Theoretical and Experimental Approaches of Liquid Entry Pressure Determination in Membrane Distillation Processes

Utilization of renewable resources is becoming increasingly important, and only sustainable processes that convert such resources into useful products can achieve environmentally beneficial economic growth. Wastewater from the pulp and paper industry is an unutilized resource offering the potential to recover valuable products such as lignin, pigments, and water [1]. The recovery of lignin is particularly important because it has many applications, and membrane technology has been investigated as the basis of innovative recovery solutions. The concentration of lignin can be increased from 62 to 285 g∙L⁻¹ using membranes and the recovered lignin is extremely pure. Membrane technology is also scalable and adaptable to different waste liquors from the pulp and paper industry.

The presence of micropollutants in aquatic environments is an increasing global concern due to their persistence and potential harmful effects on aquatic organisms. Among the most concerning of these micropollutants are microplastics, pharmaceutical compounds, personal care products, and industrial chemicals, posing a significant threat to human health and aquatic ecosystems. This issue is further exacerbated by the diverse sources and complex physicochemical properties of micropollutants, as well as the inability of conventional water and wastewater treatment systems to effectively remove these contaminants. The removal of micropollutants is therefore becoming increasingly important, leading to extensive research into various physicochemical, biological, and hybrid treatment methods aimed at minimizing their environmental impact. This review examines the classification, occurrence, and associated environmental and health risks of commonly detected micropollutants in aquatic systems. Additionally, it provides an overview of advanced treatment methods being developed to implement a fourth purification stage in wastewater treatment plants. Biological, chemical, physical, and hybrid purification technologies are critically reviewed, with a focus on their performance characteristics and potential applications.