الفهرس 
IntroductionOnly 14 pages are availabe for public view
Abstract
The objective of this study was to research the using of membrane distillation as a desalination technique for the produced water from oil fields.
Evaluation of produced water characteristics is very important and essential for both environmental and reservoir management. Produced water is a very complex mixture and contains different compounds that can have negative impact on the environment and economic problems associated with oil and gas production.
This study has evaluated the characterization properties of produced water in Sarir oil field. The evaluation included the analysis of physio-chemical parameters e.g. pH, salinity, total dissolved solids (TDS), cations and anions constituents. These parameters show a wide variation from well to another.
This study has shown that some physico-chemical properties of produced water from Sarir “C” oil fields are higher than the stipulated regulatory limit for discharge into the environment. Total dissolved solids and some other parameters are still very high, continuous discharge of these produced water without adequate treatment will further damage our fragile environment. It is therefore recommended that adequate treatment, monitoring and re-use for irrigation or as industrial process water plan for produced water in the Sirt basin be put in place to ensure compliance with best global practices.
It can be concluded that, untreated produced water discharges may be harmful to the surrounding environment. Hence, these large amounts of disposal water must be treated using the DCMD technique before drainage in the surrounding medium or reinjected into reservoir formations. This can possibly be done through preparation and modification of hydrophobic PSF flat sheet membranes with MWCNTs, SWCNTs and inorganic nanoparticles, e.g. Al2O3 and CuO and consequently evaluate their applications in the desalination of brackish and saline waters.
The Polysulfone-Polyethylene glycol (PSF/PEG) flat sheet membrane was synthesized via phase inversion technique using DMF as a solvent and distilled water was used as coagulant. Polyethylene glycol (PEG) was used as the polymeric additives (2 wt.%) and as a pore former agent in the casting solution. The PSF membrane was cast from a homogeneous polymer solution having 16 wt.% PSF pellets and 84 wt.% DMF and the resultant PSF polymer solution was casted with thickness 100 μm. Increased PSF concentration and membrane thickness could decline membrane PWF. There is a positive impact at increase of the feed temperature, feed flow rate and negative distillate pressure on the PWF. Conversely, there is a negative effect of the feed salt concentration and distillate temperature on the PWF of neat PSF and PSF/PEG membrane.
The improvement of PSF membrane was achieved through incorporation of PSF/PEG with carbon-based nanomaterial e.g. MWCNTs, SWCNTs and inorganic nanoparticles, e.g. Al2O3 and CuO for DCMD mediated water desalination. The incorporation of MWCNTs (0.1), SWCNTs (0.5), Al2O3 (0.75) and CuO (0.75 wt.%) could significantly enhance the permeate flux of neat PSF and PSF/PEG membranes. The highest permeate flux achieved in the order of SWCNTs (20.91)> Al2O3 (19.92)> CuO (18.92)> MWCNT (18.20)> (L/m2·h) with optimized concentration of 0.5, 0.75, 0.75, 0.1 wt% relative to PSF/PEG weight, i.e. 16%. The optimum operational conditions included feed and permeate temperatures 60°C and 20°C, respectively.
The PSF/PEG NC modified membranes revealed improved flux, salt rejection, mechanical properties and a stable permeability when compared with the neat PSF and PSF/PEG membranes. Among the nanocomposite membranes, PSF/PEG/SWCNTs (0.5 wt.%) showed highest flux of 20.91 (l/m2.h). Thus, PSF/PEG/SWCNTs NC membrane promises to be the best candidate in terms of quality and cost when compared to all prepared membranes for its potential application in water desalination. The PSF/PEG/SWCNTs NC modified membrane with 0.5 wt.% of SWCNTs used to treat produce water sample from Sarir oil field with flux 5.97 L/m2 h. The experiment results revealed that the M3 NC modified membrane had a stable permeability, salt rejection and it may be of magnificent prospective to be operated in the MD procedure.