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Chen Z, Jiang Y, Chang Z, Wang J, Song X, Huang Z, Chen S, Li J. Denitrification characteristics and pathways of a facultative anaerobic denitrifying strain, Pseudomonas denitrificans G1. J Biosci Bioeng 2020; 129:715-722. [DOI: 10.1016/j.jbiosc.2019.12.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 11/19/2019] [Accepted: 12/27/2019] [Indexed: 11/25/2022]
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Salahudeen JH, Reshmi RR, Anoop Krishnan K, Ragi MS, Vincent SGT. Denitrification rates in estuarine sediments of Ashtamudi, Kerala, India. ENVIRONMENTAL MONITORING AND ASSESSMENT 2018; 190:323. [PMID: 29725770 DOI: 10.1007/s10661-018-6698-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 04/24/2018] [Indexed: 06/08/2023]
Abstract
Estuarine sediments are important sites for denitrification, which is microbially mediated reduction of nitrate to dinitrogen that also influences global climate change by co-production of nitrous oxide, a potent greenhouse gas. Physicochemical properties and nutrients of sediment samples that influence denitrification rate were studied in Ashtamudi estuarine sediments. They were pH, electrical conductivity (EC), salinity, nitrate-nitrogen (NO3--N), exchangeable ammonia (NH3--N), total kjeldahl nitrogen (TKN) and organic carbon (Corg). Sediment samples were collected from six stations during summer, monsoon of 2013 and 13 stations from monsoon 2014 and summer 2015. The sedimentary denitrification potential ranged from 0.49 ± 0.05 to 4.85 ± 0.782 mmol N2O m-2 h-1. Maximum denitrification was observed in S4, which is attributed to a local anthropogenic source coupled with intense rainfall episode preceding the sampling season of monsoon 2013. However, this trend was not repeated in the subsequent monsoon samples. This shows that in Ashtamudi, monsoonal effects do not influence sedimentary denitrification. Among the various environmental variables, NO3--N, Corg and NH3-N were the key factors that influence denitrification in the Ashtamudi estuarine sediments. Among these key factors, NO3--N was the limiting factor for denitrification, and hence, it is of prime importance to understand the source of NO3--N that fuel denitrification in the sediments. In Ashtamudi, the concentration of NO3--N in overlying water was very less, which suggests reduced nitrogen yield in the estuary from the fluvial input of Kallada River and agricultural runoff. Sedimentary NO3--N correlated with denitrification which reveals that denitrification is coupled with nitrification in the sediments. This is further explained by the fact that NH3-N positively correlated with denitrification. The anoxic sediments were the source of ammonia for nitrous oxide production by nitrogen mineralisation. Also, the Corg in sediment samples were sufficient to support denitrification and Corg was an important factor favouring but not limiting denitrification. The results of sediment denitrification in Ashtamudi can be a model for tropical estuaries experiencing unpredictable rainfall as well as high temperature than temperate systems.
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Affiliation(s)
| | - R R Reshmi
- University of Kerala, Thiruvananthapuram, Kerala, India
| | - K Anoop Krishnan
- National Centre for Earth Science Studies, Thiruvananthapuram, Kerala, India
| | - M S Ragi
- National Centre for Earth Science Studies, Thiruvananthapuram, Kerala, India
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Hou J, You G, Xu Y, Wang C, Wang P, Miao L, Ao Y, Li Y, Lv B, Yang Y. Impacts of CuO nanoparticles on nitrogen removal in sequencing batch biofilm reactors after short-term and long-term exposure and the functions of natural organic matter. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:22116-22125. [PMID: 27543126 DOI: 10.1007/s11356-016-7281-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 07/18/2016] [Indexed: 06/06/2023]
Abstract
The impacts of CuO nanoparticle (NP) exposure on total nitrogen (TN) removal in a sequencing batch biofilm reactor (SBBR) as well as the effects of natural organic matter (NOM) in wastewater were studied. Short-term exposure (8 h) to 1 and 50 mg/L CuO NPs induced negligible influence on the nitrogen removal efficiency, and biofilms could recover from the slight damage caused by the prolonged exposure (45 days) to 1 mg/L CuO NPs. On the other hand, long-term exposure to 50 mg/L CuO NPs notably decreased the nitrogen removal efficiencies to 47.74 and 59.04 % in the absence and presence of bovine serum albumin (BSA), much lower than those in the control (75.43 %), mainly as the suppressed denitrification process. Analysis of key enzyme activities showed that the activities of nitrite reductase and nitrate reductase were obviously reduced with 50 mg/L CuO NP exposure. Further studies revealed that the inhibited nitrite/nitrate reductase was related to the variations of microenvironment pH and decrease of nirS and nirK by microelectrode and fluorescent quantitative polymerase chain reaction (PCR) analysis. In addition, the presence of BSA mitigated the toxicity of CuO NPs due to the enhanced particle size and Cu2+ release, electrostatic repulsion, and surface coating of CuO NPs, which indicated that lower inhibition effects of CuO NPs in NOM-rich wastewater is of importance when evaluating the environmental risk of NPs to wastewater treatment plants.
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Affiliation(s)
- Jun Hou
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
| | - Guoxiang You
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
| | - Yi Xu
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
| | - Chao Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China.
- College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China.
| | - Lingzhan Miao
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
| | - Yanhui Ao
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
| | - Yi Li
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
| | - Bowen Lv
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
| | - Yangyang Yang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China
- College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
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Kang CH, Shin Y, Anbu P, Nam IH, So JS. Biosequestration of copper by bacteria isolated from an abandoned mine by using microbially induced calcite precipitation. J GEN APPL MICROBIOL 2016; 62:206-12. [DOI: 10.2323/jgam.2016.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Chang-Ho Kang
- Department of Biological Engineering, Inha University
| | - YuJin Shin
- Department of Biological Engineering, Inha University
| | | | - In-Hyun Nam
- Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources
| | - Jae-Seong So
- Department of Biological Engineering, Inha University
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Xiao Y, Wu S, Yang ZH, Wang ZJ, Yan CZ, Zhao F. In situ probing the effect of potentials on the microenvironment of heterotrophic denitrification biofilm with microelectrodes. CHEMOSPHERE 2013; 93:1295-1300. [PMID: 23880237 DOI: 10.1016/j.chemosphere.2013.06.065] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 06/21/2013] [Accepted: 06/24/2013] [Indexed: 06/02/2023]
Abstract
Bio-electrochemical reactor provides a promising technology to remove nitrogen contaminants in water. In this study, a heterotrophic biofilm for denitrification process was developed, and stable total nitrogen removal efficiencies (>80%) were achieved. Fluorescence in situ hybridization showed that genes norB mainly transcribed in inner biofilm while genes nosZ showed similar transcription activities in the entire biofilm. The microelectrodes of pH and nitrous oxide (N₂O) were applied to profile the microenvironment of denitrification biofilm. In all measurements, the microenvironment pH decreased as a function of biofilm depth. The highest N₂O concentration of 90 μM in biofilm was detected when the bulk solution pH was 7.3, and an applied potential of -0.2V did not decrease the yield of N₂O in biofilm at pH 7.3. Nevertheless, pH 9.5 or an applied potential of -0.4V seemed not to suppress the yield of N₂O in biofilm.
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Affiliation(s)
- Yong Xiao
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
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Li P, Zuo J, Xing W, Tang L, Ye X, Zaixing L, Yuan L, Wang K, Zhang H. Starch/polyvinyl alcohol blended materials used as solid carbon source for tertiary denitrification of secondary effluent. J Environ Sci (China) 2013; 25:1972-1979. [PMID: 24494483 DOI: 10.1016/s1001-0742(12)60259-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Starch/polyvinyl alcohol (PVA) blended materials for using as a solid carbon source (SCS) were prepared by blending PVA and gelatinized starch in an aqueous solution system, in which PVA served as framework material and starch as carbon source. The optimization of starch content and temperature effects were investigated. It was indicated that higher denitrification efficiency could be achieved with more starch in the materials. The average specific denitrification rates were 0.93, 0.66, 0.37 and 0.36 mg/(g x day) corresponding to starch content of 70%, 60%, 40% and 30% respectively at 37 degrees C. The denitrification rates increased when operating temperature was raised from 23 degrees C to 30 degrees C and then 37 degrees C. The mechanism of carbon release was analyzed incorporating the experimental results of abiotic release in deionized water. The organic carbon was mainly hydrolyzed by microbes, and the biological release efficiencies were at the range of 89.2% to 96.0%. A long-term experiment with a continuous flow reactor with SCS material containing 70% starch was conducted to gain some experience for practical application. When the influent nitrate concentration was in the range of 35.2 to 39.1 mg/L, hydraulic retention time of 4 hr, and operating temperature of 30 degrees C, a nitrogen removal efficiency up to 94.6% and denitrification rate of 0.217 kg/(m3 x day) was achieved. The starch-based materials developed in this study can be used as a solid carbon source for tertiary nitrogen removal from secondary effluent.
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Affiliation(s)
- Peng Li
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
| | - Jiane Zuo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Wei Xing
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Lei Tang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiangyang Ye
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Li Zaixing
- School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China
| | - Lin Yuan
- THUNIP Holdings Co., Ltd., Beijing 100020, China
| | - Kaijun Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Hongtao Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
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7
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Mousavi S, Ibrahim S, Aroua MK, Ghafari S. Development of nitrate elimination by autohydrogenotrophic bacteria in bio-electrochemical reactors – A review. Biochem Eng J 2012. [DOI: 10.1016/j.bej.2012.04.016] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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8
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Yang X, Wang S, Zhou L. Effect of carbon source, C/N ratio, nitrate and dissolved oxygen concentration on nitrite and ammonium production from denitrification process by Pseudomonas stutzeri D6. BIORESOURCE TECHNOLOGY 2012; 104:65-72. [PMID: 22074905 DOI: 10.1016/j.biortech.2011.10.026] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 10/10/2011] [Accepted: 10/12/2011] [Indexed: 05/27/2023]
Abstract
Pseudomonas stutzeri D6, selectively isolated from activated sludge was used to study NO(2)(-) and NH(4)(+) production from denitrification processes. Changes in carbon type, C/N ratio and oxygen concentration significantly influenced the magnitude of NO(2)(-) and NH(4)(+) accumulation through denitrification. D6 showed a preference for citrate and acetate, which led to the largest quantity of nitrate reduced and which were exhausted most rapidly, with minimal intermediate products accumulation. It is found that at higher initial organic carbon concentration or for directly metabolic carbon type more complete denitrification could be obtained as a result of increase of the oxygen consumption rate by substrate stimulation. The higher the oxygen concentration in the culture was, the higher the intermediate products concentration became. The experiment showed that NO(2)(-) and NH(4)(+) production was only slightly influenced by nitrate concentration. Biological nitrogen removal systems should be optimized to promote complete denitrification to minimize NO(2)(-) and NH(4)(+) accumulation.
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Affiliation(s)
- Xinping Yang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Weigang Road 1, Nanjing 210095, PR China.
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Ma J, Yang Q, Wang S, Wang L, Takigawa A, Peng Y. Effect of free nitrous acid as inhibitors on nitrate reduction by a biological nutrient removal sludge. JOURNAL OF HAZARDOUS MATERIALS 2010; 175:518-523. [PMID: 19910113 DOI: 10.1016/j.jhazmat.2009.10.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2009] [Revised: 09/13/2009] [Accepted: 10/10/2009] [Indexed: 05/28/2023]
Abstract
Nitrite has been commonly thought to have a broad inhibitory effect on bacterial metabolism. Little is known about the impact of nitrite on nitrate reduction with pH considered as an important factor. This study investigates the nitrite inhibition on nitrate reduction during denitrification under various pH conditions by using a biological nutrient removal (BNR) sludge. The results showed that nitrate reduction performance had a much stronger relationship with the free nitrous acid (FNA) than that of nitrite concentration, implying that FNA, rather than nitrite, is likely the real inhibitor on nitrate reduction. The nitrate reduction activity of the biomass was observed to be inhibited about 60% in the range of 0.01-0.025 mg HNO(2)-N/L and was totally inhibited when FNA level was greater than the threshold concentration (0.2mg HNO(2)-N/L). Moreover, the recovery rate from inhibitory effect was found to be dependent much more strongly on the concentration of FNA, of which the biomass was exposed to during the inhibition period, than on the duration of the inhibition and the feeding mode of inhibitor. It was also found that nitrite reduction was significantly inhibited by FNA and the nitrite reduction rate was linear to nitrate reduction rate due to the inhibitory mechanism under which FNA may react with the enzymes involved in the denitrification process.
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Affiliation(s)
- Juan Ma
- Key Laboratory of Beijing Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China
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10
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Association of novel and highly diverse acid-tolerant denitrifiers with N2O fluxes of an acidic fen. Appl Environ Microbiol 2009; 76:1125-34. [PMID: 20023077 DOI: 10.1128/aem.02256-09] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Wetlands are sources of denitrification-derived nitrous oxide (N2O). Thus, the denitrifier community of an N2O-emitting fen (pH 4.7 to 5.2) was investigated. N2O was produced and consumed to subatmospheric concentrations in unsupplemented anoxic soil microcosms. Total cell counts and most probable numbers of denitrifiers approximated 10(11) cells x g(DW)(-1) (where DW is dry weight) and 10(8) cells x g(DW)(-1), respectively, in both 0- to 10-cm and 30- to 40-cm depths. Despite this uniformity, depth-related maximum reaction rate (v(max)) values for denitrification in anoxic microcosms ranged from 1 to 24 and -19 to -105 nmol N2O h(-1) x g(DW)(-1), with maximal values occurring in the upper soil layers. Denitrification was enhanced by substrates that might be formed via fermentation in anoxic microzones of soil. N2O approximated 40% of total nitrogenous gases produced at in situ pH, which was likewise the optimal pH for denitrification. Gene libraries of narG and nosZ (encoding nitrate reductase and nitrous oxide reductase, respectively) from fen soil DNA yielded 15 and 18 species-level operational taxonomic units, respectively, many of which displayed phylogenetic novelty and were not closely related to cultured organisms. Although statistical analyses of narG and nosZ sequences indicated that the upper 20 cm of soil contained the highest denitrifier diversity and species richness, terminal restriction fragment length polymorphism analyses of narG and nosZ revealed only minor differences in denitrifier community composition from a soil depth of 0 to 40 cm. The collective data indicate that the regional fen harbors novel, highly diverse, acid-tolerant denitrifier communities capable of complete denitrification and consumption of atmospheric N2O at in situ pH.
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Ghafari S, Hasan M, Aroua MK. Improvement of autohydrogenotrophic nitrite reduction rate through optimization of pH and sodium bicarbonate dose in batch experiments. J Biosci Bioeng 2009; 107:275-80. [PMID: 19269592 DOI: 10.1016/j.jbiosc.2008.11.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Revised: 11/03/2008] [Accepted: 11/04/2008] [Indexed: 10/20/2022]
Abstract
Accumulation of nitrite intermediate in autohydrogenotrophic denitrification process has been a challenging difficulty to tackle. This study showed that further growth of "true denitrifying" bacteria and adaptation to nitrite led to a faster reduction of nitrite than nitrate as a solution to circumvent nitrite accumulation. Moreover, two effective parameters namely pH and bicarbonate dose were optimized in order to achieve a better reduction rate. Sodium bicarbonate dose ranging from 20 to 2000 mg/L and pH in the range of 6.5-8.5 was selected to be examined employing 0.2 g MLVSS/L of reacclimatized denitrifying bacteria. Eleven runs of experiments were designed considering the interactive effect of these two operative parameters. A fairly close reduction time less than 4.5 h (>22.22 mg NO2(-)-N/g MLVSS/h) was gained for the pH range between 7 and 8. The highest specific nitrite reduction rate at 25 mg NO2(-)-N/g MLVSS/h was achieved applying 1000 mg NaHCO3/L at pH 7.5 and 8. The pH was found to be the leading parameter and bicarbonate as the less effective parameter on nitrite reduction removal. Central composite design (CCD) and response surface design (RSM) were employed to develop a model as well as define the optimum condition. Using the experimental data, the developed quadratic model predicted optimum condition at pH 7.8 and sodium bicarbonate dose 1070 mg/L upon which denitrifiers managed to accomplish reduction within 3.5 h and attained the specific degradation rate of 28.57 mg NO2(-)-N/g MLVSS/h.
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Affiliation(s)
- Shahin Ghafari
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
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12
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Microbial denitrification by immobilized bacteria Pseudomonas denitrificans stimulated by constant electric field. Biochem Eng J 2009. [DOI: 10.1016/j.bej.2008.12.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Ghafari S, Hasan M, Aroua MK. Effect of carbon dioxide and bicarbonate as inorganic carbon sources on growth and adaptation of autohydrogenotrophic denitrifying bacteria. JOURNAL OF HAZARDOUS MATERIALS 2009; 162:1507-1513. [PMID: 18639979 DOI: 10.1016/j.jhazmat.2008.06.039] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Revised: 06/12/2008] [Accepted: 06/12/2008] [Indexed: 05/26/2023]
Abstract
Acclimation of autohydrogenotrophic denitrifying bacteria using inorganic carbon source (CO(2) and bicarbonate) and hydrogen gas as electron donor was performed in this study. In this regard, activated sludge was used as the seed source and sequencing batch reactor (SBR) technique was applied for accomplishing the acclimatization. Three distinct strategies in feeding of carbon sources were applied: (I) continuous sparging of CO(2), (II) bicarbonate plus continuous sparging of CO(2), and (III) only bicarbonate. The pH-reducing nature of CO(2) showed an unfavorable impact on denitrification rate; however bicarbonate resulted in a buffered environment in the mixed liquor and provided a suitable mean to maintain the pH in the desirable range of 7-8.2. As a result, bicarbonate as the only carbon source showed a faster adaptation, while carbon dioxide as the only carbon source as well as a complementary carbon source added to bicarbonate resulted in longer acclimation period. Adapted hydrogenotrophic denitrifying bacteria, using bicarbonate and hydrogen gas in the aforementioned pH range, caused denitrification at a rate of 13.33 mg NO(3)(-)-N/g MLVSS/h for degrading 20 and 30 mg NO(3)(-)-N/L and 9.09 mg NO(3)(-)-N/g MLVSS/h for degrading 50mg NO(3)(-)-N/L.
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Affiliation(s)
- Shahin Ghafari
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
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14
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Nitrate removal with bacterial cells attached to quartz sand and zeolite from salty wastewaters. World J Microbiol Biotechnol 2007. [DOI: 10.1007/s11274-007-9405-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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15
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Soto O, Aspé E, Roeckel M. Kinetics of cross-inhibited denitrification of a high load wastewater. Enzyme Microb Technol 2007. [DOI: 10.1016/j.enzmictec.2006.11.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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16
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Sáez F, Pozo C, Gómez MA, Martínez-Toledo MV, Rodelas B, Gónzalez-López J. Growth and denitrifying activity of Xanthobacter autotrophicus CECT 7064 in the presence of selected pesticides. Appl Microbiol Biotechnol 2006; 71:563-7. [PMID: 16249877 DOI: 10.1007/s00253-005-0182-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2005] [Revised: 09/02/2005] [Accepted: 09/04/2005] [Indexed: 10/25/2022]
Abstract
The effects of the application of nine pesticides used commonly in agriculture (aldrin, lindane, dimetoate, methylparathion, methidation, atrazine, simazine, captan and diflubenzuron) on growth, CO2 production, denitrifying activity [as nitrous oxide (N2O) released] and nitrite accumulation in the culture medium by Xanthobacter autotrophicus strain CECT 7064 (Spanish Type Culture Collection) (a micro-organism isolated from a submerged fixed-film) were studied. The herbicide atrazine and the insecticide dimetoate totally inhibited growth and biological activity of X. autotrophicus at 10 mg l(-1), while the rest of the tested pesticides delayed the growth of strain CECT 7064 but did not drastically affect the bacterial growth after 96 h of culture. The denitrifying activity of X. autotrophicus was negatively affected by the pesticides application with the exception of fungicide captan. The release of N2O was strongly inhibited by several pesticides (aldrin, lindane, methylparathion, methidation and diflubenzuron), while dimetoate, atrazine and simazine inhibited totally the denitrifying activity of the strain. The effects of the pesticides on denitrifying submerged fixed-film reactor are discussed.
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Affiliation(s)
- Florentina Sáez
- Group of Environmental Microbiology, Institute of Water Research, University of Granada, Granada, Spain
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Foglar L, Briski F, Sipos L, Vuković M. High nitrate removal from synthetic wastewater with the mixed bacterial culture. BIORESOURCE TECHNOLOGY 2005; 96:879-888. [PMID: 15627558 DOI: 10.1016/j.biortech.2004.09.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 05/27/2004] [Accepted: 09/02/2004] [Indexed: 05/24/2023]
Abstract
The applicability of the mixed bacterial culture, originated from two-stage anaerobic-aerobic industrial yeasts production wastewater treatment plant for high rate denitrification processes was investigated. After acclimation to nitrate, the dominant strains were Pseudomonas and Paracoccus sp. Complete denitrification with low accumulation of nitrite-N (0.1 mg/l) was found in synthetic wastewater, obeying a zero-order reaction with respect to nitrate and a first-order reaction with respect to biomass concentration. Denitrification was then monitored in the continuous-flow stirred reactor at different hydraulic retention time, HRT (62-28 h) in order to achieve the optimal HRT. Nitrate was completely removed during following 45 days, at 25 degrees C with HRT, which we reduced from 62 to 28 h. Yet still, at 28 h HRT, high average specific denitrification rate of 142 mg NO3- -N/g VSS h was obtained.
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Affiliation(s)
- Lucija Foglar
- Division of Industrial Ecology, Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, HR-10000 Zagreb, Croatia.
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Mpanias CJ, Baltzis BC. An experimental and modeling study on the removal of mono-chlorobenzene vapor in biotrickling filters. Biotechnol Bioeng 1998; 59:328-43. [PMID: 10099344 DOI: 10.1002/(sici)1097-0290(19980805)59:3<328::aid-bit9>3.0.co;2-d] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Removal of mono-chlorobenzene (m-CB) vapor from airstreams was studied in a biotrickling filter (BTF) operating under counter-current flow of the air and liquid streams. Experiments were performed under various values of inlet m-CB concentration, air and/or liquid volumetric flow rates, and pH of the recirculating liquid. Conversion of m-CB was never below 70% and at low concentrations exceeded 90%. A maximum removal rate of about 60 gm-3-reactor h-1 was observed. Conversion of m-CB was found to increase as the values of liquid and air flow rate increase and decrease, respectively. The effects of pH and frequency of medium replenishment on BTF performance were also investigated. The process was successfully described with a detailed mathematical model, which accounts for mass transfer and kinetic effects based on m-CB and oxygen availability. Solution of the model equations yielded m-CB and oxygen concentration profiles in all three phases (airstream, liquid, biofilm). It is predicted that oxygen has a controling effect on the process at high inlet m-CB concentrations. From independent, suspended culture, experiments it was found that m-CB biodegradation follows Andrews inhibitory kinetics. The kinetic constants were found to remain practically unchanged after the culture was used in BTF experiments for 8 months. Copyright 1998 John Wiley & Sons, Inc.
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Affiliation(s)
- CJ Mpanias
- Department of Chemical Engineering, Chemistry, and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, USA
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