1
|
Cheng G, Chen D, Zhang D, Li H, Du K, Zhang L. The effect of reflux ratio on sulfur disproportionation tendency in anaerobic baffled reactor with the heterotrophic combining sulfur autotrophic processes under high concentration perchlorate stress. Environ Sci Pollut Res Int 2024; 31:25929-25939. [PMID: 38488916 DOI: 10.1007/s11356-024-32835-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 03/05/2024] [Indexed: 03/17/2024]
Abstract
In a laboratory scale, an anaerobic baffled reactor (ABR) consisting of eight compartments, the heterotrophic combining sulfur autotrophic processes under different reflux ratios were constructed to achieve effective perchlorate removal and alleviate sulfur disproportionation reaction. Perchlorate was efficiently removed with effluent perchlorate concentration below 0.5 μg/L when the influent perchlorate concentration was 1030 mg/L during stages I ~ V, indicating that heterotrophic combining sulfur autotrophic perchlorate reduction processes can effectively achieve high concentration perchlorate removal. Furthermore, the 100% reflux ratio could reduce the contact time between sulfur particles and water; thus, the sulfur disproportionation reaction was inhibited. However, the inhibition effect of reflux on sulfur disproportionation was attenuated due to dilute perchlorate concentration when a reflux ratio of 150% and 200% was implemented. Meanwhile, the content of extracellular polymeric substances (EPS) in the heterotrophic unit (36.79 ~ 45.71 mg/g VSS) was higher than that in the sulfur autotrophic unit (22.19 ~ 25.77 mg/g VSS), indicating that high concentration perchlorate stress in the heterotrophic unit promoted EPS secretion. Thereinto, the PN content of sulfur autotrophic unit decreased in stage III and stage V due to decreasing perchlorate concentration in the autotrophic unit. Meanwhile, the PS content increased with increasing reflux in the autotrophic unit, which was conducive to the formation of biofilm. Furthermore, the high-throughput sequencing result showed that Proteobacteria, Chloroflexi, Firmicutes, and Bacteroidetes were the dominant phyla and Longilinea, Diaphorobacter, Acinetobacter, and Nitrobacter were the dominant genus in ABR, which were associated with heterotrophic or autotrophic perchlorate reduction and beneficial for effective perchlorate removal. The study indicated that reflux was a reasonable strategy for alleviating sulfur disproportionation in heterotrophic combining sulfur autotrophic perchlorate removal processes.
Collapse
Affiliation(s)
- Guiyang Cheng
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26#, Tianjin, 300384, People's Republic of China
| | - Denghui Chen
- Beijing Enterprises Water Group (China) Investment Limited, Beijing, 100102, China
| | - Daohong Zhang
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26#, Tianjin, 300384, People's Republic of China.
| | - Haibo Li
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26#, Tianjin, 300384, People's Republic of China
| | - Kang Du
- China Energy Conservation and Environmental Group, Co., Ltd., Beijing, Beijing, 100082, China
| | - Lin Zhang
- Shandong Hualing Technology Engineering Group Co., Ltd., Dongying, 257000, Shandong, China
| |
Collapse
|
2
|
Hong P, Sun X, Yuan S, Wang Y, Gong S, Zhang Y, Sang P, Xiao B, Shu Y. Nitrogen removal intensification of biofilm through bioaugmentation with Methylobacterium gregans DC-1 during wastewater treatment. Chemosphere 2024; 352:141467. [PMID: 38387667 DOI: 10.1016/j.chemosphere.2024.141467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 10/25/2023] [Revised: 01/24/2024] [Accepted: 02/14/2024] [Indexed: 02/24/2024]
Abstract
The increasing concern for environmental remediation has led to a search for effective methods to remove eutrophic nutrients. In this study, Methylobacterium gregans DC-1 was utilized to improve nitrogen removal in a sequencing batch biofilm reactor (SBBR) via aerobic denitrification. This bacterium has the extraordinary characteristics of strong auto-aggregation and a high ability to remove nitrogen efficiently, making it an ideal candidate for enhanced treatment of nitrogen-rich wastewater. This strain was used for the bioassessment of a test reactor (SBBRbio), which showed a shorter biofilm formation time compared to a control reactor (SBBRcon) without this strain inoculation. Moreover, the enhanced biofilm was enriched in TB-EPS and had a wider variety of protein secondary structures than SBBRcon. During the stabilization phase of SBBRbio, the EPS molecules showed the highest proportion of intermolecular hydrogen bonding. It is possible that bioaugmentation with this strain positively affects the structural stability of biofilm. At influent ammonia loadings of 100 and 150 mg. L-1, the average reduction of ammonia and nitrate-nitrogen was higher in the experimental system compared to the control system. Additionally, nitrite-N accumulation was lower and N2O production decreased compared to the control. Analysis of the microbial community structure demonstrated successful colonization in the bioreactor by a highly nitrogen-tolerant strain that efficiently removed inorganic nitrogen. These results illustrate the great potential of this type of denitrifying bacteria in the application of bioaugmentation systems.
Collapse
Affiliation(s)
- Pei Hong
- School of Ecology and Environment, College of Life Sciences, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China
| | - Xiaohui Sun
- School of Ecology and Environment, College of Life Sciences, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China
| | - Saibo Yuan
- Ecological Environment Monitoring and Scientific Research Center, Ecology and Environment Supervision and Administration Bureau of Yangtze Valley, Ministry of Ecology and Environment of the People's Republic of China, Wuhan 430014, China.
| | - Yu Wang
- School of Ecology and Environment, College of Life Sciences, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China
| | - Shihao Gong
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, 100872, Hong Kong
| | - Yancheng Zhang
- School of Ecology and Environment, College of Life Sciences, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China
| | - Pengcheng Sang
- School of Ecology and Environment, College of Life Sciences, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China
| | - Bangding Xiao
- Key Laboratory of Algal Biology of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Yilin Shu
- School of Ecology and Environment, College of Life Sciences, Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, Anhui Normal University, Wuhu 241002, China.
| |
Collapse
|
3
|
Chettri P, Ganesh KM, Mahapatra SS, Vishwanathan AS, Srivastava S. A low-cost optofluidic platform for the colorimetric assessment of bacterial activity in domestic wastewater. Anal Methods 2023; 15:6031-6039. [PMID: 37916527 DOI: 10.1039/d3ay01612a] [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: 11/03/2023]
Abstract
Optofluidic chips represent a cost-effective platform for the development of miniaturized devices to perform biochemical reactions at a microscale. The dye reduction-based electron-transfer activity monitoring (DREAM) assay is a colorimetric approach that has been adopted for the rapid assessment of bacterial activity in bioreactors used in bioremediation and industrial biotechnology. A three-layered PMMA-based optofluidic chip having laser-machined microchannels coupled with a detection system comprising an LED source and a photodiode interfaced with a microcontroller for automation constituted the experimental setup. Data acquisition was executed using a user-friendly graphical user interface (GUI) that enabled real-time monitoring of bacterial activity. A performance comparison study was performed to assess the viability of replacing expensive spectrophotometers with an inexpensive photodiode for optoelectronic automation. Bacterial activity across different growth phases of a bacterial culture, initiated using untreated domestic wastewater, was assessed by the detector on the basis of voltage readings corresponding to the rate of decrease in the blue color intensity. The highest activity observed corresponded to the log phase of the growth curve. The optimal time for measurement of bacterial activity within the log phase of the growth curve was identified using different dilutions of untreated domestic wastewater. Furthermore, the device showed comparable sensitivities for samples from different time points in a bacterial growth curve and for different dilutions of untreated domestic wastewater samples. The device also demonstrated a linear response in the assessment of bacterial activity as a function of the change in strength of untreated domestic wastewater. This is the first report on colorimetric assessment of bacterial activity using a low-cost photodiode-based device at the microscale constructed using off-the-shelf components.
Collapse
Affiliation(s)
- Prajal Chettri
- FEMTO FabULLAS, CRIF, Department of Physics, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh 515134, India.
| | - Kalathur Mohan Ganesh
- STAR Laboratory, CRIF, Department of Chemistry, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh 515134, India
| | - Sahashransu Satyajeet Mahapatra
- WATER Laboratory, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh 515134, India
| | - A S Vishwanathan
- WATER Laboratory, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh 515134, India
| | - Shailesh Srivastava
- FEMTO FabULLAS, CRIF, Department of Physics, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh 515134, India.
| |
Collapse
|
4
|
Pan Y, Yu SS, Xiao ZC, Min Y, Tian T, Zheng YM, Zhao QB, Yuan ZH, Yu HQ. Re-evaluation and modification of dehydrogenase activity tests in assessing microbial activity for wastewater treatment plant operation. Water Res 2023; 246:120737. [PMID: 37857011 DOI: 10.1016/j.watres.2023.120737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 07/25/2023] [Revised: 09/24/2023] [Accepted: 10/11/2023] [Indexed: 10/21/2023]
Abstract
Reliable and cost-effective methods for monitoring microbial activity are critical for process control in wastewater treatment plants. The dehydrogenase activity (DHA) test has been recognized as an efficient measure of biological activity due to its simplicity and broad applicability. Nevertheless, the existing DHA test methods suffer from imperfections and are difficult to implement as routine monitoring techniques. In this work, an accurate and cost-effective modified DHA approach was developed and the procedure for the DHA test was critically evaluated with respect to the standard construction, sample pretreatment, incubation and extraction conditions. The feasibility of the modified DHA test was demonstrated by comparison with the oxygen uptake rate and adenosine triphosphate in a sequencing batch reactor. The sensitivities of the two typical tetrazolium salts to toxicant inhibition by heavy metals and antibiotics were compared, revealing that 2,3,5-triphenyltetrazolium chloride (TTC) exhibited a higher sensitivity. Furthermore, the sensitivity mechanism of the two DHA tests was elucidated through electrochemical experiments, theoretical analysis and molecular simulations. Both tetrazolium salts were found to be effective artificial electron acceptors due to their low redox potentials. Molecular docking simulations revealed that TTC could outperform other tetrazolium salts in accepting electrons and hydrogens from dehydrogenase. Overall, the modified DHA approach presents an accurate and cost-effective way to measure microbial activity, making it a practical tool for wastewater treatment plants.
Collapse
Affiliation(s)
- Yuan Pan
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Sheng-Song Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Zhi-Chao Xiao
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Yuan Min
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Tian Tian
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China; Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Yu-Ming Zheng
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban and Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| | - Quan-Bao Zhao
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban and Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Zhi-Hua Yuan
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban and Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China; CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban and Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| |
Collapse
|
5
|
Zhao S, Li H, Guo J, Zhang Y, Zhao J, Song Y, Lu C, Han Y, Zhang D, Hou Y. Formation of anaerobic granular sludge (AnGS) to treat high-strength perchlorate wastewater via anaerobic baffled reactor (ABR) system: Electron transfer characteristic, bacterial community and positive feedback mechanism. Sci Total Environ 2022; 828:154531. [PMID: 35292321 DOI: 10.1016/j.scitotenv.2022.154531] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [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: 12/09/2021] [Revised: 03/08/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Anaerobic granular sludge (AnGS) was cultured to treat high-strength perchlorate (reaching to 4800 mg/L) wastewater by an anaerobic baffled reactor (ABR) system with five equal-volume compartments (C1-C5 compartments). Inoculated sludge completely granulated on day 104 with granule size of 0.50-0.75 mm and perchlorate removal efficiency reaching to 97% (influent perchlorate of 2000-4800 mg/L). The Cyclic voltammetry (CV) capacitance increased from 487.5, 465.8 and 407.8 μF to 576.5, 552.4, 549.6 μF in C1, C3 and C5 compartments of ABR system, respectively, suggesting the electron transfer capacity was enhanced under high-strength perchlorate stress. Meanwhile, adenosine triphosphate (ATP) value and electron transport system activity (ETSA) increased to 25.05, 22.87, 20.43 and 6.22, 4.87, 3.95 of C1, C3 and C5 compartments, respectively. The results suggested that high-strength perchlorate stress improved the microbial metabolic activity, which promoted secretion of extracellular polymeric substances (EPS). The more EPS could facilitate the formation and stability of AnGS under high-strength perchlorate stress. In addition, more reasonable metabolic division of labor in functional bacterial (Thauera and Comamonas) was beneficial to AnGS formation, which achieved high-strength perchlorate efficient removal. Finally, a positive feedback mechanism between AnGS formation and high-strength perchlorate removal was established through EPS, microbial metabolic activity and electron transfer characteristic in ABR system. However, excessive perchlorate (5800 mg/L) would exceed the treatment capacity of AnGS, which resulted in the deterioration of removal performance. This work provided an effective information for AnGS application to treat high-strength perchlorate wastewater.
Collapse
Affiliation(s)
- Shiqi Zhao
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Haibo Li
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China.
| | - Jianbo Guo
- School of Civil Engineering and Architecture, Taizhou University, Taizhou 318000, China
| | - Yuxiang Zhang
- Jinzhou Electromechanical Engineering School, Tianshan Road 17, Jinzhou 121007, Liaoning, China
| | - Jianhai Zhao
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Yuanyuan Song
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Caicai Lu
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Yi Han
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Daohong Zhang
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Yanan Hou
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| |
Collapse
|
6
|
Zhang Z, Cao R, Jin L, Zhu W, Ji Y, Xu X, Zhu L. The regulation of N-acyl-homoserine lactones (AHLs)-based quorum sensing on EPS secretion via ATP synthetic for the stability of aerobic granular sludge. Sci Total Environ 2019; 673:83-91. [PMID: 30986684 DOI: 10.1016/j.scitotenv.2019.04.052] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [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: 01/14/2019] [Revised: 03/13/2019] [Accepted: 04/04/2019] [Indexed: 06/09/2023]
Abstract
According to the relationship among microbial activity, quorum sensing (QS) and structural stability of aerobic granular sludge, the mechanism of QS regulation for microbial activity and granular stability was investigated in AGS process. Results showed that ATP content decreased sharply from 1.8 μmol/gVSS of stable granules to 0.8 μmol/gVSS of disintegrating granules, and the relative abundance of QS-activity microbes, Rhodobacter spp. and Xanthomonadaceae decreased in initially unstable granules compared with stable granules. The main AHLs were detected in this study, and C8-HSL, 3OHC8-HSL and 3OHC12-HSL decreased significantly when structure of granules changed from stability to disintegration. Accompanying with the decrease of AHLs level, the extracellular polymeric substances (EPS) content in initially unstable granules decreased sharply from 226.8 to 163.6 mg/gVSS with the ratio of extracellular protein to exopolysaccharide (PN/PS) decreasing from 3.6 to 2.2, despite EPS-secretion microbes enriched. The effect of QS on microbial activity was proved by AHL add-back study, results indicated that ATP and EPS content in sludge increased significantly (p < 0.05) with AHLs added, but EPS production was limited when ATP synthesis was disrupted. It was concluded that the AHLs-based QS favored the granular stability via the enhancement of ATP synthesis in microbes. This study provides a new perspective for QS regulation in aerobic granular sludge system, because the ATP regulated by QS could be the energy currency for cellular metabolism, such as nutrient removal, degradation of emerging pollutants, microbial growth and other aspects.
Collapse
Affiliation(s)
- Zhiming Zhang
- Institute of Environmental Pollution Control and Treatment, Zhejiang University, Hangzhou 310058, China
| | - Runjuan Cao
- Institute of Environmental Pollution Control and Treatment, Zhejiang University, Hangzhou 310058, China
| | - Luonan Jin
- Hangzhou Urban & Rural Construction Design Institute Co., LTD, Hangzhou 310058, China
| | - Weitang Zhu
- Environmental Protection Bureau of Changxing County, Huzhou 313100, China
| | - Yatong Ji
- Institute of Environmental Pollution Control and Treatment, Zhejiang University, Hangzhou 310058, China
| | - Xiangyang Xu
- Institute of Environmental Pollution Control and Treatment, Zhejiang University, Hangzhou 310058, China; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou 310058, China; Zhejiang Provincial Engineering Laboratory of Water Pollution Control, 388 Yuhangtang Road, Hangzhou 310058, China
| | - Liang Zhu
- Institute of Environmental Pollution Control and Treatment, Zhejiang University, Hangzhou 310058, China; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou 310058, China; Zhejiang Provincial Engineering Laboratory of Water Pollution Control, 388 Yuhangtang Road, Hangzhou 310058, China.
| |
Collapse
|
7
|
Ko KS, Ha K, Kong IC. Effects of Monotypic and Binary Mixtures of Metal Oxide Nanoparticles on Microbial Growth in Sandy Soil Collected from Artificial Recharge Sites. Int J Mol Sci 2015; 16:27967-77. [PMID: 26610489 PMCID: PMC4661924 DOI: 10.3390/ijms161126066] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/17/2015] [Accepted: 11/17/2015] [Indexed: 11/16/2022] Open
Abstract
The potential effects of monotypic and binary metal oxide nanoparticles (NPs, ZnO, NiO, Co₃O₄ and TiO₂) on microbial growth were evaluated in sandy soil collected from artificial recharge sites. Microbial growth was assessed based on adenosine triphosphate (ATP) content, dehydrogenase activity (DHA), and viable cell counts (VCC). Microbial growth based on ATP content and VCC showed considerable differences depending on NP type and concentration, whereas DHA did not significantly change. In general, ZnO NPs showed the strongest effect on microbial growth in all measurements, showing an EC50 value of 10.9 mg/L for ATP content. The ranking (EC50) of NPs based on their effect on microbial growth assessed by ATP content and VCC was ZnO > Co₃O₄ > NiO > TiO₂. Upon exposure to binary NP mixtures, synergistic and additive modes of action were observed for ATP content and VCC, respectively. The ranges of observed (P(O)) and expected (P(E)) activity were 83%-92% and 78%-82% of the control (p-value 0.0010) based on ATP content and 78%-95% and 72%-94% of the control (p-value 0.8813) based on VCC under the tested conditions, respectively. The results indicate that the effects of NP mixtures on microbial growth in the sandy soil matrix were as great, or greater, than those of single NPs. Therefore, understanding the effects of single NPs and NP mixtures is essential for proper ecological risk assessment. Additionally, these findings demonstrate that the evaluation of NP effects may be profoundly influenced by the method of microbial growth measurement.
Collapse
Affiliation(s)
- Kyung-Seok Ko
- Groundwater Department, Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon 34132, Korea.
| | - Kyoochul Ha
- Groundwater Department, Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon 34132, Korea.
| | - In Chul Kong
- Department of Environmental Engineering, Yeungnam University, Gyeongbuk 38541, Korea.
| |
Collapse
|
8
|
Abstract
The primary goal of this study was to compare the pollutant removal efficiency of the reactivated activated-ferric-sludge (AFS) with that of the activated sludge (AS). Most tested organic pollutants were preferably removed by reactivated AFS. The optimal reactivated conditions for AFS were a reactivation time of 3 h, pH of 5-9, AFS dose of 5 g/L and dissolved oxygen of 2-6 mg/L. The results revealed a positive correlation between microbial activity and the removal efficiency of organic pollutants, with a higher microbial activity being associated with a better removal efficiency of organic pollutants. Additionally, variations in extracellular polymeric substances were found to be crucial to the microbial activity and adsorption capacity of reactivated AFS. After reactivation, reactivated AFS was superior to AS for the removal ofmost pollutants. Finally, the mechanism of AFS reactivation was investigated. Overall, the results of the present study demonstrate that reactivated AFS has the potential for widespread application in the removal of organic pollutants during the wastewater treatment process.
Collapse
|
9
|
Hu JJ, Wang L, Zhang SP, Wang YQ, Xi XF. Inhibitory effect of organic carbon on CO₂ fixing by non-photosynthetic microbial community isolated from the ocean. Bioresour Technol 2011; 102:7147-7153. [PMID: 21576014 DOI: 10.1016/j.biortech.2011.04.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 04/08/2011] [Accepted: 04/10/2011] [Indexed: 05/30/2023]
Abstract
The inhibitory effect of organic carbon on CO(2) fixation (CF) by the non-photosynthetic microbial community (NPMC) and its mechanism were studied. The results showed that different concentrations of glucose inhibited CF to some extent. However, when these microorganisms pre-cultured with glucose were re-cultured without organic carbon, their CF efficiency differed significantly from the control based on the glucose concentration in the pre-culture. ATP as bioenergy and NADH as reductant had no obvious inhibitory effect on CF; conversely, they improved CF efficiency to some extent, especially when both were present simultaneously. These results implied that not all organic materials inhibited CF by NPMC, and only those that acted as good carbon sources, such as glucose, inhibited CF. Moreover, some metabolites generated during the catabolism of glucose by heterotrophic metabolism of NPMC might inhibit CF, while other cumulated materials present in the cell interior, such as ATP and NADH, might improve CF.
Collapse
Affiliation(s)
- Jia-jun Hu
- School of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
| | | | | | | | | |
Collapse
|
10
|
Kong IC. Bioassessments of anaerobically decomposing organic refuse in laboratory lysimeters with and without leachate recycling and pH adjustment. Waste Manag Res 2010; 28:141-148. [PMID: 19748954 DOI: 10.1177/0734242x09104130] [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: 05/28/2023]
Abstract
In this paper, various microbial characteristics of degrading refuse in three lysimeters were compared to bioassess the operating conditions with and without leachate recycling and pH adjustment. Laboratory lysimeters with leachate recycling produced more gas and took less time to reach the highest methane percentage than a lysimeter without leachate recycling. Generally, lysimeters with leachate recycling showed high ATP (adenosine triphosphate) contents in the leachate. But there were no significant differences in dehydrogenase activities among the lysimeters. Leachate of all lysimeters inhibited the bioluminescence activities of the strain tested. Bioluminescence activity was more inhibited by the lysimeter with no leachate recycling (high inhibition corresponds to high toxicity of leachate). Generally, less inhibition was observed in the middle of the operation phase, which was related with the biodegradation activity.
Collapse
Affiliation(s)
- In Chul Kong
- Department of Environmental Engineering, Yeungnam University, Kyungbuk, Korea.
| |
Collapse
|
11
|
Shanmugam P, Horan NJ. Simple and rapid methods to evaluate methane potential and biomass yield for a range of mixed solid wastes. Bioresour Technol 2009; 100:471-4. [PMID: 18694638 DOI: 10.1016/j.biortech.2008.06.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Revised: 05/30/2008] [Accepted: 06/05/2008] [Indexed: 05/08/2023]
Abstract
This paper describes rapid techniques to evaluate the methane potential and biomass yield of solid wastes. A number of solid wastes were mixed to provide a range of C:N ratios. Empirical formulae were calculated for each waste based on the results of chemical analysis and these formulae were used to estimate the COD equivalent and stoichiometric methane potential (SMP). The actual COD and biochemical methane potential (BMP) were determined experimentally for each waste and for both parameters there was a good agreement between the empirical and experimental values. The potential of adenosine triphosphate (ATP) to act as an indicator of biomass yield (mg VSS mg(-1) COD removed) was determined during the anaerobic digestion process. The biomass yield determined from ATP analysis was in the range 0.01-0.25mg VSS mg(-1) COD removed which corroborated well with previously reported studies. Empirical formula based SMP together with ATP measurement were shown to provide rapid methods to replace or augment the traditional BMP and VSS measurements and are useful for evaluating the bioenergy and biomass potential of solid wastes for anaerobic digestion.
Collapse
Affiliation(s)
- P Shanmugam
- Public Health and Environmental Engineering, School of Civil Engineering, University of Leeds, Leeds, UK.
| | | |
Collapse
|
12
|
Kong IC. Microbial characteristics associated with six different organic wastes undergoing anaerobic decomposition in batch vial conditions. Waste Manag Res 2008; 26:261-266. [PMID: 18649574 DOI: 10.1177/0734242x07080760] [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: 05/26/2023]
Abstract
In this study, the biodegradation characteristics of six plant-based wastes were compared in anaerobic batch vial systems. The highest gas accumulation and methane (CH4) concentrations (approximately 70%) were observed in samples containing copy paper, newspaper and box paper materials, whereas the lowest were observed in samples containing wood and leaves. In samples containing steamed rice and fruit, the methanogenic activity was inhibited, which resulted in acid accumulation. The high biodegradation activity of newspaper samples was also associated with high adenosine triphosphate levels and dehydrogenase activity. No significant differences were, however, observed in the dehydrogenase activity of the samples. High bioluminescence was observed in samples with high biodegradation activities, indicative of low toxicity.
Collapse
Affiliation(s)
- In Chul Kong
- Department of Environmental Engineering, Yeungnam University, Kyungbuk, Korea.
| |
Collapse
|
13
|
Abstract
Industries that use metalworking fluids require a test method that can rapidly estimate the total number of bacteria. Such a test method would improve the ability to manage the metal working fluid by allowing near real-time decision making. The ability to manage the fluid more consistently and make critical decisions as they arise would reduce occupational exposures to contaminated metalworking fluid and likely result in fewer worker complaints and/or work stoppages. In this study, a filtration-based rapid adenosine triphosphate bioluminescence assay, which takes less than 10 min to perform, was evaluated as a test method for estimating total bacteria populations in metalworking fluid. This evaluation used two types of metalworking fluid (soluble and semisynthetic) that were inoculated using Pseudomonas aeruginosa and spoiled metalworking fluid. Daily parallel testing was completed on metalworking fluid samples using the rapid adenosine triphosphate assay and the standard plate count methods. Daily test results were evaluated by calculating r2 values using statistical correlation and regression procedures for each fluid type. Study results indicate the rapid adenosine triphosphate assay is strongly correlated to the standard plate count method for soluble and semisynthetic fluids, producing results of r2 = 0.74 and r2 = 0.89, respectively.
Collapse
Affiliation(s)
- Andrew R Webster
- TetraTech, Inc., Industrial Division, AnnArbor, Michigan 48109, USA
| | | | | |
Collapse
|
14
|
Larson EL, Aiello AE, Gomez-Duarte C, Lin SX, Lee L, Della-Latta P, Lindhardt C. Bioluminescence ATP monitoring as a surrogate marker for microbial load on hands and surfaces in the home. Food Microbiol 2003. [DOI: 10.1016/s0740-0020(03)00041-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|