| 1. |
- Feng, X. -T, et al.
(författare)
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Research and application on coupled t-h-m-c processes of geological media in china - a review
- 2004
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Ingår i: Coupled Thermo-Hydro-Mechanical-Chemical Processes in Geo-Systems — Fundamentals, Modelling, Experiments and Applications. - : Elsevier. ; , s. 37-48
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Bokkapitel (refereegranskat)abstract
- Theoretical models of coupled T-H-M-C processes of geological media and the associated numerical solutions have become an attractive research focus in geomechanics and related fields in China. This paper provides a systematic overview of the past progress in the fundamental studies of the coupled THM models and numerical methods, and their applications in the fields of oil/gas reservoir, coal mining, and water resources engineering works. The key areas of weakness in research in this field are also outlined and possible directions for the future development are discussed.
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| 2. |
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| 3. |
- Liu, Jing, et al.
(författare)
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A volumetric meter for monitoring of low gas flow rate from laboratory-scale biogas reactors
- 2004
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Ingår i: Sensors and Actuators B: Chemical. - : Elsevier BV. - 0925-4005. ; 97:2-3, s. 369-372
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Tidskriftsartikel (refereegranskat)abstract
- A reliable and inexpensive device for measuring gas with low flow rates is described. The device works based on the principle of liquid displacement and is able to measure flows from 1 to 950 ml(.)h(-1). It also has improved counting logic and data processing capacity to avoid miscounting and provide a friendly interface for data display. (C) 2003 Elsevier B.V. All rights reserved.
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| 4. |
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| 5. |
- Liu, Jing, et al.
(författare)
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Control of an anaerobic reactor towards maximum biogas production
- 2004
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Ingår i: Water Science and Technology. - 0273-1223. ; 50:11, s. 189-198
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Tidskriftsartikel (refereegranskat)abstract
- A new control strategy is introduced for operating anaerobic digestion processes efficiently at high load. The control system includes a cascade controller embedded into a rule-based supervisory system based on extremum-seeking control. The control system measures pH and biogas production rate and varies the organic load by manipulating the influent flow. Good control performances were achieved during the start-up and steady-state running operations and during rejection of disturbances. The control system can run the process under a high load condition and efficiently reject disturbances without explicit measurement of the influent characteristics.
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| 6. |
- Liu, Jing-fu, et al.
(författare)
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Ionic liquids/water distribution ratios of some polycyclic aromatic hydrocarbons
- 2004
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 1520-5134 .- 0021-9568. ; 49:5, s. 1422-1424
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Tidskriftsartikel (refereegranskat)abstract
- By using the shake-flask procedure, the distribution ratios (D) at infinite dilution and 298.1 K of 15 polycyclic aromatic hydrocarbons (PAHs) between room-temperature ionic liquids, 1-alkyl-3-methylimiazolium hexafluorophosphates ([CnMIM] [PF6], n = 4 and 8), and water were determined. The log D values are in the range of 3.34-4.36, which increased very slowly with the molar mass of PAHs.
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| 7. |
- Liu, Jing, et al.
(författare)
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Immobilised activated sludge based biosensor for biochemical oxygen demand measurement
- 2000
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Ingår i: Biosensors & Bioelectronics. - 1873-4235. ; 14:12, s. 883-893
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Tidskriftsartikel (refereegranskat)abstract
- A biochemical oxygen demand (BOD) sensor, based on an immobilised mixed culture of microorganisms in combination with a dissolved oxygen electrode, has been developed for the purpose of on-line monitoring of the biological treatment process for waste and wastewater. The sensor was designed for easy replacement of the biomembrane, thereby making it suitable for short-term use. The drawbacks of activated sludge based sensor, such as short sensor lifetime, were thereby circumvented. The sensor BOD measurements were carried out in the kinetic mode using a flow injection system, resulting in 25 s for one measurement followed by 4-8 min recovery time. Based on the results of normalised sensor responses, the OECD synthetic wastewater was considered to be a more suitable calibration solution in comparison with the GGA solution. Good agreement was achieved between the results of the sensor BOD measurement and those obtained from BOD5 analysis of a wastewater sample from a food-processing factory. Reproducibility of responses using one sensor was below +/-5.6% standard deviation. Reproducibility of responses using different sensors was within acceptable bias limits, viz. +/-15% standard deviation.
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| 8. |
- Liu, Jing
(författare)
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Instrumentation, Control and Automation in Anaerobic Digestion
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Anaerobic digestion (AD) is a biochemical process in nature. It has been used to decompose organic waste in order to reduce environmental pollution, and to destroy pathogenic microorganisms for the protection of human and animal health. The process itself produces methane, which can then be used as an energy source. The use of AD in an integrated resource recovery system is one of the most important ways of achieving economic and environmental benefits. Owing to the fact that the successful anaerobic conversion of organic waste to biogas relies on a series of biochemical reactions carried out by different groups of anaerobic microorganisms that live interdependently, the process is often considered to be unstable and sensitive to environmental changes. Apart from the need to develop advanced bioreactors, close monitoring and control of the AD process has been recognized to be a necessary factor for ensuring reliable and stable operation and guarding the process against failure. One objective of the work reported in the thesis has been to investigate new analytical methods for on-line monitoring of the AD process. More specifically, the emphasis has been very much on biosensor development for analysis of intermediate fermentation products from consecutive biochemical breakdown of organic polymers to methane and carbon dioxide, as monitored by means of short-term biochemical oxygen demand (BOD). In comparison with the conventional BOD 5-day test, the biosensor was capable of estimating the BOD value rapidly (i.e. within a minute) and of providing satisfying results regarding both precision and agreement with values obtained from the 5-day test. In order to make the sensor a suitable candidate for industrial application in the field, a novel design of BOD biosensor was developed to simplify construction of the sensor and renewal of the biochemical receptor. By using a mixed culture as the bio-receptor, the sensor design allows rapid and convenient renewal of the bio-receptor on a regular basis and on-line assay of a broad range of substrates. Another aspect of the work was to investigate new control strategies for operating AD processes efficiently at high load. One successful implementation was a control system consisting of a cascade controller that was embedded into a rule-based supervisory system, based on a new principle of probing control. The control system was not only able to respond rapidly to process imbalance, but also to schedule control tasks according to different time scales. Good control performance was achieved during start-up and steady-state running operations, and also rejection of disturbances. The controller was capable of compensating for the negative effects of different types of underload and overload, as well as the temperature variability of the reactor. Furthermore, the control system attempted to steer the reactor load progressively to a maximum value while keeping the microbial ecosystem in balance. This control strategy can be considered to be an interesting and promising approach for achievement of an economically feasible anaerobic process.
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| 9. |
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| 10. |
- Liu, Jing, et al.
(författare)
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Microbial BOD sensors for wastewater analysis
- 2002
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Ingår i: Water Research. - 1879-2448. ; 36:15, s. 3786-3802
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Tidskriftsartikel (refereegranskat)abstract
- The field of biosensors for measuring biochemical oxygen demand (BOD) is reviewed. Particularly, BOD sensors constructed on the biofilm configuration are discussed regarding performance characteristics like linearity, response time, precision, agreement between BOD values obtained from the biosensors and the conventional 5-days test, as well as toxic resistance to various compounds and operational stability. The techniques for improving the agreement between the sensor BOD and BOD5 are described. Information provided also includes BOD biosensors based on respirometers and other measuring principles, the commercial BOD instruments, as well as the current limitations of BOD biosensor development.
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