The Particle Separation SG is concerned with a wide range of aspects of science and technology in which aquatic particles are involved. It is well known that conventionally defined particles with a size range of >0. 45 µm degrade the quality of water and play many critical roles in aquatic systems. In addition, with the progress of analytical technique, there is an increasing awareness of the importance of extremely small particles with nm sizes in both natural and engineered aquatic situation. Thus, understanding of the behaviors of a wide range of “particles” is important to properly control water/wastewater treatment processes and manage natural aquatic systems, although borders between particulate, colloidal and dissolved constituents become fuzzy.

This specialist group specializes in: (1) solids removal concepts in water and wastewater treatment; (2) particles removal processes including flocculation, sedimentation, flotation and membrane processes; (3) characterization of particles and suspensions in natural and treated waters; (4) particle transport and transformation processes.

Communication with other fields would be important and necessary for the Particle Separation SG in the future. For instance, recent analytical developments provided the tools for submicron particle analysis (20-500 nm), a range not accessible before. These tools are very helpful for control of particle removal processes by low-pressure membranes: very high log-removals for viruses or artificial nano-materials are achieved in drinking water treatment. Efficiencies and integrities of such new processes are adequately assessed and maintained by collaboration with other fields, leading to the safety of consumers. To accelerate interaction with other fields and provide valuable inputs for further development of particle science and technology, the Particle Separation SG seeks the possibility to organize joint-events with other SGs, as done with the Nano & Water SG in Sapporo in June 2014.