Browsing by Subject "Osmosis"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item A reverse osmosis treatment process for produced water: optimization, process control, and renewable energy application(2009-06-02) Mareth, BrettFresh water resources in many of the world's oil producing regions, such as western Texas, are scarce, while produced water from oil wells is plentiful, though unfit for most applications due to high salinity and other contamination. Disposing of this water is a great expense to oil producers. This research seeks to advance a technology developed to treat produced water by reverse osmosis and other means to render it suitable for agricultural or industrial use, while simultaneously reducing disposal costs. Pilot testing of the process thus far has demonstrated the technology's capability to produce good-quality water, but process optimization and control were yet to be fully addressed and are focuses of this work. Also, the use of renewable resources (wind and solar) are analyzed as potential power sources for the process, and an overview of reverse osmosis membrane fouling is presented. A computer model of the process was created using a dynamic simulator, Aspen Dynamics, to determine energy consumption of various process design alternatives, and to test control strategies. By preserving the mechanical energy of the concentrate stream of the reverse osmosis membrane, process energy requirements can be reduced several fold from that of the current configuration. Process control schemes utilizing basic feedback control methods with proportional-integral (PI) controllers are proposed, with the feasibility of the strategy for the most complex process design verified by successful dynamic simulation. A macro-driven spreadsheet was created to allow for quick and easy cost comparisons of renewable energy sources in a variety of locations. Using this tool, wind and solar costs were compared for cities in regions throughout Texas. The renewable energy resource showing the greatest potential was wind power, with the analysis showing that in windy regions such as the Texas Panhandle, wind-generated power costs are approximately equal to those generated with diesel fuel.Item Biological treatment and biofouling in membrane treatment systems(2012-05) Vercellino, Tony; Morse, Audra; Reid, Ted W.; Hamood, Abdul N.; Song, LianfaAs the world’s population increases, the demand for water will increase accordingly. The corresponding demand for water puts a strain on the available sources of water and the technologies to reclaim water from non-potable sources. The use of membranes is quickly emerging as the prominent treatment technique for water purification. While the increase in use of membrane technology is providing the water that the world demands, operational problems such as fouling are limiting the potential of these membrane processes. Fouling due to biological growth, otherwise known as biofouling, is the foremost form of fouling that affects current membrane treatment systems. The use of covalently attached organo-selenium as a surface modification to reverse osmosis membranes was studied as a potential biofouling inhibition agent. The efficacy of the organo-selenium surface treatment was tested within a flow-cell system which exposed the membrane samples to high nutrient medias at low-flow, simulating a worst-case condition for biofouling to occur at the membrane surface. The surface treatment was also tested within a bench-scale reverse osmosis system, where the membranes were exposed to normal operating conditions for a reverse osmosis system. Within the low-flow system, the organo-selenium surface treatment was able to achieve a range of 2.01 to 3.98 logs of inhibition of total biomass. Within the RO system, the organo-selenium surface treatment was able to achieve between 2.2 and 3.8 logs of total biomass inhibition. However, when the polypropylene feed spacer also received the surface treatment, total biomass inhibition was increased to 5.9 logs.