Many industrial processes generate “Turbid” (dirty or contaminated) colloidal waste water whereby the small sub-micronic material in the water cannot be removed by conventional mechanical filtration methods alone such as Ultra Filtration, Reverse Osmosis, Plate and Frame Filters, or similar devices.
Industrial facilities typically cannot recycle water with high concentrations of colloidal TSS (total suspended solids) due to plugging or fouling downstream devices such as exchangers, cooling towers, and other process equipment. Solutions using dilution, waste fresh water and the excess discharge to POTW’s create costly surcharges. Some installations send a larger portion of the water to drain or waste treatment and makeup with fresh water where applicable to dilute the concentration. As a result, water usage and discharge volumes increase, and downstream treatment of the discharged water is required as well as discharge fees for compliance.
Due to the desire to recycle “turbid” or contaminated water, Filtertech utilizes proprietary dry separation (PDC) chemistry which coagulates and flocculates the sub-micronic particles into a stable floc. Once formed, the floc is removed by a “High Performance” Deep Bed Gravity Filter Model GSF15 or GSF30. The PDC process chemistry incorporates a coagulant/flocculating agent which unlike liquid chemistries do not require constant jar testing for treatment accuracy, is not sensitive to overdosing or chemical instability, and is consistently repeatable. The flocking agents are removed with the accumulated solids via the filter media.
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Mode of Operation
The “turbid“ water is typically pumped from an existing reservoir tank to the Filtertech system that incorporates a mixing tank which is specifically sized and designed for the flow rate to be treated. The PDC material is then added to the “turbid” water in the mixing tank by way of a precise volumetric solids feeder and is stored in a bulk solids hopper requiring only periodic replenishing. The volumetric solids feeder utilizes a variable speed drive which can adjust the feed rate of the PDC chemistry to coincide with changes in flow rate of “turbid” water of the system. During the mixing process, the chemistry becomes hydrated and its long chain molecule is unraveled. The sub-micronic particulates become entrapped in the molecules to form much larger floc particles in the mix tank. Specially-designed mixers are used to minimize floc degradation on the developing sludge particles.
The results, as shown below, for typical applications are greatly increased water clarity with subsequent advantages. Discharge of the water to drain is eliminated or greatly reduced with the remaining contaminant being safely discharged into a receptacle for disposal. The system is fully-automatic, continuous flow not a batch process achieving significant reductions in “NTU” values. Total operating costs which include separation chemistry, filter media, and electrical costs typically average less than $ 0.001 /gallon of water treated which varies depending on the application.
The cost of operation consists of the separation chemistry, filter media, electricity, and very minimal manpower requirement to add PDC chemistry and filter media.