Development of Mobile Dissolved Air Flotation and Filtration (DAFF) Package Plants for Emergency Water Supply or Pollution Control

Emergency, temporary, or seasonal water supply may be needed by a military hospital, a seriously flooded area, an industrial park, or a camp site. Similarly, emergency remediation may be needed when water or land pollution accidentally occurs. Financial and personnel limitations faced by municipalities, farmers, or industrial/commercial owners can be alleviated by adopting prefabricated mobile package water or wastewater treatment installations for lake water supply, lake-pond water restoration, groundwater decontamination, or site remediation. When an urgent water supply or pollution control is no longer needed, the mobile package installation may be moved to another location for similar services or sold for cost recovery. This chapter 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 (detention time (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. This chapter is one of the authors’ short memoirs for partial documentation of the R&D and engineering accomplishments of LIWT and KEC.