Wang, Lawrence K. and Wang, Mu-Hao Sung (2022). Development of mobile dissolved air flotation and filtration (DAFF) package plants for emergency water supply or pollution control . In: “Evolutionary Progress in Science, Technology, Engineering, Arts, and Mathematics (STEAM)”, Wang, Lawrence K. and Tsao, Hung-ping (editors). Volume 4, Number 7D, July 2022; pp.50. Lenox Institute Press, MA, USA. STEAM-VOL4-NUM7D-JULY2022. ISBN 978-0-9890870-3-2. ABSTRACT: This publication introduces the high-rate mobile package plants developed by the Lenox Institute of Water Technology (LIWT), but built, marketed and installed by Krofta Engineering Corporation (KEC) and its associated companies around the world. Specifically two mobile DAFF package plants consisting of chemical coagulation/flocculation, dissolved air flotation (DAF), automatic backwash filtration and post chlorination are introduced. The first mobile DAFF plant (Sandfloat Type 8; Diameter = 8 ft.) incorporates all unit processes into one single unit, and has a design capacity of 144,000 gpd. The second mobile DAFF plant (Sandfloat Type 4; Diameter = 4 ft) has identical unit process components, and has a design capacity of 14,400 gpd. Special emphasis is placed on introducing the mobile DAFF package plants’ circular high rate dissolved air flotation (DT = 3 minutes), its zero-velocity concept, unique automatic filter backwash operation, design diagrams, physicochemical unit process sequence, stainless steel construction, mobility, and the feasibility of treating reservoir water, acidic lake water and industrial effluents. The mobile DAFF plants’ various water supply applications and water pollution applications are reviewed. References are also cited for the applications of DAF/DAFF for groundwater decontamination, storm water treatment, industrial effluent pretreatment, and hydraulic fracturing wastewater treatment.