Oily wastewater is one of the most challenging streams to deal with especially if the oil exists in emulsified form. In this study, electrospinning method was used to prepare nanofiberous polyvinylidene fluoride (PVDF) membranes and study their performance in oil removal. Graphene particles were embedded in the electrospun PVDF membrane to enhance the efficiency of the membranes. The prepared membranes were characterized using a scanning electron microscopy (SEM) to verify the graphene stabilization on the surface of the membrane homogeneously; while FTIR was used to detect the functional groups on the membrane surface. The membrane wettability was assessed by measuring the contact angle. The PVDF and PVDF / Graphene membranes efficiency was tested in separation of emulsified oil from aqueous solutions. The results showed that PVDF-Graphene nanofiber membrane exhibited better performance than the plain PVDF nanofiber membrane with average water flux of 210 and 180 L.m-2.h-1, respectively. Both membranes showed high oil rejection with more than 98%.

In this study, polymeric ultrafiltration (UF) membranes were prepared by phase inversion method to obtain both antibacterial and organic antifouling properties. The membranes were cast from a solution of polyvinylidene fluoride (PVDF) and formative silver (Ag) nanoparticles were successfully immobilized on a polymer. This was done using a solvent N, N-dimethylformamide (DMF) which is a solvent for the PVDF polymer meanwhile it is a reducing agent for silver ion. The effect of silver nanoparticles additives on the performance of polymeric ultrafiltration membrane was verified. Chemical composition and morphology of the surfaces of the membranes were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The antibacterial property of modified membrane and the influence of silver nanoparticles on pure water flux of composite membrane at 0.2 Mpa were also verified. The experimental results obtained concluded that the composite membrane properties have been improved by the integration of Ag nanoparticles. The grafted membrane with silver nanoparticles has shown a clear ability to inhibit the growth of E. coli, Pseudomonas Aeruginosa, and Bacillus Cereus. While the clean PVDF membrane (without any additives) did not show any effect of preventing the growth of these species of bacteria referred to above. The pure water flux, porosity and the mean pore size of composite membrane can reach 261.8 L/m2 h, 85.4%, and 0.0206 µm, respectively, and it was much more than that of pure PVDF membrane.

In this work, the removal of hardness was studied from tap water taken from Aljadriya municipal water network-Baghdad. A parallel plate electrochemical cell was constructed using two graphite electrodes as anode, and three aluminum electrodes as cathodes. The electrodes were connected to a power supply that provides direct electrical current to the cell. Results showed that a removal efficiency of 85% can be obtained at pH of 7.5and electrical voltage of 28.5 volt with retention time of 60 minutes. The high efficiency for hardness removal suggested that the electrochemical technique might be used as an alternative technique for hardness removal.

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Operation of a one module hollow fiber submerged type MBR system was tested in this work. The system was operated at fixed permeate flowrate of 12 l/hr. The hydraulic retention time of the aeration tank was about 8.3 hr. The mixed liquor suspended solid (MLSS) concentration was maintained in the range 5000-5500 mg/l. The results show the workability of this system under Iraqi conditions without any difficulties. About 85% chemical oxygen demand (COD) removal was achieved. The value of turbidity is well below 0.61 NTU throughout the operation time.