Colloidal and interfacial separation processes factor heavily in key industrial applications, but they are energy- and water-intensive. Making these processes more efficient requires advancing our understanding of basic colloidal and interfacial phenomena. This work explores recent advances in separation methods, including those based on liquids, membranes, adsorption, ion exchange, microbiology, agricultural byproducts, and electrochemistry. Multidisciplinary Advances in Efficient Separation Processes explores new developments in wastewater treatment, managing micropollutants and microplastics, extraction of rare-earth elements and heavy metals, water desalination, and oil spill remediation. These methods are increasingly important for addressing challenges in providing potable water supplies, recovering and recycling valuable metals and minerals, and pollution prevention and mitigation.