Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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Subject: search.filters.subject.Nanofiltration membranes

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  • Master Thesis
    Development of Polyamideimide Based Nanofiltration Membranes for Separation of Dyes and Salts in Textile Wastewater Treatment
    (Izmir Institute of Technology, 2019) Metecan, Ayşe; Alsoy Altınkaya, Sacide; Alsoy Altınkaya, Sacide; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The textile wastewater contains a significant level of organic dyes and inorganic salts. Separation of a vast amount of organic dyes and inorganic salts is important not only to comply with strict regulations but also to recover dyes for reuse during the process. Nanofiltration is proposed as a cost-effective alternative solution for dye and salt separation compared to traditional techniques. The main objective of this thesis is to develop a polyamideimide based positively charged nanofiltration membranes with high permeability, and high selectivity for separation of dyes and salts in textile wastewater treatment. Polyamide-imide (PAI) is an excellent choice for membrane production because of its superior processability, good mechanical features, and high chemical and thermal resistance. Its imide groups are crosslinked with polyethyleneimine (PEI), which is a suitable material to obtain a positively charged surface. In this study, support membranes of various pore sizes were produced by changing the composition of the coagulation bath and casting solution during the phase inversion method. Then, the optimum support membrane was in-situ modified with the alginate and coordinated with the metal ions for high permeability and high selectivity. The influences of the metal concentration and reaction time on the membrane performances were examined. It has been demonstrated that resulted nanofiltration membrane has high solute permeability (>22 L / m2 h bar), high dye rejection (~ 95 %) and low salt rejection (~ 11 %). Moreover, this membrane was tested in the treatment of real textile wastewater samples. Salts in wastewater permeated, while high amounts of dye were rejected.
  • Master Thesis
    Development of Nanofiltration Membranes Through Surface Modification of Polysulfone Based Ultrafiltration Membranes
    (Izmir Institute of Technology, 2017) Bar, Canbike; Alsoy Altınkaya, Sacide; Alsoy Altınkaya, Sacide; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Stimuli responsive membranes have been used for suppressing fouling and regulating selectivity in different applications. These types of membranes are usually manufactured in thin film composite structure by either polymerizing stimuli-responsive monomer or coating stimuli-responsive polymer on a support. Responsiveness is due to their characteristic features which rely on reversible changes in mass transfer and interfacial properties as a result of changes in external environment such as pH, temperature and ionic strength. In this study, a pentablock copolymer (PBC) which consists of temperature responsive Pluronic F127 (PEO-b-PPO-b-PEO) in the middle block and pH responsive poly(N,N-(diethylamino)ethyl methacrylate) (PDEAEM) in the end blocks was used for designing a new type of thin film composite (TFC) nanofiltration membrane. The support of the composite membrane was prepared from a blend of polysulfone/sulfonated polyethersulfone using nonsolvent induced phase separation and the PBC was attached to the support via electrostatic interaction. The conformation of grafted PBC chains was determined by adsorption studies. The effects of PDEAEM block length, concentration of the copolymer and adsorption time on the adsorbed amount were investigated. Among three copolymer samples investigated (15, 20 and 25 kDa), the 25 kDa PBC displayed the highest responsiveness, thus, rejection properties were determined for the membranes prepared only from this sample. The influences of operation pH and temperature on the structure integrity of the membrane were investigated with pure water permeability measurements and the change in pore size was assessed by determining rejection of neutral solutes by the membranes. The membranes were further characterized with SEM, AFM, contact angle, XPS and zeta potential measurements. It was demonstrated that a new pH and temperature responsive, high flux TFC NF membrane was manufactured.