Author : Roshdy Korayem Roshdy Korayem
Degree : Ph.D. Electric Communication
Title: Performance Enhancement of Fuzzy Based Robust Adaptive Antenna Arrays
Abstract
Scarcity of potable water is a
world-wide problem which necessitates the application of diversified
desalination technologies. These technologies are divided mainly into thermal
and membrane processes. Thermal processes, however, have numerous limitations,
which include high energy consumption and corrosion problems while membrane
processes mainly suffer from membrane fouling and high membrane cost. Li~uid
membranes (LMs), on the other hand, which have been discovered in 1968 by Li [2
, have no pores to be blocked and cannot be fouled like solid membranes. Their
idea relies on separating two miscible phases (the donor phase (DP) and the
receptor phase (RP)) with an immiscible LM phase, through which some chemical
species can cross the LM phase whilst others are prohibited. However, their
main problem is the method of containing the liquid between the two miscible
but separated DP and RP.
In the present work, desalination
using the present type of supported liquid membrane (SLM) and the bulk liquid
membrane (BLM) techniques have been investigated in the desalination of saline
water. For the SLM, a simple apparatus devised and constructed in our lab, was
used to conduct the experiments. Various factors that would affect the progress
of desalination were studied and these were: concentration of simulated sea
water in DP, presence of emulsifier or mobile carrier (MC) in the LM,
concentration of MC in LM, presence of polyelectrolyte (sequestering agent
(SA)) in the RP, presence of magnetic stirring, and speed of stirring. The volume
ratio ofDP to RP was kept constant at 2:1. Type and thickness of LM (1,2
dichloroethane) was kept constant. Cellophane constituted the support for the
LM. The results obtained indicated that the present type of SLM desalination is
not a promising technique, which requires further profound study and
investigation. The most important findings emphasized the importance of the
presence of a MC in the LM to enhance mass transfer through the LM and that an
optimum concentration of MC existed. Also the importance of stirring in
promoting mass transfer by minimizing the boundary layer adjacent to the
cellophane support was clarified. The best conditions arrived at were, MC =
0.1286 g (Crown ether (CE)), SA = 0.5 g (soluble starch (S.S)), slow stirring
(100 rpm) of DP and using DCE as LM, 2 mm thick. The minimum time was found to
be very long, during which total desalination might have taken place.
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