Due to high toxicity and non-biodegradability, heavy metals pollution is between the major concerns of today's world. Among various techniques, membrane separation technology has taken precedence over other counterparts due to reduced separation units, low energy consumption, facile upscaling, and continuous separation. This study aims to fabricate ultrafiltration membranes made from abundant natural materials to reduce fabrication/operational costs, including precursors, sintering temperature, and filtration pressure. Moreover, SnO2/Montmorillonite nanocomposite is synthesized via the hydrothermal procedure and incorporated into the membrane matrix to decrease membrane fouling, enhance water flux, and improve heavy metals rejection rate. Results delineate 97.88–99.26%, 76.79–92.23%, and 24.97–64.74% of Cu (II), Zn (II), and Ni (II) removal from aqueous solutions in the 5–50 ppm range. An enhancement up to ∼40% is observed upon nanocomposite incorporation. Furthermore, ∼30% increase in Cu (II) removal is obtained for SnO2/MMT-incorporated membranes. Moreover, utilization of abundant natural minerals results in decreased fabrication/operational cost. Therefore, the obtained removal results and the estimated overall cost provide guidance for the large-scale utilization of low-cost membranes. As a result, the demand for heavy metals removal from wastewaters before their discharge to protect and govern the environment and implementation for agricultural purposes are fulfilled.