Grafting is a powerful method for producing substantial modification in the polysaccharide polymer properties thereby enlarging the range of its utilization. The aim of this work is to identify the appropriate conditions for grafting a candidate synthetic monomer (acrylamide) onto a blend of polysaccharides (PsB) comprising of starch, chitosan, and alginate. Grafting process was carried out in the presence of a low concentration of potassium persulfate initiator and methylenebisacrylamide crosslinker using microwave (MW) or ultraviolet (UV) irradiation techniques. Different Am/PsB weight ratios (0.6–0.96) has been performed. The produced hydrogel was characterized using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscope (SEM) as well as nitrogen percent (%N). This study is focusing on comparing hydrogel samples in terms of grafting percentage (%G), grafting efficiency (%GE) and %add‐on. UV graft PsB (PsB‐g‐Am) gave the highest %G (157.8%), %GE (84%), %add‐on (61.95%) and %N (8.79%). Swelling water ratio (SWR) for the grafted samples in distilled water (DW) and different pH solutions (3–13) has been studied. UV grafted hydrogel gave a maximum SWR of 39 g/g. Am/PsB weight ratio and irradiation source had a direct effect on SWR of the produced hydrogel.

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Laboratory studies show the existence of some strains of bacteria in field crude oils and formation waters. This work is concerned with studying the effect of the reservoir conditions such as temperature, salinity and lithology on the indigenous bacterial activities. Such study is an original contribution to the knowledge of microbial enhanced oil recovery (MEOR).Egyptian MEOR project at Cairo University succeeded to isolate a surfactant-producing microorganism "Pseudomonas Aeruginosa" from crude oil produced from an Egyptian oil field. Several displacement tests were conducted in sand pack model. A modified media was used to incubate and improve the growth rate, behavior and stimulation of Pseudomonas Aeruginosa.The results obtained from the current work showed that Pseudomonas Aeruginosa succeeded to increase the oil recovery by 20%. Pseudomonas Aeruginosa becomes able to resist the effect of temperature up to 70ºC and salinity up to 150,000 ppm, when a specific incubation technique is applied. There is no significant effect on the behavior of the bacteria in the presence of the Dolomite and Kailinite inside the reservoir. The value of the oil recovery factor in case of incubation of the bacteria outside the model is greater than its value in case of incubation inside the model by about 5%.The results obtained are discussed and analyzed in terms of surface tension, hydrogen ion concentrations, viscosity, and conductivity of the effluent solutions.

No abstract

Laboratory studies show the existence of some strains of bacteria in field crude oils and formation waters. This work is concerned with studying the effect of the reservoir conditions such as temperature, salinity and lithology on the indigenous bacterial activities. Such study is an original contribution to the knowledge of microbial enhanced oil recovery (MEOR).Egyptian MEOR project at Cairo University succeeded to isolate a surfactant-producing microorganism "Pseudomonas Aeruginosa" from crude oil produced from an Egyptian oil field. Several displacement tests were conducted in sand pack model. A modified media was used to incubate and improve the growth rate, behavior and stimulation of Pseudomonas Aeruginosa.The results obtained from the current work showed that Pseudomonas Aeruginosa succeeded to increase the oil recovery by 20%. Pseudomonas Aeruginosa becomes able to resist the effect of temperature up to 70ºC and salinity up to 150,000 ppm, when a specific incubation technique is applied. There is no significant effect on the behavior of the bacteria in the presence of the Dolomite and Kailinite inside the reservoir. The value of the oil recovery factor in case of incubation of the bacteria outside the model is greater than its value in case of incubation inside the model by about 5%.The results obtained are discussed and analyzed in terms of surface tension, hydrogen ion concentrations, viscosity, and conductivity of the effluent solutions.