Jan Scherfig
Professor Emeritus, Civil & Environmental Engineering
The Henry Samueli School of Engineering
The Henry Samueli School of Engineering
PH.D., University of California, Berkeley
University of California, Irvine
808A Engineering Tower
Mail Code: 2175
Irvine, CA 92697
808A Engineering Tower
Mail Code: 2175
Irvine, CA 92697
Research Interests
Water reclamation, waste treatment processes, environmental engineering
Academic Distinctions
Appointments
Research Abstract
Dynamic Temperature Changes in Waste Water Treatment Plants
Investigators: J. Scherfig, N. Kilde12, and L. Schleisner13
Research Assistant: R. Cuartas
Nutrient removal from waste water is an increasingly important requirement for protection of the environment. Treatment plants located in areas with cold winters can have their efficiencies reduced significantly. Biological nitrogen removal processes are especially sensitive to temperatures below 10øC as the removal efficiencies decrease by about 25% for each 1øC drop in temperature. The ability to accurately model and predict temperature behaviors therefore is a very important design tool. The objective of this project is to develop a model which can predict the temperature in the treatment tanks to within 0.5øC over a seven-day period given the initial temperatures and the typical weather conditions for the coldest weeks of the year. The model includes the eight most important energy exchange mechanisms, from energy production due to the biological process and the evaporative heat losses due to longwave back radiation at night. When verified, the model will allow plant designers to accurately size new plants and determine whether modifications, such as wind breaks, can improve the performance of existing plants.
(Niels Kilde is Senior Researcher, Department of Systems Analysis, Risþ National Laboratory, Denmark.)
(Lotte Schleisner is Senior Researcher, the Department of Systems Analysis, Risþ National Laboratory, Denmark.)
Effects of Wind Breaks on Treatment Plant Performance
Investigators: J. Scherfig and N.O. Jensen
Research Assistant: J. Cunningham
The comprehensive wind prediction program WAsP developed at Risþ National Laboratory, Denmark has been used to predict the wind at 20 meters above ground level (agl) for the selection of windmill sites (such as in the Palm Springs area in Southern California). This research is aimed at investigation the use of WAsP at lower elevations (two meters agl or less). When the program has been verified (or modified), it can be used in the design of low wind breaks around waste treatment plants. It may then also be useful for analysis of wind conditions in urban areas, in order to avoid very high wind velocities near buildings.
(Niels Otto Jensen is Senior Researcher, Department of Meteorology, Risþ National Laboratory, Denmark.)
Modeling of Fixed Film Reactors
Investigator: J. Scherfig
Research Assistants: J. Cunningham and C. Gibbons
Distributed water reclamation plants are being used increasingly for water reclamation in semiarid areas. A typical plant may be built inside a subdivision and provide water for landscape and golf course irrigation as well as groundwater recharge. The construction of many small plants in an area requires that the plants be highly reliable and perform with very little labor. Fixed film biological nitrifying reactors are being used in lieu of suspended biomass reactors because of their simple and stable operations. However, the interaction of the two main groups of bacteria, the carbon oxidizers and the nitrifiers are not well understood for fixed film bioreactors. A model of a dual culture biofilm reactor is being developed and tested against the actual reclamation plant in the City of Upland. When completed, the model will permit better selection of the recycle ratios within the plant. This is expected to result in a significant decrease in power cost and better quality of the reclaimed water.
Investigators: J. Scherfig, N. Kilde12, and L. Schleisner13
Research Assistant: R. Cuartas
Nutrient removal from waste water is an increasingly important requirement for protection of the environment. Treatment plants located in areas with cold winters can have their efficiencies reduced significantly. Biological nitrogen removal processes are especially sensitive to temperatures below 10øC as the removal efficiencies decrease by about 25% for each 1øC drop in temperature. The ability to accurately model and predict temperature behaviors therefore is a very important design tool. The objective of this project is to develop a model which can predict the temperature in the treatment tanks to within 0.5øC over a seven-day period given the initial temperatures and the typical weather conditions for the coldest weeks of the year. The model includes the eight most important energy exchange mechanisms, from energy production due to the biological process and the evaporative heat losses due to longwave back radiation at night. When verified, the model will allow plant designers to accurately size new plants and determine whether modifications, such as wind breaks, can improve the performance of existing plants.
(Niels Kilde is Senior Researcher, Department of Systems Analysis, Risþ National Laboratory, Denmark.)
(Lotte Schleisner is Senior Researcher, the Department of Systems Analysis, Risþ National Laboratory, Denmark.)
Effects of Wind Breaks on Treatment Plant Performance
Investigators: J. Scherfig and N.O. Jensen
Research Assistant: J. Cunningham
The comprehensive wind prediction program WAsP developed at Risþ National Laboratory, Denmark has been used to predict the wind at 20 meters above ground level (agl) for the selection of windmill sites (such as in the Palm Springs area in Southern California). This research is aimed at investigation the use of WAsP at lower elevations (two meters agl or less). When the program has been verified (or modified), it can be used in the design of low wind breaks around waste treatment plants. It may then also be useful for analysis of wind conditions in urban areas, in order to avoid very high wind velocities near buildings.
(Niels Otto Jensen is Senior Researcher, Department of Meteorology, Risþ National Laboratory, Denmark.)
Modeling of Fixed Film Reactors
Investigator: J. Scherfig
Research Assistants: J. Cunningham and C. Gibbons
Distributed water reclamation plants are being used increasingly for water reclamation in semiarid areas. A typical plant may be built inside a subdivision and provide water for landscape and golf course irrigation as well as groundwater recharge. The construction of many small plants in an area requires that the plants be highly reliable and perform with very little labor. Fixed film biological nitrifying reactors are being used in lieu of suspended biomass reactors because of their simple and stable operations. However, the interaction of the two main groups of bacteria, the carbon oxidizers and the nitrifiers are not well understood for fixed film bioreactors. A model of a dual culture biofilm reactor is being developed and tested against the actual reclamation plant in the City of Upland. When completed, the model will permit better selection of the recycle ratios within the plant. This is expected to result in a significant decrease in power cost and better quality of the reclaimed water.
Link to this profile
https://faculty.uci.edu/profile/?facultyId=2955
https://faculty.uci.edu/profile/?facultyId=2955
Last updated
03/29/2002
03/29/2002