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Lan L, Shao LM, Xiong F, Xie LY, Yu L, Han B, Wang QJ. [The ability of gap detection in patients with acoustic neuroma]. Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2019; 33:1053-1056. [PMID: 31914293 DOI: 10.13201/j.issn.1001-1781.2019.11.011] [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] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Indexed: 06/10/2023]
Abstract
Objective:We aimed to provide a basis for the clinical study of acoustic neuroma through investigating the ability of temporal gap detection in acoustic neuroma patients and comparing the abilities with those in people with normal and impaired hearing. Method:Twenty-two patients with confirmed acoustic neuroma, 30 normal hearing patients and 16 patients with sensorineural hearing loss were enrolled in this study, and the interval threshold for awareness of each group was tested. Result:The mean temporal gap detection test(TGDT) threshold of the normal hearing group was (3.56±0.82) ms; the sensorineural hearing loss group's was (3.91±1.46) ms; TGDT threshold of healthy side of acoustic neuroma patients was (4.01±1.86) ms; TGDT threshold of the impaired side of acoustic neuroma patients was (9.48±9.46)ms. After statistical analysis, we found that excepting for the test of phonetically balanced maximum (PBmax) and TGDT, other results in the sensorineural hearing loss group and normal hearing group is of no statistical difference. The difference between the affected side of the acoustic neuroma group and the other groups was statistically significant (P<0.05). There was no linear correlation between the value of TGDT threshold and PBmax (P> 0.05). TGDT value of normal people has no significant difference among people of different genders and ears of different individuals. Conclusion:The TGDT of the healthy ear of the patients with acoustic neuroma is not affected, and there is no significant change compared with normal people. The TGDT test has a good consistency with the PBmax results. The time interval response ability of the affected ear of the acoustic neuroma is significantly weaker than that of the normal person. The combined test of PBmax and TGDT will contribute to the diagnosis of retrocochlear disease.
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Affiliation(s)
- L Lan
- Department of Otorhinolaryngology Head and Neck Surgery,General Hospital of Chinese People's Liberation Army,Beijing,100853,China
| | - L M Shao
- Otolaryngology Clinical Hearing Center,Shenzhen Hospital of Southern Medical University
| | - F Xiong
- Department of Otorhinolaryngology Head and Neck Surgery,General Hospital of Chinese People's Liberation Army,Beijing,100853,China
| | - L Y Xie
- Department of Otorhinolaryngology Head and Neck Surgery,General Hospital of Chinese People's Liberation Army,Beijing,100853,China
| | - L Yu
- Department of Otorhinolaryngology Head and Neck Surgery,General Hospital of Chinese People's Liberation Army,Beijing,100853,China
| | - B Han
- Department of Otorhinolaryngology Head and Neck Surgery,General Hospital of Chinese People's Liberation Army,Beijing,100853,China
| | - Q J Wang
- Department of Otorhinolaryngology Head and Neck Surgery,General Hospital of Chinese People's Liberation Army,Beijing,100853,China
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Xu GS, Wan BN, Wang HQ, Guo HY, Naulin V, Rasmussen JJ, Nielsen AH, Wu XQ, Yan N, Chen L, Shao LM, Chen R, Wang L, Zhang W. Low-to-High Confinement Transition Mediated by Turbulence Radial Wave Number Spectral Shift in a Fusion Plasma. Phys Rev Lett 2016; 116:095002. [PMID: 26991181 DOI: 10.1103/physrevlett.116.095002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Indexed: 06/05/2023]
Abstract
A new model for the low-to-high (L-H) confinement transition has been developed based on a new paradigm for turbulence suppression by velocity shear [G. M. Staebler et al., Phys. Rev. Lett. 110, 055003 (2013)]. The model indicates that the L-H transition can be mediated by a shift in the radial wave number spectrum of turbulence, as evidenced here, for the first time, by the direct observation of a turbulence radial wave number spectral shift and turbulence structure tilting prior to the L-H transition at tokamak edge by direct probing. This new mechanism does not require a pretransition overshoot in the turbulent Reynolds stress, shunting turbulence energy to zonal flows for turbulence suppression as demonstrated in the experiment.
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Affiliation(s)
- G S Xu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - B N Wan
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - H Q Wang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - H Y Guo
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - V Naulin
- PPFE, Department of Physics, Technical University of Denmark, DK 2800 Kongens Lyngby, Denmark
| | - J Juul Rasmussen
- PPFE, Department of Physics, Technical University of Denmark, DK 2800 Kongens Lyngby, Denmark
| | - A H Nielsen
- PPFE, Department of Physics, Technical University of Denmark, DK 2800 Kongens Lyngby, Denmark
| | - X Q Wu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - N Yan
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
- PPFE, Department of Physics, Technical University of Denmark, DK 2800 Kongens Lyngby, Denmark
| | - L Chen
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - L M Shao
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - R Chen
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - L Wang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - W Zhang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
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Wang HQ, Xu GS, Wan BN, Ding SY, Guo HY, Shao LM, Liu SC, Xu XQ, Wang E, Yan N, Naulin V, Nielsen AH, Rasmussen JJ, Candy J, Bravenec R, Sun YW, Shi TH, Liang YF, Chen R, Zhang W, Wang L, Chen L, Zhao N, Li YL, Liu YL, Hu GH, Gong XZ. New edge coherent mode providing continuous transport in long-pulse H-mode plasmas. Phys Rev Lett 2014; 112:185004. [PMID: 24856704 DOI: 10.1103/physrevlett.112.185004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Indexed: 06/03/2023]
Abstract
An electrostatic coherent mode near the electron diamagnetic frequency (20-90 kHz) is observed in the steep-gradient pedestal region of long pulse H-mode plasmas in the Experimental Advanced Superconducting Tokamak, using a newly developed dual gas-puff-imaging system and diamond-coated reciprocating probes. The mode propagates in the electron diamagnetic direction in the plasma frame with poloidal wavelength of ∼8 cm. The mode drives a significant outflow of particles and heat as measured directly with the probes, thus greatly facilitating long pulse H-mode sustainment. This mode shows the nature of dissipative trapped electron mode, as evidenced by gyrokinetic turbulence simulations.
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Affiliation(s)
- H Q Wang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - G S Xu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - B N Wan
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - S Y Ding
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - H Y Guo
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China and General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - L M Shao
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - S C Liu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - X Q Xu
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E Wang
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - N Yan
- Association EURATOM-DTU, Physics Department, DK 2800 Kgs. Lyngby, Denmark
| | - V Naulin
- Association EURATOM-DTU, Physics Department, DK 2800 Kgs. Lyngby, Denmark
| | - A H Nielsen
- Association EURATOM-DTU, Physics Department, DK 2800 Kgs. Lyngby, Denmark
| | - J Juul Rasmussen
- Association EURATOM-DTU, Physics Department, DK 2800 Kgs. Lyngby, Denmark
| | - J Candy
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - R Bravenec
- Fourth State Research, 503 Lockhart Drive, Austin, Texas 78704-4335, USA
| | - Y W Sun
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - T H Shi
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - Y F Liang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - R Chen
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - W Zhang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - L Wang
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - L Chen
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - N Zhao
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - Y L Li
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - Y L Liu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - G H Hu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - X Z Gong
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
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He PJ, Mao B, Lü F, Shao LM, Lee DJ, Chang JS. The combined effect of bacteria and Chlorella vulgaris on the treatment of municipal wastewaters. Bioresour Technol 2013; 146:562-568. [PMID: 23973976 DOI: 10.1016/j.biortech.2013.07.111] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [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: 05/10/2013] [Revised: 07/22/2013] [Accepted: 07/25/2013] [Indexed: 06/02/2023]
Abstract
Impacts of Chlorella vulgaris with or without co-existing bacteria on the removal of nitrogen, phosphorus and organic matter from wastewaters were studied by comparing the wastewater treatment effects between an algae-bacteria consortium and a stand-alone algae system. In the algae-bacteria system, C.vulgaris played a dominant role in the removal of nitrogen and phosphorus, while bacteria removed most of the organic matter from the wastewater. When treating unsterilized wastewater, bacteria were found to inhibit the growth of algae at >231 mg/L dissolved organic carbon (DOC). Using the algae-bacteria consortium resulted in the removal of 97% NH4(+), 98% phosphorus and 26% DOC at a total nitrogen (TN) level of 29-174 mg/L. The reaction rate constant (k) values in sterilized and unsterilized wastewaters were 2.17 and 1.92 mg NH4(+)-N/(mg algal cell ·d), respectively.
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Affiliation(s)
- P J He
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - B Mao
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - F Lü
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - L M Shao
- Research and Training Center on Rural Waste Management, Ministry of Housing and Urban-Rural Development of PR China, China
| | - D J Lee
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan; Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan
| | - J S Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan; Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan; Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
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He PJ, Mao B, Shen CM, Shao LM, Lee DJ, Chang JS. Cultivation of Chlorella vulgaris on wastewater containing high levels of ammonia for biodiesel production. Bioresour Technol 2013; 129:177-81. [PMID: 23246758 DOI: 10.1016/j.biortech.2012.10.162] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 09/06/2012] [Accepted: 10/31/2012] [Indexed: 05/07/2023]
Abstract
The feasibility of cultivating Chlorella vulgaris with wastewater containing high ammonia nitrogen concentrations was examined. The average specific growth rate of C. vulgaris was 0.92 d(-1) at 17 mg L(-1) NH4+-N, but declined to 0.33 d(-1) at NH4+-N concentrations of 39-143 mg L(-1). At 39 mg L(-1) NH4+-N, lipid productivity reached a maximum value (23.3 mg L(-1)d(-1)) and dropped sharply at higher NH4+-N levels, which demonstrated NH4+-N should be controlled for biodiesel production. C16 and C18 fatty acids accounted for 80% of total fatty acids. Increasing NH4+-N from 17 to 207 mg L(-1) yielded additional short-chain and saturated fatty acids. Protein content was in positive correlation with NH4+-N content from 17 mg L(-1) (12%) to 207 mg L(-1) (42%). Carbohydrate in the dried algae cell was in the range of 14-45%, with a peak value occurring at 143 mg L(-1) NH4+-N. The results demonstrate that product quality can be manipulated by NH4+-N concentrations of the initial feeds.
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Affiliation(s)
- P J He
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
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Liu SC, Shao LM, Zweben SJ, Xu GS, Guo HY, Cao B, Wang HQ, Wang L, Yan N, Xia SB, Zhang W, Chen R, Chen L, Ding SY, Xiong H, Zhao Y, Wan BN, Gong XZ, Gao X. New dual gas puff imaging system with up-down symmetry on experimental advanced superconducting tokamak. Rev Sci Instrum 2012; 83:123506. [PMID: 23277986 DOI: 10.1063/1.4770122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Gas puff imaging (GPI) offers a direct and effective diagnostic to measure the edge turbulence structure and velocity in the edge plasma, which closely relates to edge transport and instability in tokamaks. A dual GPI diagnostic system has been installed on the low field side on experimental advanced superconducting tokamak (EAST). The two views are up-down symmetric about the midplane and separated by a toroidal angle of 66.6°. A linear manifold with 16 holes apart by 10 mm is used to form helium gas cloud at the 130×130 mm (radial versus poloidal) objective plane. A fast camera is used to capture the light emission from the image plane with a speed up to 390,804 frames/s with 64×64 pixels and an exposure time of 2.156 μs. The spatial resolution of the system is 2 mm at the objective plane. A total amount of 200 Pa.L helium gas is puffed into the plasma edge for each GPI viewing region for about 250 ms. The new GPI diagnostic has been applied on EAST for the first time during the recent experimental campaign under various plasma conditions, including ohmic, L-mode, and type-I, and type-III ELMy H-modes. Some of these initial experimental results are also presented.
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Affiliation(s)
- S C Liu
- Institute of Plasma Physics, Chinese Academy of Science, P. O. Box 1126, Hefei 230031, China.
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Shao LM, Zhang CY, He PJ, Lü F. Comparison of different fluorescence spectrum analysis techniques to characterize humification levels of waste-derived dissolved organic matter. Environ Technol 2012; 33:2569-2573. [PMID: 23437656 DOI: 10.1080/09593330.2012.673016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In the present work, the humification level of waste-derived dissolved organic matter (DOM) at different waste biostability was investigated, by using fluorescent excitation-emission matrix (EEM) scanning. Different fluorescence spectrum analysis techniques were applied and compared. Experimental results demonstrate that parallel factor (PARAFAC) analysis was sensitive to reflect DOM humification, and the most reasonable to deconstruct DOM compositions, when compared with other spectrum analysis techniques. It suggests applying the DOM-EEM-PARAFAC pipeline for rapid estimation of waste biostability.
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Affiliation(s)
- L M Shao
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China
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Zheng Z, He PJ, Zhang H, Shao LM. Role of dissolved humic substances surrogates on phthalate esters migration from sewage sludge. Water Sci Technol 2008; 57:607-612. [PMID: 18360003 DOI: 10.2166/wst.2008.030] [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: 05/26/2023]
Abstract
The facilitated transport of dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP), the priority endocrine disrupting chemicals in sludge, by dissolved humic substances (HS) was evaluated by batch extraction. The DBP, much less hydrophobic than DEHP, was inclined to migrate from sludge matrix into humic substances solutions, while the DEHP could not migrate facilitated by most humic and fulvic acids solutions, except the humic acid surrogate of high humification. This result revealed that the affinity of DEHP in sludge matrix exceeded DBP and was not susceptible by weak HS. The hydrophobic property controlled the association of phthalic acid esters on sludge residual phases. Migration rate of DBP was positively correlated to the weight-average molecular weight of HS surrogates and the aromatic extents of HA. Some functional groups in HS molecules benefited to the facilitated transport of DBP.
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Affiliation(s)
- Z Zheng
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, PR China.
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Lü F, He PJ, Hao LP, Shao LM. Impact of recycled effluent on the hydrolysis during anaerobic digestion of vegetable and flower waste. Water Sci Technol 2008; 58:1637-1643. [PMID: 19001719 DOI: 10.2166/wst.2008.511] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Two trials were established to investigate the effect of recycled effluent on hydrolysis during anaerobic co-digestion of vegetable and flower waste. Trial I evaluated the effect by regulating the flow rate of recycled effluent, while Trial II regulated the ratio of hydrolytic effluent to methanogenic effluent, which were recycled to hydrolysis reactor. Results showed that the recirculation of methanogenic effluent could enhance the buffer capability and operation stability of hydrolysis reactor. Higher recycled flow rate was favourable for microbial anabolism and further promoted hydrolysis. After 9 days of hydrolysis, the cumulative SCOD in the hydrolytic effluent reached 334, 407, 413, 581 mg/g at recycled flow rates of 0.1, 0.5, 1.0, 2.0 m3/(m3 x d), respectively. It was feasible to recycling a mixture of hydrolytic and methanogenic effluent to the hydrolysis reactor. This research showed that partially introducing hydrolytic effluent into the recycled liquid could enhance hydrolysis, while excessive recirculation of hydrolytic effluent will inhibit the hydrolysis. The flow ratio 1:3 of hydrolytic to methanogenic effluent was found to provide the highest hydrolysis efficiency and degradation rate of lignocelluloses-type biomass, among four ratios of 0:1, 1:3, 1:1 and 3:1. Under this regime, after 9 days of hydrolysis, the cumulative TOC and TN in the hydrolytic effluent reached 162 mg/g and 15 mg/g, the removal efficiency of TS, VS, C and cellulose in the solid phase were 60.66%, 62.88%, 58.35% and 49.12%, respectively. The flow ratio affected fermentation pathways, i.e. lower ratio favoured propionic acid fermentation and the generation of lactic acid while higher ratio promoted butyric acid fermentation.
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Affiliation(s)
- F Lü
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
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He PJ, Lü F, Shao LM, Pan XJ, Lee DJ. Effect of alkali metal cation on the anaerobic hydrolysis and acidogenesis of vegetable waste. Environ Technol 2006; 27:317-27. [PMID: 16548212 DOI: 10.1080/09593332708618646] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Five batch testing scenarios were designed to evaluate the effects of alkali metal cations on anaerobic hydrolysis and acidogenesis. These scenarios were A (c=0 g l(-1)), B (cNa+=25 g l(-1)), C (cNa+=50 g l(-1)), D (cK+=25 g l(-1)), and E (cK+=50 g l(-1), pH 7.0). A solution pH of 7.0 or above favored protein hydrolysis, higher proteinase activity and higher ammonia production. However, such a pH suppressed carbohydrate hydrolysis, as indicated by low alpha-amylase activity. Cation interference at pH 5.0-6.0 seemed not to affect carbohydrate hydrolysis, as showed by the unimpaired alpha-amylase activity at 50 g l(-1) K+. Acidogenesis was more sensitive to alkali metal cations, so acid production and the drop in pH were lowest in a 25-50 g l(-1) Na+, acidic environment (pH 4.0-6.0). It was insensitive to cations when the pH was maintained at 7.0-8.0. When the pH was uncontrolled and decreased freely to acidic values, 25 g l(-1) of cation inhibited the action of the microbes, which rapidly acclimated, as presented by the slow transformation of soluble polymers to soluble metabolites. However, acidogenetic microbes could not easily recover from inhibition by 50 g l(-1) of cation. When the pH was maintained at over 7.0, the microbes were not inhibited by cation (50 g l(-1)) as indicated by the more active acidogenesis. The metabolic pathways to lactate, acetate and alcohols were not fully coupled.
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Affiliation(s)
- P J He
- State Key Laboratory of Pollution Control & Reclamation, Tongji University, Shanghai, PR China
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He PJ, Shao LM, Guo HD, Li GJ, Lee DJ. Nitrogen removal from recycled landfill leachate by ex situ nitrification and in situ denitrification. Waste Manag 2006; 26:838-45. [PMID: 16459070 DOI: 10.1016/j.wasman.2005.11.014] [Citation(s) in RCA: 2] [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] [Received: 07/04/2004] [Revised: 05/09/2005] [Accepted: 11/08/2005] [Indexed: 05/06/2023]
Abstract
A three-compartment system, comprising a landfill column with fresh municipal solid waste, a column with a well-decomposed refuse layer as methane producer, and a sequential batch reactor as ex situ nitrifying reactor, was employed to remove nitrogen from municipal solid waste leachate. Since food waste comprised a major portion of refuse collected in Shanghai, an intense hydrolysis reaction occurred and caused the rapid accumulation of ammonia nitrogen (NH(3)-N) and total organic carbon in the leachate. This paper discusses the role of the three mentioned units and the design and operation of the proposed system. With most NH(3)-N being converted to nitrite nitrogen (NO(2)(-)-N) or nitrate nitrogen (NO(3)(-)-N) by the nitrifying reactor, and with the well-decomposed refuse layer transforming most dissolved organic compounds to CO(2), carbonates and methane, it was found that the fresh refuse column could efficiently denitrify the hydrolyzed nitrogen to N(2) gas. The role of the three mentioned units and comments on the design and operation of the proposed system are also discussed.
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Affiliation(s)
- P J He
- State Key Laboratory of Pollution Control and Reclamation, Tongji University, Shanghai 200092, China.
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Abstract
The municipal solids waste (MSW) collected at Shanghai includes a high proportion of food waste, which is easily hydrolyzed to generate ammonia-nitrogen in leachate. This study investigated the efficiency of nitrogen removal from landfill leachate employing four different treatment processes. The simulated rainfall and direct leachate recycling produced strong leachate with high ammonia-nitrogen content, and resulted in the removal of only a small amount of nitrogen. Although pretreating the leachate using an aerobic reactor removed some nitrogen, most of which was transformed to biomass because of the high organic loading applied. Using the three-compartment system, which comprises a landfill column with fresh MSW, a column with well-decomposed refuse layer as the methane generator, and a nitrifier, the ammonia-nitrogen was converted into nitrogen gas and hence removed. Experimental results demonstrated the feasibility of adopting the three-compartment system for managing nitrogen in landfill leachate generated from high-nitrogen-content MSW.
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Affiliation(s)
- P J He
- State Key Laboratory of Pollution Control & Reclamation, Tongji University, Shanghai, 200092, PR China
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He PJ, Shao LM, Gu GW, Bian CL, Xu C. Clean-up and disposal process of polluted sediments from urban rivers. J Environ Sci (China) 2001; 13:435-438. [PMID: 11723928] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In this paper, the discussion is concentrated on the properties of the polluted sediments and the combination of clean-up and disposal process for the upper layer heavily polluted sediments with good flowability. Based on the systematic analyses of various clean-up processes, a suitable engineering process has been evaluated and recommended. The process has been applied to the river reclamation in Yangpu District of Shanghai City, China. An improved centrifuge is used for dewatering the dredged sludge, which plays an important role in the combination of clean-up and disposal process. The assessment of the engineering process shows its environmental and technical economy feasibility, which is much better than that of traditional dredging-disposal processes.
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Affiliation(s)
- P J He
- State Key Laboratory of Pollution Control and Resource Reuse School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
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