A profound investigation into the viability of calcium bentonite as a new alternative ceramic material for the development of a highly porous ceramic hollow fiber membrane for the remediation of oily produced water

Abstract

Background: Ceramic hollow fiber membranes (CHFMs) have been recognized as an effective method in treating oily produced water (OPW). However, the high cost of CHFMs deters industries for implementing them on a large scale. Methods: This research investigates the feasibility of using calcium bentonite as CHFMs for treating OPW and examines the effect of sintering temperatures on the physical properties, mechanical properties and performance of calcium bentonite hollow fiber membranes (CaB-HFMs). The calcium bentonite undergoes several pre-treatment processes and is subsequently characterized. The fabricated CaB-HFM with 45 wt% of calcium bentonite content (CaB-HFM 45) is characterized and examined for water permeation and OPW rejection performance in a cross-flow filtration mode for 3 h. Significant finding: Among the CaB-HFM 45, the membrane sintered at 1100 °C displayed optimum characteristics for OPW treatment, including a good morphology with adequate sponge-like and void-like pore structure, a mechanical strength of 95.33 ± 2.6 MPa, an average pore size of 1.015 µm and a porosity of 51.04%. Surprisingly, the membrane also displayed strong hydrophilic behavior (26.05°) and strong underwater oleophobic behavior (141.20°), resulting in outstanding water permeation performance (505.7 ± 29.5 L/m2.h.bar) and oil rejection performance of up to 97%. These remarkable features highlight the membrane's potential as a promising solution for OPW treatment.