Fabrication and Characterization of Polyphenylsulfone Based Ultrafiltration Hollow Fiber Membranes for Groundwater Treatment Studies

Abstract

Groundwater is a vital resource that furnishes drinking water to human beings. Liquid and solid wastes, animal wastes, sewage plants, and septic tanks are all main sources of contamination in the groundwater. Furthermore, sewage, industrial effluents, agricultural discharge and residential waste, inorganic pollutants, fertilizer, run-off from urban areas, thermal contaminants, organic compounds, radioactive pollutants and toxic metals all cause a hazard to the groundwater quality. Drinking water is derived from groundwater, which is a valuable natural resource. Drinking water continues to be a significant source of many of the water-borne diseases and death of human beings in the world due to untreated and uncontrolled release of contaminated water to rivers and many other water collecting ponds. Drinking water purification by low-pressure ultrafiltration hollow fiber membrane has become more popular. It replaces many traditional separation technologies due to their high surface area to volume ratio, high packing density, high flux and resistance to chemical degradation. Polyphenylsulfone (PPSU) is a versatile polymer for membrane preparation with high chemical/thermal stability, increased heat resistance, hydrolysis stability and excellent mechanical properties. However, membranes prepared by PPSU as a base polymer are more prone to fouling, hydrophobic and offer less water permeability. In current research work, various inorganic hydrophilic nanoparticles are incorporated into the hydrophobic PPSU membrane matrix to improve hydrophilicity, antifouling and separation efficacy of the fabricated hollow fiber membrane. In present study, the hydrophobic PPSU hollow fiber membranes were fabricated with different dosages of zirconium oxide (ZrO2), zinc–magnesium oxide (ZnO-MgO), aluminum oxide (Al2O3) and polydopamine (PDA) along with constant dosages of cellulose derivatives (cellulose acetate and cellulose acetate phthalate) using non-solvent induced phase separation (NIPS) process. The blended membranes surface morphologies and topologies were analyzed using scanning electron microscopy (SEM) and atomic force microscopy (AFM) respectively. Also studied hydrophilicity, thermal properties and surface charge properties of the fabricated membranes. A cross-flow filtration system was used for analyzing the water permeability, antifouling properties and separation performance of arsenic-V from laboratory prepared arsenic-V solution. The PPSU membranes with 1.5 wt% and 1 wt% of Al2O3 and 3 wt% of cellulose acetate showed improved arsenate oxide removal of 98.67% and 94.89% with permeabilities were 88.41 L/m2h bar and 88.41 L/m2h bar respectively. A 0.6 wt% of ZnO-MgO in CAP/PPSU and 1 wt% of ZnO-MgO in CA/PPSU decontaminated 81.31% and 78.48% with permeabilities of 69.58 L/m2h bar and 198.47 L/m2h bar respectively. Membranes prepared by 1 wt% of ZrO2 in CA/PPSU exhibited arsenic (As-V) rejection of 87.24% with permeabilities of 89.94 L/m2h bar. A 3 wt% of PDA in PPSU/PVP executed enhanced (As-V) removal as 87.15% with flux of 31.80 L/m2h. The modified membranes exhibited enhanced hydrophilicity, antifouling and efficient arsenic-V removal properties.