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Xu JM, Dong H, Xu HR, Sun YL, Yu Y, Zhang LY, Yi GP, He WK, Wu CM, Wang AJ, Cheng HY. Water flush boosts performance of elemental sulfur-based denitrification packed-bed systems: Optimization and mechanisms. BIORESOURCE TECHNOLOGY 2024:131158. [PMID: 39059589 DOI: 10.1016/j.biortech.2024.131158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Revised: 07/17/2024] [Accepted: 07/23/2024] [Indexed: 07/28/2024]
Abstract
Despite the promising potential of elemental sulfur-based denitrification (ESDeN) packed-bed progresses, challenges such as excessive biofilm growth and gas entrapment persist, leading to denitrification deterioration. Water flush (WF) is recognized as an effective strategy, yet its effects remain underexplored. To address this knowledge gap, this study systematically investigated WF effects on ESDeN packed-bed denitrification. Results demonstrated that controlling WF effectively regulated denitrification, achieving superior and stable rates. Compared to no WF (0.45 kgN·m-3·d-1), rates improved by 1.20 ∼ 1.56 times under low-frequency (weekly WF, 0.54 kgN·m-3·d-1) and low-intensity WF (0.54 ∼ 0.70 kgN·m-3·d-1). High-frequency (hours WF) and high-intensity WF (30 & 50 m/h) further amplified denitrification rates by 1.73 ∼ 2.29 times. The enhanced denitrifications under low-frequency/intensity WF were mainly attributed to prolonged actual hydraulic retention time (AHRT), while high-frequency/intensity WF improved both AHRT prolonging and biofilm thinning, facilitating mass transfer. This study offers a promising avenue for fine-tuning denitrification rates via strategic WF adjustments.
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Affiliation(s)
- Jia-Min Xu
- State Key Laboratory of Urban Water Resources and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Heng Dong
- State Key Laboratory of Urban Water Resources and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; CSD Water Service Co. Ltd. R&D Branch, Wuxi 214200, China
| | - Hao-Ran Xu
- State Key Laboratory of Urban Water Resources and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Yi-Lu Sun
- Cas Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yang Yu
- State Key Laboratory of Urban Water Resources and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Li-Ying Zhang
- State Key Laboratory of Urban Water Resources and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Gen-Ping Yi
- State Key Laboratory of Urban Water Resources and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Wen-Ke He
- State Key Laboratory of Urban Water Resources and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Chang-Min Wu
- CSD Water Service Co. Ltd. R&D Branch, Wuxi 214200, China
| | - Ai-Jie Wang
- State Key Laboratory of Urban Water Resources and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; Cas Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Hao-Yi Cheng
- State Key Laboratory of Urban Water Resources and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China.
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Adarsha JR, Ravishankar TN, Ananda A, Manjunatha CR, Shilpa BM, Ramakrishnappa T. Hydrothermal synthesis of novel heterostructured Ag/TiO 2 /CuFe 2 O 4 nanocomposite: Characterization, enhanced photocatalytic degradation of methylene blue dye, and efficient antibacterial studies. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2022; 94:e10744. [PMID: 35662318 DOI: 10.1002/wer.10744] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 05/12/2022] [Indexed: 06/15/2023]
Abstract
In this work, we reported the successful synthesis of novel Ag/TiO2 /CuFe2 O4 ternary nanocomposite by hydrothermal technique by using TiO2 /CuFe2 O4 binary nanocomposite precursor that was also prepared by hydrothermal treatment by using TiO2 nanoparticles and CuFe2 O4 nanoparticles synthesized via sol-gel method. The synthesized nanomaterials were accessed for their morphological, structural, and optical properties. X-ray diffraction (XRD) study reveals the formation of pure Ag/TiO2 /CuFe2 O4 ternary nanocomposite in which the Ag, TiO2 , and CuFe2 O4 are in anatase, spinal, and cubic crystal phases, respectively. Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) analyses of Ag/TiO2 /CuFe2 O4 ternary nanocomposite indicated granule-shaped morphology with bright spots of silver. The existence of Ti, O, Cu, Fe, and Ag without any other elements in the energy-dispersive X-ray spectroscopy (EDS) spectra of the prepared ternary nanocomposite depict its purity and its polycrystalline nature was confirmed by its selected area electron diffraction (SAED) pattern. The ternary nanocomposite was utilized for the methylene blue dye degradation with an optimum dose of 1.00 g/100 ml under ultraviolet (UV) light; the enhanced photocatalytic activity of the composite is attributed mainly due to the appreciable magnitudinal difference of positive charge of the valence band and negative charge of the conduction band of TiO2 and CuFe2 O4 ; meanwhile, the interfacially placed Ag acts as a sink for the elections. Also, the ternary nanocomposite showed satisfactory antibacterial activities. PRACTITIONER POINTS: The prepared ternary nanocomposite showed effective results in dye degradation and satisfactory antibacterial property. The concentration of methylene dye has decreased considerably in every degradation process which was accessed through UV-vis studies. The highest degradation by using the ternary nanocomposite archived at pH = 6 Appreciable antibacterial activity was achieved against a few Gram-positive strains and Gram-negative strains of bacteria. This research activity can open a broad area of research towards textile dye degradation and antibacterial studies.
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Affiliation(s)
- J R Adarsha
- Centre for Nano Science and Nano Technology, Department of chemistry, Global Academy of Technology, Bangalore, India
| | - T N Ravishankar
- Centre for Nano Science and Nano Technology, Department of chemistry, Global Academy of Technology, Bangalore, India
| | - A Ananda
- Department of Chemistry, Dayananda Sagar Academy of Technology and Management Udayapura, Bengaluru, India
| | - C R Manjunatha
- Department of Chemistry, Navkis College of Engineering, Hassan, India
| | - B M Shilpa
- School of Basic and Applied Sciences, Dayananda Sagar University, Bengaluru, India
| | - T Ramakrishnappa
- Department of Chemistry, BMS Institute of Technology and Management, Bangalore, India
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Reed Biochar Addition to Composite Filler Enhances Nitrogen Removal from BDBR Systems in Eutrophic Rivers Channel. WATER 2021. [DOI: 10.3390/w13182501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
With the rapid development of urbanization in China, the eutrophication or black stink of urban rivers has become a critical environmental problem. As a research hotspot in wastewater purification, biofilm technology has shortcomings, such as insufficient carbon sources for denitrification. This study used a Biofilm Denitrification Batch Reactor (BDBR) system constructed using reed biochar as the carbon source required in denitrification, significantly accelerating the biofilm formation. To determine the suitable amount of biochar for water purification from the urban eutrophic rivers by the BDBR system, 0%, 5%, 10%, and 15% reed biochar was added to the viscose fiber combined packing. The combined packing reactor involved in this study had a high removal efficiency of the eutrophication channel COD throughout the experiment. However, adding 5% and 10% biochar in the combined filler effectively increased the number of nitrifying and denitrifying bacteria on the biofilm, improved the dominant bacteria diversity and microbial activity, and enhanced denitrification efficiency in the BDBR system. It provides new ideas and methods for developing and applying in situ denitrification technology for urban polluted rivers.
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Wang J, Yang Z, Wang H, Wu S, Lu H, Wang X. Decomposition process of cefotaxime sodium from antibiotic wastewater by Up-flow Blanket Filter (UBF) reactor: Reactor performance, sludge characteristics and microbial community structure analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 758:143670. [PMID: 33257062 DOI: 10.1016/j.scitotenv.2020.143670] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/28/2020] [Accepted: 11/09/2020] [Indexed: 06/12/2023]
Abstract
In this study, a novel Up-flow Blanket Filter (UBF) reactor was applied to the degradation of antibiotic wastewater. The experiments showed that when the hydraulic retention time (HRT) was 24 h and the ratio of volatile fatty acids (VFA) to alkalinity (ALK) was 0.3, the best removal efficiency was achieved in the combined packing UBF reactor, and the COD removal efficiency reached 80.1%-84.6%, exhibiting a significant difference in reaction performance from the other two reactors (P < 0.05) and a good efficiency of cefotaxime sodium removal. Moreover, the microstructure and surface characteristics of the reactor fillers were studied through scanning electron microscope (SEM) analysis, which showed that three fillers all had biofilm adhesion, but the combined packing gave best performance. Energy dispersive spectrometer (EDS) tests indicated abundant element components in the combined packing. The particle size distribution of sludge was also considered in the experiment, and the result showed the particle size of sludge increased with the operation of the reactor. In addition, microbial community structures of sludge and biofilm with the combined packing were analyzed. High-throughput sequencing confirmed the existence of Pseudomonas, which had good adaptability to antibiotic wastewater and became the dominant bacteria. Decomposition process of cefotaxime sodium after hydrolysis and anaerobic treatment was analyzed through Fourier transform infrared spectroscopy (FTIR). The reactor, which is economical, exhibited favorable performance in degrading the pollutions in the antibiotic wastewater.
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Affiliation(s)
- Jia Wang
- College of Civil and Architectural Engineering, North China University of Science and Technology, Tangshan, PR China
| | - Zhinian Yang
- College of Civil and Architectural Engineering, North China University of Science and Technology, Tangshan, PR China
| | - Hao Wang
- College of Civil and Architectural Engineering, North China University of Science and Technology, Tangshan, PR China.
| | - Shuangrong Wu
- College of Civil and Architectural Engineering, North China University of Science and Technology, Tangshan, PR China
| | - Huan Lu
- College of Civil and Architectural Engineering, North China University of Science and Technology, Tangshan, PR China
| | - Xingguo Wang
- College of Civil and Architectural Engineering, North China University of Science and Technology, Tangshan, PR China
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Zhang L, Cui B, Yuan B, Zhang A, Feng J, Zhang J, Han X, Pan L, Li L. Denitrification mechanism and artificial neural networks modeling for low-pollution water purification using a denitrification biological filter process. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2020.117918] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Huang X, Lu Y, Wu G, Liu Z. Research on the experiment of the enhancement removal of fine sand by hydrocyclone in sewage treatment plant. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:337-353. [PMID: 32812160 DOI: 10.1007/s11356-020-10493-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 08/10/2020] [Indexed: 06/11/2023]
Abstract
The content of fine sand (< 200 μm) in primary sludge is relatively high in Chongqing sewage treatment plant owing to the part of rainwater will be mixed with sand and discharged into the municipal pipe network. Due to the insufficient separation of the sand, different obstacles to subsequent treatment processes may increase equipment wear, reduce effective volume of the tank, or shorten the cleaning cycle. There is a common use of grit chamber for the separation. Nevertheless, the use of hydrocyclone shows an outstanding performance in cost effectiveness and ease operation. The primary sludge in a sewage plant in Chongqing was monitored, and the average concentration of total suspend solids (TSS), total sand content, and volatile suspended solid (VSS) were 40.25 g/L, 17.51 g/L, and 13.41 g/L, respectively. The size of sand in the sludge was small, and the sand below 30 μm accounted for about 70% of the total sand. It formed flocs with organic matter and was removed in subsequent process units. While the size between 30-200 μm, called fine sand, was the main separation object, accounted for about 28.5%. According to XRF and XRD analysis, the sludge composition was mainly composed of quartz (SiO2), plagioclase (Na(AlSi3O8)), and calcite (CaCO3), which were similar to the main mineral composition of surface sediments and mountain rocks in the main urban area of Chongqing. A single-factor experiment on two types (FX100 and FX50) of hydrocylones was conducted to determine their abilities concerning the separation of fine sand and enrichment of organic matters from primary sludge. FX100 and FX50 showed best performance in the case of P = 0.17 Mpa, underflow diameter (Du) = 18 mm and P = 0.20 Mpa, Du = 6 mm, respectively. The removal efficiency of fine sand by hydrocyclone FX50 was 71.39%. While, it had poor performance on organic matter enrichment and the removal efficiency of which was 17.38%. By contrast, the removal rate by FX100 reached 61.89% for fine sand and only 6.89% for organic matters detached. The superimposition effect did not appear in the serial experiments on hydrocylone FX100 and FX50, but the power is 3.5 times of that of single-stage hydrocylone FX100. Comprehensive consideration of the processing capacity per unit time and operating power, the hydrocylone FX100 was more suitable for actual operation.
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Affiliation(s)
- Xiaohua Huang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Chongqing University, Chongqing, 400045, China
| | - Yingying Lu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Chongqing University, Chongqing, 400045, China
| | - Guobo Wu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Chongqing University, Chongqing, 400045, China
| | - Zhiping Liu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Chongqing University, Chongqing, 400045, China.
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Mielcarek A, Rodziewicz J, Janczukowicz W, Struk-Sokołowska J. The impact of biodegradable carbon sources on nutrients removal in post-denitrification biofilm reactors. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137377. [PMID: 32143032 DOI: 10.1016/j.scitotenv.2020.137377] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/28/2020] [Accepted: 02/15/2020] [Indexed: 06/10/2023]
Abstract
Wastewater from households wastewater treatment plants (HWWTP) is discharged to the ground or to the surface waters. Special consideration should be given to the improvement of HWWTP effectiveness, particularly in relation to nutrients. The addition of biodegradable carbon sources to biofilm reactor, can enhance microbial activity but may also lead to filling clogging. The study aimed to compare 3 different organic substrates: acetic acid (commonly applied)and two untypical - citric acid and waste beer, under the same operational conditions in a post-denitrification biofilm reactor. The study investigated the impact of a type of organic substrate, low pH and time on: (1) biofilm growth, (2) the characteristics of extracellular polymeric substances (EPS), (3) the kinetics of nutrients removal and (4) reactor clogging. Results were referred to (5) the effectiveness of nutrients removal. The study demonstrated that low pH assured the development of a thinbiofilm. Citric acid ensured the lowest biomass volume, being by 53% lower than in the reactor with acetic acid and by as much as 61% lower than in the reactor with waste beer. The soluble EPS fraction prevailed in the total EPS in all reactors. The content of the tightly bound EPS fraction ranged from 26.93% (citric acid) to 36.32% (waste beer). Investigations showed also a high ratio of exoproteins to polysaccharide in all fractions, which indicated a significant role of proteins in developing a highly-proliferating biofilm. The treated wastewater met requirements of Polish regulations concerning COD and nitrogen concentrations.
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Affiliation(s)
- Artur Mielcarek
- University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, Warszawska St. 117a, Olsztyn 10-719, Poland.
| | - Joanna Rodziewicz
- University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, Warszawska St. 117a, Olsztyn 10-719, Poland.
| | - Wojciech Janczukowicz
- University of Warmia and Mazury in Olsztyn, Department of Environment Engineering, Warszawska St. 117a, Olsztyn 10-719, Poland.
| | - Joanna Struk-Sokołowska
- Bialystok University of Technology, Department of Environmental Engineering Technology, Wiejska St. 45E, Bialystok 15-351, Poland.
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Hu X, Zhang Q, Nan H, Wang M, Qiao L, Tian H. Heterojunction Cu2O/RGO/BiVO4 ternary nanocomposites with enhanced photocatalytic activities towards degradation of rhodamine B and tetracycline hydrochloride. NEW J CHEM 2019. [DOI: 10.1039/c9nj04351a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synergy of BVO, Cu2O and RGO inhibits the recombination of photogenic carriers to enhance the photocatalytic activity.
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Affiliation(s)
- Xiaoying Hu
- College of Science and Laboratory of Materials Design and Quantum Simulation
- Changchun University
- Changchun
- China
| | - Qi Zhang
- College of Science and Laboratory of Materials Design and Quantum Simulation
- Changchun University
- Changchun
- China
| | - Haoshan Nan
- College of Science and Laboratory of Materials Design and Quantum Simulation
- Changchun University
- Changchun
- China
| | - Ming Wang
- College of Science and Laboratory of Materials Design and Quantum Simulation
- Changchun University
- Changchun
- China
| | - Liang Qiao
- College of Science and Laboratory of Materials Design and Quantum Simulation
- Changchun University
- Changchun
- China
| | - Hongwei Tian
- Key Laboratory of Automobile Materials of MOE and School of Materials Science and Engineering
- Jilin University
- Changchun
- China
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