To fabricate a hollow fiber ultrafiltration (UF) membrane for drinking water using a new material such as polyketone and polyimide, a Non-Solvent Induced Phase Separation (NIPS) method is applied for fabricating a pore size below 0.1 μm hollow fiber UF membrane. Additionally, a surface modification technique will use to increase water permeation. The fabricated hollow fiber UF membrane will be employed for a 100 m3/d pilot-scale experiment in Korea Water Cluster (Korea Environment Corporation). 

Semiconductor wastewater is recently an emerging issue along with the development of semiconductor production due to its toxicity and treatment complexity. The increasing amount of semiconductor wastewater production and discharge and the use of various chemicals in the semiconductor fabrication process highlights the necessity and importance of semiconductor wastewater treatment. Various technologies will be investigated to remove and degrade the compounds such as fluoride, nitrogen, phosphate, turbidity, and organic compounds, including photoresist and washing solutions generally used in semiconductor fabrication. 

Developing a loose polyamide thin-film composite (PA-TFC) membrane has become a solution for the preparation of an RO membrane with high permeability without affecting salt rejection. Improving miscibility between the aqueous and organic solutions at the time of the IP process has been effective in enhancing the membrane surface hydrophilicity by decreasing the membrane layer density and increasing the reactivity of the monomers. Recently, the addition of a co-solvent in the organic phase, known as co-solvent assisted interfacial polymerization (CAIP), has been applied to increase the solubility and reactivity between the two monomers. The CAIP method can improve the overall membrane performance owing to changes in the network structure, thickness, and morphology of the PA layer. Hexane organic solvent is widely used as an organic phase solution to form an interface with an aqueous phase solution. Acetone was used as it was found to be more effective in smaller concentrations. The effect of acetone as a co-solvent in different organic solvents, such as heptane and hexane, was compared and optimized under the same operating condition. 

The ENMs demonstrate improved performances. However, the single-nozzle ENMs are susceptible to wetting issues and have poor mechanical strength due to poor bonding between the randomly oriented nanofibers. The co-axial electrospinning technique is one of the most favorable and straightforward options for fabricating membranes with three-dimensional hierarchical structures. Three-dimensional hierarchical structure formation using co-axial electrospinning is a much more efficient method to achieve membrane surface superhydrophobicity than other modification methods. Co-axial electrospinning is a more attractive method for fabricating an ideal water purification membrane.

Omniphobic means: “omni = all” and “phobic = repelling”. In other words, omniphobic membranes are supposed to repel all liquids including low surface tension liquids such as oil. The main reason why omniphobicity contributed by membrane surface modification is preferred is that it maintains the highly porous structure of the base polymer membrane while creating multi-layered structure with relatively rough surface. Creating hierarchical structure is one of the major ways to achieve omniphobicity on the membrane surface by surface modification. Among the many modification techniques, the layer-by-layer (LBL) assembly technique is one of the simplest to create hierarchical structure on the membrane surface, with good potential for scalability.