This paper reports a theoretical analysis of osmotic transients and an experimental evaluation both of rapid time resolution of lumen to bath osmosis and of bidirectional steady-state osmosis in isolated rabbit cortical collecting tubules exposed to antidiuretic hormone (ADH). For the case of a membrane in series with unstirred layers, there may be considerable differences between initial and s...

I eliminate hundred years old notion of ‘plug-flow’ in electro-osmosis, which was predicted by incomplete ‘electric double layer’ (EDL) theory. A recently developed ‘electric triple layer’ (ETL) theory removes some serious shortcomings of EDL theory regarding conservation of electric charge, and when applied to electro-osmosis, shows that the velocity profile is not ‘plug-like’ at all, but more...

An optimal control of Reverse Osmosis (RO) plant is studied in this paper utilizing the auto tuning concept in conjunction with PID controller. A control scheme composing an auto tuning stochastic technique based on an improved Genetic Algorithm (GA) is proposed. For better evaluation of the process in GA, objective function defined newly in sense of root mean square error has been used. Also i...

The presently used hollow fiber membrane modules consist of a bundle of fibers in a cylindrical polymer or metal shell parallel to the shell axis. The feed solution flows either through the lumen or at the outside parallel to the fibers. This paper compares the performance of these modules with a new transverse flow module where the hollow fibers are positioned perpendicularly to the flow direc...

The first experimental and theoretical evidence was provided for the non-negligible role of a diffusio-osmosis in the ion concentration polarization (ICP) layer, which had been reported to be in a high Peclet number regime. Under the assumption that the hydrated shells of cations were stripped out with the amplified electric field inside the ICP layer, its concentration profile possessed a stee...

one of the most important concerns in tehran municipal landfill is the production of leachate and its potential for water resources pollution, this study was undertaken to examine feasibility of biological and physico/chemical treating of high-strength landfill leachate that was collected from tehran municipal landfill. average cod of the leachate in aerobic submerged membrane bioreactor is 680...

background: reverse osmosis (ro) is an increasingly common method of desalination. a full scale water desalination system by membrane technology (ro) evaluated in a southern city (jask) in iran. methods: first, data collection on water supply and network were performed. analysis on most of the water quality parameters (turbidity, ph, ec, cl-, na+, alkalinity, ca, na, k, no3, no2, fe, mg, mn, nh...

1. It is impossible to reproduce Loeb's observations on anomalous osmosis with membranes prepared from relatively pure brands of collodion, whereas positive effects can be obtained using collodion containing acidic impurities. 2. The inactive (purer) collodion membranes may be activated by oxidation with NaOBr solution. 3. Properly oxidized membranes give much greater anomalous osmotic effects ...

Reverse osmosis (RO) is a compact process that has potential for the removal of ionic and organic pollutants for recycling space mission wastewater. Seven candidate RO membranes were compared using a batch stirred cell to determine the membrane flux and the solute rejection for synthetic space mission wastewaters. Even though the urea molecule is larger than ions such as Na+, Cl-, and NH4+, the...