Indigenous bentonite based tubular ceramic microfiltration membrane: Elaboration, characterization, and evaluation of environmental impacts using life cycle techniques

Abstract

This work fabricated a tubular ceramic microfiltration membrane from local bentonite clay and further characterized it to evaluate the membrane properties. The extrusion method followed by sintering was used to prepare the membrane. Rice husk ash (RHA) and activated charcoal were added as additives to improve the mechanical stability and porosity of the membrane. The synthesized tubular-shaped membrane was 100 mm in length, and it has 10 mm outside diameter and 5 mm inside diameter. X-ray diffraction and thermogravimetric and differential thermal analysis techniques were used to characterize the raw materials. The resulting bentonite membrane was analyzed by field emission scanning electron microscopy, mechanical strength, porosity, pure water flux, permeability, and pore size. In addition, the impact of sintering temperature on membrane properties was extensively studied. The membrane sintered at a temperature of 900 °C possesses a good porosity of 37% and exhibited an excellent flexural strength of 18 MPa. Besides, the membrane has shown better corrosion resistance towards acidic and basic environments. Permeability of the elaborated membrane was identified as 5.805 × 10−8 m3/m2 s kPa from pure water flux measurements, and its average pore size was estimated as 0.11 μm. Therefore, the prepared low-cost ceramic membrane could be predictable as a promising applicant for microfiltration applications due to its remarkable properties. The fabrication cost of the prepared tubular ceramic membrane was calculated as 96 $/m2. In addition, the environmental impacts of the fabricated membrane were assessed using GaBi ts 9.5.2.49 Pro software. It was observed that the majority of the impacts were primarily due to the power consumed during fabrication, and moving away from the conventional source of energy (fossil fuels) significantly (92.9%) reduced the impacts.