C) anaerobic reactor with immobilized biomass, mechanically stirred and operated in sequential batch and fed batch (AnSBBR) for environmental compliance and methane production by co-digesting cheese whey (W) and sugarcane vinasse (V). The assays were performed in four steps. In the first step the composition of 75%W:25%V (on a COD basis) was determined to be the most adequate for the anaerobic process. In the second step the applied volumetric organic load (AVOL) was increased and in the third step the feed strategy was modified achieving best results at AVOL of 25 gCOD.m-3.d-1, in which the removed organic matter efficiency was 72%, the molar productivity was 278 molCH4.m-3.d-1 and methane yield was 15.3 mmolCH4.gCOD-1. In the fourth step the temperature was modified to 50 °C and 45 °C, achieving worse results. From the kinetic model adjusted to experimental data it was identified that the acetoclastic route was predominant in methane generation. The estimated energy recovered by co-digesting cheese whey and sugarcane vinasse using industrial information was 2.2 × 104 MW h per month, equivalent (in Brazil) to the electricity consumption of about 135 × 103 inhabitants or monthly savings of US$ 1,653,000 replacing the diesel oil consumed in the industry.
Collapse
Affiliation(s)
- J N Albuquerque
- São Carlos School of Engineering, São Paulo University (EESC/USP), Av. Trabalhador São Carlense 400, CEP 13,.566-590, São Carlos-SP, Brazil
| | - S M Ratusznei
- Mauá School of Engineering, Mauá Institute of Technology (EEM/IMT), Praça Mauá 1, CEP 09,.580-900, São Caetano Do Sul-SP, Brazil
| | - J A D Rodrigues
- Mauá School of Engineering, Mauá Institute of Technology (EEM/IMT), Praça Mauá 1, CEP 09,.580-900, São Caetano Do Sul-SP, Brazil.
| |
Collapse
|
2
|
Albuquerque JND, Orellana MR, Ratusznei SM, Rodrigues JAD. THERMOPHILIC BIOMETHANE PRODUCTION BY VINASSE IN AN AnSBBR: START-UP STRATEGY AND PERFORMANCE OPTIMIZATION. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2019. [DOI: 10.1590/0104-6632.20190362s20170611] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
3
|
Lovato G, Batista LPP, Preite MB, Yamashiro JN, Becker ALS, Vidal MFG, Pezini N, Albanez R, Ratusznei SM, Rodrigues JAD. Viability of Using Glycerin as a Co-substrate in Anaerobic Digestion of Sugarcane Stillage (Vinasse): Effect of Diversified Operational Strategies. Appl Biochem Biotechnol 2019; 188:720-740. [PMID: 30680702 DOI: 10.1007/s12010-019-02950-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/11/2019] [Indexed: 11/28/2022]
Abstract
Vinasse, from sugar and ethanol production, stands out as one of the most problematic agroindustry wastes due to its high chemical oxygen demand, large production volume, and recalcitrant compounds. Therefore, the viability of using glycerin as a co-substrate in vinasse anaerobic digestion was tested, to increase process efficiency and biogas productivity. The effect of feeding strategy, influent concentration, cycle length, and temperature were assessed to optimize methane production. Glycerin (1.53% v/v) proved to be a good co-substrate since it increased the overall methane production in co-digestion assays. CH4 productivity enhanced exponentially as influent concentration increased, but when temperature was increased to 35 °C, biogas production was impaired. The highest methane productivity and yield were achieved using fed-batch mode, at 30 °C and at an organic loading rate of 10.1 kg COD m-3 day-1: 139.32 mol CH4 m-3 day-1, 13.86 mol CH4 kg CODapplied, and 15.30 mol CH4 kg CODremoved. Methane was predominantly produced through the hydrogenotrophic route. In order to treat all the vinasse produced by a mid-size sugar and ethanol plant, nine reactors with 7263.4 m3 each would be needed. The energy generated by burning the biogas in boilers would reach approximately 92,000 MW h per season and could save up to US$ 240,000.00 per month in diesel oil demand.
Collapse
Affiliation(s)
- Giovanna Lovato
- Mauá School of Engineering, Mauá Institute of Technology (EEM/IMT), Praça Mauá 1, São Caetano do Sul, SP, 09580-900, Brazil
| | - Lia P P Batista
- Mauá School of Engineering, Mauá Institute of Technology (EEM/IMT), Praça Mauá 1, São Caetano do Sul, SP, 09580-900, Brazil
| | - Marina B Preite
- Mauá School of Engineering, Mauá Institute of Technology (EEM/IMT), Praça Mauá 1, São Caetano do Sul, SP, 09580-900, Brazil
| | - Jessica N Yamashiro
- Mauá School of Engineering, Mauá Institute of Technology (EEM/IMT), Praça Mauá 1, São Caetano do Sul, SP, 09580-900, Brazil
| | - Ana L S Becker
- Mauá School of Engineering, Mauá Institute of Technology (EEM/IMT), Praça Mauá 1, São Caetano do Sul, SP, 09580-900, Brazil
| | - Maria F G Vidal
- Mauá School of Engineering, Mauá Institute of Technology (EEM/IMT), Praça Mauá 1, São Caetano do Sul, SP, 09580-900, Brazil
| | - Nathalia Pezini
- Mauá School of Engineering, Mauá Institute of Technology (EEM/IMT), Praça Mauá 1, São Caetano do Sul, SP, 09580-900, Brazil
| | - Roberta Albanez
- Mauá School of Engineering, Mauá Institute of Technology (EEM/IMT), Praça Mauá 1, São Caetano do Sul, SP, 09580-900, Brazil
| | - Suzana M Ratusznei
- Mauá School of Engineering, Mauá Institute of Technology (EEM/IMT), Praça Mauá 1, São Caetano do Sul, SP, 09580-900, Brazil
| | - José A D Rodrigues
- Mauá School of Engineering, Mauá Institute of Technology (EEM/IMT), Praça Mauá 1, São Caetano do Sul, SP, 09580-900, Brazil.
| |
Collapse
|
4
|
Lovato G, Albanez R, Triveloni M, Ratusznei SM, Rodrigues JAD. Methane Production by Co-Digesting Vinasse and Whey in an AnSBBR: Effect of Mixture Ratio and Feed Strategy. Appl Biochem Biotechnol 2018; 187:28-46. [DOI: 10.1007/s12010-018-2802-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/30/2018] [Indexed: 11/28/2022]
|
5
|
Albanez R, Lovato G, Ratusznei SM, Zaiat M, Rodrigues JAD. Feasibility of biohydrogen production by co-digestion of vinasse (sugarcane stillage) and molasses in an AnSBBR. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2018. [DOI: 10.1590/0104-6632.20180351s20150807] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Roberta Albanez
- Mauá Institute of Technology, Brazil; University of São Paulo, Brazil
| | - Giovanna Lovato
- Mauá Institute of Technology, Brazil; University of São Paulo, Brazil
| | | | | | | |
Collapse
|
6
|
Lovato G, Lazaro C, Zaiat M, Ratusznei S, Rodrigues J. Biohydrogen production by co-digesting whey and glycerin in an AnSBBR: Performance optimization, metabolic pathway kinetic modeling and phylogenetic characterization. Biochem Eng J 2017. [DOI: 10.1016/j.bej.2017.09.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
7
|
Almeida WA, Ratusznei SM, Zaiat M, Rodrigues JAD. AnSBBR applied to biomethane production for vinasse treatment: effects of organic loading, feed strategy and temperature. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2017. [DOI: 10.1590/0104-6632.20170343s20150584] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
| | | | - M. Zaiat
- Universidade de São Paulo, Brazil
| | | |
Collapse
|
8
|
Rajasimman M, Babu SV, Rajamohan N. Biodegradation of textile dyeing industry wastewater using modified anaerobic sequential batch reactor – Start-up, parameter optimization and performance analysis. J Taiwan Inst Chem Eng 2017. [DOI: 10.1016/j.jtice.2017.01.027] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
9
|
Wang J, Gao M, Wang Q, Zhang W, Shirai Y. Pilot-scale open fermentation of food waste to produce lactic acid without inoculum addition. RSC Adv 2016. [DOI: 10.1039/c6ra22760k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A pilot-scale study on lactic acid production from non-sterilized open fermentation of food waste with indigenous microorganisms.
Collapse
Affiliation(s)
- Juan Wang
- Department of Environmental Engineering
- University of Science and Technology Beijing
- Beijing 100083
- China
| | - Ming Gao
- Department of Environmental Engineering
- University of Science and Technology Beijing
- Beijing 100083
- China
| | - Qunhui Wang
- Department of Environmental Engineering
- University of Science and Technology Beijing
- Beijing 100083
- China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants
| | - Wenyu Zhang
- Beijing Municipal Research Institute of Environmental Protection
- Beijing
- China
| | - Yoshihito Shirai
- Department of Biological Functions and Engineering
- Kyushu Institute of Technology
- Kitakyushu 808-0196
- Japan
| |
Collapse
|
10
|
Co-digestion of Whey with Glycerin in an AnSBBR for Biomethane Production. Appl Biochem Biotechnol 2015; 178:126-43. [DOI: 10.1007/s12010-015-1863-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 09/14/2015] [Indexed: 11/26/2022]
|
11
|
Albanez R, Chiaranda BC, Ferreira RG, França ALP, Honório CD, Rodrigues JAD, Ratusznei SM, Zaiat M. Anaerobic Biological Treatment of Vinasse for Environmental Compliance and Methane Production. Appl Biochem Biotechnol 2015; 178:21-43. [DOI: 10.1007/s12010-015-1856-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 09/14/2015] [Indexed: 11/29/2022]
|
12
|
Contrera RC, Silva KCDC, Silva GHR, Morita DM, Zaiat M, Schalch V. THE "CHEMICAL OXYGEN DEMAND / TOTAL VOLATILE ACIDS" RATIO AS AN ANAEROBIC TREATABILITY INDICATOR FOR LANDFILL LEACHATES. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2015. [DOI: 10.1590/0104-6632.20150321s00003024] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Affiliation(s)
| | | | | | | | - M. Zaiat
- Universidade de São Paulo (USP), Brazil
| | | |
Collapse
|
13
|
Anaerobic Treatment of Industrial Biodiesel Wastewater by an ASBR for Methane Production. Appl Biochem Biotechnol 2013; 170:105-18. [DOI: 10.1007/s12010-013-0171-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 02/28/2013] [Indexed: 10/27/2022]
|
14
|
Effect of feed strategy on methane production and performance of an AnSBBR treating effluent from biodiesel production. Appl Biochem Biotechnol 2012; 166:2007-29. [PMID: 22373928 DOI: 10.1007/s12010-012-9627-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 02/20/2012] [Indexed: 10/28/2022]
Abstract
The aim of this work was to investigate the effect of different feeding times (2, 4 and 6 h) and applied volumetric organic loads (4.5, 6.0 and 7.5 gCOD L(-1) day(-1)) on the performance of an anaerobic sequencing batch biofilm reactor (AnSBBR) treating effluent from biodiesel production. Polyurethane foam cubes were used as inert support in the reactor, and mixing was accomplished by recirculating the liquid phase. The effect of feeding time on reactor performance showed to be more pronounced at higher values of applied volumetric organic loads (AVOLs). Highest organic material removal efficiencies achieved at AVOL of 4.5 gCOD L(-1) day(-1) were 87 % at 4-h feeding against 84 % at 2-h and 6-h feeding. At AVOL of 6.0 gCOD L(-1) day(-1), highest organic material removal efficiencies achieved with 4-h and 6-h feeding were 84 %, against 71 % at 2-h feeding. At AVOL of 7.5 gCOD L(-1) day(-1), organic material removal efficiency achieved with 4-h feeding was 77 %. Hence, longer feeding times favored minimization of total volatile acids concentration during the cycle as well as in the effluent, guaranteeing process stability and safety.
Collapse
|
15
|
Bezerra RA, Rodrigues JAD, Ratusznei SM, Canto CSA, Zaiat M. Effect of organic load on the performance and methane production of an AnSBBR treating effluent from biodiesel production. Appl Biochem Biotechnol 2011; 165:347-68. [PMID: 21494753 DOI: 10.1007/s12010-011-9255-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 04/04/2011] [Indexed: 12/01/2022]
Abstract
Currently, there is an increasing demand for the production of biodiesel and, consequently, there will be an increasing need to treat wastewaters resulting from the production process of this biofuel. The main objective of this work was, therefore, to investigate the effect of applied volumetric organic load (AVOL) on the efficiency, stability, and methane production of an anaerobic sequencing batch biofilm reactor applied to the treatment of effluent from biodiesel production. As inert support, polyurethane foam cubes were used in the reactor and mixing was accomplished by recirculating the liquid phase. Increase in AVOL resulted in a drop in organic matter removal efficiency and increase in total volatile acids in the effluent. AVOLs of 1.5, 3.0, 4.5 and 6.0 g COD L(-1) day(-1) resulted in removal efficiencies of 92%, 81%, 67%, and 50%, for effluent filtered samples, and 91%, 80%, 63%, and 47%, for non-filtered samples, respectively, whereas total volatile acids concentrations in the effluent amounted to 42, 145, 386 and 729 mg HAc L(-1), respectively. Moreover, on increasing AVOL from 1.5 to 4.5 g COD L(-1) day(-1) methane production increased from 29.5 to 55.5 N mL CH(4) g COD(-1). However, this production dropped to 36.0 N mL CH(4) g COD(-1) when AVOL was increased to 6.0 g COD L(-1) day(-1), likely due to the higher concentration of volatile acids in the reactor. Despite the higher concentration of volatile acids at the highest AVOL, alkalinity supplementation to the influent, in the form of sodium bicarbonate, at a ratio of 0.5-1.3 g NaHCO(3) g COD (fed) (-1) , was sufficient to maintain the pH near neutral and guarantee process stability during reactor operation.
Collapse
Affiliation(s)
- Roberto Antonio Bezerra
- Departamento de Engenharia Química e de Alimentos, Escola de Engenharia Mauá, Instituto Mauá de Tecnologia, Praça Mauá 1, CEP 09.580-900, São Caetano do Sul, SP, Brazil
| | | | | | | | | |
Collapse
|
16
|
Selma VC, Cotrim LHB, Rodrigues JAD, Ratusznei SM, Zaiat M, Foresti E. ASBR applied to the treatment of biodiesel production effluent: effect of organic load and fill time on performance and methane production. Appl Biochem Biotechnol 2010; 162:2365-80. [PMID: 20556540 DOI: 10.1007/s12010-010-9009-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Accepted: 06/07/2010] [Indexed: 10/19/2022]
Abstract
The effect of organic matter and fill time on anaerobic sequencing batch reactor (5 L, 30 °C, 8-h cycles, 50 rpm) efficiency has been analyzed. Organic matter was increased by the influent concentration. Fill times investigated were in the batch mode and fed-batch followed by batch. In the batch mode organic matter removal were 93%, 81%, and 66% for influent concentration of 500, 1,000, and 2,000 mgCOD/L (0.6, 1.29, and 2.44 g COD/L.d), respectively. At 3,000 mgCOD/L (3.82 gCOD/L x d) operational stability could not be achieved. Removal efficiency was improved by increasing the fill time, and was 85% for the 1,000 mgCOD/L condition and fill times of 2 and 4 h, and 80 and 77% for the 2,000 mgCOD/L condition and fill times of 2 and 4 h, respectively. Hence, gradual feeding seemed to improve and to smooth the profiles of organic matter and volatile acids along the cycle with 78 to 96 NmLCH₄/gCOD.
Collapse
Affiliation(s)
- Vivian C Selma
- Escola de Engenharia Mauá-Instituto Mauá de Tecnologia (EEM/IMT), Praça Mauá 1, CEP 09.580-900, São Caetano do Sul, São Paulo, Brazil
| | | | | | | | | | | |
Collapse
|
17
|
AnSBBR Applied to the Treatment of Metalworking Fluid Wastewater: Effect of Organic and Shock Load. Appl Biochem Biotechnol 2010; 162:1708-24. [DOI: 10.1007/s12010-010-8952-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 03/10/2010] [Accepted: 03/15/2010] [Indexed: 10/19/2022]
|
18
|
de Oliveira DS, Prinholato AC, Ratusznei SM, Rodrigues JAD, Zaiat M, Foresti E. AnSBBR applied to the treatment of wastewater from a personal care industry: effect of organic load and fill time. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2009; 90:3070-3081. [PMID: 19497659 DOI: 10.1016/j.jenvman.2009.04.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Revised: 03/16/2009] [Accepted: 04/22/2009] [Indexed: 05/27/2023]
Abstract
The objective of this work was to study the technological feasibility of treating wastewater from a personal care industry (PCI-WW) in a mechanically stirred anaerobic sequencing batch biofilm reactor (AnSBBR) containing immobilized biomass on polyurethane foam. An assessment was made on how system efficiency and stability would be affected by: increasing organic load; supplementation of nutrients and alkalinity; and different feed strategies. The AnSBBR operated with 8-h cycles, stirring speed of 400 rpm, temperature of 30 degrees C, and treated with 2.0 L wastewater per cycle. First the efficiency and stability of the AnSBBR were studied when submitted to an organic loading rate (OLR) of 3.1-9.4 gCOD/(L d), and when the PCI-WW was supplemented with nutrients (sucrose, urea, trace metals) and alkalinity. The AnSBBR was shown to be robust and presented stability and removal efficiency exceeding 90%. At an OLR of 12.0 gCOD/(L d) efficiency became difficult to maintain due to the presence of commercial cleansers and disinfectants in the wastewater lots. In a subsequent stage the AnSBBR treated the wastewater supplemented with alkalinity, but with no nutrients at varying feed strategies and maintaining an OLR of approximately 9.0 gCOD/(L d). The first strategy consists of feeding 2.0 L of the influent batchwise [OLR of 9.4 gCOD/(L d)]. In the second 1.0 L of influent was fed-batchwise and an additional 1.0 L was fed fed-batchwise [OLR of 9.2 gCOD/(L d)], i.e., in relation to the first strategy the feed volume was maintained but supplied in different periods. In the third strategy 1.0 L of treated effluent was maintained in the reactor and 1.0 L of influent was fed fed-batchwise [OLR of 9.0 gCOD/(L d)], i.e., in relation to the first strategy the feed volume was different but the feed period was the same and the OLR was maintained by increasing the influent concentration. Comparison of the first and second strategies revealed that organic matter removal efficiency was unaffected (exceeding 90%). The third strategy resulted in a reduction in average removal efficiency from 91 to 83% when compared to the first one. A kinetic study resulted in first order kinetic parameters ranges from 0.42 to 1.46 h(-1) at OLRs from 3.1 to 12.0 gCOD/(L d), respectively, and the second feed strategy [OLR of 9.2 gCOD/(L d)] was shown to be the most favorable.
Collapse
Affiliation(s)
- Daniela Sotirchos de Oliveira
- Escola de Engenharia Mauá, Instituto Mauá de Tecnologia (EEM/IMT), Departamento de Engenharia Quimica e de Alimentos, Praça Mauá 1, CEP 09 580-900, São Caetano do Sul, SP, Brazil
| | | | | | | | | | | |
Collapse
|
19
|
Michelan R, Zimmer TR, Rodrigues JAD, Ratusznei SM, de Moraes D, Zaiat M, Foresti E. Effect of impeller type and mechanical agitation on the mass transfer and power consumption aspects of ASBR operation treating synthetic wastewater. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2009; 90:1357-1364. [PMID: 18814952 DOI: 10.1016/j.jenvman.2008.08.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Revised: 04/14/2008] [Accepted: 08/03/2008] [Indexed: 05/26/2023]
Abstract
The effect of flow type and rotor speed was investigated in a round-bottom reactor with 5 L useful volume containing 2.0 L of granular biomass. The reactor treated 2.0 L of synthetic wastewater with a concentration of 800 mgCOD/L in 8-h cycles at 30 degrees C. Five impellers, commonly used in biological processes, have been employed to this end, namely: a turbine and a paddle impeller with six-vertical-flat-blades, a turbine and a paddle impeller with six-45 degrees -inclined-flat-blades and a three-blade-helix impeller. Results showed that altering impeller type and rotor speed did not significantly affect system stability and performance. Average organic matter removal efficiency was about 84% for filtered samples, total volatile acids concentration was below 20 mgHAc/L and bicarbonate alkalinity a little less than 400 mgCaCO3/L for most of the investigated conditions. However, analysis of the first-order kinetic model constants showed that alteration in rotor speed resulted in an increase in the values of the kinetic constants (for instance, from 0.57 h(-1) at 50 rpm to 0.84 h(-1) at 75 rpm when the paddle impeller with six-45 degrees -inclined-flat-blades was used) and that axial flow in mechanically stirred reactors is preferable over radial-flow when the vertical-flat-blade impeller is compared to the inclined-flat-blade impeller (for instance at 75 rpm, from 0.52 h(-1) with the six-flat-blade-paddle impeller to 0.84 h(-1) with the six-45 degrees -inclined-flat-blade-paddle impeller), demonstrating that there is a rotor speed and an impeller type that maximize solid-liquid mass transfer in the reaction medium. Furthermore, power consumption studies in this reduced reactor volume showed that no high power transfer is required to improve mass transfer (less than 0.6 kW/10(3)m3).
Collapse
Affiliation(s)
- Rogério Michelan
- Departamento de Hidráulica e Saneamento, Escola de Engenharia de São Carlos, Universidade de São Paulo (SHS/EESC/USP), Av. Trabalhador São-Carlense 400, CEP 13.566-590, São Carlos, SP, Brazil
| | | | | | | | | | | | | |
Collapse
|
20
|
Ndon UJ, Zhao JC, Siguan ML. Modeling and computational simulation of dilution and biochemical materials balance equations for partially emptied batch reactors. Appl Biochem Biotechnol 2007; 136:97-118. [PMID: 17416980 DOI: 10.1007/bf02685941] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 03/25/2006] [Accepted: 03/31/2006] [Indexed: 10/22/2022]
Abstract
Sequencing batch reactors (SBRs) including aerobic SBRs and anaerobic SBRs (ASBRs) are partially emptied batch reactors that are widely used as bioprocesses in pollution control. We present dilution and biochemical materials balance modeling equations and simulation results for the partially emptied batch reactors, especially for ASBR treatment of low-strength wastewater. The simulated substrate and microbial concentrations for both dilution and materials balance equations follow the same pattern during both feeding and reaction times. However, the results of the materials balance equations show microbial activities during feeding as well as during reaction times and were found to be more appropriate for the biologic system in which substrate removal is associated with microbial growth. Furthermore, the simulation results point to the need to foster high microbial accumulation in the system during startup to optimize the process performance and the need to operate the system at a short reaction time, especially for low substrate concentrations. The results were found to be in agreement with the results of prior laboratory studies.
Collapse
Affiliation(s)
- Udeme J Ndon
- Civil and Environmental Engineering Department, San Jose State University, San Jose, CA 95192-0083, USA.
| | | | | |
Collapse
|